Gene Therapy for Hearing Loss: Cure, Eligibility, Risks & Future
Welcome to the hearing circle. I'm Dr.
Shri Rao and today my guest is professor
Chi Yang Yun from Seol, South Korea. He
is an ear surgeon. He is a researcher.
He is a scientist and more than any of
this he is the CEO of Sensory Cure, a
gene therapy company which has found the
cure for hearing loss. We are very
fortunate to have him on this hearing
circle podcast. And in this podcast,
I'll be covering most of the commonly
asked questions about this gene therapy.
What is this gene gene therapy? What is
the eligibility criteria for this gene
therapy? What are the risks for this
gene therapy? What is the minimal age
group that a child can undergo this gene
therapy in case if this is available
India? What is the cost of it? And what
are the things that parents should look
for when they are suspecting any hearing
loss related for this gene therapy and
many more. Thank you, professor, for
accepting for our hearing circle
podcast. Thank you so much for coming
and
>> it's my great pleasure,
>> professor. Uh let me ask you the most
commonly asked question by our uh
viewersh.
>> Is gene therapy a cure for hearing loss?
>> It's very good questions. the um the
gene therapy is actually offers uh
biological cure of the hearing loss
while the coke implantation u actually
enable us to rehabilitate rehabilitate
the the hearing loss. So that's the main
difference. But here's a uh limitation
>> and the gene therapy is very fantastic,
but it's not a magic one
>> for all type of the hearing loss. Only a
very specific type of the hearing loss
can benefit from the genet the gene
therapy of the hearing loss.
>> You work with uh researchers and
scientists across regeneron the company
which has found the cure for auto
related uh hearing loss which is
completely US FDA approved. M
>> how far are we to call this as a cure
for deafness? I mean about the other
forms of hearing loss also. How far are
we?
>> But um I would like to focus that I
would like to stress the fact that the
autof
>> is as a very unique
>> and it actually uh was in the very
unique biological conditions. So not all
definite u genes can immediately benefit
from the gene therapy. So I would like
to mention that. So for example the art
>> um is um uh usually think about think of
the gene therapy as a kind of delivering
kind of software update
>> to the cellular machines.
>> So it does not cure
>> the hardware. So once hair cells
>> if the hair cells are already dead
>> and especially if it is reversibly dead
then there is no way to bring them back.
So even gene therapy cannot do that. M
>> so delivering the software software
update
>> for example auto
>> although the the parent the patients
with the auto the variants
>> show the profound deafness severe to
profound deafness as you already know
>> nonetheless the hair cells
>> such as the hardware so-called hardware
the software hair cells are intact
>> and healthy at least until their early
life
>> although the uh with age the hair cells
just go die but at least for the early
stages of the the life the hair cells
are intact in auto related deafness. So
think about that. So the only the gene
therapy just offers the just the
software updates. So if the the the uh
the hardware is gone then there's no way
for gene therapy there's no room for
gene therapy. So but in a tough cases
>> the hair cells are intact. the hardwares
are intact and healthy. And if we just
inject the uh the cDNA of the auto that
can produce the odor protein which the
uh DFNB9 patients
only lack
>> the the the auto related patients lack
the the protein autofillion that's all
>> while the all the other the cellular
structures are remain intact. So in this
type of the uh situations make the auto
is a very unique position and that's why
the auto uh has been remarked as the
first successful target of gene therapy
but but not all gene therapy uh not all
genetic definitions can benefit from the
gene therapy.
That's well said professor and the way
the analogy that you were using a
hardware and the software
>> you mean by the external year the middle
ear structures the inner ear structures
if we consider as a hardware
>> hardware is completely intact
>> and it's just a bug which is there
within the software and we are giving a
software update
>> exactly
>> out of gene therapy and the patient will
be able to hear well
>> if the hardware is not good some broken
things no hair cells it's useless so it
the gene therapy will not work even
though if we upgrade the software that's
what you mean.
>> Exactly. Exactly right.
>> Very well put uh professor.
>> You're exactly right. Right.
>> Uh before getting into this science
proper, we want to know something about
you professor. How can an ear surgeon
just like us build a cure for toughness?
Is there any particular patient that
triggered you? Oh no, this is not the
end. I think I have to go beyond this.
Is there any situation that you felt? uh
because before I become a US surgeons
actually I was trained as a geneticist
actually I just spent my uh the postoc
uh the four years in the United States
the national institute of health NIH in
United States uh and I worked in the um
genetic deafness lab
>> and my role was to uh find out the cost
gene of deafness at that point and then
I was um my effort was also focused to
delineate and clarify the topiology of
deafness genes
>> and and also at that point the auto one
of my interesting gene because as I
mentioned that is a very um auto the the
problems in the auto can lead to the
only the uh defect in the synaptic the
vesicle release while the all the other
hair cells looked intact. So uh that
kind of the experience in the as a
geneticist can make me get uh interested
and get interested in the uh the gene
therapy naturally. So that's the reason
actually I uh become interested in the
gene therapy and then I also had a
chance to uh work with the um decibel
company actually now actually it uh it
has been merged into the uh regenerant
the big pharmaceutical company
regenerant. So I we actually worked
together um to uh rescue the phenotype
of the autophilated mice and then we
were successful. So through that
experiences actually I just um I want to
just build up some some company that
invent new type of the gene therapy
material not only for the congenital
cost but also for adult the progress of
the hearing loss. That's the reason why
I just uh founded the the company the
sensory cure.
>> That's fantastic professor. You're doing
so much good for the entire world
especially people who are going through
this deafness.
So now let's get into the science proper
>> mainly the basics I can say.
>> Imagine I'm not here. Imagine a parent
is sitting here in front of you
>> who [clears throat] has not studied any
science who does not know anything about
science.
>> Can you explain what is this gene
therapy for a parent who has never
studied science in a very simple
possible manner because for them this is
just like a science fiction movie
unbelievable thing
>> and what is exactly happening in the
child when they do this gene therapy if
you could just
>> tell us. is [laughter] very difficult
task very difficult but okay so I just
um uh previously I mentioned that the
gene therapy is like a uh software
update uh while the there are intact the
the hardwares so that's the actually the
main main uh the explanation that
usually how I put the gene therapy in
the in the in the in the novice uh for
the u the gene therapy that that's the
uh main uh uh way of explaining the gene
therapy to the patients. But as I
mentioned the most important thing uh is
that so far
autogene is the only gene that can
benefit from the gene therapy. So uh
once the hair cells before the hair cell
die eventually the autorelated
definition can show the the definition
uh the degeneration of hair cells.
Before the hair cells degenerate, we can
inject
>> the um normal un um mutated nonmutated
auto gene um with the viral vectors
viral vehicles so-called AAV adeno
associated virus AAV into the coia that
that's all actually. So um so we just
usually generate the normal autog gene
encapsulated with the vital vectors
called the AAV but which has a lifespan
into the cookia. So and then then
injected the um uh normal autogene
can produce normal the protein product
odapurene and which
uh revive the uh impaired the neuro
transmitter release and then uh it can
elicit the the the the colear nerve and
then it can just revive the the normal
auditory pathway. Right.
>> So that's actually how it just the gene
therapy for the autorelate patients
works.
>> So you were telling about this
autofurlin protein professor
>> for the parents who are watching this
one.
>> What is this wordlinin? Why is it
required for the patients for the kids?
>> What role does this autofurlin has?
>> Okay, let me put this this way. So
there's the hair cells. Here's the most
uh peripheral the receptors
>> that convert the the sound into the
electrical signals.
>> So but to be to achieve that purpose the
hair cell should release the
neurotransmitters
to the the colear nerve.
>> But without the odorillain
>> the hair cell cannot release the
neurotransmitters.
So but once the new auto oto gene is
introduced and it just can if it can
produce the normal autofilling then the
neurotransmitter release can be
restarted and then it can uh produce it
can stimulate the auditory nerve so
people can hear and people can uh
recognize what other people say. That's
the pathway and that's what the oto gene
does
>> for parents. Uh to put this out
>> if you imagine the cell to be a mic like
this.
>> Okay. The mic
>> microphone.
>> Right. Right.
>> And the nerve it if it is nerve or the
brain that is a recording system.
>> Right. Recording system. Right.
>> The cable is missing. That cable is
something which is formed by this
autofolin protein.
>> Right. Right. Right.
>> Microphone is good.
>> The recording system is good. But but
without the cable the cable is
autoerlin.
>> So that's why you inject a genetically
modified virus
>> which codes for this auto gene and
finally produces this
autoferlin protein.
>> Wow. Fantastic way of put
>> right you're right
>> cable.
>> Exactly.
>> So is a cable right [laughter]
fantastic way of putting it. Okay.
That's uh that's something which is very
fascinating professor because uh for
normal people this just looks like a
science fiction movie to be very frank
with you. they they are not even
believing that really just with an
injection is this happening why can't it
cure our hearing loss as well I mean the
people who had normal hearing and later
they lost their hearing
>> right right
>> so I was trying to tell them that no
this is only for auto related genes
because for them the microphone is there
this is there but the cable is not there
>> and they were like no even this should
work so even that's a question Mark for
me professor there are many several
other causes for this congenital hearing
loss and sensory neural severe sensory
neural hearing loss
>> on top of this just contributes to 2% of
this congenital hearing loss
>> there are GJB2 mutations SLC26 A4
mutations myo 15A mutations which
contribute to almost 80 to 90% of this
hearing loss why only this what got this
special
>> attention Why only this? Yeah, the
that's what I already mentioned because
the auto is a only gene where the
hardware is and looks intact and and the
software update was was enough actually
to restore the whole new whole the
hearing the echo system for let's say
the the masin 15A you know the mass 15A
actually involved with the um sterilia
elongation there is a um the three rows
of the sterily has a different length of
the um uh the different length and to
but without the mas 15A the sterilia of
the hair cell doesn't grow after birth
you know in the animal models in the
mouse model uh having the the hearing
loss can be misleading because uh the
mouse coia kept developing after birth
but in humans the coia development
actually just finished way before birth
so for example you're right for example
SLC 26 6A4 and catering 23 and for GJB2
>> see the mouse models carrying that type
of mutations can benefit from the gene
therapy in the mouse models.
>> Oh
>> because their coia develops keep
developing after birth. we inject their
this normal gene into the the mouse coia
and then uh because the coia is still
developing but in humans for example
GJB2 mutation can affect the spiral
ligament and the the supporting uh
supporting cell the organ of cordi and
uh and which in turn affects the hair
cell. So the GJB2 kids was born is born
with the hair cell already damaged. So
as I mentioned so which the the hair
cell which were already damaged
irreversibly cannot be revived with the
gene therapy. Gene therapy just offer
only the software update not uh just
restoring the the hardware of the
impairment. So that's the reason why so
far only the G auto is can is a
beneficiary of the um the gene therapy
unfortunately but many companies uh
actually are working on the the other
genes. So think about that who would be
the next which genes would come next
after which could be the progressive
hearing loss
>> progress. So we can inject the gene
therapy materials before the hair cells
are largely irreversibly damaged. So
that's that's the uh situation and
that's the uh uh how we can think about
the next target for the hearing loss the
gene therapy.
>> So you're very clearly mentioning that
uh the mouse the laboratory mice where
many people all the scientists like you
work on. Mhm.
>> For them the coccia keeps developing
even after birth
>> and that's why it was completely
misleading. So you you would have
thought that okay because this is
working on mice this should also work on
human beings.
>> That was not
>> surprisingly
>> it's not possible because the human
coccia is not once again growing after
birth that's it. So professor if I could
ask you now after this regeneron company
got this USFDA approval for yes for
related hearing loss
>> right
>> the sensorion the other company
>> right
>> they have withdrew from the trials and
they started this GJB2 gene mutation
>> exactly
>> as their clinical trials
>> right right
>> immediately how do you square that
>> the the French this scientist the the
Christian who who is very f famous in
this field and is actually she is mainly
working on that in collaboration with
the sensorian and um you know you know
what GJB2 knockkin mice so the mut the
mice uh who which carries the mutation
GJB2
>> actually significantly benefited from
the gene therapy in the mouse model
actually the based on that they actually
the many scientists actually working on
that here's are some u unique uh point
of in in in GJB2 because the GJB2 main
expression is not in the hair cells but
in the supporting cells.
>> Yes.
>> So for example the myosin 15A is mainly
in the sterilia of the hair cells. So
actually initially attacks the hair
cells. So
>> but GJB2 initially attacks the
supporting cells
>> and then that insult in turn affects the
hair cell. So I think the their thought
that sensor censorian thought is that we
can intervene before the um the problems
in the supporting cell affect the hair
cell that's how they thinks but I I'm
not sure about that but I don't I'm not
100% positive effect of the gene gene
therapy in the GJB2 related deafness but
but let's see let's see how it goes
>> because GJB2's main expression is not in
the hair cell that's actually uh one of
the point that we can um think about for
the future possibility of although I'm
not 100% positive about that. No.
>> So [clears throat] it's it's very
clearly established as of now the gene
therapy for hearing loss is right now
available only for auto related
>> right
>> and we cannot expect the hearing loss
treatment with gene therapy for other
forms of congenital hearing loss like
GJB2 especially which contributes to
significant amount because of the
mechanism of action that it it does.
That's something which all the parents
should understand. Professor
>> right
>> uh professor uh if we look at the actual
thing what's happening here
>> a clear implant has been considered
as the gold standard for all forms of
congenital hearing loss
>> you're right
>> till date
>> of course for this auto related right
now gene therapy has come
>> what do you think is better the cocklear
implant or gene therapy or do you think
that gene therapy will replace the
cocklear implant
>> they're very tough questions So at least
for the uh uh let's talk about the auto
related deafness first. I think so far
the it it seems to be kind of routine or
it seems to be uh appropriate to um do a
gene therapy in in one side and then to
to do an the implant on the contrlateral
side and to see if how how it goes
because uh to do a genetic uh gene
therapy in the bilateral side is kind of
could impose some risk because not all
the patient benefited from the gene
therapy. Some of them about 10 to 15%
did not respond to the gene therapy. We
don't know exactly why. There could be
some kind of the um some neutralizing
antibbody is kind of uh result of the
immune reactions because the AAV virus
can elicit the immune reactions. But if
some of the uh the patient that already
had some kind of antibodies against that
AAV virus
>> uh in that cases the autogene therapy
even otogene therapy uh could could
fails. So uh you know thinking about the
importance of the only intervention
along the uh side of the um the the
speech development. So considering that
risk so just one side gen therapy and
one side coal implantation is a safer
options at least for the autopheness
and then uh for the other part of the
deafness I think the scientists are
working on now turn their focus on the
GJB2 and other rapidly progressive
sensory neuro hearing loss. For example,
tempest gene TMP RSS gene is a very
rapidly progressive hearing loss in
pediatric patients and it initially it
manifest as a normal low frequency
hearing loss and a mild uh decrease in
the mid to high frequencies but over
time it rapidly the high frequency
hearing progressive declines and then
followed by the the decline in the
mid-frequency and the low frequencies.
So in that type of the hearing loss can
benefit from the uh the gene therapy uh
because actually the many scientists are
working on that TMPR SF3. So eventually
that type of the the the hearing loss
can benefit from the gene therapy
because uh we can have kind of w time
window
before the the the outer hair cells or
in hair cell dies. So probably uh the
the the focus of the gene therapy can
move toward kind of rapidly progressive
hearing loss. uh but before that I can
we just wish it uh the the followup on
the how the gene therapy for the GJB2 uh
by the sensorian company uh goes
>> very very well put uh professor and
you're being very clean and crisp here
stating that auto related gene therapy
the success what we expect almost 10%
that is what you were mentioning 10% of
the kids they didn't benefit from this
yes auto and also So you were mentioning
about the AAV associated immune reaction
>> right
>> which [snorts] was happening.
>> So uh if I could just elongate this
question
>> uh see professor if we look at the
safety profile of the cocklear implant
it has decades of safety data behind it
and uh we know what are the risks what
are the benefits of it what are the pros
versus cons to do when not to do
>> but this gene therapy is just on the
bleeding edge right now right
>> right now. So if you could just
enlighten us what are the risks that
every patient parent should know when
they are proceeding for this gene
therapy to expect is there any child who
didn't benefit completely from this as
you said earlier
>> if you could just let us know about that
professor
>> okay judge um to be honest we don't have
a long-term availability of long-term
effect and long-term safety profile
either we don't have that data either
because the FDA approval of the out of
or that the name of the drug is or many
so many utili
is actually um doesn't cover the long
term because it just approved just four
months ago and then the uh the the four
papers which addressed the effect of the
gene therapy was published only uh at
2024 so we don't have any we don't know
what would happen so the injected adeno
associate virus, the vehicle could
elicit in the future unknown immune
reaction. We don't know that. And then
we don't know either about the long-term
durability of that the gene therapy
material. So if let's say if the AAV
virus the the lifespan is only 10 years
and we have to inject
>> the second round of injection. But the
you know what once the AV virus is
introduced in the our the health system
actually the antibbody the immune system
can generate the antibbody. So we don't
know what would happen if the uh if the
second injection happens. Many people
worry that the second injection would
fail due to the the antibbody which was
generated from the first injection. So
in that case we have to modify the virus
vehicles to avoid the the immune
reaction. So, so that type of things
actually has not been addressed well.
Honestly, we have to that type of risk
against the the potential benefits of
the hearing uh of the gene therapy
because you know you know gene therapy
restores the normal hearing ecosystem.
So they don't need the hearing aid, they
don't need the coke implantation and
they can um they hear the music and they
can enjoy the music just in the same way
as just the normal people do. So there's
a uh clear and huge advantage but also
there are some unknown
>> there could be unknown the um the side
effects or there could be unknown
limitations such as the uh only the
durability the short durability. So at
this point we should very carefully the
risk this potential risk against the the
benefits.
>> Very well said professor. If I could
just for my understanding as well, I
could take two crucial points from this.
One is the durability, the timeline. How
long is that going to be there? We never
know. As I can just compare it to with a
battery that we buy, we buy a new cell
phone, the battery will be there. It'll
be full.
>> But as time goes on, right,
>> it fades off.
>> Exactly. So once again we'll have to buy
a new one or probably we have to change
the battery.
>> Similarly the for the auto we have
injected once a genetically modified AV
wirus vector
>> but we cannot comment on the durability
and you were mentioning around 10 years
is the span.
>> I don't know actually some people say
would say just 5 years or some people
say 10 years we don't who knows we don't
know.
>> Yeah yeah so we don't know about the
durability. So if it fades off there is
no option of giving once again one more.
It becomes an anaphylactic reaction kind
of stuff because it's after all a virus.
It it does its job. It penetrates it
penetrates into the cells and sometimes
it of course it it definitely causes
this immune reaction antibbody
production and the second time if we
inject that's something which is very
bad. So durability and once again immune
reactions are something which are the
crucial risks that a parent should
understand when they pose their kids for
uh gene therapy.
>> That's that's what I understood
professor. Is that correct?
>> Yeah. Yeah. But um uh I have to mention
that the most devastating part of the of
the virus has actually was removed. the
the only the um the the vehicle role the
vector role vehicle role is retained
while the removing the most uh dangerous
part of the uh the virus has has been
removed. So uh we don't have to worry
about that point but still it could
elicit the immune response. That's the
most
>> just critical part.
>> This is one more important what you
mentioned doctor people may think that
we are injecting some virus into the
ear. Um
>> that's not correct. Vehicle it is just
being used as a vehicle itself. The
dangerous part the DNA or RNA within the
virus is being removed and the shell
itself is used and then you are placing
that material and then you are injecting
>> into the ear. Am I correct professor?
You're right. Exactly.
>> That's why we call it as a genetically
modified virus viral vector.
>> Right. Right. Right. Exactly. modified
vectors to to remove the uh critical
dangerous part
>> and that is called adino associated
>> adeno associated virus it doesn't it
doesn't integrate into genome it just
delivers
>> kind of kind of kind of delivers it it's
just deliver the normal uh the DNA into
the nucleus that's all
>> no penetration
>> no pen into the genomes
>> okay
>> at least
>> as a as at least the current type of the
gene therapy is like that
[clears throat]
>> perfect Nowadays actually genome editing
technology has been developed. It's
genome editing technology technology is
actually correct is correct the the
nucleotide. So it's a it's a little bit
different story but the autofilling gene
therapy is actually um uh is developed
in a way that it just delivers the
normal auto gene into the nucleus of the
uh the hair cells of the
>> uh the coia that's all
>> perfect
>> professor. So if I may ask one more
important question that many people are
asking. Can any person in case if a
child is born completely deaf as of
right now
>> u they are born with this hearing loss
GJP2 [clears throat] or any kind of
congenital hearing loss
>> can they wait for this gene therapy
>> or should they have to proceed with
colear implant
>> that's very tough questions to answer
but um if so that for for the patients I
just um proposed the strategies of one
side gen therapy on one side coke
implantation because you know the the
speech development requires the timely
intervention so I don't want to just
wait until the the gen therapies
available. So that's it and another
interesting study from our laboratory is
tells that even after co implantation
>> the hair cells in hair cells and out
hair cells looks intact especially in
the auto patients.
>> So the criteria I didn't talk about the
criteria
>> after colear implantation.
>> Yeah. Yeah. So, so people think that oh
once we implant then probably hair cells
probably would die and the the chance of
gene therapy just completely diminished
and that doesn't seem to be the case
because I think at least about 30 to 40%
of the DFN9 because related patients who
were implanted
>> shows the presence of the auto otocostic
emissions OE auto emission at least
until um after six six years after the
implantations. Yeah.
>> So in that case uh I don't know probably
the gene therapy in the implanted ear is
very difficult because you know but I
have to tell that I want to mention that
klay implantation itself abol doesn't
abolish
>> the future potential the possibility of
the gene therapy that's what I want to
mention
>> but anyway so at this point the one side
gene therapy and one side implantation
is seems to be uh appropriate in at
least is in the autoph related patients
and for other uh the patients I think I
don't want them to just wait for the
other gen therapy becomes available
because you know timely intervention is
very important so I think just people
should get the implantation yeah
>> and then see how it goes or sometimes
people can um be implanted only one side
but I don't think it is reasonable just
uh so at at point so uh let's say So
other than the OT patients,
>> the other deafness patients I think
should get implanted in a timely
fashion. That's what I'm
>> Thank you professor. Thank you for this
clarity.
>> If there are auto related genetic
deafness then they have to go ahead with
implant on one side
>> and the other side they can wait for
gene therapy.
>> That could be a ideal options. any
genetic mutations apart from they should
not wait for gene therapy because the
amount of time we never know and it is
humanly impossible for the brain to just
stay static. So that brain development
has to happen and hence they have to go
ahead with the colear implantation.
>> Exactly.
>> Perfect.
>> You put it beautifully.
>> Thank you. Thank you professor.
>> Now these questions are for from my side
also not just for the parents. Mhm.
>> I know how a cocklear implant sounds
like because this is a neuroprothetic
device.
>> Um it's it it just collects the sound
from through the microphones and then
>> finally electrically it stimulates the
cockia nerve.
>> Right. Right.
>> So it's a kind of electrical stimulus.
>> What about this gene therapy? How does a
child who underwent gene therapy, how
does this sound sound like?
>> Yeah.
>> Is it normal? perfectly normal just like
us or
>> den therapy is to restore the normal
hearing ecosystem. So if it works
>> it makes people just um uh hear just
like a normal people hear. But one main
difference lies in the fact that
actually so let's say that oh I got the
gene therapy yesterday so and then don't
and and the next day it it just doesn't
um come out just immediately after gene
therapy. it just because we have to wait
for the new genes new corrected normal
gene to produce the protein and then the
reproduce the protein should work and
you should restore the functions. So it
takes time. So usually according to the
the four papers published in 2024
regarding the autogen therapy um
according to their papers people would
restore their normal not normal hearing
restore their substantial um portion of
the normal hearing uh over times. So
probably three months or six months. So
there the hearing level just goes higher
until about the three to six month and
then at that point the hearing normal
hearing the um final hearing threshold
just um ranges probably 35 to 50 dB.
>> So it's not perfectly normal but but but
significantly good and then their speech
the recognition
uh reaches about range of the 75%.
>> Then the music perception is almost
normal.
>> Wow. That's usual. That's the average
the the level of the the B gene therapy
the uh the imp gene therapy recipients
uh the fields.
>> Oh wow. That's
>> so if it works it is fantastic actually.
>> Yeah. So PTA the pureon aometry levels
they range between 35 which is quite
good
>> which is quite good right
>> and speech discrimination score or SRT
levels around 70%. 75% exactly
>> excellent
>> and music which cannot be appreciated
>> right that's strongest point of gene
therapy but 10% of patient didn't
respond to gene therapy at all I have to
mention that
>> yes that's a thing 10 person they didn't
respond at all so professor you were
mentioning that the PTI ranges between
35 to 50
>> so does these patient do they require
any hearing aid after undergoing this
gene therapy or any external devices
because 50 dibbels they cannot
understand the clarity of speech, the
volume. You're right. Do they require
any hearing aid later rather than the
cockar implant?
>> Here's an interesting point. Usually the
um it's actually the the phenotype of
autoph related deafness is audiary
neuropathy spectrum disorder. They
actually uh their um response to hearing
aid doesn't seem to be great compared
with the other people. But
interestingly,
>> gene therapy recipients, let's say their
hearing threshold is um is restored to a
level of the 50 dB.
Usually the uh the neuropathy auditor
neuropathy patient doesn't respond well
to the hearing aid but recipients does
respond well
>> to the to the hearing aid. So right the
if the hearing restoration is just is 50
dB then right it requires hearing aids
but there the responsiveness to the
hearing aid is way better than
non-recipients to gener therapy. So
you're right hearing aids is actually um
is mandatory for them but 35 decibel
then they can do without the hearing
aids. Okay.
>> Oh wow. [laughter]
>> Yes.
>> Until 40 decibels they don't require any
hearing aid. They're completely normal.
>> So just advancing so good.
>> I mean they are born with some hearing
loss and
>> boom with gene therapy they are able to
hear. That's why the United States FDA
approved the or many and three months
ago.
>> That's fantastic.
>> Professor, I would also like to know
about the permanency of the results.
>> Mhm.
>> Are the results going to be permanent?
>> Or do they require first or second dose
or third dose of injection? Because this
is something what every person they ask.
>> You're born with this hearing and this
will be permanent until unless we age.
Is that the same thing with this auto
related gene therapy also once we inject
are the results going to be permanent?
>> See very important questions. So far the
the strategy of auto related definition
is a gene transfer type of gene therapy.
There is a several type of gene therapy.
Eventually
gene therapy moves toward the genome
editing type of gene therapy. Genome
editing is just to correct the
mutations. So it could be permanent
right?
>> Mhm.
>> But the current type of gene therapy is
a gene transfer driven by the um a aav
virus. So inevitably current type of the
gene therapy depends on the lifespan of
the AAV virus which about which we we
don't know exactly. So if the lifespan
of AAV in human bodies if let's say it's
10 years then in 10 years later and
their autofillion protein expression is
significantly diminished and then
neurotransmitter release is stopped and
then we have to inject again.
>> So that's what we think. So that's the
reason why many scientists actually um
turn their focus onto the developing of
the genome editing technology in a type
of therapy which require only one type
of just a injection. Mhm.
>> Okay. Okay. Now it makes sense.
>> Yeah. Yeah. Yeah.
>> Okay.
>> So now our company is also working on
the developing the general editing drug
>> to um correct the rapidly progressive
type of the hearing loss. So that's the
reason because you know the um regenery
the big pharmaceutical company already
approved the gain the approval from the
FDA. So uh our small company doesn't
have any room for uh competing with them
in the congenital auto for example auto.
So uh our company actually has turned
our focus on the different genes which
um shows the rapidly progressive hearing
loss. Yeah. Okay. You should succeed
super fast uh professor because there
are millions of people with this rapidly
progressive hearing loss and the amount
of uh problems that they face because
this is something which is hidden
deformity everything looks good they say
this you look perfectly fine are you
dumb but they should understand that
>> he's deaf that's why he's not responding
it's not just because of his IQ or
something
>> exactly
>> so please I wish you all the best
regarding that uh development of uh
progressive hearing loss therapy gene
therapy for that.
>> Oh, thank you for your kind words.
>> Professor uh this is for the clinicians
who are watching this gene therapy
thing. M
>> I read a couple of your articles and one
of the [clears throat] article it just
mentioned that
>> the treatment for this auto related
hearing loss.
>> It's an unusually fortunate case
>> right
>> because we didn't get the we were
completely blindfolded by the uh
response that they got in the mouse
models but it's not happening in the
human models.
>> Exactly. Why did you mention so why is
this auto related gene therapy an
unusually fortunate case?
>> Because fortunately it meets the
criteria which um criteria which the
gene therapy should meet. So but it's
very difficult for many other genes to
meet that criteria. So it should be the
the the hair cells should be intact uh
before the interventions. the the degree
of the hearing loss should be eventually
profound. Let's say that for example uh
the hearing loss caused by the mutations
in STRC which is the most decommon cause
of the moderate degree of hearing loss
STRC
>> it the hearing level is 40 decibel and
then it doesn't progress at all until
the prespicus is imposed if and the gene
therapy the cost is for example let's
say the million dollars
>> are you gonna are you going to have that
therapy
Let's say the the hearing threshold is
only 40 decel and even hearing aid it
would suffice and then it doesn't
progress and what do what do you what do
you think are you going to are you
willing to get the gen therapy in that
cases um paying the billions of dollars?
>> No.
>> Yeah. So in that point actually there
are not many genes that cause the
profound duffness. So and then the while
the the preserving the hair cells think
about that not many genes actually meet
that criteria.
>> So and then the auto uh the prevalence
autotogene is is relatively uh as
prevalent in the kind of Spanish
populations and in United States there
are many the Spanish the people there.
So there are many situations which
renders the auto to be a candidate of
the genes but I I I don't think many
genes can be can meet that criteria. So
that that's the reason why I just
mentioned that uh gene therapy utov is a
very very unusually fortunate case.
Well said professor. It's very lucky.
>> Very lucky.
>> Very lucky.
>> Very lucky.
>> You were mentioning about the criteria
professor. That's something which is
very very uh important.
>> Imagine there is a 25 year old person
who has been going through this profound
hearing loss.
>> This person he never used a hearing aid.
He does not have any speech. Suddenly he
understood that autoph related gene
therapy is there. He gets his he gets
his genetic evaluation done and it turns
out to be autof
>> and now can this person undergo gene
therapy and if he under goes where how
will the results be?
>> Okay. So we have to take the OA test
first
>> because if even if he uh his hearing
loss is caused by the auto mutations if
the auto oto acoustic emission is gone
>> then he's just he's not he's not
eligible for the gene therapy. If he
luckily has the intact OA then he could
be a candidate of gene therapy but you
know gene therapy doesn't rescue the
brain you know you know what you know
the term of the auditory brain so it
does gene therapy doesn't doesn't rescue
the um the neurotransmitter release into
an audiary nerve not affecting the brain
plasticity so let's say if um he has the
normal OA until the age of the 25 the if
he gets the gene therapy then he can
detect the sound normally
>> and okay he can uh enjoy the music but
he cannot recognize the word and he
cannot have the speech um the
perceptions that's what I expect
>> very well said if I could just extend
this beyond you mean to say that he will
be there for the eligibility criteria
because he has OA pass the autoacostic
emission which tells that the hair cells
I'm good. I'm intact. So that's why once
you inject he'll be able to produce
autofallene protein and he'll be able to
hear.
>> Exactly.
>> But
>> the brain
>> it cannot understand what it is.
>> No.
>> Because of neuroplasticity.
>> Exactly.
>> That window period is already gone.
>> Mhm. So
>> this 25 year old person maybe if he
would have had speech and he suddenly
lost his hearing and it turned out to be
auto then he'll be getting any benefit
with the auto of related gene therapy
but not immediately after gene therapy
when he was not using anything is that
makes sense from
>> right exactly
>> that's that's perfect
>> now
>> another let me another so there here's
an interesting story that um you know
what is most important for eligibility
of gene therapy especially in terms of
the um uh in auto fields hair cells
integrity is very important
>> but hearing aid
turn out to be kind of kind of um bad
prognostic factors for survival so let's
say there is a patient if he wears the
hearing aid so much then it is more
likely that hair cells could have
>> damage Ed
>> due to the kind of noise induced.
>> So uh if in there is a kids and then for
some reason he cannot have the coke
implant and he could not have the gene
therapy at this point. But using too
much of time of the hearing aid actually
would potentially negatively affect the
eligibility of gene therapy.
>> Oh my god.
>> That is specifically that is um only for
the ot.
So that's the what um that's published
probably a couple of years ago by the
Christian PT lab or yeah this
>> so this hearing aid it causes noise
induced hearing loss and it causes death
of hair cells
>> yeah especially out of patient
>> out of patients
>> okay and that's why
could you just brush up the knowledge of
all the surgeons the clinicians and also
the parents who are watching
>> what is the eligibility criteria for the
patients who can undergo auto related
gene therapy. officer. Yes. Can you just
>> Okay. So, um currently so bilateral co
implantes are excluded.
>> Bilateral unilateral co implantes can be
included because the contrlateral site
is preserved reserved for the gen
therapy. So number one bilateral co
implantes are excluded. Number two dpoa
oae should be intact. Mhm.
>> U it doesn't have to be 100 perfect but
just I think at least uh at least from
the three frequencies there should be
significant OE responses. It doesn't
have to be five or six frequencies three
frequencies. So if you can observe the
uh meaningful OA responses uh at least
from the three frequencies and then
there should be genetic documentations
two mutant alals two mutations of auto
should be documented.
>> So currently the three are the main uh
the eligibility criteria for autogen
therapy
>> and severe to profound hearing. Yeah, of
course. Of course. The ABR should be at
least I think over 80 dB 70 or 80
decibel. Right. Right. Sometimes uh for
example the temperature sensitive auto
variants there are
>> it's a unique type of the auto variance
and not all auto patients
>> show the severe to profound duffness.
>> Some of the p some of the variants of
auto can cause only the temperature
sensitive audiary neuropathy.
>> What does it mean? So uh usual
conditions the he can speak and he can
uh understand perfectly but with uh high
fevers temperature high fever he doesn't
she doesn't he or she doesn't recognize
anything at all. So ABR responses just
go down to the 100 dB threshold only for
the time of the high fevers. So but
there is a mutations there is a certain
of mutations are documented to uh uh the
result in that kind of temperature
sensitive al so the fourth algebraic
criteria is that
>> even though the patient have the auto
variance it should not be related to the
temperature sensitive al that's the
fourth conditions
>> perfect I mean it's sounding really like
a science fiction movie even for me
professor Yeah. Right. Right. But
interesting. Yeah. So yeah, so for for
we should remember the four conditions.
So exclude bilateral implantes are not
the candidates and then OA should be um
meaningfully present at least from the
three frequencies and then it the auto
varants are documented but uh the uh
temperature sensitive uh the alil auto
variant should be excluded. That's what
the current elig eligibility criteria
mentioned.
>> Professor, just now you mentioned about
temperature sensitive cottoalin
mutations.
>> Mhm.
>> U there are couple of patients who have
been asking me doctor if you just look
at me from front
>> and talk I'll be able to hear.
>> Mhm. But if you just go behind
>> or if someone two or three members call
me or some conversation is happening I'm
not able to understand anything.
>> It's a classic case of auditory
neuropathy A and SD. So for them are
there any specific things that they need
to get testing done any specific testing
apart from whole exam sequencing so that
we can rule out certain things? Uh very
good question. Um actually um um you
know so the there are kids ov kids that
means that their parents carried at
least one
>> mutations of auto right even though they
are perfectly normal.
>> The their parents tends to show the
hidden type of hearing loss. Hidden
hearing loss means that uh they are
somewhat affected uh their spiranga
cells or their inner hair synapses are
certain amount affected but not leading
to the u significant hearing loss. So
actually their parents shows some u
problems in the uh the discrimination in
especially in the low frequencies and
then they can not hear in in noisy
conditions. So we call that type of
situations as a hidden hidden hearing
loss because their purton threshold is
normal
>> but they actually doesn't produce uh in
noisy conditions either in the noise
conditions or either in the um uh uh in
in in certain distance u the locations.
So uh in that case actually what I
usually do is actually to see if there
is any uh uh uh kids the pat the kids
and then the other possibility is that
um uh so in that case the parent might
have only one mutations of
>> then the p the that that
>> not patient that carriers
>> parents
>> may yeah may tend that kind of
situations. So difficulty in uh having a
conversation in noisy conditions that's
the first conditions and there are in
that case actually uh I do the auto
sequencing and uh uh and the other
possibility is I just take the ABR
responses
>> and then in that case the wave one the
amplitude is diminished compared with
the normal hearing people. So I usually
do the abr responses ABR test. So that
the uh the uh uh so hidden hearing loss
patients show the decrease in the
amplitude in the ABR especially in the
first wave.
>> So in that case the patients tend to
show that kind of phenotypes
difficulty although their hearing
threshold is perfectly normal.
>> They complain of the difficulty in
conversation in
>> in in certain situations.
>> We call that as hidden hearing loss.
>> Hidden hearing loss. Exactly. Right.
>> How do we treat such situations?
Unfortunately, no treatment at so far.
Just just counsel them. You may have the
hidden hearing loss. And unfortunately,
at this point, there's no cure or no
treatment.
>> But it it's good to know.
>> Will their kids go through the same
situation or will their kids go through
profound hearing loss?
>> No. No. They won't develop the just full
minute on the the auditory neuropathy.
just complain of some difficulty in
certain situations. Yeah.
>> Okay. Professor, there are many many
parents who are asking once again the
same question. [laughter] This gene
therapy is not available in our India.
>> In almost all the developing countries,
it's not available in India. But we have
huge population and we have many kids
who are going through auto related
hearing loss.
>> What can all these kids do? what any
guidance for our Indian parents. Is
there any way that u they can approach
our drd hospital and we can guide them
to you?
>> Okay, tough questions but very important
questions for Indian um DFM denine
patients. I think uh first of all at
this point there are two ways actually
the first official way through the
official
establishment of the gene therapy
>> through the FDA approval in in Indian uh
FDA approval that's the official way of
course it would take time I think that's
what you I think you uh you should do
first so given that the the United
States FDA has already approved the uh
utani. So I think it's not it would not
that difficult for Indian the FDA to
approve the gene therapy. So I think the
first thing you have to do is just
contact the uh Indian FDA and or Indian
uh the ministry of welfare to see if
there is availability of [clears throat]
um the approval of the um the many or
other type of the auto gene therapy
materials. That's the first thing. The
second thing is that although the
regenerance uh there was actually three
companies which was involved with the um
developing the oaf related deafness gen
therapy the first one is regeneran which
turned out to be a winner and the lilies
uh liies is is another country another
company I'm sorry and the third one was
sensorian so given that the uh the
regenerant has already approved the um
has already obtained the approval from
the FDA but still the lily and censorian
still running the clinical trials. So
the another way of Indian DFNB9 patients
to have the uh the autogen therapy is to
contact Lily could be a contact point
>> or so or I can help the the Indian DF
main patients to contact Lily because I
was working with the regenerant and I
actually our I was trying to uh perform
the clinical trial in our university
hospital but uh unfortunately there the
clinical trial has finished because they
already have obtained the FDA approval.
So they don't need to run the clinical
trial. So so the contact the regenerate
actually has has actually meaningless
actually. So contact contacting Lily
which actually is still running the
clinical trial is uh I think gives could
potentially give us a proposed give us
an opportunity to for Indian the FM9
patients to have the gene therapy is as
a clinical trial the form. So I think
that there are two two u forms of the
possibility.
So we should open open up the the
opportunity for Indian DFM9 patients in
some ways.
>> We'll do professor and we we'll be
requiring your help for that.
>> I I would I would
>> thank you so much professor for that.
>> Prophecy you are forget that you are a
doctor now you forget that you are a
surgeon. Mhm.
>> Just imagine
>> you have operated on kids. You have seen
them hearing getting back their hearing.
>> Right. Right.
>> And you have performed gene therapy
without performing any surgery and you
have seen kids recover their hearing.
>> How do you feel inside as a human being?
>> Yeah. Yeah. Yeah.
But well, I just um it's I think it's a
privilege of of our ENT surgeons to be
able to witness the kids with the
hearing impairment to recover their
hearing and to uh can to be able to
listen to able to enjoy the music. So
yeah, I think uh it is our privilege and
I'm very happy to be able to be in that
position just like you. So I think yeah
just I think it's our privilege and I
really appreciate that as a human
beings.
>> Yes professor after all we do all this
at the end of the day for to satisfy our
little heart and
>> Right. Right.
>> You are truly following your passion and
you're doing the best and helping
millions and millions of people who are
going through this hearing loss. Sincere
thanks to you regarding that.
>> That's my pleasure. So, professor, this
is almost the final question that I'm
asking you.
>> What is the future of this gene therapy?
What are you really excited about now at
the moment?
>> Okay. Um, which is are very your your
actually comments are very important
actually. the um uh the future the
trends or future direction of the gene
therapy should move I think um just
beyond the congenital deafness
>> probably it would expand or it would
evolve to involve the rapidly
progressive hearing loss
>> uh that would be like the next target
which actually has a higher the
prevalence actually
>> so and then uh as you mentioned as we
already discussed
uh single injection should be mandatory
to avoid the multiple injection. So
rather than just this gene transfer
um just performing the genome editing
which requires only one injection one
fix. So probably uh our gene therapies
uh would evolve into that direction. So
to involve the rapidly progressive
hearing loss and to involve the genome
editing rather than the simple gene
transfer that I think that that's the
way I think
>> perfect professor
>> thank you so much for this for your
science for your dedication
>> uh for the entire patients well-being um
>> that's all professor
>> thank you thank you so
>> heartful heartful
>> thank you so for your invitation and
it's it's my privilege to um to
participate in this the hearing circle.
It's my great honor.
[laughter]
>> Thank you so much professor. Thank you
for flying all the way from Seol, South
Korea to India and answering all the
questions that our Indian parents have.
Thank you.
>> Thank you.
>> Thank you. Namaste.
>> Namaste. Namaste. No.
View full transcript
00:00:00 Welcome to the hearing circle. I'm Dr.
00:00:02 Shri Rao and today my guest is professor
00:00:06 Chi Yang Yun from Seol, South Korea. He
00:00:10 is an ear surgeon. He is a researcher.
00:00:13 He is a scientist and more than any of
00:00:16 this he is the CEO of Sensory Cure, a
00:00:19 gene therapy company which has found the
00:00:21 cure for hearing loss. We are very
00:00:23 fortunate to have him on this hearing
00:00:26 circle podcast. And in this podcast,
00:00:28 I'll be covering most of the commonly
00:00:31 asked questions about this gene therapy.
00:00:33 What is this gene gene therapy? What is
00:00:35 the eligibility criteria for this gene
00:00:37 therapy? What are the risks for this
00:00:39 gene therapy? What is the minimal age
00:00:41 group that a child can undergo this gene
00:00:43 therapy in case if this is available
00:00:46 India? What is the cost of it? And what
00:00:48 are the things that parents should look
00:00:50 for when they are suspecting any hearing
00:00:52 loss related for this gene therapy and
00:00:55 many more. Thank you, professor, for
00:00:57 accepting for our hearing circle
00:00:59 podcast. Thank you so much for coming
00:01:01 and
00:01:02 >> it's my great pleasure,
00:01:03 >> professor. Uh let me ask you the most
00:01:06 commonly asked question by our uh
00:01:08 viewersh.
00:01:09 >> Is gene therapy a cure for hearing loss?
00:01:13 >> It's very good questions. the um the
00:01:15 gene therapy is actually offers uh
00:01:18 biological cure of the hearing loss
00:01:21 while the coke implantation u actually
00:01:24 enable us to rehabilitate rehabilitate
00:01:27 the the hearing loss. So that's the main
00:01:28 difference. But here's a uh limitation
00:01:32 >> and the gene therapy is very fantastic,
00:01:34 but it's not a magic one
00:01:36 >> for all type of the hearing loss. Only a
00:01:39 very specific type of the hearing loss
00:01:41 can benefit from the genet the gene
00:01:43 therapy of the hearing loss.
00:01:45 >> You work with uh researchers and
00:01:46 scientists across regeneron the company
00:01:49 which has found the cure for auto
00:01:52 related uh hearing loss which is
00:01:54 completely US FDA approved. M
00:01:56 >> how far are we to call this as a cure
00:01:58 for deafness? I mean about the other
00:02:01 forms of hearing loss also. How far are
00:02:02 we?
00:02:03 >> But um I would like to focus that I
00:02:05 would like to stress the fact that the
00:02:07 autof
00:02:09 >> is as a very unique
00:02:11 >> and it actually uh was in the very
00:02:14 unique biological conditions. So not all
00:02:16 definite u genes can immediately benefit
00:02:19 from the gene therapy. So I would like
00:02:22 to mention that. So for example the art
00:02:26 >> um is um uh usually think about think of
00:02:29 the gene therapy as a kind of delivering
00:02:32 kind of software update
00:02:34 >> to the cellular machines.
00:02:36 >> So it does not cure
00:02:39 >> the hardware. So once hair cells
00:02:41 >> if the hair cells are already dead
00:02:44 >> and especially if it is reversibly dead
00:02:47 then there is no way to bring them back.
00:02:49 So even gene therapy cannot do that. M
00:02:52 >> so delivering the software software
00:02:54 update
00:02:55 >> for example auto
00:02:57 >> although the the parent the patients
00:02:59 with the auto the variants
00:03:02 >> show the profound deafness severe to
00:03:04 profound deafness as you already know
00:03:06 >> nonetheless the hair cells
00:03:10 >> such as the hardware so-called hardware
00:03:12 the software hair cells are intact
00:03:16 >> and healthy at least until their early
00:03:19 life
00:03:20 >> although the uh with age the hair cells
00:03:23 just go die but at least for the early
00:03:26 stages of the the life the hair cells
00:03:28 are intact in auto related deafness. So
00:03:31 think about that. So the only the gene
00:03:33 therapy just offers the just the
00:03:35 software updates. So if the the the uh
00:03:38 the hardware is gone then there's no way
00:03:40 for gene therapy there's no room for
00:03:42 gene therapy. So but in a tough cases
00:03:45 >> the hair cells are intact. the hardwares
00:03:47 are intact and healthy. And if we just
00:03:50 inject the uh the cDNA of the auto that
00:03:55 can produce the odor protein which the
00:03:58 uh DFNB9 patients
00:04:00 only lack
00:04:02 >> the the the auto related patients lack
00:04:05 the the protein autofillion that's all
00:04:08 >> while the all the other the cellular
00:04:11 structures are remain intact. So in this
00:04:14 type of the uh situations make the auto
00:04:17 is a very unique position and that's why
00:04:20 the auto uh has been remarked as the
00:04:23 first successful target of gene therapy
00:04:25 but but not all gene therapy uh not all
00:04:28 genetic definitions can benefit from the
00:04:30 gene therapy.
00:04:32 That's well said professor and the way
00:04:34 the analogy that you were using a
00:04:36 hardware and the software
00:04:38 >> you mean by the external year the middle
00:04:41 ear structures the inner ear structures
00:04:42 if we consider as a hardware
00:04:44 >> hardware is completely intact
00:04:46 >> and it's just a bug which is there
00:04:48 within the software and we are giving a
00:04:50 software update
00:04:51 >> exactly
00:04:51 >> out of gene therapy and the patient will
00:04:53 be able to hear well
00:04:55 >> if the hardware is not good some broken
00:04:57 things no hair cells it's useless so it
00:05:00 the gene therapy will not work even
00:05:02 though if we upgrade the software that's
00:05:04 what you mean.
00:05:05 >> Exactly. Exactly right.
00:05:06 >> Very well put uh professor.
00:05:08 >> You're exactly right. Right.
00:05:09 >> Uh before getting into this science
00:05:12 proper, we want to know something about
00:05:14 you professor. How can an ear surgeon
00:05:16 just like us build a cure for toughness?
00:05:20 Is there any particular patient that
00:05:22 triggered you? Oh no, this is not the
00:05:25 end. I think I have to go beyond this.
00:05:27 Is there any situation that you felt? uh
00:05:30 because before I become a US surgeons
00:05:33 actually I was trained as a geneticist
00:05:35 actually I just spent my uh the postoc
00:05:39 uh the four years in the United States
00:05:41 the national institute of health NIH in
00:05:44 United States uh and I worked in the um
00:05:46 genetic deafness lab
00:05:48 >> and my role was to uh find out the cost
00:05:52 gene of deafness at that point and then
00:05:55 I was um my effort was also focused to
00:05:59 delineate and clarify the topiology of
00:06:02 deafness genes
00:06:04 >> and and also at that point the auto one
00:06:06 of my interesting gene because as I
00:06:09 mentioned that is a very um auto the the
00:06:12 problems in the auto can lead to the
00:06:15 only the uh defect in the synaptic the
00:06:18 vesicle release while the all the other
00:06:21 hair cells looked intact. So uh that
00:06:24 kind of the experience in the as a
00:06:26 geneticist can make me get uh interested
00:06:29 and get interested in the uh the gene
00:06:31 therapy naturally. So that's the reason
00:06:34 actually I uh become interested in the
00:06:36 gene therapy and then I also had a
00:06:38 chance to uh work with the um decibel
00:06:42 company actually now actually it uh it
00:06:45 has been merged into the uh regenerant
00:06:48 the big pharmaceutical company
00:06:49 regenerant. So I we actually worked
00:06:52 together um to uh rescue the phenotype
00:06:55 of the autophilated mice and then we
00:06:58 were successful. So through that
00:07:00 experiences actually I just um I want to
00:07:03 just build up some some company that
00:07:06 invent new type of the gene therapy
00:07:09 material not only for the congenital
00:07:11 cost but also for adult the progress of
00:07:14 the hearing loss. That's the reason why
00:07:15 I just uh founded the the company the
00:07:19 sensory cure.
00:07:20 >> That's fantastic professor. You're doing
00:07:23 so much good for the entire world
00:07:25 especially people who are going through
00:07:26 this deafness.
00:07:29 So now let's get into the science proper
00:07:33 >> mainly the basics I can say.
00:07:36 >> Imagine I'm not here. Imagine a parent
00:07:39 is sitting here in front of you
00:07:41 >> who [clears throat] has not studied any
00:07:43 science who does not know anything about
00:07:45 science.
00:07:46 >> Can you explain what is this gene
00:07:48 therapy for a parent who has never
00:07:51 studied science in a very simple
00:07:53 possible manner because for them this is
00:07:55 just like a science fiction movie
00:07:57 unbelievable thing
00:07:59 >> and what is exactly happening in the
00:08:01 child when they do this gene therapy if
00:08:04 you could just
00:08:06 >> tell us. is [laughter] very difficult
00:08:08 task very difficult but okay so I just
00:08:12 um uh previously I mentioned that the
00:08:14 gene therapy is like a uh software
00:08:17 update uh while the there are intact the
00:08:20 the hardwares so that's the actually the
00:08:22 main main uh the explanation that
00:08:25 usually how I put the gene therapy in
00:08:27 the in the in the in the novice uh for
00:08:30 the u the gene therapy that that's the
00:08:33 uh main uh uh way of explaining the gene
00:08:36 therapy to the patients. But as I
00:08:39 mentioned the most important thing uh is
00:08:43 that so far
00:08:45 autogene is the only gene that can
00:08:48 benefit from the gene therapy. So uh
00:08:52 once the hair cells before the hair cell
00:08:55 die eventually the autorelated
00:08:57 definition can show the the definition
00:08:59 uh the degeneration of hair cells.
00:09:02 Before the hair cells degenerate, we can
00:09:06 inject
00:09:08 >> the um normal un um mutated nonmutated
00:09:13 auto gene um with the viral vectors
00:09:17 viral vehicles so-called AAV adeno
00:09:20 associated virus AAV into the coia that
00:09:24 that's all actually. So um so we just
00:09:30 usually generate the normal autog gene
00:09:35 encapsulated with the vital vectors
00:09:37 called the AAV but which has a lifespan
00:09:41 into the cookia. So and then then
00:09:44 injected the um uh normal autogene
00:09:48 can produce normal the protein product
00:09:52 odapurene and which
00:09:56 uh revive the uh impaired the neuro
00:10:01 transmitter release and then uh it can
00:10:04 elicit the the the the colear nerve and
00:10:08 then it can just revive the the normal
00:10:11 auditory pathway. Right.
00:10:12 >> So that's actually how it just the gene
00:10:15 therapy for the autorelate patients
00:10:16 works.
00:10:17 >> So you were telling about this
00:10:18 autofurlin protein professor
00:10:21 >> for the parents who are watching this
00:10:24 one.
00:10:24 >> What is this wordlinin? Why is it
00:10:27 required for the patients for the kids?
00:10:29 >> What role does this autofurlin has?
00:10:32 >> Okay, let me put this this way. So
00:10:34 there's the hair cells. Here's the most
00:10:37 uh peripheral the receptors
00:10:40 >> that convert the the sound into the
00:10:44 electrical signals.
00:10:46 >> So but to be to achieve that purpose the
00:10:49 hair cell should release the
00:10:52 neurotransmitters
00:10:54 to the the colear nerve.
00:10:57 >> But without the odorillain
00:11:00 >> the hair cell cannot release the
00:11:02 neurotransmitters.
00:11:04 So but once the new auto oto gene is
00:11:07 introduced and it just can if it can
00:11:10 produce the normal autofilling then the
00:11:14 neurotransmitter release can be
00:11:16 restarted and then it can uh produce it
00:11:20 can stimulate the auditory nerve so
00:11:22 people can hear and people can uh
00:11:24 recognize what other people say. That's
00:11:26 the pathway and that's what the oto gene
00:11:29 does
00:11:30 >> for parents. Uh to put this out
00:11:32 >> if you imagine the cell to be a mic like
00:11:35 this.
00:11:36 >> Okay. The mic
00:11:37 >> microphone.
00:11:38 >> Right. Right.
00:11:38 >> And the nerve it if it is nerve or the
00:11:41 brain that is a recording system.
00:11:44 >> Right. Recording system. Right.
00:11:45 >> The cable is missing. That cable is
00:11:48 something which is formed by this
00:11:50 autofolin protein.
00:11:51 >> Right. Right. Right.
00:11:52 >> Microphone is good.
00:11:53 >> The recording system is good. But but
00:11:55 without the cable the cable is
00:11:57 autoerlin.
00:11:58 >> So that's why you inject a genetically
00:12:01 modified virus
00:12:03 >> which codes for this auto gene and
00:12:06 finally produces this
00:12:09 autoferlin protein.
00:12:10 >> Wow. Fantastic way of put
00:12:13 >> right you're right
00:12:13 >> cable.
00:12:14 >> Exactly.
00:12:15 >> So is a cable right [laughter]
00:12:18 fantastic way of putting it. Okay.
00:12:20 That's uh that's something which is very
00:12:23 fascinating professor because uh for
00:12:26 normal people this just looks like a
00:12:27 science fiction movie to be very frank
00:12:30 with you. they they are not even
00:12:32 believing that really just with an
00:12:34 injection is this happening why can't it
00:12:37 cure our hearing loss as well I mean the
00:12:40 people who had normal hearing and later
00:12:42 they lost their hearing
00:12:44 >> right right
00:12:45 >> so I was trying to tell them that no
00:12:47 this is only for auto related genes
00:12:50 because for them the microphone is there
00:12:52 this is there but the cable is not there
00:12:55 >> and they were like no even this should
00:12:57 work so even that's a question Mark for
00:13:00 me professor there are many several
00:13:03 other causes for this congenital hearing
00:13:06 loss and sensory neural severe sensory
00:13:08 neural hearing loss
00:13:10 >> on top of this just contributes to 2% of
00:13:13 this congenital hearing loss
00:13:15 >> there are GJB2 mutations SLC26 A4
00:13:19 mutations myo 15A mutations which
00:13:21 contribute to almost 80 to 90% of this
00:13:24 hearing loss why only this what got this
00:13:27 special
00:13:28 >> attention Why only this? Yeah, the
00:13:32 that's what I already mentioned because
00:13:34 the auto is a only gene where the
00:13:37 hardware is and looks intact and and the
00:13:41 software update was was enough actually
00:13:43 to restore the whole new whole the
00:13:46 hearing the echo system for let's say
00:13:49 the the masin 15A you know the mass 15A
00:13:52 actually involved with the um sterilia
00:13:54 elongation there is a um the three rows
00:13:57 of the sterily has a different length of
00:13:59 the um uh the different length and to
00:14:02 but without the mas 15A the sterilia of
00:14:04 the hair cell doesn't grow after birth
00:14:06 you know in the animal models in the
00:14:09 mouse model uh having the the hearing
00:14:12 loss can be misleading because uh the
00:14:16 mouse coia kept developing after birth
00:14:19 but in humans the coia development
00:14:23 actually just finished way before birth
00:14:27 so for example you're right for example
00:14:30 SLC 26 6A4 and catering 23 and for GJB2
00:14:34 >> see the mouse models carrying that type
00:14:36 of mutations can benefit from the gene
00:14:40 therapy in the mouse models.
00:14:42 >> Oh
00:14:43 >> because their coia develops keep
00:14:45 developing after birth. we inject their
00:14:48 this normal gene into the the mouse coia
00:14:51 and then uh because the coia is still
00:14:54 developing but in humans for example
00:14:58 GJB2 mutation can affect the spiral
00:15:01 ligament and the the supporting uh
00:15:03 supporting cell the organ of cordi and
00:15:05 uh and which in turn affects the hair
00:15:08 cell. So the GJB2 kids was born is born
00:15:14 with the hair cell already damaged. So
00:15:17 as I mentioned so which the the hair
00:15:20 cell which were already damaged
00:15:22 irreversibly cannot be revived with the
00:15:25 gene therapy. Gene therapy just offer
00:15:27 only the software update not uh just
00:15:30 restoring the the hardware of the
00:15:32 impairment. So that's the reason why so
00:15:35 far only the G auto is can is a
00:15:38 beneficiary of the um the gene therapy
00:15:41 unfortunately but many companies uh
00:15:43 actually are working on the the other
00:15:46 genes. So think about that who would be
00:15:48 the next which genes would come next
00:15:51 after which could be the progressive
00:15:54 hearing loss
00:15:55 >> progress. So we can inject the gene
00:15:59 therapy materials before the hair cells
00:16:03 are largely irreversibly damaged. So
00:16:07 that's that's the uh situation and
00:16:10 that's the uh uh how we can think about
00:16:13 the next target for the hearing loss the
00:16:15 gene therapy.
00:16:16 >> So you're very clearly mentioning that
00:16:19 uh the mouse the laboratory mice where
00:16:22 many people all the scientists like you
00:16:25 work on. Mhm.
00:16:26 >> For them the coccia keeps developing
00:16:28 even after birth
00:16:29 >> and that's why it was completely
00:16:30 misleading. So you you would have
00:16:33 thought that okay because this is
00:16:34 working on mice this should also work on
00:16:37 human beings.
00:16:38 >> That was not
00:16:38 >> surprisingly
00:16:40 >> it's not possible because the human
00:16:41 coccia is not once again growing after
00:16:44 birth that's it. So professor if I could
00:16:48 ask you now after this regeneron company
00:16:52 got this USFDA approval for yes for
00:16:56 related hearing loss
00:16:57 >> right
00:16:57 >> the sensorion the other company
00:16:59 >> right
00:17:00 >> they have withdrew from the trials and
00:17:03 they started this GJB2 gene mutation
00:17:07 >> exactly
00:17:07 >> as their clinical trials
00:17:09 >> right right
00:17:10 >> immediately how do you square that
00:17:12 >> the the French this scientist the the
00:17:15 Christian who who is very f famous in
00:17:18 this field and is actually she is mainly
00:17:20 working on that in collaboration with
00:17:21 the sensorian and um you know you know
00:17:23 what GJB2 knockkin mice so the mut the
00:17:27 mice uh who which carries the mutation
00:17:29 GJB2
00:17:31 >> actually significantly benefited from
00:17:33 the gene therapy in the mouse model
00:17:35 actually the based on that they actually
00:17:37 the many scientists actually working on
00:17:39 that here's are some u unique uh point
00:17:42 of in in in GJB2 because the GJB2 main
00:17:45 expression is not in the hair cells but
00:17:49 in the supporting cells.
00:17:51 >> Yes.
00:17:51 >> So for example the myosin 15A is mainly
00:17:54 in the sterilia of the hair cells. So
00:17:57 actually initially attacks the hair
00:17:59 cells. So
00:18:00 >> but GJB2 initially attacks the
00:18:03 supporting cells
00:18:04 >> and then that insult in turn affects the
00:18:08 hair cell. So I think the their thought
00:18:10 that sensor censorian thought is that we
00:18:13 can intervene before the um the problems
00:18:17 in the supporting cell affect the hair
00:18:19 cell that's how they thinks but I I'm
00:18:22 not sure about that but I don't I'm not
00:18:24 100% positive effect of the gene gene
00:18:28 therapy in the GJB2 related deafness but
00:18:30 but let's see let's see how it goes
00:18:34 >> because GJB2's main expression is not in
00:18:36 the hair cell that's actually uh one of
00:18:39 the point that we can um think about for
00:18:42 the future possibility of although I'm
00:18:45 not 100% positive about that. No.
00:18:48 >> So [clears throat] it's it's very
00:18:49 clearly established as of now the gene
00:18:52 therapy for hearing loss is right now
00:18:54 available only for auto related
00:18:57 >> right
00:18:57 >> and we cannot expect the hearing loss
00:19:01 treatment with gene therapy for other
00:19:03 forms of congenital hearing loss like
00:19:05 GJB2 especially which contributes to
00:19:07 significant amount because of the
00:19:10 mechanism of action that it it does.
00:19:13 That's something which all the parents
00:19:14 should understand. Professor
00:19:17 >> right
00:19:18 >> uh professor uh if we look at the actual
00:19:21 thing what's happening here
00:19:24 >> a clear implant has been considered
00:19:26 as the gold standard for all forms of
00:19:29 congenital hearing loss
00:19:30 >> you're right
00:19:31 >> till date
00:19:32 >> of course for this auto related right
00:19:34 now gene therapy has come
00:19:36 >> what do you think is better the cocklear
00:19:38 implant or gene therapy or do you think
00:19:40 that gene therapy will replace the
00:19:43 cocklear implant
00:19:44 >> they're very tough questions So at least
00:19:46 for the uh uh let's talk about the auto
00:19:49 related deafness first. I think so far
00:19:52 the it it seems to be kind of routine or
00:19:55 it seems to be uh appropriate to um do a
00:19:59 gene therapy in in one side and then to
00:20:02 to do an the implant on the contrlateral
00:20:05 side and to see if how how it goes
00:20:07 because uh to do a genetic uh gene
00:20:10 therapy in the bilateral side is kind of
00:20:12 could impose some risk because not all
00:20:14 the patient benefited from the gene
00:20:17 therapy. Some of them about 10 to 15%
00:20:20 did not respond to the gene therapy. We
00:20:22 don't know exactly why. There could be
00:20:24 some kind of the um some neutralizing
00:20:26 antibbody is kind of uh result of the
00:20:29 immune reactions because the AAV virus
00:20:32 can elicit the immune reactions. But if
00:20:35 some of the uh the patient that already
00:20:37 had some kind of antibodies against that
00:20:40 AAV virus
00:20:41 >> uh in that cases the autogene therapy
00:20:44 even otogene therapy uh could could
00:20:47 fails. So uh you know thinking about the
00:20:52 importance of the only intervention
00:20:54 along the uh side of the um the the
00:20:57 speech development. So considering that
00:21:00 risk so just one side gen therapy and
00:21:03 one side coal implantation is a safer
00:21:05 options at least for the autopheness
00:21:08 and then uh for the other part of the
00:21:10 deafness I think the scientists are
00:21:12 working on now turn their focus on the
00:21:16 GJB2 and other rapidly progressive
00:21:19 sensory neuro hearing loss. For example,
00:21:21 tempest gene TMP RSS gene is a very
00:21:25 rapidly progressive hearing loss in
00:21:27 pediatric patients and it initially it
00:21:30 manifest as a normal low frequency
00:21:33 hearing loss and a mild uh decrease in
00:21:35 the mid to high frequencies but over
00:21:38 time it rapidly the high frequency
00:21:40 hearing progressive declines and then
00:21:42 followed by the the decline in the
00:21:44 mid-frequency and the low frequencies.
00:21:46 So in that type of the hearing loss can
00:21:48 benefit from the uh the gene therapy uh
00:21:51 because actually the many scientists are
00:21:52 working on that TMPR SF3. So eventually
00:21:56 that type of the the the hearing loss
00:22:00 can benefit from the gene therapy
00:22:01 because uh we can have kind of w time
00:22:04 window
00:22:06 before the the the outer hair cells or
00:22:09 in hair cell dies. So probably uh the
00:22:13 the the focus of the gene therapy can
00:22:15 move toward kind of rapidly progressive
00:22:18 hearing loss. uh but before that I can
00:22:21 we just wish it uh the the followup on
00:22:24 the how the gene therapy for the GJB2 uh
00:22:28 by the sensorian company uh goes
00:22:31 >> very very well put uh professor and
00:22:33 you're being very clean and crisp here
00:22:36 stating that auto related gene therapy
00:22:39 the success what we expect almost 10%
00:22:43 that is what you were mentioning 10% of
00:22:45 the kids they didn't benefit from this
00:22:47 yes auto and also So you were mentioning
00:22:50 about the AAV associated immune reaction
00:22:53 >> right
00:22:53 >> which [snorts] was happening.
00:22:54 >> So uh if I could just elongate this
00:22:57 question
00:22:58 >> uh see professor if we look at the
00:23:01 safety profile of the cocklear implant
00:23:04 it has decades of safety data behind it
00:23:06 and uh we know what are the risks what
00:23:09 are the benefits of it what are the pros
00:23:11 versus cons to do when not to do
00:23:14 >> but this gene therapy is just on the
00:23:16 bleeding edge right now right
00:23:18 >> right now. So if you could just
00:23:20 enlighten us what are the risks that
00:23:22 every patient parent should know when
00:23:25 they are proceeding for this gene
00:23:26 therapy to expect is there any child who
00:23:29 didn't benefit completely from this as
00:23:31 you said earlier
00:23:32 >> if you could just let us know about that
00:23:35 professor
00:23:35 >> okay judge um to be honest we don't have
00:23:39 a long-term availability of long-term
00:23:42 effect and long-term safety profile
00:23:44 either we don't have that data either
00:23:46 because the FDA approval of the out of
00:23:48 or that the name of the drug is or many
00:23:51 so many utili
00:23:55 is actually um doesn't cover the long
00:23:58 term because it just approved just four
00:24:02 months ago and then the uh the the four
00:24:05 papers which addressed the effect of the
00:24:07 gene therapy was published only uh at
00:24:09 2024 so we don't have any we don't know
00:24:14 what would happen so the injected adeno
00:24:17 associate virus, the vehicle could
00:24:19 elicit in the future unknown immune
00:24:21 reaction. We don't know that. And then
00:24:24 we don't know either about the long-term
00:24:27 durability of that the gene therapy
00:24:29 material. So if let's say if the AAV
00:24:32 virus the the lifespan is only 10 years
00:24:35 and we have to inject
00:24:37 >> the second round of injection. But the
00:24:39 you know what once the AV virus is
00:24:41 introduced in the our the health system
00:24:44 actually the antibbody the immune system
00:24:46 can generate the antibbody. So we don't
00:24:48 know what would happen if the uh if the
00:24:51 second injection happens. Many people
00:24:54 worry that the second injection would
00:24:57 fail due to the the antibbody which was
00:24:59 generated from the first injection. So
00:25:02 in that case we have to modify the virus
00:25:05 vehicles to avoid the the immune
00:25:07 reaction. So, so that type of things
00:25:09 actually has not been addressed well.
00:25:11 Honestly, we have to that type of risk
00:25:13 against the the potential benefits of
00:25:16 the hearing uh of the gene therapy
00:25:17 because you know you know gene therapy
00:25:19 restores the normal hearing ecosystem.
00:25:22 So they don't need the hearing aid, they
00:25:24 don't need the coke implantation and
00:25:26 they can um they hear the music and they
00:25:28 can enjoy the music just in the same way
00:25:31 as just the normal people do. So there's
00:25:33 a uh clear and huge advantage but also
00:25:37 there are some unknown
00:25:39 >> there could be unknown the um the side
00:25:42 effects or there could be unknown
00:25:44 limitations such as the uh only the
00:25:47 durability the short durability. So at
00:25:49 this point we should very carefully the
00:25:51 risk this potential risk against the the
00:25:53 benefits.
00:25:54 >> Very well said professor. If I could
00:25:56 just for my understanding as well, I
00:25:59 could take two crucial points from this.
00:26:02 One is the durability, the timeline. How
00:26:05 long is that going to be there? We never
00:26:08 know. As I can just compare it to with a
00:26:11 battery that we buy, we buy a new cell
00:26:14 phone, the battery will be there. It'll
00:26:16 be full.
00:26:17 >> But as time goes on, right,
00:26:20 >> it fades off.
00:26:21 >> Exactly. So once again we'll have to buy
00:26:23 a new one or probably we have to change
00:26:25 the battery.
00:26:26 >> Similarly the for the auto we have
00:26:29 injected once a genetically modified AV
00:26:31 wirus vector
00:26:33 >> but we cannot comment on the durability
00:26:34 and you were mentioning around 10 years
00:26:36 is the span.
00:26:37 >> I don't know actually some people say
00:26:39 would say just 5 years or some people
00:26:41 say 10 years we don't who knows we don't
00:26:43 know.
00:26:43 >> Yeah yeah so we don't know about the
00:26:45 durability. So if it fades off there is
00:26:48 no option of giving once again one more.
00:26:50 It becomes an anaphylactic reaction kind
00:26:52 of stuff because it's after all a virus.
00:26:56 It it does its job. It penetrates it
00:26:59 penetrates into the cells and sometimes
00:27:02 it of course it it definitely causes
00:27:04 this immune reaction antibbody
00:27:06 production and the second time if we
00:27:08 inject that's something which is very
00:27:10 bad. So durability and once again immune
00:27:14 reactions are something which are the
00:27:16 crucial risks that a parent should
00:27:18 understand when they pose their kids for
00:27:20 uh gene therapy.
00:27:22 >> That's that's what I understood
00:27:24 professor. Is that correct?
00:27:25 >> Yeah. Yeah. But um uh I have to mention
00:27:28 that the most devastating part of the of
00:27:30 the virus has actually was removed. the
00:27:33 the only the um the the vehicle role the
00:27:36 vector role vehicle role is retained
00:27:39 while the removing the most uh dangerous
00:27:42 part of the uh the virus has has been
00:27:44 removed. So uh we don't have to worry
00:27:47 about that point but still it could
00:27:50 elicit the immune response. That's the
00:27:52 most
00:27:53 >> just critical part.
00:27:54 >> This is one more important what you
00:27:55 mentioned doctor people may think that
00:27:57 we are injecting some virus into the
00:27:59 ear. Um
00:28:01 >> that's not correct. Vehicle it is just
00:28:03 being used as a vehicle itself. The
00:28:06 dangerous part the DNA or RNA within the
00:28:10 virus is being removed and the shell
00:28:12 itself is used and then you are placing
00:28:16 that material and then you are injecting
00:28:18 >> into the ear. Am I correct professor?
00:28:20 You're right. Exactly.
00:28:21 >> That's why we call it as a genetically
00:28:23 modified virus viral vector.
00:28:26 >> Right. Right. Right. Exactly. modified
00:28:28 vectors to to remove the uh critical
00:28:31 dangerous part
00:28:33 >> and that is called adino associated
00:28:35 >> adeno associated virus it doesn't it
00:28:38 doesn't integrate into genome it just
00:28:40 delivers
00:28:41 >> kind of kind of kind of delivers it it's
00:28:43 just deliver the normal uh the DNA into
00:28:46 the nucleus that's all
00:28:47 >> no penetration
00:28:48 >> no pen into the genomes
00:28:50 >> okay
00:28:50 >> at least
00:28:51 >> as a as at least the current type of the
00:28:53 gene therapy is like that
00:28:56 [clears throat]
00:28:56 >> perfect Nowadays actually genome editing
00:28:59 technology has been developed. It's
00:29:01 genome editing technology technology is
00:29:04 actually correct is correct the the
00:29:06 nucleotide. So it's a it's a little bit
00:29:08 different story but the autofilling gene
00:29:11 therapy is actually um uh is developed
00:29:13 in a way that it just delivers the
00:29:15 normal auto gene into the nucleus of the
00:29:18 uh the hair cells of the
00:29:20 >> uh the coia that's all
00:29:23 >> perfect
00:29:24 >> professor. So if I may ask one more
00:29:27 important question that many people are
00:29:30 asking. Can any person in case if a
00:29:33 child is born completely deaf as of
00:29:36 right now
00:29:37 >> u they are born with this hearing loss
00:29:39 GJP2 [clears throat] or any kind of
00:29:41 congenital hearing loss
00:29:42 >> can they wait for this gene therapy
00:29:45 >> or should they have to proceed with
00:29:48 colear implant
00:29:49 >> that's very tough questions to answer
00:29:51 but um if so that for for the patients I
00:29:56 just um proposed the strategies of one
00:29:58 side gen therapy on one side coke
00:30:00 implantation because you know the the
00:30:02 speech development requires the timely
00:30:05 intervention so I don't want to just
00:30:08 wait until the the gen therapies
00:30:10 available. So that's it and another
00:30:12 interesting study from our laboratory is
00:30:15 tells that even after co implantation
00:30:19 >> the hair cells in hair cells and out
00:30:21 hair cells looks intact especially in
00:30:23 the auto patients.
00:30:25 >> So the criteria I didn't talk about the
00:30:28 criteria
00:30:29 >> after colear implantation.
00:30:30 >> Yeah. Yeah. So, so people think that oh
00:30:32 once we implant then probably hair cells
00:30:36 probably would die and the the chance of
00:30:39 gene therapy just completely diminished
00:30:41 and that doesn't seem to be the case
00:30:44 because I think at least about 30 to 40%
00:30:47 of the DFN9 because related patients who
00:30:51 were implanted
00:30:52 >> shows the presence of the auto otocostic
00:30:56 emissions OE auto emission at least
00:31:00 until um after six six years after the
00:31:03 implantations. Yeah.
00:31:05 >> So in that case uh I don't know probably
00:31:09 the gene therapy in the implanted ear is
00:31:11 very difficult because you know but I
00:31:13 have to tell that I want to mention that
00:31:16 klay implantation itself abol doesn't
00:31:20 abolish
00:31:21 >> the future potential the possibility of
00:31:24 the gene therapy that's what I want to
00:31:26 mention
00:31:27 >> but anyway so at this point the one side
00:31:30 gene therapy and one side implantation
00:31:32 is seems to be uh appropriate in at
00:31:34 least is in the autoph related patients
00:31:36 and for other uh the patients I think I
00:31:40 don't want them to just wait for the
00:31:42 other gen therapy becomes available
00:31:44 because you know timely intervention is
00:31:46 very important so I think just people
00:31:49 should get the implantation yeah
00:31:51 >> and then see how it goes or sometimes
00:31:54 people can um be implanted only one side
00:31:57 but I don't think it is reasonable just
00:32:00 uh so at at point so uh let's say So
00:32:04 other than the OT patients,
00:32:06 >> the other deafness patients I think
00:32:08 should get implanted in a timely
00:32:10 fashion. That's what I'm
00:32:12 >> Thank you professor. Thank you for this
00:32:13 clarity.
00:32:16 >> If there are auto related genetic
00:32:18 deafness then they have to go ahead with
00:32:20 implant on one side
00:32:22 >> and the other side they can wait for
00:32:23 gene therapy.
00:32:24 >> That could be a ideal options. any
00:32:26 genetic mutations apart from they should
00:32:30 not wait for gene therapy because the
00:32:32 amount of time we never know and it is
00:32:36 humanly impossible for the brain to just
00:32:39 stay static. So that brain development
00:32:42 has to happen and hence they have to go
00:32:44 ahead with the colear implantation.
00:32:46 >> Exactly.
00:32:47 >> Perfect.
00:32:47 >> You put it beautifully.
00:32:48 >> Thank you. Thank you professor.
00:32:51 >> Now these questions are for from my side
00:32:53 also not just for the parents. Mhm.
00:32:56 >> I know how a cocklear implant sounds
00:32:58 like because this is a neuroprothetic
00:33:00 device.
00:33:01 >> Um it's it it just collects the sound
00:33:04 from through the microphones and then
00:33:06 >> finally electrically it stimulates the
00:33:09 cockia nerve.
00:33:10 >> Right. Right.
00:33:11 >> So it's a kind of electrical stimulus.
00:33:14 >> What about this gene therapy? How does a
00:33:16 child who underwent gene therapy, how
00:33:18 does this sound sound like?
00:33:21 >> Yeah.
00:33:21 >> Is it normal? perfectly normal just like
00:33:24 us or
00:33:24 >> den therapy is to restore the normal
00:33:28 hearing ecosystem. So if it works
00:33:31 >> it makes people just um uh hear just
00:33:34 like a normal people hear. But one main
00:33:37 difference lies in the fact that
00:33:39 actually so let's say that oh I got the
00:33:42 gene therapy yesterday so and then don't
00:33:44 and and the next day it it just doesn't
00:33:48 um come out just immediately after gene
00:33:50 therapy. it just because we have to wait
00:33:52 for the new genes new corrected normal
00:33:56 gene to produce the protein and then the
00:33:59 reproduce the protein should work and
00:34:02 you should restore the functions. So it
00:34:04 takes time. So usually according to the
00:34:05 the four papers published in 2024
00:34:08 regarding the autogen therapy um
00:34:10 according to their papers people would
00:34:13 restore their normal not normal hearing
00:34:15 restore their substantial um portion of
00:34:18 the normal hearing uh over times. So
00:34:22 probably three months or six months. So
00:34:24 there the hearing level just goes higher
00:34:27 until about the three to six month and
00:34:30 then at that point the hearing normal
00:34:32 hearing the um final hearing threshold
00:34:34 just um ranges probably 35 to 50 dB.
00:34:39 >> So it's not perfectly normal but but but
00:34:42 significantly good and then their speech
00:34:44 the recognition
00:34:46 uh reaches about range of the 75%.
00:34:49 >> Then the music perception is almost
00:34:52 normal.
00:34:53 >> Wow. That's usual. That's the average
00:34:56 the the level of the the B gene therapy
00:34:59 the uh the imp gene therapy recipients
00:35:02 uh the fields.
00:35:04 >> Oh wow. That's
00:35:05 >> so if it works it is fantastic actually.
00:35:08 >> Yeah. So PTA the pureon aometry levels
00:35:12 they range between 35 which is quite
00:35:14 good
00:35:15 >> which is quite good right
00:35:16 >> and speech discrimination score or SRT
00:35:18 levels around 70%. 75% exactly
00:35:21 >> excellent
00:35:22 >> and music which cannot be appreciated
00:35:25 >> right that's strongest point of gene
00:35:26 therapy but 10% of patient didn't
00:35:28 respond to gene therapy at all I have to
00:35:30 mention that
00:35:31 >> yes that's a thing 10 person they didn't
00:35:34 respond at all so professor you were
00:35:36 mentioning that the PTI ranges between
00:35:38 35 to 50
00:35:39 >> so does these patient do they require
00:35:42 any hearing aid after undergoing this
00:35:44 gene therapy or any external devices
00:35:47 because 50 dibbels they cannot
00:35:49 understand the clarity of speech, the
00:35:50 volume. You're right. Do they require
00:35:52 any hearing aid later rather than the
00:35:54 cockar implant?
00:35:55 >> Here's an interesting point. Usually the
00:35:56 um it's actually the the phenotype of
00:35:59 autoph related deafness is audiary
00:36:01 neuropathy spectrum disorder. They
00:36:03 actually uh their um response to hearing
00:36:06 aid doesn't seem to be great compared
00:36:08 with the other people. But
00:36:09 interestingly,
00:36:11 >> gene therapy recipients, let's say their
00:36:13 hearing threshold is um is restored to a
00:36:16 level of the 50 dB.
00:36:18 Usually the uh the neuropathy auditor
00:36:20 neuropathy patient doesn't respond well
00:36:22 to the hearing aid but recipients does
00:36:25 respond well
00:36:27 >> to the to the hearing aid. So right the
00:36:30 if the hearing restoration is just is 50
00:36:32 dB then right it requires hearing aids
00:36:35 but there the responsiveness to the
00:36:37 hearing aid is way better than
00:36:39 non-recipients to gener therapy. So
00:36:41 you're right hearing aids is actually um
00:36:44 is mandatory for them but 35 decibel
00:36:46 then they can do without the hearing
00:36:48 aids. Okay.
00:36:49 >> Oh wow. [laughter]
00:36:51 >> Yes.
00:36:52 >> Until 40 decibels they don't require any
00:36:54 hearing aid. They're completely normal.
00:36:57 >> So just advancing so good.
00:36:59 >> I mean they are born with some hearing
00:37:01 loss and
00:37:03 >> boom with gene therapy they are able to
00:37:04 hear. That's why the United States FDA
00:37:07 approved the or many and three months
00:37:10 ago.
00:37:10 >> That's fantastic.
00:37:12 >> Professor, I would also like to know
00:37:14 about the permanency of the results.
00:37:16 >> Mhm.
00:37:17 >> Are the results going to be permanent?
00:37:20 >> Or do they require first or second dose
00:37:23 or third dose of injection? Because this
00:37:26 is something what every person they ask.
00:37:29 >> You're born with this hearing and this
00:37:31 will be permanent until unless we age.
00:37:35 Is that the same thing with this auto
00:37:37 related gene therapy also once we inject
00:37:39 are the results going to be permanent?
00:37:41 >> See very important questions. So far the
00:37:43 the strategy of auto related definition
00:37:46 is a gene transfer type of gene therapy.
00:37:50 There is a several type of gene therapy.
00:37:53 Eventually
00:37:54 gene therapy moves toward the genome
00:37:57 editing type of gene therapy. Genome
00:38:00 editing is just to correct the
00:38:02 mutations. So it could be permanent
00:38:04 right?
00:38:04 >> Mhm.
00:38:05 >> But the current type of gene therapy is
00:38:06 a gene transfer driven by the um a aav
00:38:10 virus. So inevitably current type of the
00:38:12 gene therapy depends on the lifespan of
00:38:16 the AAV virus which about which we we
00:38:20 don't know exactly. So if the lifespan
00:38:22 of AAV in human bodies if let's say it's
00:38:24 10 years then in 10 years later and
00:38:27 their autofillion protein expression is
00:38:30 significantly diminished and then
00:38:31 neurotransmitter release is stopped and
00:38:34 then we have to inject again.
00:38:35 >> So that's what we think. So that's the
00:38:38 reason why many scientists actually um
00:38:40 turn their focus onto the developing of
00:38:43 the genome editing technology in a type
00:38:45 of therapy which require only one type
00:38:48 of just a injection. Mhm.
00:38:51 >> Okay. Okay. Now it makes sense.
00:38:54 >> Yeah. Yeah. Yeah.
00:38:55 >> Okay.
00:38:55 >> So now our company is also working on
00:38:58 the developing the general editing drug
00:39:01 >> to um correct the rapidly progressive
00:39:04 type of the hearing loss. So that's the
00:39:05 reason because you know the um regenery
00:39:09 the big pharmaceutical company already
00:39:11 approved the gain the approval from the
00:39:13 FDA. So uh our small company doesn't
00:39:16 have any room for uh competing with them
00:39:18 in the congenital auto for example auto.
00:39:21 So uh our company actually has turned
00:39:23 our focus on the different genes which
00:39:27 um shows the rapidly progressive hearing
00:39:30 loss. Yeah. Okay. You should succeed
00:39:31 super fast uh professor because there
00:39:33 are millions of people with this rapidly
00:39:36 progressive hearing loss and the amount
00:39:40 of uh problems that they face because
00:39:42 this is something which is hidden
00:39:43 deformity everything looks good they say
00:39:46 this you look perfectly fine are you
00:39:49 dumb but they should understand that
00:39:52 >> he's deaf that's why he's not responding
00:39:56 it's not just because of his IQ or
00:39:58 something
00:39:58 >> exactly
00:39:59 >> so please I wish you all the best
00:40:02 regarding that uh development of uh
00:40:04 progressive hearing loss therapy gene
00:40:07 therapy for that.
00:40:08 >> Oh, thank you for your kind words.
00:40:11 >> Professor uh this is for the clinicians
00:40:14 who are watching this gene therapy
00:40:15 thing. M
00:40:16 >> I read a couple of your articles and one
00:40:18 of the [clears throat] article it just
00:40:19 mentioned that
00:40:21 >> the treatment for this auto related
00:40:23 hearing loss.
00:40:24 >> It's an unusually fortunate case
00:40:27 >> right
00:40:28 >> because we didn't get the we were
00:40:31 completely blindfolded by the uh
00:40:34 response that they got in the mouse
00:40:36 models but it's not happening in the
00:40:38 human models.
00:40:39 >> Exactly. Why did you mention so why is
00:40:42 this auto related gene therapy an
00:40:44 unusually fortunate case?
00:40:46 >> Because fortunately it meets the
00:40:49 criteria which um criteria which the
00:40:53 gene therapy should meet. So but it's
00:40:56 very difficult for many other genes to
00:40:59 meet that criteria. So it should be the
00:41:02 the the hair cells should be intact uh
00:41:05 before the interventions. the the degree
00:41:07 of the hearing loss should be eventually
00:41:09 profound. Let's say that for example uh
00:41:13 the hearing loss caused by the mutations
00:41:15 in STRC which is the most decommon cause
00:41:19 of the moderate degree of hearing loss
00:41:21 STRC
00:41:23 >> it the hearing level is 40 decibel and
00:41:26 then it doesn't progress at all until
00:41:28 the prespicus is imposed if and the gene
00:41:32 therapy the cost is for example let's
00:41:33 say the million dollars
00:41:36 >> are you gonna are you going to have that
00:41:37 therapy
00:41:39 Let's say the the hearing threshold is
00:41:42 only 40 decel and even hearing aid it
00:41:44 would suffice and then it doesn't
00:41:46 progress and what do what do you what do
00:41:49 you think are you going to are you
00:41:51 willing to get the gen therapy in that
00:41:53 cases um paying the billions of dollars?
00:41:57 >> No.
00:41:58 >> Yeah. So in that point actually there
00:42:02 are not many genes that cause the
00:42:03 profound duffness. So and then the while
00:42:06 the the preserving the hair cells think
00:42:09 about that not many genes actually meet
00:42:11 that criteria.
00:42:12 >> So and then the auto uh the prevalence
00:42:15 autotogene is is relatively uh as
00:42:18 prevalent in the kind of Spanish
00:42:20 populations and in United States there
00:42:22 are many the Spanish the people there.
00:42:25 So there are many situations which
00:42:28 renders the auto to be a candidate of
00:42:30 the genes but I I I don't think many
00:42:33 genes can be can meet that criteria. So
00:42:36 that that's the reason why I just
00:42:38 mentioned that uh gene therapy utov is a
00:42:40 very very unusually fortunate case.
00:42:46 Well said professor. It's very lucky.
00:42:49 >> Very lucky.
00:42:49 >> Very lucky.
00:42:51 >> Very lucky.
00:42:53 >> You were mentioning about the criteria
00:42:55 professor. That's something which is
00:42:56 very very uh important.
00:43:00 >> Imagine there is a 25 year old person
00:43:03 who has been going through this profound
00:43:05 hearing loss.
00:43:07 >> This person he never used a hearing aid.
00:43:10 He does not have any speech. Suddenly he
00:43:13 understood that autoph related gene
00:43:15 therapy is there. He gets his he gets
00:43:17 his genetic evaluation done and it turns
00:43:20 out to be autof
00:43:22 >> and now can this person undergo gene
00:43:24 therapy and if he under goes where how
00:43:27 will the results be?
00:43:28 >> Okay. So we have to take the OA test
00:43:30 first
00:43:32 >> because if even if he uh his hearing
00:43:35 loss is caused by the auto mutations if
00:43:37 the auto oto acoustic emission is gone
00:43:40 >> then he's just he's not he's not
00:43:42 eligible for the gene therapy. If he
00:43:45 luckily has the intact OA then he could
00:43:49 be a candidate of gene therapy but you
00:43:52 know gene therapy doesn't rescue the
00:43:54 brain you know you know what you know
00:43:56 the term of the auditory brain so it
00:43:58 does gene therapy doesn't doesn't rescue
00:44:01 the um the neurotransmitter release into
00:44:04 an audiary nerve not affecting the brain
00:44:07 plasticity so let's say if um he has the
00:44:11 normal OA until the age of the 25 the if
00:44:14 he gets the gene therapy then he can
00:44:17 detect the sound normally
00:44:19 >> and okay he can uh enjoy the music but
00:44:22 he cannot recognize the word and he
00:44:24 cannot have the speech um the
00:44:26 perceptions that's what I expect
00:44:29 >> very well said if I could just extend
00:44:32 this beyond you mean to say that he will
00:44:37 be there for the eligibility criteria
00:44:38 because he has OA pass the autoacostic
00:44:41 emission which tells that the hair cells
00:44:44 I'm good. I'm intact. So that's why once
00:44:46 you inject he'll be able to produce
00:44:48 autofallene protein and he'll be able to
00:44:50 hear.
00:44:51 >> Exactly.
00:44:52 >> But
00:44:52 >> the brain
00:44:54 >> it cannot understand what it is.
00:44:57 >> No.
00:44:57 >> Because of neuroplasticity.
00:44:59 >> Exactly.
00:45:00 >> That window period is already gone.
00:45:02 >> Mhm. So
00:45:03 >> this 25 year old person maybe if he
00:45:06 would have had speech and he suddenly
00:45:09 lost his hearing and it turned out to be
00:45:11 auto then he'll be getting any benefit
00:45:14 with the auto of related gene therapy
00:45:18 but not immediately after gene therapy
00:45:20 when he was not using anything is that
00:45:22 makes sense from
00:45:23 >> right exactly
00:45:24 >> that's that's perfect
00:45:26 >> now
00:45:27 >> another let me another so there here's
00:45:30 an interesting story that um you know
00:45:34 what is most important for eligibility
00:45:36 of gene therapy especially in terms of
00:45:38 the um uh in auto fields hair cells
00:45:42 integrity is very important
00:45:44 >> but hearing aid
00:45:47 turn out to be kind of kind of um bad
00:45:50 prognostic factors for survival so let's
00:45:53 say there is a patient if he wears the
00:45:55 hearing aid so much then it is more
00:45:58 likely that hair cells could have
00:46:01 >> damage Ed
00:46:01 >> due to the kind of noise induced.
00:46:05 >> So uh if in there is a kids and then for
00:46:09 some reason he cannot have the coke
00:46:12 implant and he could not have the gene
00:46:13 therapy at this point. But using too
00:46:16 much of time of the hearing aid actually
00:46:19 would potentially negatively affect the
00:46:22 eligibility of gene therapy.
00:46:23 >> Oh my god.
00:46:24 >> That is specifically that is um only for
00:46:27 the ot.
00:46:29 So that's the what um that's published
00:46:31 probably a couple of years ago by the
00:46:34 Christian PT lab or yeah this
00:46:37 >> so this hearing aid it causes noise
00:46:39 induced hearing loss and it causes death
00:46:41 of hair cells
00:46:42 >> yeah especially out of patient
00:46:43 >> out of patients
00:46:45 >> okay and that's why
00:46:48 could you just brush up the knowledge of
00:46:50 all the surgeons the clinicians and also
00:46:52 the parents who are watching
00:46:54 >> what is the eligibility criteria for the
00:46:58 patients who can undergo auto related
00:47:00 gene therapy. officer. Yes. Can you just
00:47:02 >> Okay. So, um currently so bilateral co
00:47:07 implantes are excluded.
00:47:10 >> Bilateral unilateral co implantes can be
00:47:13 included because the contrlateral site
00:47:15 is preserved reserved for the gen
00:47:17 therapy. So number one bilateral co
00:47:19 implantes are excluded. Number two dpoa
00:47:23 oae should be intact. Mhm.
00:47:26 >> U it doesn't have to be 100 perfect but
00:47:29 just I think at least uh at least from
00:47:33 the three frequencies there should be
00:47:35 significant OE responses. It doesn't
00:47:38 have to be five or six frequencies three
00:47:40 frequencies. So if you can observe the
00:47:44 uh meaningful OA responses uh at least
00:47:47 from the three frequencies and then
00:47:49 there should be genetic documentations
00:47:52 two mutant alals two mutations of auto
00:47:54 should be documented.
00:47:58 >> So currently the three are the main uh
00:48:01 the eligibility criteria for autogen
00:48:03 therapy
00:48:04 >> and severe to profound hearing. Yeah, of
00:48:06 course. Of course. The ABR should be at
00:48:08 least I think over 80 dB 70 or 80
00:48:12 decibel. Right. Right. Sometimes uh for
00:48:15 example the temperature sensitive auto
00:48:18 variants there are
00:48:20 >> it's a unique type of the auto variance
00:48:22 and not all auto patients
00:48:24 >> show the severe to profound duffness.
00:48:27 >> Some of the p some of the variants of
00:48:29 auto can cause only the temperature
00:48:32 sensitive audiary neuropathy.
00:48:34 >> What does it mean? So uh usual
00:48:37 conditions the he can speak and he can
00:48:40 uh understand perfectly but with uh high
00:48:42 fevers temperature high fever he doesn't
00:48:45 she doesn't he or she doesn't recognize
00:48:47 anything at all. So ABR responses just
00:48:50 go down to the 100 dB threshold only for
00:48:53 the time of the high fevers. So but
00:48:57 there is a mutations there is a certain
00:48:58 of mutations are documented to uh uh the
00:49:02 result in that kind of temperature
00:49:04 sensitive al so the fourth algebraic
00:49:06 criteria is that
00:49:08 >> even though the patient have the auto
00:49:10 variance it should not be related to the
00:49:12 temperature sensitive al that's the
00:49:14 fourth conditions
00:49:18 >> perfect I mean it's sounding really like
00:49:22 a science fiction movie even for me
00:49:25 professor Yeah. Right. Right. But
00:49:26 interesting. Yeah. So yeah, so for for
00:49:30 we should remember the four conditions.
00:49:32 So exclude bilateral implantes are not
00:49:36 the candidates and then OA should be um
00:49:39 meaningfully present at least from the
00:49:41 three frequencies and then it the auto
00:49:44 varants are documented but uh the uh
00:49:47 temperature sensitive uh the alil auto
00:49:50 variant should be excluded. That's what
00:49:53 the current elig eligibility criteria
00:49:55 mentioned.
00:49:56 >> Professor, just now you mentioned about
00:49:59 temperature sensitive cottoalin
00:50:01 mutations.
00:50:02 >> Mhm.
00:50:03 >> U there are couple of patients who have
00:50:05 been asking me doctor if you just look
00:50:08 at me from front
00:50:10 >> and talk I'll be able to hear.
00:50:12 >> Mhm. But if you just go behind
00:50:15 >> or if someone two or three members call
00:50:18 me or some conversation is happening I'm
00:50:21 not able to understand anything.
00:50:24 >> It's a classic case of auditory
00:50:25 neuropathy A and SD. So for them are
00:50:29 there any specific things that they need
00:50:31 to get testing done any specific testing
00:50:34 apart from whole exam sequencing so that
00:50:37 we can rule out certain things? Uh very
00:50:39 good question. Um actually um um you
00:50:43 know so the there are kids ov kids that
00:50:47 means that their parents carried at
00:50:49 least one
00:50:51 >> mutations of auto right even though they
00:50:53 are perfectly normal.
00:50:55 >> The their parents tends to show the
00:50:59 hidden type of hearing loss. Hidden
00:51:01 hearing loss means that uh they are
00:51:03 somewhat affected uh their spiranga
00:51:06 cells or their inner hair synapses are
00:51:08 certain amount affected but not leading
00:51:10 to the u significant hearing loss. So
00:51:13 actually their parents shows some u
00:51:16 problems in the uh the discrimination in
00:51:18 especially in the low frequencies and
00:51:20 then they can not hear in in noisy
00:51:22 conditions. So we call that type of
00:51:24 situations as a hidden hidden hearing
00:51:27 loss because their purton threshold is
00:51:30 normal
00:51:31 >> but they actually doesn't produce uh in
00:51:33 noisy conditions either in the noise
00:51:35 conditions or either in the um uh uh in
00:51:39 in in certain distance u the locations.
00:51:43 So uh in that case actually what I
00:51:46 usually do is actually to see if there
00:51:48 is any uh uh uh kids the pat the kids
00:51:52 and then the other possibility is that
00:51:56 um uh so in that case the parent might
00:51:59 have only one mutations of
00:52:01 >> then the p the that that
00:52:04 >> not patient that carriers
00:52:06 >> parents
00:52:06 >> may yeah may tend that kind of
00:52:09 situations. So difficulty in uh having a
00:52:12 conversation in noisy conditions that's
00:52:14 the first conditions and there are in
00:52:16 that case actually uh I do the auto
00:52:19 sequencing and uh uh and the other
00:52:22 possibility is I just take the ABR
00:52:25 responses
00:52:27 >> and then in that case the wave one the
00:52:30 amplitude is diminished compared with
00:52:32 the normal hearing people. So I usually
00:52:36 do the abr responses ABR test. So that
00:52:41 the uh the uh uh so hidden hearing loss
00:52:43 patients show the decrease in the
00:52:45 amplitude in the ABR especially in the
00:52:48 first wave.
00:52:49 >> So in that case the patients tend to
00:52:52 show that kind of phenotypes
00:52:54 difficulty although their hearing
00:52:56 threshold is perfectly normal.
00:52:58 >> They complain of the difficulty in
00:53:00 conversation in
00:53:02 >> in in certain situations.
00:53:03 >> We call that as hidden hearing loss.
00:53:05 >> Hidden hearing loss. Exactly. Right.
00:53:06 >> How do we treat such situations?
00:53:08 Unfortunately, no treatment at so far.
00:53:10 Just just counsel them. You may have the
00:53:13 hidden hearing loss. And unfortunately,
00:53:16 at this point, there's no cure or no
00:53:18 treatment.
00:53:19 >> But it it's good to know.
00:53:22 >> Will their kids go through the same
00:53:24 situation or will their kids go through
00:53:27 profound hearing loss?
00:53:28 >> No. No. They won't develop the just full
00:53:31 minute on the the auditory neuropathy.
00:53:33 just complain of some difficulty in
00:53:37 certain situations. Yeah.
00:53:38 >> Okay. Professor, there are many many
00:53:41 parents who are asking once again the
00:53:43 same question. [laughter] This gene
00:53:45 therapy is not available in our India.
00:53:48 >> In almost all the developing countries,
00:53:50 it's not available in India. But we have
00:53:53 huge population and we have many kids
00:53:56 who are going through auto related
00:53:57 hearing loss.
00:53:59 >> What can all these kids do? what any
00:54:02 guidance for our Indian parents. Is
00:54:04 there any way that u they can approach
00:54:07 our drd hospital and we can guide them
00:54:10 to you?
00:54:12 >> Okay, tough questions but very important
00:54:14 questions for Indian um DFM denine
00:54:17 patients. I think uh first of all at
00:54:22 this point there are two ways actually
00:54:23 the first official way through the
00:54:26 official
00:54:28 establishment of the gene therapy
00:54:31 >> through the FDA approval in in Indian uh
00:54:33 FDA approval that's the official way of
00:54:36 course it would take time I think that's
00:54:38 what you I think you uh you should do
00:54:41 first so given that the the United
00:54:45 States FDA has already approved the uh
00:54:48 utani. So I think it's not it would not
00:54:51 that difficult for Indian the FDA to
00:54:54 approve the gene therapy. So I think the
00:54:56 first thing you have to do is just
00:54:58 contact the uh Indian FDA and or Indian
00:55:02 uh the ministry of welfare to see if
00:55:06 there is availability of [clears throat]
00:55:08 um the approval of the um the many or
00:55:11 other type of the auto gene therapy
00:55:13 materials. That's the first thing. The
00:55:16 second thing is that although the
00:55:18 regenerance uh there was actually three
00:55:21 companies which was involved with the um
00:55:24 developing the oaf related deafness gen
00:55:27 therapy the first one is regeneran which
00:55:30 turned out to be a winner and the lilies
00:55:33 uh liies is is another country another
00:55:36 company I'm sorry and the third one was
00:55:38 sensorian so given that the uh the
00:55:41 regenerant has already approved the um
00:55:44 has already obtained the approval from
00:55:46 the FDA but still the lily and censorian
00:55:50 still running the clinical trials. So
00:55:54 the another way of Indian DFNB9 patients
00:55:57 to have the uh the autogen therapy is to
00:56:02 contact Lily could be a contact point
00:56:05 >> or so or I can help the the Indian DF
00:56:09 main patients to contact Lily because I
00:56:11 was working with the regenerant and I
00:56:13 actually our I was trying to uh perform
00:56:17 the clinical trial in our university
00:56:19 hospital but uh unfortunately there the
00:56:22 clinical trial has finished because they
00:56:24 already have obtained the FDA approval.
00:56:26 So they don't need to run the clinical
00:56:27 trial. So so the contact the regenerate
00:56:30 actually has has actually meaningless
00:56:33 actually. So contact contacting Lily
00:56:36 which actually is still running the
00:56:38 clinical trial is uh I think gives could
00:56:42 potentially give us a proposed give us
00:56:44 an opportunity to for Indian the FM9
00:56:47 patients to have the gene therapy is as
00:56:49 a clinical trial the form. So I think
00:56:52 that there are two two u forms of the
00:56:55 possibility.
00:56:57 So we should open open up the the
00:56:59 opportunity for Indian DFM9 patients in
00:57:02 some ways.
00:57:03 >> We'll do professor and we we'll be
00:57:05 requiring your help for that.
00:57:07 >> I I would I would
00:57:08 >> thank you so much professor for that.
00:57:11 >> Prophecy you are forget that you are a
00:57:14 doctor now you forget that you are a
00:57:16 surgeon. Mhm.
00:57:17 >> Just imagine
00:57:18 >> you have operated on kids. You have seen
00:57:22 them hearing getting back their hearing.
00:57:24 >> Right. Right.
00:57:25 >> And you have performed gene therapy
00:57:27 without performing any surgery and you
00:57:29 have seen kids recover their hearing.
00:57:32 >> How do you feel inside as a human being?
00:57:35 >> Yeah. Yeah. Yeah.
00:57:37 But well, I just um it's I think it's a
00:57:40 privilege of of our ENT surgeons to be
00:57:44 able to witness the kids with the
00:57:47 hearing impairment to recover their
00:57:49 hearing and to uh can to be able to
00:57:52 listen to able to enjoy the music. So
00:57:55 yeah, I think uh it is our privilege and
00:57:59 I'm very happy to be able to be in that
00:58:01 position just like you. So I think yeah
00:58:05 just I think it's our privilege and I
00:58:06 really appreciate that as a human
00:58:08 beings.
00:58:09 >> Yes professor after all we do all this
00:58:12 at the end of the day for to satisfy our
00:58:15 little heart and
00:58:16 >> Right. Right.
00:58:16 >> You are truly following your passion and
00:58:19 you're doing the best and helping
00:58:21 millions and millions of people who are
00:58:23 going through this hearing loss. Sincere
00:58:25 thanks to you regarding that.
00:58:27 >> That's my pleasure. So, professor, this
00:58:30 is almost the final question that I'm
00:58:33 asking you.
00:58:34 >> What is the future of this gene therapy?
00:58:37 What are you really excited about now at
00:58:40 the moment?
00:58:41 >> Okay. Um, which is are very your your
00:58:44 actually comments are very important
00:58:46 actually. the um uh the future the
00:58:48 trends or future direction of the gene
00:58:51 therapy should move I think um just
00:58:55 beyond the congenital deafness
00:58:58 >> probably it would expand or it would
00:59:00 evolve to involve the rapidly
00:59:03 progressive hearing loss
00:59:05 >> uh that would be like the next target
00:59:08 which actually has a higher the
00:59:09 prevalence actually
00:59:11 >> so and then uh as you mentioned as we
00:59:14 already discussed
00:59:16 uh single injection should be mandatory
00:59:19 to avoid the multiple injection. So
00:59:21 rather than just this gene transfer
00:59:25 um just performing the genome editing
00:59:28 which requires only one injection one
00:59:31 fix. So probably uh our gene therapies
00:59:35 uh would evolve into that direction. So
00:59:38 to involve the rapidly progressive
00:59:40 hearing loss and to involve the genome
00:59:43 editing rather than the simple gene
00:59:46 transfer that I think that that's the
00:59:48 way I think
00:59:49 >> perfect professor
00:59:51 >> thank you so much for this for your
00:59:53 science for your dedication
00:59:56 >> uh for the entire patients well-being um
01:00:01 >> that's all professor
01:00:02 >> thank you thank you so
01:00:04 >> heartful heartful
01:00:07 >> thank you so for your invitation and
01:00:09 it's it's my privilege to um to
01:00:12 participate in this the hearing circle.
01:00:15 It's my great honor.
01:00:17 [laughter]
01:00:18 >> Thank you so much professor. Thank you
01:00:19 for flying all the way from Seol, South
01:00:22 Korea to India and answering all the
01:00:25 questions that our Indian parents have.
01:00:28 Thank you.
01:00:28 >> Thank you.
01:00:29 >> Thank you. Namaste.
01:00:30 >> Namaste. Namaste. No.
About this Podcast

Dr. Shree Rao
MS (ENT) | Cochlear Implant Super Specialist | Director, Dr. Rao's ENT Super Speciality International Hospital
Dr. Shree Rao is one of India’s leading cochlear implant specialists with over 12 years of experience and 200+ successful cochlear implant surgeries. She completed specialized fellowship training under Padmashri Awardee Dr. Milind V. Kirtane and has trained at Singapore General Hospital for rhinoplasty and facial plastic surgery. As Director of Asia’s largest ENT Super Speciality Hospital, she leads teams across 7 OPDs, 3 operation theaters, and specialized units with a 99.9% success rate. Dr. Shree Rao is passionate about creating a “Deaf-Free India” and partners with NGOs to provide free cochlear implant surgeries to underprivileged children.

Professor Choi Byung Yoon
Ear Surgeon, Researcher & Scientist | CEO, Sensory Cure
Professor Choi Byung Yoon is an ear surgeon, researcher and scientist from South Korea, as well as the CEO of Sensory Cure. In this conversation, he discusses gene therapy for hearing loss, OTOF-related deafness, eligibility criteria, potential risks, treatment outcomes and the future of gene therapy and genome editing for hearing loss.
Podcast Summary
Gene therapy for hearing loss is opening a new area of possibilities for people with certain types of genetic deafness. In this episode of the Hearing Circle podcast, I have an in-depth conversation with Professor Choi Byung Yoon, an ear surgeon, researcher, scientist and CEO of Sensory Cure, about how gene therapy works and where it currently fits in the treatment of hearing loss.
We discuss gene therapy in simple terms, including the difference between a biological cure and hearing rehabilitation through cochlear implantation. Professor Choi uses a helpful “hardware and software” analogy to explain why gene therapy can work in specific conditions where the inner-ear structures and hair cells remain intact.
A major part of our conversation focuses on OTOF-related hearing loss and DFNB9, which Professor Choi describes as a unique target for gene therapy. We discuss how the OTOF gene helps produce the protein needed for communication between hair cells and the auditory nerve, and how gene therapy aims to restore this function.
We also discuss gene therapy eligibility criteria, including genetic confirmation, preserved otoacoustic emissions and severe to profound hearing loss. We explain why children with other genetic forms of congenital hearing loss should not simply wait for future gene therapies when timely intervention with a cochlear implant may be important for speech and brain development.
Another important part of our conversation is the risks and uncertainties of gene therapy for hearing loss, including immune reactions and the lack of long-term data on durability. Professor Choi explains that current gene transfer approaches may not necessarily provide permanent results, while future genome-editing approaches could potentially offer longer-lasting solutions.
We also have an in-depth discussion about cochlear implants and gene therapy. Gene therapy and cochlear implants work in very different ways, and understanding this difference is particularly important for parents trying to make decisions for a child with hearing loss. For children with congenital hearing loss, timely intervention remains an important consideration rather than waiting indefinitely for future treatments.
Finally, we look toward the future, including research into rapidly progressive hearing loss and the development of genome-editing approaches that may eventually expand the role of gene therapy beyond its current applications.
What You Will Learn in This Podcast
- What gene therapy for hearing loss actually means
- How gene therapy differs from cochlear implantation
- Why OTOF-related hearing loss is a unique target for gene therapy
- What the OTOF gene and otoferlin protein do in hearing
- How gene therapy delivers a functional gene to the inner ear
- Who may be eligible for OTOF-related gene therapy
- Why otoacoustic emissions are important for eligibility
- The potential risks and uncertainties of gene therapy
- Whether gene therapy results are permanent
- Why children should not delay appropriate hearing treatment while waiting for future therapies
- How gene therapy may develop in the future
Gene Therapy vs Cochlear Implant
One of the key questions we discuss is whether gene therapy for hearing loss could eventually replace cochlear implants.
Professor Choi explains that, for OTOF-related deafness, gene therapy aims to restore the biological hearing system, while a cochlear implant rehabilitates hearing by electrically stimulating the auditory pathway.
For children with congenital hearing loss caused by other genetic mutations, we emphasize the importance of timely intervention because speech and auditory development depend on appropriate stimulation during important developmental periods.
Who May Be Eligible for OTOF Gene Therapy?
During our conversation, we discuss several eligibility considerations for OTOF-related gene therapy. These include genetic confirmation of OTOF mutations, preserved otoacoustic emissions indicating remaining hair-cell function, severe to profound hearing loss, appropriate ABR findings, exclusion of certain temperature-sensitive OTOF variants, and consideration of whether a cochlear implant has already been performed bilaterally.
Professor Choi explains that the current criteria are specific and that not every person with genetic hearing loss will qualify for gene therapy.
What Are the Risks of Gene Therapy for Hearing Loss?
We also have a detailed discussion about the fact that gene therapy is still a developing field, so long-term safety and durability remain important questions.
Potential concerns include immune reactions to the viral vector, uncertainty about how long the treatment may remain effective, questions surrounding the possibility of repeat treatment, limited long-term data, and the fact that some patients may not respond to treatment.
Professor Choi stresses the importance of carefully weighing these uncertainties against the potential benefits.
Need Expert Care?
Speaking with an experienced ENT and hearing specialist can help families understand whether hearing aids, cochlear implantation, genetic evaluation or other treatment approaches may be appropriate.
Podcast Highlights
What is gene therapy for hearing loss?
Gene therapy for hearing loss aims to introduce a functional gene into specific inner-ear cells to restore a biological function affected by a genetic mutation. In our conversation, Professor Choi explains this using a hardware-and-software analogy.
Can gene therapy cure all types of deafness?
No. We discuss how gene therapy is not a treatment for every type of hearing loss. Our conversation focuses particularly on OTOF-related hearing loss, where the relevant hair-cell structures may remain intact during the appropriate treatment window.
What is OTOF-related hearing loss?
OTOF-related hearing loss is a genetic form of hearing loss associated with mutations affecting the OTOF gene. The gene is involved in producing otoferlin, a protein required for neurotransmitter release from hair cells to the auditory nerve.
Is gene therapy better than a cochlear implant?
There is no single answer for everyone. Gene therapy and cochlear implants work differently, and the appropriate approach depends on the type of hearing loss, genetic cause, hearing status and individual eligibility.
Should parents wait for gene therapy before getting a cochlear implant?
We advise against simply waiting when a child needs timely hearing intervention. Speech and auditory development are important considerations, and treatment decisions should be made based on the child’s individual condition and the options currently available.
Is gene therapy for hearing loss permanent?
The long-term durability of the current gene-transfer approach is not yet fully known. We discuss how future genome-editing approaches could potentially provide a more permanent correction.
Can adults receive gene therapy for hearing loss?
We discuss an example of an adult with OTOF-related hearing loss and explain that eligibility depends on factors such as preserved hair-cell function and other clinical criteria. The potential benefit may also depend on auditory and speech development.
Is gene therapy for hearing loss currently available in India?
We discuss the limited availability of gene therapy in India and the possibility of accessing treatment through regulatory approval or clinical trials. Availability can change, so patients should seek current guidance from qualified specialists and relevant clinical-trial or regulatory sources.