Targeted Medicines for the Ear - OTO-413 Program Review
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Targeted
Medicines
for the Ear
OTO-413 Program Review
November 5, 2018
Forward-Looking Statements
Safe Harbor Statement
These slides and the accompanying oral presentation (the “Presentation”) contain forward-looking statements within the meaning of
the Private Securities Litigation Reform Act of 1995. Forward-looking statements generally relate to future events or future financial or
operating performance of Otonomy, Inc. (“Otonomy”). Forward-lookingstatements in this Presentation include, but are not limited to,
the timing of the Phase 1/2 clinical trial for OTO-413, the potential market opportunity for OTO-413, and expectations regarding
program advancement. Otonomy’s expectations regarding these matters may not materialize, and actual results in future periods are
subject to risks and uncertainties. Actual results may differ materially from those indicated by these forward-looking statements as a
result of these risks and uncertainties, including but not limited to: Otonomy’s limited operating history and its expectation that it will
incur significant losses for the foreseeable future; Otonomy’s ability to obtain additional financing; Otonomy’s dependence on the
regulatory success and advancement of product candidates, such as OTO-413; the uncertainties inherent in the drug development
process, including, without limitation, Otonomy’s ability to adequately demonstrate the safety and efficacy of its product candidates,
the nonclinical and clinical results for its product candidates, which may not support further development, and challenges related to
patient enrollment in clinical trials; the risk of the occurrence of any event; Otonomy’s ability to obtain regulatory approval for its
product candidates; side effects or adverse events associated with Otonomy's product candidates; Otonomy’s ability to successfully
commercialize its product candidates, if approved; competition in the biopharmaceutical industry; Otonomy’s dependence on third
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property related to its product candidates in the United States and throughout the world; expectations regarding potential market size,
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plans for its business, products and technology; and other risks. Information regarding the foregoing and additional risks may be found
in the section entitled "Risk Factors" in Otonomy's Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission
(the "SEC") on November 5, 2018, and Otonomy’s future reports to be filed with the SEC. This Presentation is dated as of November 5,
2018, and Otonomy undertakes no obligation to update any forward-looking statements, whether as a result of new information,
future events or otherwise, except as required by applicable law.
2
Hearing Loss: Large and Growing Unmet Need
Hearing Loss is 4th Leading Cause of Disability Globally1
1 Lancet, July 2017 NEJM, Dec 2017
Review The n e w e ng l a n d j o u r na l of m e dic i n e
Review Article
Global hearing health care: new findings and perspectives Allan H. Ropper, M.D., Editor
Blake S Wilson, Debara L Tucci, Michael H Merson, Gerard M O’Donoghue
Hearing Loss in Adults
In 2015, approximately half a billion people had disabling hearing loss, about 6·8% of the world’s population. These Published Online
numbers are substantially higher than estimates published before 2013, and point to the growing importance of July 10, 2017 Lisa L. Cunningham, Ph.D., and Debara L. Tucci, M.D., M.B.A.
http://dx.doi.org/10.1016/
hearing loss and global hearing health care. In this Review, we describe the burden of hearing loss and offer our and
H
S0140-6736(17)31073-5
others’ recommendations for halting and then reversing the continuing increases in this burden. Low-cost
possibilities exist for prevention of hearing loss, as do unprecedented opportunities to reduce the generally high
Division of Head and Neck earing loss in adults is encountered in all medical settings From the Section on Sensory Cell Biology,
Surgery and Communication National Institute on Deafness and Other
treatment costs. These possibilities and opportunities could and should be exploited. Additionally, a comprehensive Sciences, Department of and frequently influences medical encounters. This disorder constitutes a
Communication Disorders, Bethesda, MD
worldwide initiative like VISION 2020 but for hearing could provide a focus for support and also enable and facilitate Surgery, Duke University substantial burden on the adult population in the United States, yet (L.L.C.); and the Division of Head and
Medical Center, Durham, NC,
the increased efforts that are needed to reduce the burden. Success would produce major personal and societal
USA (Prof B S Wilson DSc,
screening for hearing loss is not routine,1 and treatments are often inaccessible Neck Surgery and Communication Sci-
gains, including gains that would help to fulfil the “healthy lives” and “disability inclusive” goals in the UN’s new Prof D L Tucci MD); Duke Global because of the high cost or perceived ineffectiveness. ences, Duke University Medical Center,
2030 Agenda for Sustainable Development. Health Institute Durham, NC (D.L.T.). Address reprint re-
(Prof B S Wilson, Prof D L Tucci, quests to Dr. Tucci at the Division of
H d dN kS dC i
• Most prevalent neurologic health issue: > 360M people have disabling hearing loss2
• High economic burden: medical costs + impact of lower work productivity
• Leads to social isolation, lower QoL, and higher rates of dementia and depression
• Common causes: aging, noise, ototoxic drugs and genetics
• Established clinical outcome measures that are objective patients assessments
2 World Health Organization, Global Estimates on Prevalence of Hearing Loss, 2012. 3
OTO-413 Addresses Significant Population with Cochlear Synaptopathy
Speech-in-Noise (SiN) ILLUSTRATIVE
Hearing Difficulty
• Problem hearing in presence
PTA Hearing Deficit
of background noise • Hearing loss in standard
• U.S. prevalence1 ≈ 9M with test (soundproof booth)
SiN only (no PTA changes)
• U.S. prevalence2-5 ≈ 42M
• Loss/damage to cochlear
synapses • Loss/damage to hair cells
and/or synapses
SIN Difficulty and PTA Deficit
Mixed Pathology
OTO-413 • Includes patients with age-
related and noise-induced
Target Patient hearing loss
Population
• Prevalence ≈ ?? 1 Tremblay et
2 Hoffman
al., Ear Hear, 2015
et al., JAMA Otolaryngol HNS, 2017
3 Nash et al., Arch Otolaryngol HNS, 2011
4 Morton et al., N Engl J Med, 2006
5 Brooke et al., JAMA Otolaryngol HNS, 2017
4Cochlear Synaptopathy and Hearing Loss
• In the last decade, research has
identified loss or dysfunction of
synaptic connections between inner
hair cells (IHC) and spiral ganglion
neurons (SGN) as playing important
role in hearing loss pathology
• Synapses can be damaged or lost due
to loud noise, aging, and/or exposure
to ototoxic chemicals
• “Cochlear synaptopathy” contributes
to speech-in-noise difficulties as well
as age-related and noise-induced
hearing loss
• Potential to repair synaptopathy using
neurotrophic factors
Figure from Moser and Starr, Nature Reviews: Neurology (2016) 5Extensive Support for Synaptopathy and Repair by Neurotrophins
Hearing Research xxx (2015) 1e9
Contents lists available at ScienceDirect
Hearing Research
journal homepage: www.elsevier.com/locate/heares
F1000Research 2017, 6(F1000 Faculty Rev):927 Last updated: 16 JUN 2017
Synaptopathy in the noise-exposed and aging cochlea: Primary neural
REVIEW
Noise-induced
degeneration in acquired sensorineural and age-related
hearing loss hearing loss: new perspectives Hearing Research xxx (2017) 1e10
and
Sharon G. Kujawa a, b, c, M. Charles Liberman potential
a, b, *
therapies [version 1; referees: 4 approved]
Contents lists available at ScienceDirect
a
Department of Otology and Laryngology, Harvard Medical School, Boston, MA, USA
M Charles Liberman
b
Eaton-Peabody Laboratory, Massachusetts Eye & Ear Infirmary, Boston, MA, USA
c
Department of Audiology, Massachusetts Eye and Ear, Boston, MA, USA
Department of Otolaryngology, Harvard Medical School, Eaton Peabody Laboratories, Massachusetts Eye and Ear, 243 Charles
Otology St., Boston,
& Neurotology
Hearing Research
MA, 02114, USA 37:1223–1230 2016, Otology & Neurotology, Inc.
a r t i c l e i n f o a b s t r a c t journal homepage: www.elsevier.com/locate/heares
Article history: The classic view of sensorineural hearing loss (SNHL) is that the “primary” targets are hair cells, and that
cochlear-nerve lossFirst
v1
published:to 16 Juncell2017, 6(F1000 Faculty Rev):927 (doi: Open Peer Review
Received 2 December 2014 is “secondary” hair degeneration. Our recent Review
work in Article
mouse and guinea pig
Received in revised form has challenged that10.12688/f1000research.11310.1
view. In noise-induced hearing loss, ) exposures causing only reversible threshold
26 January 2015
Accepted 25 February 2015
shifts (and no hair cell loss) nevertheless cause permanent loss of >50% of cochlear-nerve/hair-cell
Latest published: 16 Jun 2017, 6(F1000 Faculty Rev):927 (doi: Cochlear synaptopathy in acquired sensorineural hearing loss:
Referee Status:
Manifestations and mechanismsApplying Neurotrophins to the Round Window Rescues Auditory
synapses. Similarly, in age-related hearing loss, degeneration of cochlear synapses precedes both hair
Available online xxx 10.12688/f1000research.11310.1)
cell loss and threshold elevation. This primary neural degeneration has remained hidden for three
reasons: 1) the spiral ganglion cells, the cochlear neural elements commonly assessed in studies of SNHL,
nerve fibers The
Abstract
survive for years despite loss of synaptic connection with hair cells, 2) the synaptic terminals of cochleara, b
are unmyelinated and difficult to see in the light M.
microscope, Charles
classic view of sensorineural hearing loss has been that the primary
and 3) the Liberman
degeneration is , Sharon G. Kujawa a, b, *
1
Invited Referees
2 3 4
Function and Reduces Inner Hair Cell Synaptopathy After
ISAAR Special Issue
damage targets
selective for cochlear-nerve fibersare hair
with cells
high and thatAlthough
thresholds. auditory
quiet (e.g. threshold audiometry or auditory brainstem response threshold),
nerve
not
to hair cell degeneration. Recent work has challenged that view. In
a
b
lossforisthreshold
required
Department typically secondary
of Otologydetection
these high-threshold
Eaton-Peabody
in
and Laryngology,
fibers
Harvard Medical School, Boston MA, USA
Laboratories, Massachusetts Eye & Ear Infirmary, Boston MA, USA Noise-induced Hearing Loss Trends in Hearing
2016, Vol. 20: 1–9
are critical for hearing in noisy environments. Our research suggests that 1) primary neural degeneration version 1
David J. Sly, Luke Toward a Diagnostic Test for
is an importantnoise-induced
contributor tohearing loss, exposures
the perceptual handicap incausing
SNHL, andonly
2) reversible
in cases where threshold
the hairshifts
cells published
! The Author(s) 2016
(and no hair
survive, neurotrophin cell loss)
therapies nevertheless
can elicit cause permanent
neurite outgrowth from spiralloss
a r t iofc >50% l e iofnthe
ganglion neurons and re-
f o 16 Jun 2017
a b s t r a c t
Campbell, Aaron Uschakov, Saieda Tasfia Saief, Reprints and permissions:
establishment synaptic connections
of their peripheral between hair cells and the auditory nerve. Similarly, in
synapses.
This article is part of a Special Issue entitled .
Hidden
yMatthew Hearing
Lam, and Stephen J. Loss
O’Leary
sagepub.co.uk/journalsPermissions.nav
DOI: 10.1177/2331216516657466
age-related hearing loss, degeneration of cochlear Article synapses
history:precedes both Common causes of hearing loss in humans - exposure to loud noise or ototoxic drugs and aging - often tia.sagepub.com www.nature.com/scientificreports
RESEARCH ARTICLE
hair cell loss and threshold elevation. This primary neural
Received 13 June 2016
degeneration has F1000 Faculty
damage Reviews
sensoryarehaircommissioned
cells, reflected as elevated thresholds on the clinical audiogram. Recent studies in
Received in revised form
© 2015 Elsevier B.V. All rights reserved. animal models suggest, however, Otolaryngology,
that well before Department of Surgery,
this overt hearing loss can beUniversity
seen, a moreof Melbourne; and yMonash School of Medicine,
insidious,
remained a “hidden hearing loss” for two reasons: 1) 19 the neuronal
2016 cell bodies
survive for years despite loss of synaptic connection
December
with hair
Accepted cells,2017
5 January
Available online xxx
and 2) the
from members of the prestigious F1000
but likely more common, process is taking place that permanently
Faculty. In order to make these reviews as
between sensory inner hair cells and subsets of cochlear nerve
Monash interrupts
fibers. The
synapticMelbourne,
University,
silencing of
communication
affected
VIC,
1
neurons
Australia 1
Christopher J. Plack , Agnès Léger , Garreth Prendergast , 1 Improved Auditory Nerve Survival with
degeneration is selective for auditory nerve fibers with high thresholds. alters auditory information processing, whether accompanied by threshold elevations or 1not, and is a
Although not required for threshold detection whenKeywords: quiet, these high-threshold
comprehensive and accessible
likely contributor as possible,
to a variety
1
Karolina Kluk , Hannah Guest , and Kevin J. Munro
of perceptual abnormalities, including speech-in-noise difficulties, tinnitus
1
Nanoengineered Supraparticles for
fibers are critical peer review andtakes place before
hyperacusis. Workpublication;
described herethe will review structural and functional manifestations of this
orfor hearing in noisy environments. Research
Auditory nervesuggests that
Hypothesis: and Applying
will considerneurotrophins to the rounditswindow
appearance and Results:
progres- After exposure to 105 dB noise, threshold did not
1. Primary vs. secondary neural degeneration in
sensorineural hearing loss
grossly
primary neural degeneration
abnormal
brainstem response
cochlear
is an (ABR).
important
neural responses,
contributor
Although the underlying
Cochlear
such as the auditory
Cochlear synaptopathy
to neuropathy
the perceptual
histopathology
cochlear synaptopathy
referees sion
are listed
in earsbelow, but their
immediately
with and reports
withoutafter aare
possible mechanisms
single
traditional noiseloss’
‘hearing exposure
underlying
willseveral
arising from prevent noise-causes inchange,
common humans. but the amplitude growth of the auditory brainstem Neurotrophin Delivery into the Deafened
handicap in sensorineural hearing loss,
is poorly understood, theand it may be
dysfunction keyhearing
can
Hidden to thelossgeneration
theoretically of
originate not formally published. induced hidden hearing loss. 2017 Elsevier B.V. All rights response
© Abstract reserved. was significantly reduced in control ears in
Sensorineural hearing loss (SNHL), as a category tinnitus and other
of hearing associated
anywhere fromperceptual anomalies.
hair cell synaptic In cases
transmission to where the hair of
Noise-induced hearing loss
the conduction Background: Loud noise can eliminate neural connections
Cochlear synaptopathyresponse to 16hearing
(or hidden and 32loss),
kHz tones.
due toThe amplitude
noise growth
exposure was Cochlea
or aging, has been demonstrated in animal models
impairment, includes those etiologies in which the cells survive, neurotrophin
underlying therapies
action potentials can elicit
in auditory neurite
nerve fibersoutgrowth
(ANFs). One from surviving
clearcut eti- between inner hair cells and their afferent neurons (thereby also reduced neurotrophin ears, but to a lesser degree and
pathology involves the sensory cells and/or the sensoryauditory
neurons neurons
of ology 1 Christoph Schreiner , Kavli Institute for using histological techniques. However, diagnosis of the condition in individual humans is problematic because of (a) test
andisre-establishment
a genetic mutation in otoferlin
of their (Santarelli
peripheral synapses;et al., 2009), a
thus, diminishing sound perception) without causing a detectable the reduction was not significant. Similar results were 1,2,3 3 4
Fundamental Neuroscience, of This phenomenon isreliability and (b) lack of a gold standard validation measure. Wave I of the transient-evoked auditory *, Justin Tan
brainstem response
, YajunisWang
a , Frank Caruso4, Robert K. Shepherd1,2,3
the inner ear. Although primary neural degeneration, i.e. neural loss protein expressed in inner hair cells (IHCs)
treatments may be on the horizon.
and thought to control
Contents change onUniversity audiogram. termed hidden obtained from control ears exposed to 95 dB, but amplitude Andrew K. Wise
OPEN Round-window delivery of
without hair cell loss, is recognized as a subclass of SNHL, it has vesicle release at the synapses with ANFs (Beurg et al., 2010). noninvasive electrophysiological measureinofneurotrophin-treated
auditory nerve function
California, USA hearing loss. growth recovered ears, and
this has been validated in the animal models. However, in
reaching 1 The Bionics Institute, 384–388 Albert Street, East Melbourne, Melbourne, Australia, 2 The Department of
been considered rare, comprising mainly cases of congenital and/or In cases of acquired SNHL, far and away 1. the most
Overt common
vs. ‘hidden’ formloss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .humans,
hearing
Methods: Guinea pigs were exposed for 2. .hours . . . . . . . .Wave
to. . .4. . to
. .I . amplitude
. . . . . . . . . . . shows
00
statistical high variability
significance both between
in response to 16 kHzand tones.
within There
individuals.
MedicalThe frequency-following
Bionics, University of response,
Melbourne, a Australia, 3 Department of Otolaryngology, University
Melbourne,
hereditary defects (Starr et al., 2000, 1996). As a clinical entity, of SNHL, it has been widely believed 2. thatCochlear
the hair cells are the
synaptopathy and neurodegeneration in noise-exposed and aging and mice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00
2 Richard Salvi , Center 8 kHz fornoise Hearing at either 95 or 105 dB SPL. sustainedImmediately evoked potential were reflecting
significantly morea11111
synchronous neural activity
presynaptic ribbons,in postsynaptic
the rostral ofbrainstem,
Melbourne,isMelbourne,
potentially more4robust thanof Excellence in Convergent Bio-Nano Science and
neurotrophin 3 regenerates
auditory neuropathy, as it is called, is defined by normal hair cell primary targets, and that the degeneration 3. of sensory
Glutamate neurons
excitotoxicity as an instigating factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00 Australia, ARC Centre
function (as seen in normal otoacoustic emissions) despite absent occurs almost exclusively as a secondary4.consequence
Functional effects
of theofloss
synaptopathy
of . . .Deafness,
. . . . . . . . . . .University . . . . .at
. . . . . .afterward . . Buffalo,
. . . . . . .a. . New
.4 . . York,
. . ml . . . bolus
. . . . . . . . .of
. . . .neurotrophins . . (brain-derived
. . . . . . . . . . . . . .auditory
. . . . . . . .brainstem . . . glutamate
. . . . . . . . . . . response
. . . . . 00Wavereceptors, and colocalized
I. However, ribbons after response
the frequency-following neurotro- Technology,
is a measure
andof thecentral activity
Department and may
of Chemical andbe
Biomolecular Engineering, the University of Melbourne,
5. Johnsson,
their hair cell targets (Bohne et al., 2000; Cochlear1974).
neurodegeneration
This view and SR types: neurotrophic factor 1 mg/ml, and neurotrophin-3
USA special vulnerability of low-SR neurons . . . . . . . . . . . . . . . . . . . . . . . . . . .dependent . . . . 1. .mg/ml) . .was
. . . . . . on . . . . . . . . phin
. .individual . . . treatment.
. . differences
00 in central processing. Psychophysical measuresMelbourne, Australia by intersubject variability
are also affected
cochlear synapses after acoustic
5.1.
arises from observing the time course of histopathologySingle unit evidence
in the two for low-SR vulnerability . . .delivered. . . . . . . . . . . .to
. . . the
. . . . . round
. . . . . . . . window
. . . . . . . . . . .of
. . . one
. . . . .ear,
. . . . and
. . . . .saline
. . . . . . .to. . .the
. . . . . . . . . .Conclusion:
. . . . 00 A single dose of neurotrophins delivered to the
5.2. Morphology of synaptic vulnerability . . . . . . . . . . .other.
. . . . . . . .Auditory
. . . . . . . . . . . .brainstem
. . . . . . . . . . . . .responses
. . . . . . . . . . . .to . . . in
. . . central
. . .pure-tone . . . .processing.
. . . . .pips . . . . . . . . . . . Differential
. were .round
. . . . 00window measures may help to reduce intersubject variability due to unrelated factors. A measure
reduced synaptopathy and recovered high- * awise@bionicsinstitute.org
most common animal models of acquired SNHL i.e. acoustic trauma 3 Tobias Moser , Universitätsmedizin
* Corresponding author. Eaton-Peabody Laboratories, Massachusetts Eye and Ear 6. Cochlear synaptopathy and relevance to human SNHL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .can . . . . be
. . . .compared,
. . . . . . . . . . . . within
. . . . . . .an individual,
. . 00 between conditions that aredBaffected differently by cochlear synaptopathy. Validation of
Infirmary, 243 Charles St., Boston, MA 02114-3096, USA. Tel.: þ1 617 573 3745;
and ototoxic antibiotics. Numerous studies over the last 5 decades
6.1. Göttingen,
Synaptopathy in human temporal bones . .Germany
acquired preoperatively, and at 1 and 2 weeks’
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . the
postexposure.
. . . . .metrics
. . . . . . . . .is. . also
. . . . . an
frequency
. . . .issue.
. . . . 00
hearing in ears exposed to 95 noise. These
Comparisons with animal models, computational modeling, auditory nerve imaging, and human
overexposure
fax: þ1 617 720 4408. have shown that within 24 h, or less, after a noise exposure or drug
6.2. Cochleae
Synaptopathy, low-SR neuropathy and human auditory were
function . . . .removed
. . . . . . . . . . . and
. . . . . whole
. . . . . . . . .mounted
. . . . . . . . . . .for . . . . . . . . . . . . . . . . . . .findings
. . . .immunohis- . . . . 00 suggest that hidden hearing loss may be reduced by recei�e�: 11 �anuar� 2016
E-mail address: Charles_Liberman@meei.harvard.edu (M.C. Liberman). treatment, there can be massive hair cell 6.3.
loss, whereas
Monitoringthe
for first 4 Robert
synaptic injury Fettiplace
and treatment , Department
tochemical
efficacy . . .of
. . . . . . . . . analysis,
. . . . . . . . .with
. . . . . . .presynaptic . . . . . temporal
. . . . . . . . . . . . . . ribbons . . . . of . . . .bone
. . . inner . . . histology
. . .hair . . .are
. 00all potential
. . . . . . . .providing optionstofor
trophic support thevalidation, but
cochlea after there
injury.are Key
technical and practical hurdles and difficulties in
7. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .cells
Neuroscience, University
. . . . . . . .and
. . . . . . associated
. . . . . . . . . . . . . .postsynaptic
of Wisconsin
. . . . . . . . . . . . . . .glutamatergic. . . . . . . . . . AMPA
. . . . . .interpretation. . . . . . . . Words:
. . . . . . .Despite . . the
. . . 00 BDNF—Glutamate
obstacles, a diagnostic Abstract
OPENreceptor—Hidden
ACCESS
test for hidden hearing
hearingloss— accepte�: 04 �pri�
loss is a worthwhile goal,2016
with important impli-
http://dx.doi.org/10.1016/j.heares.2015.02.009 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .receptors . . . . . . . . . . . . .identified
. . . . . . . . . . . . . using
. . . . . . . .CtBP2
. . . . . . . . and
. . . . . .GluA2
. . . . . . . . antibodies
0378-5955/© 2015 Elsevier B.V. All rights reserved.
References . . . . . . . . . . . . . . . . . . . . . . . . . Medical
. . . . . . . . . School,
. . . . . . . . .USA
cations. .for . . . . . . . . . . . . . . . .Neurotrophin—Noise—NT-3—Synaptic
clinical practice . . . . 00
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 00
and health surveillance. ribbon.
Citation: Wise AK, Tan J, Wang Y, Caruso F,
Pu��is�e�: 2� �pri� 2016
Suzuki1,2,3
Junstimulate , Gabriel Corfas4
& M.(SGNs)
Charlesin
Liberman 1,2
respectively. Otol Neurotol 37:1223–1230, 2016. Cochlear implants electrically spiral ganglion neurons order to provide
Shepherd RK (2016) Improved Auditory Nerve
Survival with Nanoengineered Supraparticles for speech cues to severe-profoundly deaf
In acquired patients. In hearing
sensorineural normal loss,
hearing
suchcochleae the SGNs
as that produced by noise or aging, there can be massive
Please cite this article in press as: Kujawa, S.G., Liberman, M.C., Synaptopathy in the noise-exposed and aging cochlea: Primary neural
degeneration in acquired sensorineural hearing loss, Hearing Research (2015), http://dx.doi.org/10.1016/j.heares.2015.02.009
Discuss this article Keywords
Neurotrophin Delivery into the Deafened Cochlea. loss of the synaptic
depend on endogenous neurotrophins connections
secreted between
by sensory cells incochlear sensory
the organ cells
of Corti forand primary sensory neurons, without
noise-induced hearing loss, aging, cochlear nerve, auditory brainstem response, frequency-following response
PLoS ONE 11(10): e0164867. doi:10.1371/journal. loss of the sensory cells themselves. Because the cell bodies and central projections of these cochlear
Comments (0) survival. SGNs gradually degenerate following deafness and consequently there is consid-
1. Overt vs. ‘hidden’ hearing loss (SNHL) has been that cochlear hair cells are among the most
damage hair 25 cells, pone.0164867
with excitotoxicity causing neurons survive for months to years, there is a long therapeutic window in which to re-establish
The classic view of hearing loss over the last Datefew decades
received: 24 November
vulnerable elements in the cochlea and that, in the vast majority of
2015; revised: January 2016; accepted: 2 March 2016 a wide- erable interest in developing clinically relevant strategies to provide exogenous neurotro-
spread loss of connections between inner University hair cells phins to preserve SGN survival. functional connections and improve hearing ability. Here we show in noise-exposed mice that local
A longstanding view of acquired sensorineural hearing has been loss thatcases,
aftercochlear
exposurenerveof thedegenerate
ear to aif,noxious
and only long after, the Editor: Olivia Bermingham-McDonogh, The
fibers delivery ofpresent study investigated
neurotrophin-3 (NT-3) to thethe safety
round windowand efficacy
niche, 24of a after an exposure that causes an
hours
stimulus, such loss as excessively loud sound,
of their peripheral hair cellthere This view arose,(IHC)
is primary
targets. funda-and their afferent neurons
of Washington, (2). STATES
UNITED This ‘‘synaptopathy’’
drug delivery system for theimmediate
cochlea using loss ofnanoengineered
up to 50% loss ofsilica synapses in the cochlear
supraparticles. basal region, can regenerate pre- and post-
In the
damage to the mentally,sensory hair cellsofofthe
because thetemporal
inner ear,offsetfollowed results in the loss of both presynaptic ribbons on the IHC
between post-insult
Received: January 24, 2016 synaptic elements at the hair cell / cochlear nerve
overinterface.
a period This synaptic regeneration, as documented
* Corresponding author. Eaton-Peabody Laboratories, Massachusetts
byEye and Ear
secondary degeneration ofofhair
degeneration
Page 1 of 11
cells and auditory
connected loss of the spiral ganglion
nerves cell
and postsynaptic receptors on the afferent nerve. It does not present study we deliveredby Brain-derived
confocal
neurotrophic
microscopy of
factor
immunostained
(BDNF)
cochlear sensory
of four
epithelia, was coupled with a corresponding
Infirmary, 243 Charles St., Boston, MA 02114-3096, USA.
(1). However, (SGC)
E-mail address: Sharon_Kujawa@meei.harvard.edu (S.G. Kujawa).
bodies of the primary auditory neurons with which
a series of recent studies has changed this theythe detectionAccepted:
affect of quiet sounds
October (3), but is expected to weeks and evaluated SGN functional
3, 2016 survival as a measure of efficacy. Supraparticles were bilater-
recovery, as seen in the suprathreshold amplitude of auditory brainstem response
view by showing that after noise exposure, Introduction
neural injury make it difficult to Published:
differentiate between competing sound ally implanted into the basal turn 1. of cochleaedeliveryin profoundly deafenedinguinea pigs. Oneachievable
ear
http://dx.doi.org/10.1016/j.heares.2017.01.003 October 27, 2016 neuropathy, cochlear synaptopathy, and
Wave popularly
Cochlear of neurotrophins humans is likely as an office procedure via
0378-5955/© 2017 Elsevier B.V. All rights reserved.
occurs at exposure levels lower than those
Hearingrequiredabilityto is sources,
usually such
assessed as a
using speaker among
pure-tone background
audi- hidden noise. Con-
hearing loss (Schaette & McAlpine, transtympanic
2011), because injection, making our
received BDNF-loaded supraparticles and the other ear control (unloaded) supraparticles. results highly significant in a translational context.
sequently, Copyright: © 2016 Wise
ometry (Johnson, 1970), whichthismeasures
so-called ‘‘hidden
the smallest hearing
et al. Thisloss’’
the loss(HHL)
is an open
is notisthought to be detectable using pure-tone
not detected on access article distributed
conventional hearing under testing the the After one month of treatment the cochleae were examined histologically. There was signifi-
the terms of(i.e.,
Please cite this article in press as: Liberman, M.C., Kujawa,AddressS.G., Cochlear synaptopathy
correspondence andinreprint
acquired detectable
sensorineural
requests to Prof.hearing level
Stephenloss: of pure tones at a range
J. Manifestations of Commons
Creative
frequencies.Attribution
audiometry.
License, which
The loss greater
cantly seems to affectofselectively
survival SGNs in the low that received BDNF supraparticles compared
cochleae
The resulting audiogram audiogram),
is sensitive butto nonetheless
dysfunction is anticipated
ofuse,
thedistribution,to impede com- Recent work on noise-induced and age-related hearing loss shows that the most vulnerable elements in the inner
and mechanisms, Hearing Research (2017), http://dx.doi.org/10.1016/j.heares.2017.01.003
O’Leary, M.D., Ph.D., Otolaryngology, Department of Surgery, Uni- spontaneous rate (SR) fibers that have high thresholds
munication dailypermits unrestricted Soand ear are not (repeated
to the contralateral control cochleae the sensorymeasures
cells, but their
ANOVA,synapsesp with cochlear
= 0.009). SGN nerve terminals1. A noise exposure causing a large,
survival
versity of Melbourne, 5th Floor, Peter Howson Wing, outerRoyalhair cells. However,
Victorian it isinbecoming listening
reproduction
situations
increasingly (4).and
in any medium, provided
far,
are
the
synapt-
thought to be responsible forbut
original coding
ultimately sound
reversible,The elevation of cochlear thresholds, can immediately, and permanently, destroy these syn-
Eye and Ear Hospital, 32 Gisborne St, East Melbourne, 3002theVIC,audiogram opathy has been found to occur after noise exposure, drug- was observed over a wide extent ofKujawa,
the cochlea. supraparticles were well tolerated
clear that is much less author sensitive to inner
and source are credited. intensity at moderate-to-high levels (Furman, apses, thereby silencing up to 50% of the fibers in the cochlear nerve, despite no immediate or delayed loss of hair
Australia; E-mail: sjoleary@unimelb.edu.au induced hearing loss (ototoxicity) (5,6), and also presby- within the cochlea with a tissue cells response
1,3
. Although that
this was localised
cochlear to
synaptopathy the site
does of
notimplantation
elevate in thethe loss of neural channels likely causes
thresholds,
This work was funded by the National Health andhair cellResearch
Medical (IHC) loss (up to 80% IHC loss may occur
acusis in human ears (7).
Data It has been
Availability found
Statement:
& Liberman, 2013). This may explain why the loss
Allin the mouse
relevant data are (2),
Council (Australia) and the Garnett Passe and without affecting audiometric
Rodney Williams thresholds; Lobarinas, does(7). notThere cochlear base.
affectissensitivity Although
to quiet sounds. difficulties
mild, the tissue understanding
responsespeech in noisy or reverberant
was significantly greater inenvironments
cochleae and may also cause tinnitus , the phan-
2 3,4
Memorial Foundation.
guinea pig (8), and within
primates including humans
the paper. tom sounds commonly brought on by acoustic overexposure. This type of cochlear synaptopathy has been called
Salvi, & Ding, 2013)also andcompelling
to some clinical
types ofevidenceperipheral that tinnitus Themay extent
also totreated
be which with
hidden
BDNFhearing loss
supraparticlesis a contribu-
“hidden compared
hearing to5,the
loss” controls
because the (repeated
auditory measures
deficits can hide ANOVA,
behind a p
normal threshold audiogram.
The authors disclose no conflicts of interest. Funding: This work was funded by
DOI: 10.1097/MAO.0000000000001191
neural dysfunction. aInclinical particular, results
manifestation from
of rodent
synaptopathy torNational
(9).
Health
to hearing difficulties experienced
= 0.003). These by humans
data support In the
the is still
adult
clinical ear, cochlear
potential of nerve fibers often degenerate
this technology particularly after
as cochlear
the insult, including noise damage and oto-
models suggest that noise exposureandand Medical Research Council Project Grant
aging can supraparticles can be loaded toxicwithantibiotics
a variety. This
6
degenerationdrugs.
of therapeutic occurs with a variable time course, depending on the nature and severity of
APP1005071 and APP1064375, Australian the insult; however, the unmyelinated terminal dendrites within the organ of Corti disappear first (within hours
cause permanent 1223 loss of synapses between the IHCs
Research Council under the Australian Laureate to days), followed more slowly by the peripheral axons in the osseous spiral lamina (within days to weeks), and,
and auditory nerve fibers, without permanently affecting 1
Fellowship scheme (120100030),University and Nationalof Manchester, UK only on a much slower time course, the cell bodies in the spiral ganglion and their central axons that compose
sensitivity to quiet sounds (Kujawa & Institutes Liberman,of Health2009,
(USA) HHS-N-263-2007- the cochlear nerve (over weeks to months and longer)7–9. Given that cochlear implants can continue to provide
Corresponding author:
2015; Sergeyenko, Lall, Liberman, &00053-C. Kujawa, 2013). useful hearing
Christopher J. Plack, University of Manchester, Ellen Wilkinson for years after hair cell loss, these long-surviving neurons must remain electrically excitable and
Building,
The disconnected nerve fibers subsequently degenerate. Manchester M13 9PL, UK. appropriately connected to their central targets10. Thus, in many types of sensorineural hearing loss, there is
Copyright © 2016 Otology & NeThis urotolodisorder
gy, Inc. Unhas authbeen
orized variously
reproductioCompeting
n of thisInterests:
termed acochlear
rticle The
is pauthors
rohEmail:
ibhave
itedchris.plack@manchester.ac.uk
.
declared a long therapeutic window wherein a treatment to elicit neurite outgrowth could reconnect silenced cochlear
that no competing interests exist. ganglion cells with hair cells, and thereby potentially improve speech in noise performance and reduce tinnitus.
Neurotrophin-3 (NT-3) is a member of the neurotrophic factor family that contributes to neuronal differen-
Creative Commons CC-BY-NC: This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 3.0 License (http://www.
tiation,
creativecommons.org/licenses/by-nc/3.0/) which permits non-commercial use, reproduction and distribution of the work without further permission providedsurvival and axonal outgrowth via its interactions with TrkC receptors11,12. Neurotrophins are necessary
the original
work is attributed as specified on the SAGE and Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage). for normal development of cochlear innervation13–16, and NT-3 is necessary for the formation and maintenance
PLOS ONE | DOI:10.1371/journal.pone.0164867 October 27, 2016
Downloaded from tia.sagepub.com at UCI MEDICAL CENTER on September 12, 2016
1 / 17
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Scientific RepoRts | 6:24907 | DOI: 10.1038/srep24907 1
6Background on OTO-413 Program
• Selected BDNF after extensive evaluation of multiple neurotrophic
factors and Trk antibodies
- Cochlear explant assay, in vitro testing and in vivo evaluations
• OTO-413 comprised of BDNF in thermosensitive polymer (same
used for OTIPRIO® and OTIVIDEX™)
• IP covers proprietary formulation and manufacturing know-how
• Single intratympanic injection of OTO-413 provides sustained-
exposure of BDNF to the inner ear
• Therapeutic potential of OTO-413 demonstrated in cochlear
synaptopathy animal model – presentation selected as “Hot Topic”
at 2018 Society for Neuroscience Annual Meeting (November 6)
7Therapeutic Effects of BDNF in the Cochlea
Brain-derived neutrophic factor (BDNF) activates TrkB receptors on SGNs to:
• Promote survival of SGNs
SGN survival (normalized to 1nM NT-3)
140%
120%
100%
80%
BDNF
60%
Control
hIgG4
40%
20%
0%
0.001 0.01 0.1 1 10
concentration (nM)
• Increase neurite outgrowth of SGNs
Control 10nM BDNF 35
**
30 **pOTO-413 Proof-of-Concept in Synaptopathy Animal Model
Recovery of both synapse numbers and auditory function with OTO-413
30
Synapse Counts Visualization of Synapses on Hair Cells
Synaptopathy (Punctae/IHC)
25
20
15
10
4 10 20 40 Naïve
Frequency (kHz)
Noise + Vehicle
Noise + OTO-413
1.6
Auditory Function
1.4
Wave 1 amplitude (µV)
1.2
1.0
0.8
0.6
0.4
0.2
0.0
4 10 20 40
Frequency (kHz) 9OTO-413 Program Status and Plan
• Pre-IND meeting completed with FDA
• IND enabling activities ongoing
• Expect to initiate Phase 1/2 study in hearing loss patients in 1H19
• Initial study population: speech-in-noise hearing difficulty
- Common and growing problem not improved by hearing aids
- Objective clinical endpoints
- Extensive discussions with KOLs about study design
• Will outline clinical trial plan and timing in January
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