Aimmune Therapeutics Announces COO Transition

— COO Howard Raff to Retire from Leadership Position to Focus on
Future
Pipeline Development —

— Aimmune Builds Clinical Team with Key Allergist / Immunologist
Hires —

BRISBANE, Calif.–(BUSINESS WIRE)–Aimmune Therapeutics, Inc. (Nasdaq:AIMT), a biopharmaceutical company
developing desensitization treatments for food allergies, today
announced that Aimmune’s Chief Operating Officer, Howard Raff, Ph.D.,
who joined the company as its second employee upon its 2011 founding as
Allergen Research Corporation, will retire from his position on October
31, 2015. Dr. Raff will become a consultant for Aimmune, working on
developing future product opportunities for food allergens.

Aimmune expects to announce a new Chief Operating Officer, with
substantial commercial experience, in the coming weeks.

“Many of Aimmune’s accomplishments to date, especially around our drug
development and regulatory pathway, are direct results of Howie’s
rolling up his sleeves and making them happen,” said Aimmune CEO Stephen
Dilly, M.B.B.S., Ph.D. “I have had the pleasure of working with Howie
for more than a decade, and I am delighted for him to take this
opportunity, after getting us to a Phase 3-ready state, to move from
day-to-day functions to a visionary role and explore other potential
applications of our expertise to help food allergy patients. Everyone at
Aimmune is grateful for Howie’s contributions and appreciates the robust
operations team he has assembled. I know that he is looking forward to
working closely with our new COO to transition effectively when that
individual comes on board.”

Aimmune has also enhanced the capabilities of its clinical team with the
additions of Brian Vickery, M.D., and Sean Bennett, M.D., Ph.D., as
Senior Medical Directors in the United States and Andrea Vereda, M.D.,
Ph.D., as Medical Affairs Director for Europe. Dr. Vickery, who is
board-certified in allergy and immunology and completed a fellowship in
allergy and clinical immunology at Yale University, will also be an
Adjunct Professor of Pediatrics at the University of North Carolina at
Chapel Hill. As an Assistant Professor of Pediatrics at UNC and at Duke
University, Dr. Vickery worked closely with Dr. Wesley Burks, a leading
expert on food allergy. Dr. Bennett, a pediatrician who earned his M.D.
and Ph.D. in microbiology and immunology from the University of
Colorado, joined Aimmune from Gilead Sciences, where he focused on
pediatric development programs. Dr. Vereda, an allergist who earned her
M.D. and Ph.D. at the Universidad Autónoma de Madrid and received
additional training and conducted research in allergy at Mt. Sinai
Hospital in New York City, has also collaborated with the World Allergy
Organization on global projects.

“Brian, Sean and Andrea all bring key understanding and experience to
our clinical team, and each contributes a unique perspective as we
prepare to launch our Phase 3 clinical trial for AR101,” said Aimmune’s
Chief Medical Officer, Robert Elfont, M.D., Ph.D. “In addition to seeing
and treating food allergy patients, Brian has worked extensively with
academic clinical trials, including as the lead investigator for the
ongoing DEVIL (Determining the Efficacy and Value of Immunotherapy on
the Likelihood of Peanut Tolerance) study. Sean is the ideal biotech
complement, with deep experience leading global cross-functional teams
for several compounds through the various phases of clinical
development. And Andrea has performed important research and
investigated issues with leading allergists around the world. Our team
is excited to apply our collective expertise to advance the development
of much-needed treatments for food allergy sufferers.”

About AR101 and CODIT™

Aimmune Therapeutics is developing AR101 as a potential desensitization
therapy for patients with peanut allergy to provide them with protection
from peanut allergens at a level believed to substantially exceed the
amount typically encountered in an accidental exposure. AR101 is a
complex mixture of naturally occurring proteins and pharmaceutical-grade
inactive ingredients designed to enable the convenient dosing of
consistent amounts of peanut protein with well-defined concentrations of
peanut allergens. Patients ingest AR101 mixed into small amounts of
palatable, age-appropriate food.

AR101 is part of Aimmune’s approach to treating food allergies using its
characterized oral desensitization immunotherapy, or CODIT™, system. The
CODIT system leverages extensive independent scientific research on oral
immunotherapy, or OIT, demonstrating that food allergy patients can be
desensitized to food allergens by being administered well-defined,
gradually increasing doses of the allergen over a period of months.
Aimmune’s CODIT system is designed to precisely control the amounts of
the allergens administered in a systematic dosing regimen, beginning
with very low doses of the allergens. Once a patient attains
desensitization to a clinically meaningful level, the patient continues
to take a daily maintenance dose of the CODIT system product in order to
maintain the desensitization.

About Food Allergies

Food allergies are a significant and growing health problem in the
United States, Europe and throughout the developed world. It is
estimated that more than 30 million people in the United States and
Europe have a food allergy, and more than five million people in the
United States and Europe have peanut allergy, including more than two
million children. The prevalence of peanut allergy in children in the
United States is estimated to have increased at a constant annual growth
rate of approximately 10 percent between 1997 and 2008, and experts
believe it has continued to rise since 2008. For people living with food
allergies, certain foods can cause severe allergic reactions, including
potentially life-threatening anaphylaxis. There are no approved medical
therapies to cure food allergies or prevent their effects. Currently,
food-allergic patients manage their condition by strict allergen
avoidance and carrying epinephrine auto-injectors for use in case of
accidental exposure. Thus, in addition to the unmet medical need, food
allergies can impose a significant quality of life burden. For more
information, please see www.foodallergy.org
and www.niaid.nih.gov/topics/foodallergy.

About Aimmune Therapeutics

Aimmune Therapeutics, Inc., founded in 2011 as Allergen Research
Corporation (ARC), is a clinical-stage biopharmaceutical company
developing treatments for peanut allergy and other food allergies.
Aimmune Therapeutics’ characterized oral desensitization immunotherapy
(CODIT™) system, an approach to oral immunotherapy (OIT), uses
rigorously characterized product candidates with gradual, controlled
up-dosing protocols to obtain clinically meaningful desensitization to
food allergens. Aimmune Therapeutics recently completed a Phase 2 study
of its lead product, AR101, a complex mixture of naturally occurring
proteins and pharmaceutical-grade ingredients for the treatment of
peanut allergy, one of the most common food allergies. For more
information, please see www.aimmune.com.

Forward-Looking Statements

Statements contained in this press release regarding matters that are
not historical facts are “forward-looking statements” within the meaning
of the Private Securities Litigation Reform Act of 1995. Because such
statements are subject to risks and uncertainties, actual results may
differ materially from those expressed or implied by such
forward-looking statements. Such statements include, but are not limited
to, statements regarding: Aimmune’s clinical development plans and
anticipated executive hiring. Risks that contribute to the uncertain
nature of the forward-looking statements include: the expectation that
Aimmune will incur losses for the foreseeable future and will need
additional funds to finance its operations; the accuracy of the
company’s estimates regarding its ability to initiate and/or complete
clinical trials; the unpredictability of the regulatory process;
reliance on third parties for the manufacture of the Company’s product
candidates; regulatory developments in the United States and foreign
countries; and the Company’s ability to attract and retain senior
management personnel. These and other risks and uncertainties are
described more fully in Aimmune’s most recent filings with the
Securities and Exchange Commission, including the prospectus relating to
the initial public offering dated August 5, 2015, and the Quarterly
Report on Form 10-Q for the second quarter of 2015 dated August 31,
2015. All forward-looking statements contained in this press release
speak only as of the date on which they were made. Aimmune undertakes no
obligation to update such statements to reflect events that occur or
circumstances that exist after the date on which they were made.

This press release concerns a product that is under clinical
investigation and which has not yet been approved for marketing by the
U.S. Food and Drug Administration (FDA) or the European Medicines Agency
(EMA). It is currently limited to investigational use, and no
representation is made as to its safety or effectiveness for the
purposes for which it is being investigated.

Contacts

Media:
Edelman
Amanda Breeding, 415-229-7649
amanda.breeding@edelman.com
or
Investors:
Aimmune
Therapeutics, Inc.
Amy Figueroa, 650-352-1039
investorrelations@aimmune.com