Aimmune Therapeutics Announces First Quarter 2019 Financial Results and Provides Operational Highlights

• Potential FDA approval of AR101 for peanut allergy expected by late
  January 2020; Company on target to be launch-ready in Q4 2019
• Submission of marketing application for AR101 in Europe on track
  for mid-2019, following positive topline results of ARTEMIS European
  Phase 3 trial
• Initiation of AR201 phase 2 trial in egg allergy expected in
  mid-2019
• Strong balance sheet expected to fund commercialization of AR101 in
  the U.S. and Europe and development of pipeline
• Webcast and conference call today at 4:30 p.m. ET

BRISBANE, Calif.–(BUSINESS WIRE)–Aimmune Therapeutics, Inc. (Nasdaq: AIMT), a biopharmaceutical company
developing treatments for life-threatening food allergies, today
announced financial results for the quarter ended March 31, 2019. For
the quarter ended March 31, 2019, net loss was $54.3 million and cash,
cash equivalents, and investments totaled $296.3 million on March 31,
2019.

“We are well on track to introduce AR101 as potentially the first-ever
approved treatment for peanut allergy, a significant milestone for our
Company, the allergist community, and the millions of people who live
with the daily risk of serious reactions to accidental peanut exposure,”
said Jayson Dallas, M.D., President and CEO of Aimmune Therapeutics.
“The FDA’s acceptance of our BLA was a key step forward and now we
continue to work with the FDA to facilitate an expeditious review. In
parallel, in the U.S., we are continuing our medical education through
our MSL Team and are fully ramping up our commercial efforts and scaling
our organization to be launch-ready by Q4 this year. Recent market
research has provided additional focus to this effort. For example, we
have found that the approximately 30 percent of allergists who are most
eager and ready to offer AR101 to their patients, if approved, today see
approximately 70 percent of peanut allergic patients.”

Dr. Dallas added: “We also continue to advance efforts toward submitting
a marketing authorization application for AR101 to the European
Medicines Agency in mid-2019, following our positive ARTEMIS European
phase 3 study. We are excited to present the full ARTEMIS results at
EAACI in early June. In addition, we expect to initiate a phase 2 trial
of AR201 in egg allergy in mid-2019. Moreover, we remain in a strong
financial position to commercialize AR101 and advance our pipeline
programs.”

AR101 Highlights

• Biologics License Application (BLA) for AR101 was accepted for
  review by the U.S. Food and Drug Administration (FDA). In March
  2019, the FDA accepted for review the BLA for AR101 for the treatment
  of peanut allergy in children and adolescents ages 4 to 17, which
  Aimmune had submitted to the agency in December 2018. The FDA informed
  Aimmune that the BLA will be reviewed under a 12-month target review
  period, as measured from the January 2019 start date. Review of the
  BLA may therefore take until late January 2020. The FDA expects to
  convene an advisory committee meeting to discuss the application.
• Positive phase 3 ARTEMIS topline data announced; submission of
  marketing authorization application (MAA) to European Medicines Agency
  (EMA) on track. In March 2019, the Company announced that the
  phase 3 ARTEMIS European clinical trial of AR101 for the treatment of
  peanut allergy in children and adolescents ages 4 to 17 met its
  primary efficacy endpoint. Topline data showed the proportion of
  AR101-treated patients who tolerated a 1,000-mg dose of peanut protein
  (2,043 mg cumulative) in a blinded exit challenge after approximately
  nine months of AR101 treatment was significantly higher (p<0.00001)
  than in the placebo group. The median tolerated dose of peanut protein
  for AR101-treated patients improved 100-fold, from 10 mg at baseline
  to 1,000 mg at exit. The trial also greatly exceeded a 15% lower-bound
  of the 95% confidence interval (CI) of the difference between
  treatment arms for the primary endpoint. The safety profile and
  completion rate observed in ARTEMIS were consistent with results seen
  in previous AR101 clinical trials, and no cases of anaphylaxis or
  eosinophilic esophagitis (EoE) were observed. Aimmune intends to
  submit a MAA for AR101 to the EMA in mid-2019. Aimmune also plans to
  present full results of the ARTEMIS trial in an oral presentation at
  the European Academy of Allergy and Clinical Immunology (EAACI)
  Congress on June 2, 2019.

POSEIDON trial and AR101 with adjunctive dupilumab trials ongoing.
In December 2018, Aimmune initiated its phase 3 POSEIDON trial to
explore the efficacy and safety of AR101 in young peanut-allergic
children, ages 1 to 3. In October 2018, a phase 2 trial of AR101 with
adjunctive dupilumab was initiated in peanut-allergic patients.
Regeneron is the trial’s sponsor, and Aimmune is supplying AR101
clinical trial material.

AR201 Highlights

• Phase 2 trial initiation on track for mid-2019. Aimmune’s
  Investigational New Drug (IND) application for AR201 was cleared by
  the FDA, as previously announced, and the Company remains on track to
  begin a phase 2 trial in egg allergy in mid-2019.

First Quarter Financial Results

For the quarter ended March 31, 2019, net loss was $54.3 million,
compared to net loss of $49.5 million for the comparable period in 2018.

On a per share basis, net loss for the quarter ended March 31, 2019, was
$0.87, compared to net loss per share of $0.92 for the comparable period
in 2018. The weighted average shares outstanding for the quarter ended
March 31, 2019, were 62.0 million, compared 53.6 million shares for the
comparable period in 2018.

Research and development expenses for the quarter ended March 31, 2019,
were $31.3 million, compared to $33.4 million for the comparable period
in 2018. The decrease was primarily due to lower costs from the
progression of certain AR101 clinical trials offset by higher contract
manufacturing costs to support clinical development and regulatory
activities.

General and administrative expenses for the quarter ended March 31,
2019, were $23.7 million, compared to $16.7 million for the comparable
period in 2018. The increase was primarily due to additional
employee-related costs and external professional services as Aimmune
continued to build its infrastructure to support the development and
potential commercialization of AR101.

Cash, cash equivalents, and investments totaled $296.3 million on March
31, 2019, compared to $303.9 million on December 31, 2018. The decrease
primarily reflects net cash used in operating activities of $45.8
million partially offset by cash provided by financing activities,
including net borrowings from our debt issuance in January 2019 of $36.1
million.

Conference Call

In connection with this announcement, Aimmune Therapeutics will host a
conference call and webcast today at 4:30 p.m. ET. To access the live
call by phone, dial (877) 497-1438 (domestic) or (262) 558-6296
(international) and enter the passcode 5667779. To access a live or
recorded webcast of the call, please visit the Investor Relations
section of the Aimmune Therapeutics website at www.aimmune.com.
The recorded webcast will be available for approximately 30 days
following the call.

About Aimmune Therapeutics

Aimmune Therapeutics, Inc., is a biopharmaceutical company developing
oral treatments for life-threatening food allergies. The company’s Characterized
Oral Desensitization
ImmunoTherapy
(CODIT™) approach is intended to provide meaningful levels of protection
against allergic reactions resulting from exposure to food allergens by
desensitizing patients with defined, precise amounts of key allergens.
Aimmune’s first investigational biologic product, AR101, is being
developed as a treatment to reduce the frequency and severity of adverse
events following exposure to peanut. The BLA for AR101 is under review
by the U.S. FDA, which in 2015 granted AR101 Breakthrough Therapy
Designation for the desensitization of peanut-allergic patients 4 to 17
years of age. Aimmune expects to file for marketing approval of AR101 in
Europe in mid-2019. Aimmune has filed an IND application for its second
product, AR201 for the treatment of egg allergy, and intends to start a
randomized phase 2 clinical trial in mid-2019. 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 expectations regarding the potential
benefits of AR101; Aimmune’s expectations regarding the potential
commercial launch of AR101, including the review period of the BLA for
AR101; Aimmune’s expectations regarding the planned timing and filing
for marketing approval of AR101 in Europe; Aimmune’s expectations on the
timing of initiating a phase 2 clinical trial for AR201; Aimmune’s
expectations on the planned timing for the announcement of data from the
ARTEMIS clinical trial for AR101; Aimmune’s expectations regarding the
sufficiency of its cash resources; and Aimmune’s expectations regarding
potential applications of the CODIT™ approach to treating
life-threatening food allergies. Risks and uncertainties that contribute
to the uncertain nature of the forward-looking statements include: the
expectation that Aimmune will need additional funds to finance its
operations; Aimmune’s or any of its collaborative partners’ ability to
initiate and/or complete clinical trials; the unpredictability of the
regulatory process; the possibility that Aimmune’s or any of its
collaborative partners’ clinical trials will not be successful;
Aimmune’s dependence on the success of AR101; Aimmune’s reliance on
third parties for the manufacture of Aimmune’s product candidates;
possible regulatory developments in the United States and foreign
countries; and Aimmune’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 its Quarterly Report on Form 10-Q for the quarter
ended March 31, 2019. 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 AR101, a product candidate that is under
clinical investigation, and AR201, a product candidate that Aimmune
expects will be under clinical investigation in 2019. Neither AR101 nor
AR201 has been approved for marketing by the FDA or the European
Medicines Agency (EMA). AR101 and AR201 are currently limited to
investigational use, and no representation is made as to their safety or
effectiveness for the purposes for which they are being investigated.

Contacts

Investors:
Eric Bjerkholt
(650) 376-5582 or
[email protected]

Media:
Jerica
Pitts
(312) 858-3469
[email protected]