Aimmune Announces New PALFORZIA™ Data Suggesting Increased Desensitization, Improved Tolerability and Continued Immunomodulation After 18 and 24 Months of Treatment

— Additional Data Highlight PALISADE Study Patient Baseline Characteristics and Associated Treatment Response — and Improvements in Self-Reported Quality of Life Following Long-Term Treatment with PALFORZIA

— Survey Results Reinforce Immunotherapy Practice Patterns for Food Allergy in Real-World Setting and Daily Impact of Peanut Allergy on Quality of Life Among Patients and Caregivers—

— Company to Host Conference Call on March 16 at 12:15 p.m. ET —

BRISBANE, Calif.–(BUSINESS WIRE)–Aimmune Therapeutics, Inc. (Nasdaq: AIMT), a biopharmaceutical company developing and bringing new treatments to people with potentially life-threatening food allergies, today announced new data from the clinical development program for PALFORZIA™ [Peanut (Arachis hypogaea) Allergen Powder-dnfp], the first peanut allergy treatment approved by the U.S. Food and Drug Administration (FDA).

An analysis from ARC004, the open-label follow-on trial to the 52-week PALISADE trial, showed that patients tolerated more peanut protein, experienced fewer adverse events and continued immunomodulation – changes in the body’s immune system – as evidenced by reductions in peanut-specific immunoglobulin (IgE) blood levels after an additional 56 weeks of daily treatment with PALFORZIA. These data were accepted for presentation at the American Academy of Allergy, Asthma & Immunology (AAAAI) 2020 Annual Meeting; due to the cancellation of the meeting, the Company will host a conference call Monday, March 16 at 12:15 p.m. ET to discuss the data, and posters will be available on Aimmune’s website prior to the call.

Additional data announced include:

• An analysis of patient baseline characteristics and associated treatment response which demonstrated that all subgroups experienced clinically meaningful treatment effects during the PALISADE trial with PALFORZIA.
• A survey that assessed quality of life (QoL) of PALFORZIA-treated patients aged 8 to 17 who were followed for an additional 28 or 56 weeks of therapeutic dosing in the open-label extension trial to PALISADE, ARC004, that suggested clinically significant improvements in emotional and social impacts of peanut allergy after long-term treatment with PALFORZIA.
• Three additional quality of life studies that reinforced the real-world burden and daily impact of peanut allergy on adolescents and caregivers in the U.S.
• Findings from two real-world surveys of allergists and immunologists practicing oral immunotherapy (OIT) that revealed largely consistent practice patterns and indicated successful implementation of food allergy OIT in clinical practice.

PALFORZIA Long-term Clinical Trial Data

• Patients who completed the 52-week PALISADE clinical trial and could tolerate at least 300 mg (443 mg cumulative) peanut protein at the exit double-blind, placebo-controlled food challenge (DBPCFC) were eligible to continue treatment with PALFORZIA (300 mg/day) for either 28 (cohort 1; n=103) or 56 weeks (cohort 3a; n=26) in the open-label follow-on trial ARC004.
  • The trial showed that the ability to tolerate cumulative doses of peanut protein was sustained or improved between PALISADE and ARC004, after an additional 28 or 56 weeks of treatment, and that an increased number of patients in both cohorts tolerated peanut protein doses of more than 300 mg during the ARC004 exit food challenge compared to the PALISADE exit food challenge.
  • During the exit food challenge of ARC004, four out of five (80.8%) of patients who completed the trial in cohort 3a were able to tolerate 2,000 mg (or 3,443 cumulative) of peanut protein (the equivalent of approximately 12 peanuts) after 56 weeks of continued dosing, and in cohort 1 (28 weeks of additional daily dosing) approximately half (49%) of patients tolerated 2,000 mg, suggesting progressive desensitization to peanut protein over time during treatment with PALFORZIA.
  • With continued daily dosing beyond one year, the number of related adverse events per patient-year of exposure dropped by 59% and 85% in cohorts 1 and 3a, respectively, from PALISADE to ARC004, and no deaths or life-threatening AEs were observed. In addition, as expected, immunomodulation continued over time, including a reduction in peanut-specific IgE below baseline in all patient subgroups.

• Separately, survey results assessed the impact of PALFORZIA treatment on quality-of-life parameters, including allergen avoidance, dietary restrictions, risk of accidental exposure and emotional and social impact, in patients who completed PALISADE and were eligible to enroll into one of three dosing cohorts in the open label extension study, ARC004.
  • Patients completed an age-appropriate Food Allergy Quality of Life Questionnaire (FAQLQ) and Food Allergy Independent Measure (FAIM), and results across both questionnaires showed that overall self-reported quality of life measurements consistently exceeded the minimally important difference (MID) of ≥0.5 for total scores following the transition to open-label ARC004 at both 28 and 56 weeks of additional PALFORZIA therapeutic dosing, suggesting clinically significant improvements in emotional and social impacts of peanut allergy after long-term treatment with PALFORZIA.
• In an analysis that aimed to determine whether baseline variables affect the immunological response to PALFORZIA, researchers calculated the proportion of PALISADE study participants aged four through 17 years who achieved the primary endpoint in the clinical trial (tolerating ≥600 mg peanut protein at DBPCFC) based on age, sex, asthma, peanut-related anaphylaxis history, allergic rhinitis, multiple food allergies and atopic dermatitis.
  • Overall, the difference in the primary endpoint between PALFORZIA and placebo was 63.2% and in all subgroups the difference exceeded 55%.
  • While all patient subgroups experienced clinically meaningful treatment effects with PALFORZIA, trends toward higher desensitization rates exceeding 70% were observed for some variables, including female gender and no history of asthma or anaphylaxis.

Peanut Allergy Data

• Data from the Peanut Allergy Burden Study (PABS), which assessed the real-world burden of peanut allergy on adolescents (aged 13 to 17) and caregivers in the U.S. using the validated Pediatric Quality of Life Inventory (PedsQL) showed that adolescents with peanut allergy have lower PedsQL scores than a general population of 8 to 16-year-olds.
  • Adolescents experiencing one or more peanut allergy-related reactions in the past year had a lower PedsQL, as did those receiving clinician intervention for one or more peanut allergy reactions in the past year.

• A second PABS assessment of the real-world burden of peanut allergy on adolescents using the Food Allergy Quality of Life Questionnaire (FAQLQ) showed that adolescents with peanut allergy are constantly impacted by a number of psychosocial variables, including living with the fear of a reaction on emotional well-being, daily life limitations, worry regarding epinephrine autoinjector access, confidence managing a reaction, and the severity of their most severe reaction.

• A third PABS assessment evaluated the real-world burden of peanut allergy on adolescents and caregivers of adolescents aged 13 to 17 with peanut allergy using the FAQLQ.
  • Results showed that adolescents reported a significantly greater burden than caregivers on the limitations that peanut allergy placed on their day-to-day life, noting a fear of a reaction impacting emotional well-being and poorer quality of life.
  • Adolescents also differed significantly from caregivers on the most concerning aspects of peanut allergy, with adolescents expressing more concern regarding physical symptoms during a reaction and the impact of peanut allergy on family.
  • Nearly one-third more adolescents also reported greater concern regarding the impact of PA on their mental health than did caregivers; more than one-third more adolescents than caregivers reported physical symptoms experienced during a reaction as most concerning, and twice as many adolescents reported impact on their family as most concerning.

Real-World OIT Practice Data

• To assess clinical practice management of food OIT, 80 U.S.-based allergists and immunologists who treated five or more patients with food OIT during the past two years were surveyed.
  • The survey showed that, regardless of practice size, allergists/immunologists who have implemented OIT into their practice reported largely consistent OIT practice patterns, including observation times, the use of spirometry in patients with asthma, and management of GI symptoms.
  • Nearly three out of four allergists reported that more than half of their patients reached the target maintenance dose. Although adverse reactions occurred, maintenance was generally achieved, with small proportions of patients discontinuing due to gastrointestinal adverse events and low rates of medication use for OIT-associated gastrointestinal (GI) symptoms. Respondents who treated fewer OIT patients were more likely to conduct an oral food challenge prior to initiating OIT.

• Among the same group of allergists and immunologists, which also examined physician-reported epinephrine use during food OIT, in-clinic OIT reactions requiring epinephrine were infrequently seen in practice and in-home reactions were generally mild-to-moderate.
  • The majority of physicians (~80%) saw less than 10% of OIT patients experience an in-clinic reaction that required epinephrine use. Additionally, in general, in-clinic OIT-induced reactions did not occur frequently.
  • Furthermore, the survey reported that epinephrine-treated OIT and environmental subcutaneous immunotherapy-induced reactions were perceived as comparable in severity. Peanut allergy was the most common food allergy treated.

“We are excited to share new long-term PALFORZIA data, which indicate that as patients remain on treatment, the immune system appears to develop an increased tolerance to the allergen, as demonstrated by the reduced frequency and severity of side effects, along with the potential for continued desensitization over time,” said Daniel Adelman, M.D., Chief Medical Officer of Aimmune Therapeutics. “Additional studies announced today further reinforce the daily burden of living with peanut allergy and suggest that treatment with PALFORZIA may improve its emotional and social impact on adolescents and caregivers alike. This, coupled with results from real-world surveys, suggests that most allergists who practice OIT for food allergy are seeing promising results and that patients with a wide range of baseline characteristics may benefit from treatment with PALFORZIA, is encouraging as we continue to advance our knowledge on the potential benefits of oral immunotherapy for food allergy.”

Conference Call Details

In connection with this announcement, Aimmune Therapeutics will host a conference call and webcast Monday March 16 at 12:15 p.m. ET. To access the live call by phone, dial (877) 497-1438 (domestic) or (262) 558-6296 (international) and enter the passcode 1277785. 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.

PALFORZIA (previously known as AR101) was approved by the U.S. Food and Drug Administration (FDA) on January 31, 2020. PALFORZIA is the first approved treatment for patients with peanut allergy.

INDICATION

PALFORZIA is an oral immunotherapy indicated for the mitigation of allergic reactions, including anaphylaxis, that may occur with accidental exposure to peanut. PALFORZIA is approved for use in patients with a confirmed diagnosis of peanut allergy. Initial Dose Escalation may be administered to patients aged 4 through 17 years. Up-Dosing and Maintenance may be continued in patients 4 years of age and older.

PALFORZIA is to be used in conjunction with a peanut-avoidant diet.

Limitations of Use: Not indicated for the emergency treatment of allergic reactions, including anaphylaxis.

IMPORTANT SAFETY INFORMATION

Boxed WARNING:

PALFORZIA can cause anaphylaxis, which may be life threatening and can occur at any time during PALFORZIA therapy.

Prescribe injectable epinephrine, instruct and train patients on its appropriate use, and instruct patients to seek immediate medical care upon its use.

Do not administer PALFORZIA to patients with uncontrolled asthma.

Dose modifications may be necessary following an anaphylactic reaction.

Observe patients during and after administration of the Initial Dose Escalation and the first dose of each Up-Dosing level, for at least 60 minutes.

PALFORZIA is available only through a restricted program called the PALFORZIA REMS.

CONTRAINDICATIONS

PALFORZIA is contraindicated in patients with uncontrolled asthma, or with a history of eosinophilic esophagitis and other eosinophilic gastrointestinal disease

WARNINGS AND PRECAUTIONS

Anaphylaxis

PALFORZIA can cause anaphylaxis, which may be life threatening. PALFORZIA is available only through a restricted program under a Risk Evaluation and Mitigation Strategy (REMS) called the PALFORZIA REMS because of the risk of anaphylaxis. Only prescribers, healthcare settings, pharmacies, and patients certified and enrolled in the REMS Program can prescribe, receive, dispense or administer PALFORZIA.

Anaphylaxis has been reported during all phases of PALFORZIA dosing, including Maintenance and in subjects who have undergone recommended Up-Dosing and dose modification procedures.

Do not initiate PALFORZIA treatment in a patient who has had severe or life-threatening anaphylaxis within the previous 60 days. PALFORZIA may not be suitable for patients with certain medical conditions that may reduce the ability to survive anaphylaxis, including but not limited to markedly compromised lung function, severe mast cell disorder, or cardiovascular disease. In addition, PALFORZIA may not be suitable for patients taking medications that can inhibit or potentiate the effects of epinephrine.

All Initial Dose Escalation doses and the first dose of each Up-Dosing level must be administered in a certified health care setting.

Patients may be more likely to experience allergic reactions following PALFORZIA administration in the presence of cofactors such as exercise, hot water exposure, intercurrent illness (e.g., viral infection), or fasting. Other potential cofactors may include menstruation, sleep deprivation, nonsteroidal anti-inflammatory drug use, or uncontrolled asthma. Patients should be proactively counseled about the potential for the increased risk of anaphylaxis in the presence of these cofactors. If possible, adjust the time of dosing to avoid these cofactors. If it is not possible to avoid these cofactors, consider withholding PALFORZIA temporarily.

Asthma

Uncontrolled asthma is a risk factor for a serious outcome, including death, in anaphylaxis. Ensure patients with asthma have their asthma under control prior to initiation of PALFORZIA.

PALFORZIA should be temporarily withheld if the patient is experiencing an acute asthma exacerbation. Following resolution of the exacerbation, resumption of PALFORZIA should be undertaken cautiously. Re-evaluate patients who have recurrent asthma exacerbations and consider discontinuation of PALFORZIA.

Eosinophilic Gastrointestinal Disease

Discontinue PALFORZIA and consider a diagnosis of eosinophilic esophagitis in patients who experience severe or persistent gastrointestinal symptoms, including dysphagia, vomiting, nausea, gastroesophageal reflux, chest pain, or abdominal pain.

Gastrointestinal Adverse Reactions

Gastrointestinal adverse reactions were commonly reported in PALFORZIA-treated subjects, and dose modification should be considered for patients who report these reactions. For severe or persistent gastrointestinal symptoms consider a diagnosis of eosinophilic esophagitis.

ADVERSE REACTIONS

The most common adverse events reported in subjects treated with PALFORZIA (incidence ≥ 5% and ≥ 5% than placebo) are abdominal pain, vomiting, nausea, oral pruritus, oral paresthesia, throat irritation, cough, rhinorrhea, sneezing, throat tightness, wheezing, dyspnea, pruritus, urticaria, anaphylactic reaction, and ear pruritus.

Please see full Prescribing Information, including Boxed WARNING, and Medication Guide at www.PALFORZIA.com.

For more information about PALFORZIA, please call 1-844-PALFORZ (1-844-725-3679) or visit www.PALFORZIA.com.

About Aimmune

Aimmune Therapeutics, Inc. is a biopharmaceutical company developing and bringing new treatments to people with potentially life-threatening food allergies. With a mission to improve the lives of people with food allergies, Aimmune is developing and commercializing oral treatments for potentially 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 accidental exposure to food allergens by desensitizing patients with defined, precise amounts of key allergens. Aimmune has one FDA-approved medicine for peanut allergy and other investigational therapies in development to treat other food allergies. For more information, please visit 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 PALFORZIA; the potential for PALFORZIA to increase desensitization over time and to improve patient quality of life; 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 dependence on the success of PALFORZIA; Aimmune’s ability to build a commercial field organization and distribution network; the degree of acceptance of PALFORZIA among physicians, patients, healthcare payors, patient advocacy groups and the general medical community; Aimmune’s ability to obtain favorable coverage and reimbursement from third-party payors for PALFORZIA; Aimmune’s reliance on third parties for the manufacture of PALFORZIA; Aimmune’s ability to implement and comply with the REMS for PALFORZIA; 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 Annual Report on Form 10-K for the year ended December 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 PALFORZIA (AR101), which has been approved for marketing by the FDA in the United States and has not been approved for marketing by the EMA or Swissmedic. AR101 in Europe 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.

PALFORZIA™, AIMMUNE™, AIMMUNE THERAPEUTICS™ and CODIT™ are trademarks of Aimmune Therapeutics, Inc.

Contacts

Investors:
ir@aimmune.com
(650) 376-6492

Media:
Julie Normart

(559) 947-3245

jnormart@w2ogroup.com

Lauren Barbiero

(646) 564-2156

lbarbiero@w2ogroup.com