— Unique Dataset of Double-Blind, Placebo-Controlled Food Challenges from Phase 3 PALISADE North American Screened Population Is Largest Ever Collected on Peanut-Allergic Patients and Provides Valuable Insights for Future Study —
— 95% Adherence to Daily At-Home AR101 Dosing in Blinded Phase 2 Study —

BRISBANE, CA, USA I March 6, 2017 I Aimmune Therapeutics, Inc. (Nasdaq:AIMT), a biopharmaceutical company developing treatments for life-threatening food allergies, announced clinical data presented today at the 2017 American Academy of Allergy, Asthma & Immunology (AAAAI) Annual Meeting in Atlanta. The presentations included Phase 3 screening data and Phase 2 adherence data from Aimmune’s AR101 program. AR101 is Aimmune’s investigational biologic oral immunotherapy for desensitization of patients with peanut allergy.

“As we work to bring AR101 through clinical trials with the aim of providing physicians and patients with a desensitization treatment for peanut allergy, we are also committed to contributing to the scientific understanding of food allergy,” said Daniel Adelman, M.D., Chief Medical Officer of Aimmune. “Our Phase 3 program constitutes the largest dataset available in peanut-allergic patients and supports the exploration of fundamental immunologic mechanisms of desensitization and immunomodulation.”

Aimmune’s late-breaking abstract presented baseline characteristics from 583 peanut-allergic patients who were screened to determine eligibility for the Phase 3 PALISADE trial in North America. Among the inclusion criteria, a double-blind, placebo-controlled food challenge (DBPCFC) administered at screening allowed a progression of doses of peanut protein up to a dose of 100 mg (1 mg, 3 mg, 10 mg, 30 mg, and 100 mg). Subjects who reacted with dose-limiting symptoms at or before the 100 mg dose (“reactors”) were eligible for randomization into the trial. This unique dataset of screening DBPCFCs is the largest ever collected on peanut-allergic patients in the clinical trial context and yielded the following observations and insights:

  • 457 patients (78%) were reactors, who experienced dose-limiting symptoms in the DBPCFC at or before the 100 mg dose (median = 44 mg cumulative amount of peanut protein); 116 subjects (20%) were “non-reactors” who consumed all 144 mg in the DBPCFC with only mild symptoms or no symptoms at all; 10 subjects (2%) reacted to placebo
  • Reactors demonstrated higher baseline peanut-specific IgE (psIgE) and Ara h2-specific IgE levels and larger peanut skin prick test (SPT) wheal diameters than non-reactors, and psIgE appeared to provide the greatest utility to discriminate between reactors and non-reactors
  • The median psIgE in reactors was 70.2 kUA/L, compared with 5.3 kUA/L in non-reactors (a threshold psIgE of 19.25 kUA/L showed the greatest sensitivity and specificity for predicting reactors)
  • Sensitivity to peanut and severity of symptoms during screening DBPCFCs were not closely linked, and neither was associated with baseline immune parameters or age

“In general, our findings build on the published literature and highlight the clinical and immunologic heterogeneity among patients with peanut allergy,” said Dr. Adelman. “More specifically, insights on our PALISADE screening population are helping to guide our clinical development strategy and design of future AR101 clinical trials. In our PALISADE screening analysis, we saw that psIgE was a valuable predictor of whether or not patients would react at or before the 100 mg dose of peanut protein. For our upcoming RAMSES trial, entry will not require a food challenge but will be based on stringent enrollment criteria to ensure that patients are peanut allergic, including a clinical history, positive skin prick test and elevated peanut-specific IgE.”

Also at the AAAAI meeting, Blake Rust, Ph.D., and Erik Wambre, Ph.D., of the Benaroya Research Institute at Virginia Mason (BRI) presented data on peanut-specific effector and regulatory T cells in a blinded subset of samples from patients screened for PALISADE. Key findings from this work include:

  • Percent of activated CD4+ effector T cells were significantly higher after individuals underwent the DBPCFC as compared to their pre-challenge levels
  • At baseline, peanut-allergic individuals exhibit higher frequency of peanut-specific effector T cells relative to DBPCFC non-reactors. Peanut-allergic individuals exhibit low frequencies of peanut-specific regulatory T cells at baseline, but higher than those seen in DBPCFC non-reactors
  • Within the group of patients who reacted to the DBPCFC, two distinct immunophenotypes were observed as defined by mutually exclusive CRTH2 and CCR6 expression

“Based on these observations, we believe the absence of a food challenge in our RAMSES study not only reflects a real-world clinical setting but also has the potential to improve the tolerability profile of AR101 in early stages of dosing by removing exposure to high levels of peanut allergen that appear to prime the immune system prior to treatment,” continued Dr. Adelman. “In addition, we look forward to tracking the clinical outcomes of our Phase 3 patients to see whether the immunophenotypes observed at screening correlate with patient responses to AR101 therapy.”

The Aimmune Phase 3 PALISADE screening data were presented in the late-breaking abstract “Outcome of 583 entry double-blind placebo-controlled peanut challenges during screening for the PALISADE Phase 3 oral immunotherapy trial” (#L20, Vickery BP, et al.) and the abstract “Dual assessment of peanut-specific effector and regulatory T cells in patients undergoing oral immunotherapy” (#807, Rust B, et al.).

The Phase 2 adherence data, showing 95% adherence to daily at-home AR101 dosing in the randomized, double-blind, placebo-controlled ARC001 study, were presented in the abstract “At-home dosing adherence during characterized oral desensitization immunotherapy (CODIT) for peanut allergy” (#803, Jones S, et al.).

The posters associated with the abstracts are available at www.aimmune.com in the Events section under the News & Events tab.

About Aimmune Therapeutics

Aimmune Therapeutics, Inc., is a clinical-stage biopharmaceutical company developing treatments for life-threatening food allergies. The company’s Characterized Oral Desensitization ImmunoTherapy (CODIT™) approach is intended to achieve meaningful levels of protection by desensitizing patients with defined, precise amounts of key allergens. Aimmune’s first investigational biologic product using CODIT™, AR101 for the treatment of peanut allergy, has received the FDA’s Breakthrough Therapy Designation for the desensitization of peanut-allergic patients 4-17 years of age and is currently being evaluated in Phase 3 clinical trials. For more information, please see www.aimmune.com.

SOURCE: Aimmune Therapeutics