Blueprint Medicines Highlights AYVAKIT Long-Term Efficacy And Safety Data And Advances In Mast Cell Disease Research At 2024 AAAAI Annual Meeting

Author: Benzinga Newsdesk | February 23, 2024 09:04am

-- AYVAKIT data in patients with indolent systemic mastocytosis show durable efficacy and favorable safety supporting long-term treatment, consistent with real-world experience observed in commercial setting --

-- Preclinical data for BLU-808, a highly selective and potent oral wild-type KIT inhibitor with best-in-class potential, supports development in chronic urticaria and other mast cell diseases; on track to submit IND to FDA in Q2 2024 --

-- Breadth of data across 9 presentations, including 2 oral, highlight scientific and clinical leadership --

CAMBRIDGE, Mass., Feb. 23, 2024 /PRNewswire/ -- Blueprint Medicines Corporation (NASDAQ:BPMC) today announced PIONEER trial results highlighting the long-term efficacy and safety of AYVAKIT® (avapritinib) in patients with indolent systemic mastocytosis (ISM), as well as foundational preclinical data for BLU-808, an investigational highly selective and potent oral inhibitor of wild-type KIT. Blueprint Medicines will report a total of nine data presentations, including two oral presentations, reflecting the company's long-standing commitment to transform care for patients living with mast cell disorders. The datasets are being reported at the 2024 American Academy of Allergy, Asthma & Immunology (AAAAI) Annual Meeting being held February 23-26 in Washington, D.C.

"PIONEER data show that long-term treatment with AYVAKIT led to robust and durable clinical efficacy across a wide range of symptoms, and a well-tolerated safety profile that has remained remarkably consistent over time," said Becker Hewes, M.D., Chief Medical Officer at Blueprint Medicines. "These compelling long-term data, combined with the real-world experience of more than a thousand patients currently on therapy in the U.S., indicate our continued momentum in establishing AYVAKIT as a new standard of care for patients living with ISM. With an SM franchise anchored by AYVAKIT, and the opportunity to expand and extend our reach with elenestinib, Blueprint Medicines is transforming treatment across the spectrum of the disease and redefining what well-controlled means for patients."

AYVAKIT: Durable Symptom Impact and Well-Tolerated Safety Profile in Patients with ISM

Long-term data from the PIONEER trial show that AYVAKIT led to robust improvements across all symptom domains (skin, gastrointestinal, neurocognitive) at 24 weeks, with sustained benefits through 48 weeks. In addition, patients treated with placebo during the blinded portion of the trial had rapid and durable symptom improvements upon cross-over to AYVAKIT. Symptom improvements were assessed by the validated Indolent Systemic Mastocytosis Symptom Assessment Form (ISM-SAF). After 48 weeks of treatment with AYVAKIT, 35 percent of patients reduced or discontinued use of best supportive care medicines. As of the updated data cut, the last patient treated with AYVAKIT in the blinded portion of the trial reached the 48-week timepoint.

With a median patient follow-up of 18 months, the safety profile of AYVAKIT was consistent with previously reported results from the 6-month placebo-controlled portion of the trial, with no new safety signals observed. Most adverse events (AEs) were mild or moderate (Grade 1-2), and the most common treatment-related AEs (≥5 percent) were peripheral edema, headache, periorbital edema and nausea. The rate of treatment-related AEs leading to discontinuation remained low (3 percent).

BLU-808: An Investigational, Potent and Selective Wild-type KIT Inhibitor for Chronic Urticaria and Other Mast Cell Diseases

Mast cells play a critical frontline role in a healthy immune response; activation through KIT and other receptors leads to degranulation and release of downstream effectors that mediate inflammation. However, when mast cells are dysregulated, they are drivers of multiple common allergic and inflammatory diseases such as chronic urticaria, for which wild-type KIT is a clinically validated therapeutic target. BLU-808 is an investigational, highly selective and potent oral wild-type KIT inhibitor designed to enable tolerability and flexibility to tailor treatment based on disease severity and patient needs.

"The development of BLU-808 is another example of our proven track record of designing exquisitely selective molecules that inhibit important biologic targets. Specifically, our scientists engineered BLU-808 to potently target wild-type KIT, while maintaining a wide therapeutic index conducive to chronic treatment," said Percy Carter, Ph.D., Chief Scientific Officer at Blueprint Medicines. "The BLU-808 program highlights our focused efforts to scale our science in allergy/inflammation, leveraging our expertise in mast cell biology and fully integrated R&D and commercial capabilities. By targeting the root cause of a variety of inflammatory diseases, BLU-808 represents a potential best-in-class mast cell modulator that may benefit large patient populations with high medical needs."

In foundational preclinical data reported at AAAAI, BLU-808 demonstrated a best-in-class selectivity and potency profile in vitro. In multiple in vivo studies, BLU-808 treatment led to dose-dependent inhibition and depletion of mast cells. In addition, BLU-808 improved lung function in an ovalbumin-induced asthma model. Based on these data, Blueprint Medicines expects to submit an investigational new drug application for BLU-808 in the second quarter of 2024, and subsequently plans to initiate a Phase 1 study in healthy volunteers. The initial development focus for BLU-808 will be in chronic urticaria.

Blueprint Medicines' AAAAI data presentations are listed below. Copies of the data presentations are available in the "Science—Publications and Presentations" section of the company's website at www.BlueprintMedicines.com.

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