Blueprint Medicines Corp BPMC

-- Breadth of data across 7 presentations, including 4 oral, reflects continued leadership in advancing the understanding and treatment of systemic mastocytosis --

CAMBRIDGE, Mass., May 30, 2024 /PRNewswire/ -- Blueprint Medicines Corporation (Nasdaq: BPMC) today announced multiple upcoming datasets across two key conferences that reinforce the significant real-world burden of systemic mastocytosis (SM), and highlight the durable clinical outcomes of AYVAKIT^®/AYVAKYT^® (avapritinib) across the spectrum of the disease. The presentations, which build on over a decade of pioneering research with clinical experts and patient advocates, will be reported at the following meetings:

• European Academy of Allergy and Clinical Immunology (EAACI) Congress 2024, May 31 to June 3
• European Hematology Association 2024 (EHA24) Hybrid Congress, June 13 to 16

"Our data reinforce the efficacy and safety of prolonged durations of AYVAKIT therapy, and highlight the urgency to diagnose and treat patients living with systemic mastocytosis," said Becker Hewes, M.D., Chief Medical Officer at Blueprint Medicines. "Based on unprecedented clinical datasets and the strength of our ongoing commercial launches in the U.S. and Europe, we have made significant progress toward establishing AYVAKIT as the global standard of care. We look forward to continued collaboration with the SM community to redefine what 'well-controlled' means for patients across the spectrum of the disease."

PIONEER: With a median follow-up of more than two years, AYVAKIT showed durable efficacy and a favorable safety profile in patients with ISM. Safety data were consistent for the small number of patients (~10 percent) who dose escalated to 50 mg once daily.

• AYVAKIT led to sustained improvements in total symptom score and all symptom domains (assessed by the Indolent Systemic Mastocytosis Symptom Assessment Form), as well as quality of life (assessed by the Mastocytosis Quality of Life Score).
• AYVAKIT had a favorable safety and tolerability profile, with patients receiving up to four-plus years of treatment. The most common treatment-related adverse event (AE) was edema, with the majority reported as Grade 1, and the rate of treatment-related AEs leading to discontinuations remained low (3 percent).

PATHFINDER: With a median follow-up of more than three years, the median overall survival (OS) for AYVAKIT has not been reached in patients with advanced SM.

• The median OS has not yet been reached regardless of disease subtype or prior therapy, reflecting the durable clinical benefits of AYVAKIT. In advanced SM, the historical median OS has ranged from less than six months to about 3.5 years.¹
• The overall response rate² was 73 percent, and the rate of complete remission with full or partial hematologic recovery was 29 percent.
• AYVAKIT had a favorable benefit/risk profile consistent with previously reported data. Common treatment-related AEs were periorbital edema, thrombocytopenia, peripheral edema and anemia.

PRISM: The largest European study to evaluate patient perspectives in SM reinforces the significant burden of disease, highlighting the urgency to treat.

• The Perceptions, Realities & Insights on SM (PRISM) Survey – a collaborative research project led by Blueprint Medicines and involving disease experts and patient organizations across seven countries – further illustrates the substantial impact of SM on patients' quality of life.
• Patients reported debilitating symptoms, impaired physical and mental health functioning, meaningful impacts on the ability to work, and significant polypharmacy use.
• Healthcare providers broadly recognized the burden of SM; 65 percent reported the disease affected patients' lives "quite a bit" or "a great deal," and 58 percent reported patients lost employment opportunities.

At the start of their respective oral and poster sessions, data presentations will be made available in the "Science―Publications and Presentations" section of Blueprint Medicines' website.

EAACI Congress 2024

• Oral Presentation: Safety of Avapritinib in Indolent Systemic Mastocytosis (ISM): Longer Term Follow-up from the PIONEER Study (Abstract 000223)
• Oral Presentation: The Burden of Indolent Systemic Mastocytosis in Europe: Results from the PRISM Patient Survey (Abstract 000405)
• Oral Presentation: Identifying KIT D816V Mutation in Patients with Evidence of Systemic Mast Cell Activation (MCA) and Enriched for Hereditary Alpha-Typtasemia (HaT): Results from the PROSPECTOR Clinical Trial (Abstract 000403)
• Poster Presentation: Healthcare Provider Perspectives on Management of European Patients with Systemic Mastocytosis (Abstract 000413)

EHA2024 Congress

• Oral Presentation: Avapritinib in Patients with Advanced Systemic Mastocytosis (AdvSM): Efficacy and Safety Analysis from the Phase 2 PATHFINDER Study with 3-Year Follow-up (Abstract S224)
• Poster Presentation: The Burden of Systemic Mastocytosis in Europe: Results from the PRISM Patient Survey (Abstract P1676)
• ePoster Presentation: Patient Diagnostic Journey of Systemic Mastocytosis in Europe: Results from the PRISM Survey (Abstract P2292)

About Systemic Mastocytosis

Systemic mastocytosis (SM) is a rare disease driven by the KIT D816V mutation in about 95 percent of cases. Uncontrolled proliferation and activation of mast cells result in chronic, severe and often unpredictable symptoms across multiple organ systems. The vast majority of those affected have indolent systemic mastocytosis (ISM). A broad range of symptoms, including anaphylaxis, maculopapular rash, pruritis, diarrhea, brain fog, fatigue and bone pain, frequently persist in patients with ISM despite treatment with multiple symptom-directed therapies. This burden of disease can lead to a profound, negative impact on quality of life. Patients often live in fear of severe, unexpected symptoms, have limited ability to work or perform daily activities, and isolate themselves to protect against unpredictable triggers. Until 2023, there were no approved therapies for the treatment of ISM.

A minority of patients have advanced SM, which encompasses a group of high-risk SM subtypes including aggressive SM (ASM), SM with an associated hematological neoplasm (SM-AHN) and mast cell leukemia (MCL). In addition to mast cell activation symptoms, advanced SM is associated with organ damage due to mast cell infiltration and poor survival.

About AYVAKIT (avapritinib)

AYVAKIT (avapritinib) is approved by the U.S. Food and Drug Administration (FDA) for the treatment of three indications: adults with ISM, adults with advanced SM, including ASM, SM-AHN and MCL, and adults with unresectable or metastatic gastrointestinal stromal tumor (GIST) harboring a PDGFRA exon 18 mutation, including PDGFRA D842V mutations. Under the brand name AYVAKYT (avapritinib), this medicine is approved by the European Commission for the treatment of adults with ISM with moderate to severe symptoms inadequately controlled on symptomatic treatment, adults with ASM, SM-AHN and MCL, after at least one systemic therapy, and adults with unresectable or metastatic GIST harboring the PDGFRA D842V mutation. The therapy is not recommended for the treatment of patients with low platelet counts (less than 50,000/µL).

Please click here to see the full U.S. Prescribing Information for AYVAKIT, and click here to see the European Summary of Product Characteristics for AYVAKYT.

To learn about ongoing or planned clinical trials, contact Blueprint Medicines at medinfo@blueprintmedicines.com or 1-888-BLU-PRNT (1-888-258-7768). Additional information is available at blueprintclinicaltrials.com or clinicaltrials.gov.

Important Safety Information

Intracranial Hemorrhage—Serious intracranial hemorrhage (ICH) may occur with AYVAKIT treatment; fatal events occurred in <1% of patients. Overall, ICH (eg, subdural hematoma, ICH, and cerebral hemorrhage) occurred in 2.9% of 749 patients who received AYVAKIT in clinical trials. In Advanced SM patients who received AYVAKIT at 200 mg daily, ICH occurred in 2 of 75 patients (2.7%) who had platelet counts ≥50 x 10⁹/L prior to initiation of therapy and in 3 of 80 patients (3.8%) regardless of platelet counts. In ISM patients, no events of ICH occurred in the 246 patients who received any dose of AYVAKIT in the PIONEER study.

Monitor patients closely for risk factors of ICH which may include history of vascular aneurysm, ICH or cerebrovascular accident within the prior year, concomitant use of anticoagulant drugs, or thrombocytopenia.

Symptoms of ICH may include headache, nausea, vomiting, vision changes, or altered mental status. Advise patients to seek immediate medical attention for signs or symptoms of ICH.

Permanently discontinue AYVAKIT if ICH of any grade occurs. In Advanced SM patients, a platelet count must be performed prior to initiating therapy. AYVAKIT is not recommended in Advanced SM patients with platelet counts <50 x 10⁹/L. Following treatment initiation, platelet counts must be performed every 2 weeks for the first 8 weeks. After 8 weeks of treatment, monitor platelet counts every 2 weeks or as clinically indicated based on platelet counts. Manage platelet counts of <50 x 10⁹/L by treatment interruption or dose reduction.

Cognitive Effects—Cognitive adverse reactions can occur in patients receiving AYVAKIT and occurred in 33% of 995 patients overall in patients who received AYVAKIT in clinical trials including: 28% of 148 Advanced SM patients (3% were Grade ≥3), and 7.8% of patients with ISM who received AYVAKIT + best supportive care (BSC) versus 7.0% of patients who received placebo + BSC (<1% were Grade 3). Depending on the severity and indication, withhold AYVAKIT and then resume at same dose or at a reduced dose upon improvement, or permanently discontinue.

Photosensitivity—AYVAKIT may cause photosensitivity reactions. In all patients treated with AYVAKIT in clinical trials (n=1049), photosensitivity reactions occurred in 2.5% of patients. Advise patients to limit direct ultraviolet exposure during treatment with AYVAKIT and for one week after discontinuation of treatment.

Embryo-Fetal Toxicity—AYVAKIT can cause fetal harm when administered to a pregnant woman. Advise pregnant women of the potential risk to a fetus. Advise females and males of reproductive potential to use an effective method of contraception during treatment with AYVAKIT and for 6 weeks after the final dose of AYVAKIT. Advise women not to breastfeed during treatment with AYVAKIT and for 2 weeks after the final dose.

Adverse Reactions—The most common adverse reactions (≥20%) in patients with Advanced SM were edema, diarrhea, nausea, and fatigue/asthenia.

The most common adverse reactions (≥10%) in patients with ISM were eye edema, dizziness, peripheral edema, and flushing.

Drug Interactions—Avoid coadministration of AYVAKIT with strong or moderate CYP3A inhibitors. If coadministration with a moderate CYP3A inhibitor cannot be avoided in patients with Advanced SM, reduce dose of AYVAKIT. Avoid coadministration of AYVAKIT with strong or moderate CYP3A inducers.

To report suspected adverse reactions, contact Blueprint Medicines Corporation at 1-888-258-7768 or the FDA at 1-800-FDA-1088 or http://www.fda.gov/medwatch.

Please click here to see the full Prescribing Information for AYVAKIT.

About Blueprint Medicines

Blueprint Medicines is a global, fully integrated biopharmaceutical company that invents life-changing medicines. We seek to alleviate human suffering by solving important medical problems in two core focus areas: allergy/inflammation and oncology/hematology. Our approach begins by targeting the root causes of disease, using deep scientific knowledge in our core focus areas and drug discovery expertise across multiple therapeutic modalities. We have a track record of success with two approved medicines, including AYVAKIT^®/AYVAKYT^® (avapritinib) which we are bringing to patients with systemic mastocytosis (SM) in the U.S. and Europe. Leveraging our established research, development, and commercial capability and infrastructure, we now aim to significantly scale our impact by advancing a broad pipeline of programs ranging from early science to advanced clinical trials in mast cell diseases including SM and chronic urticaria, breast cancer and other solid tumors. For more information, visit www.BlueprintMedicines.com and follow us on X (formerly Twitter; @BlueprintMeds) and LinkedIn.

Cautionary Note Regarding Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation: statements regarding plans, strategies, timelines and expectations for Blueprint Medicines' operations, including its expectations for our current or future approved drugs and drug candidates; the potential benefits of AYVAKIT/AYVAKYT or any of our current or future drug candidates in treating patients; the strength of the AYVAKIT/AYVAKYT launches in the U.S. and Europe; and Blueprint Medicines' ability to establish AYVAKIT/AYVAKYT as the global standard of care for the treatment of SM. The words "aim," "may," "will," "could," "would," "should," "expect," "plan," "anticipate," "intend," "believe," "estimate," "predict," "project," "potential," "opportunity," "continue," "target" and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Any forward-looking statements in this press release are based on management's current expectations and beliefs and are subject to a number of risks, uncertainties and important factors that may cause actual events or results to differ materially from those expressed or implied by any forward-looking statements contained in this press release, including, without limitation, risks and uncertainties related to: the delay of any current or planned clinical trials or the development of the company's current or future drug candidates; the company's ability to successfully demonstrate the safety and efficacy of its drug candidates and gain approval of its drug candidates on a timely basis, if at all; the possibility that preclinical and clinical results for the company's drug candidates may not support further development of such drug candidates either as monotherapies or in combination with other agents or may impact the anticipated timing of data or regulatory submissions; the timing of the initiation of clinical trials and trial cohorts at clinical trial sites and the possibility patient enrollment rates may be delayed or slower than anticipated; the actions of regulatory agencies and how this may affect the initiation, timing and progress of clinical trials; the company's ability to obtain, maintain and enforce patent and other intellectual property protection for its products and current or future drug candidates it is developing; and the success of the company's current and future collaborations, partnerships or licensing arrangements. These and other risks and uncertainties are described in greater detail in the section entitled "Risk Factors" in Blueprint Medicines' filings with the Securities and Exchange Commission (SEC), including Blueprint Medicines' most recent Annual Report on Form 10-K, as supplemented by its most recent Quarterly Report on Form 10-Q and any other filings that Blueprint Medicines has made or may make with the SEC in the future. Any forward-looking statements contained in this press release represent the company's views only as of the date hereof and should not be relied upon as representing its views as of any subsequent date. Except as required by law, the company explicitly disclaims any obligation to update any forward-looking statements contained in this press release as a result of new information, future events or otherwise. Accordingly, readers are cautioned not to place undue reliance on these forward-looking statements.

Footnotes

¹ Sperr WR, Kundi M, Alvarez-Twose I, et al. International prognostic scoring system for mastocytosis (IPSM): a retrospective cohort study. Lancet Haematol. 2019;6(12):e638-e649.

² Treatment response was defined as complete remission with full or partial hematologic recovery, partial remission or clinical improvement.

Trademarks

Blueprint Medicines, AYVAKIT, AYVAKYT and associated logos are trademarks of Blueprint Medicines Corporation.

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