Midostaurin

导读上一期我们讲到RTKs的分类、结构功能，并以一个重要的家族—表皮生长因子受体（EGFR）家族RTK为例，阐述配体和受体的结合方式（学懂通路第一期）。本期我们对其他家族的RTKs进行概述。01血小板衍生生长因子 (PDGF) 受体及相关受体家族上图是血小板衍生生长因子（PDGF）受体家族配体与受体激活模式示意图。目前鉴定出能够激活PDGFR的配体主要有四种：PDGFA、PDGFB、PDGFC与PDGFD。它们通过二硫键形成具有活性的同源二聚体(AA, BB, CC、DD)以及异源二聚体（AB）。当二聚体配体与受体结合后，引起受体不同亚型（PDGFR-α, PDGFR-β）的二聚化（αα, ββ，αβ），进一步将信号传递到细胞内，引起胞内效应产生。研究发现，PDGF与肿瘤发生生长过程关系密切，尤其是能够促进肿瘤血管生成。PDGFR通路与另一种肿瘤血管生成有关的信号通路—VEGFR通路关系密切。涉及PDGFR的药物大多为双靶点或多靶点，例如Sunitinib、Axitinib、Cediranib 。此外，除了上述PDGF的受体（PDGFR-α, PDGFR-β）外，本家族还包括SCF、Flt-3LG 和M-CSF/IL-34的受体（参见上期表1）。注：SCF ：Stem Cell Factor干细胞因子，也称作：KITLG (即：KIT配体)；受体为：KIT/ SCFR；FLT3LG: FMSlike tyrosine kinase-3 ligand，FMS样酪氨酸激酶3配体；受体为 FLT3；MCSF: 巨噬细胞集落刺激因子（MCSF）和白介素- 34 (IL34) 受体均为 CSF1R；02血管内皮生长因子（VEGF）受体家族血管内表皮生长因子（VEGF）主要由VEGF-A、VEGF-B、VEGF-C、VEGF-D和胎盘生长因子PGF/PIGF 等5个成员组成（VEGF E和VEGF F是蛇毒来源，此处不作论述）。而血管内表皮生长因子受体（VEGFR）包括三种类型：VEGFR1, VEGFR2 及VEGFR3。VEGF与VEGFR的主要作用模式如上图所示。其中VEGFR-2主要表达在血管内皮细胞，是VEGF的主要受体，VEGFA/VEGFR-2是诱导血管生成的最主要通路。由于肿瘤细胞生长代谢旺盛，需要通过新生血管供应能量，因此靶向VEGF/VEGFR 通路是一种抑制肿瘤生长的思路。前面我们也提到，很多RTKs通路之间存在交叉，VEGFR也不例外。目前FDA批准的涉及VEGFR靶点的药物均为多靶点药物：分别为midostaurin（急性髓细胞性白血病、肥大细胞白血病）、lenvatinib（分化型甲状腺癌）、nintedanib（特发性肺纤维化）、axitinib（肾细胞癌）、regorafenib（结肠直肠癌、肺细胞癌、胃肠道间质瘤）、cabozantinib（肾细胞癌、肺细胞癌、髓甲状腺癌）、ponatinib（慢性粒细胞性白血病、急性淋巴细胞性白血病）、vandetanib（甲状腺癌）、pazopanib（肾细胞癌、软组织肉瘤）、sunitinib（肾细胞癌、胃肠道间质瘤、胰腺神经内分泌肿瘤）和sorafenib（甲状腺癌、肾细胞癌）。针对VEGF的单抗也已经批准上市，例如:贝伐珠单抗（Bevacizumab）能够高亲和力且特异性地结合VEGF，抑制肿瘤血管增生的作用，获批上市用于转移性结肠癌治疗。03胰岛素受体（INSR）家族胰岛素受体家族包括胰岛素受体( insulin receptor，INSR) ，胰岛素样生长因子受体( insulin-like growth factor receptor，IGFR)，胰岛素受体相关受体( insulin receptor-relatedreceptor，INSRR) 。胰岛素受体家族成员可以与各自的配体：胰岛素(Insulin，INS) 、胰岛素样生长因子( IGF-1或IGF-2)结合发挥激酶作用。配体INS、IGF1、IGF2与不同受体之间的作用模式图如上图所示。根据组织特异性，胰岛素受体（INSR）有A和B两种亚型，IGF-2和INS能够与许多上皮组织表达的INSR-A受体结合（诱导同源二聚化或与INSR-B异源二聚化)，促进细胞生长；而INSR-B是一种高度特异性的胰岛素受体，主要在INS敏感组织中表达，只有INS能够诱导INSR-B同源二聚体的产生，调节葡萄糖稳态。此外，IGF1和IGF2能够诱导IGF1R的同源二聚化，也可以诱导INSR（A或者B）与IGF1R的异源二聚化。写到这里肯定有读者要问：有没有IGF2R？其实是有的，但是IGF2R结合IGF2之后，并不能转录信号，反而引起通路抑制，因此我们这里就不提了。研究表明，INSR-A和IGF1R在肿瘤细胞高表达；PI3K途径（第四期介绍）是INS、IGF激活相应受体下游的主要通路。反之，IGF2R则表现出肿瘤抑制的功能。04成纤维细胞生长因子（FGF）及其受体成纤维细胞因子家族一共有18种细胞因子，而与之对应的是4种成纤维细胞因子受体（FGR1、FGR2、FGR3、FGR4）。FGF-FGFR的主要功能是将FGF信号转导到RAS-ERK和PI3K-AKT等途径的信号级联放大。FGR1、FGR2、FGR3都存在两种b、c亚型，在间质(结膜)组织或上皮组织表达。简易的作用模式图如上图，图中仅展示了7种FGF。FGFR的功能异常在多种肿瘤中发现，其中基因扩增、基因突变以及染色体重排是导致FGFR异常激活的主要原因。目前，单一针对FGFR的抑制剂很少，大多是多靶点抑制剂。05肝细胞生长因子(HGF)和c-MET受体肝细胞生长因子(HGF)主要通过细胞膜上的特异性受体c-MET发挥生物学作用。c-MET是原癌基因c-MET编码的具有自主磷酸化活性的跨膜受体，由50 KD的α亚基和145 KD的β亚基组成的异二聚体。HGF具有两个c-MET受体结合域，其前体经蛋白水解酶水解作用产生活性形式。成熟的HGF分子由分子量为96KD的α链和分子量为34KD的β链组成。HGF是由间质细胞分泌，但c-MET受体却主要在上皮细胞表达，故认为HGF是上皮-间质相互作用的介质。细胞癌变的一个典型标志是出现上皮-间质转化，而c-MET被认为在其中起到了关键驱动作用。研究发现，由于c-MET基因扩增、突变、染色体重排等导致c-MET在多种肿瘤中异常表达，而c-MET的不适当激活促进细胞增殖、细胞运动、侵袭性和血管生成，并与更具侵袭性的表型和较低的生存率相关。   06胶质细胞神经营养因子(GDNF)和RET受体胶质细胞神经营养因子（GDNF）家族包括 neurturin、persephin、artemin及 GDNF 四个成员。GDNF能够被胞外蛋白GFRα1/2/3/4特异性地结合,但由于GFRα1/2/3/4缺乏跨膜和胞内结构域，无法单独完成信号传导。因此，GFRα通过促进RET蛋白受体的磷酸化并使RET进入激活状态，激活下游通路。RET是由c-RET原癌基因编码的一种受体酪氨酸激酶，磷酸化的RET激活其下游的丝裂原活化蛋白激酶MAPK、P13激酶等，导致一系列胞内途径的激活，从而发挥GDNF家族神经营养因子的生理功能。RET的突变与II型多发性内分泌肿瘤相关，甲状腺髓样癌（MTC）中可观察到RET基因的突变，突变形式主要是点突变。总的来说，RET基因突变比较低频，主要的突变形式是与其他基因发生融合。07间变性淋巴瘤激酶受体（ALK）和白细胞受体酪氨酸激酶受体(LTK)ALK(间变性淋巴瘤激酶)和LTK(白细胞受体酪氨酸激酶)，最早是在淋巴瘤中被发现。在大部分正常细胞中ALK呈非活化状态，当ALK基因发生突变，常导致蛋白异常活化。ALK激活突变主要发生在神经母胶质瘤（neuroblastoma）中，在甲状腺癌、肺癌等肿瘤中也能检测到ALK激活型突变。由于没有鉴定出ALK的配体，长久以来ALK一直是一个孤儿受体（orphan receptor）（曾有研究人员鉴定出Pleiotrophin (PTN) 和Midkine (MK)可以与ALK结合，但是争议很大）。2015年1月，耶鲁大学医学院药理学系主任Joseph Schlessinger的研究团队在science发文称：herparin（肝素）是ALK真正的受体。目前已经上市的ALK 小分子抑制剂包括1代的克唑替尼（Crizotinib）；2代的塞瑞替尼（Ceritinib）、阿来替尼（Alectinib）、布加替尼（Brigatinib）；以及3代的劳拉替尼（Lorlatinib）。国产的2代药恩沙替尼（Ensartinib）也已经在去年上市。08血管生成素(ANG)和TIE受体血管生成通过人体中存在的诸多互补和复杂的信号途径调节的。其中主要的三条通路有：血管内皮生长因子 (VEGF)- 血管内皮生长因子受体 (VEGFR) 、血管生成素 (ANG)-TIE2 轴和 DLL4-Notch通路。ANG家族是唯一既含激动作用又含抑制作用的促血管生成因子，包含ANG1, 2 和 4三个成员，通过诱导内皮细胞上的酪氨酸激酶受体TIE-2同源二聚化，参与血管生成；同时，ANG-2也可以通过诱导TIE-1、TIE-2 异源二聚化，从而抑制血管生成。09肝配蛋白（Ephrins）及EPH受体促红细胞生成素产生肝细胞受体 (Eph)及其配体ephrins作为酪氨酸蛋白激酶受体家族最大的亚群，在细胞黏附、定位、迁移和分化过程中起关键作用。Ephrins可分为A、B两类，对应两类EPH受体，其相互作用模式目前还未完全研究清楚。EPH受体介导的分子内信号传递主要由细胞内酪氨酸激酶ABL及Rho GTP酶的鸟苷酸交换因子介导，对细胞的增值/迁徙产生激活或抑制作用。10神经营养酪氨酸激酶受体（NTRK）/ 原肌凝蛋白受体激酶(TRK )Tropomyosin receptor kinase （原肌球蛋白受体激酶，TRK ），也称作Neurotrophin receptor kinase（神经营养受体酪氨酸激酶，NTRK），是一类受体酪氨酸激酶家族，包括分别由NTRK1、NTRK 2和NTRK3基因编码的TrkA、TrkB和TrkC三种受体。在健康组织中，NTRK与神经生长因子（NGF）等配体组成的通路参与神经系统的发育和功能以及细胞存活，在健康组织中起重要的作用。在某些情况下，NTRK 基因与一个不相关的基因融合，导致 Trk 信号不受控制地激活，从而导致癌症发生。在常见的癌症如肺癌，乳腺癌，结直肠癌中，只有1%~5%的患者存在NTRK 基因融合，而一些罕见的癌症，比如婴儿纤维肉瘤和分泌型乳腺癌，存在NTRK融合的频率却高达90%~100%。针对NTRK融合突变上市的药物及在研的药物临床效果显著，因此NTRK也称为“钻石”基因。目前，全球上市的用于治疗NTRK融合基因实体瘤的药物有两个，分别是拜耳/LOXO的拉罗替尼（2018年11月被FDA批准上市）以及罗氏的恩曲替尼（2019年8月被FDA批准上市）。11TAM受体 TAM受体包括三个成员，即：TYRO3、AXL和MERTK受体。与之对应的是两个配体：GAS6和PROS1。该受体家族的基因最初从白血病细胞中克隆出来的，并被认为是原癌基因，其表达水平与实体肿瘤，尤其是胶质母细胞瘤的恶性程度有关，但未发现基因突变或重排。12盘状结构域受体（DDR受体）盘状结构域受体（discoidindomain receptors, DDRs）是一种受体型蛋白酪氨酸激酶，包括 DDR1 和 DDR2，该类蛋白的胞外结构域上含有一个类似于盘基网柄菌凝集素盘状结构域 1的结构，也称盘状结构域（DR 区）；其次，在 DR 区与跨膜区之间有很长的近膜区（JM区）。     DDRs 在人和小鼠组织中表达广泛，能与多种胶原蛋白特异性结合并被激活,参与多种疾病过程,如肿瘤、炎性反应和纤维化的发生发展。13受体酪氨酸激酶样孤儿受体（ROR）受体酪氨酸激酶样孤儿受体（ROR）家族包括ROR1、ROR2两个受体，与核受体中的ROR家族不同，ROR是一类膜受体，由于ROR蛋白最初发现时配体未知，所以被定义为孤儿受体 。有研究表明：ROR1通过识别WNT蛋白介导的非经典WNT信号通路传递，在多种生理过程中发挥重要作用，包括调节细胞分裂、增殖、迁移和细胞趋化等。14ROS 受体ROS受体是由原癌基因c-ROS编码的受体酪氨酸激酶，其配体未知。ROS基因重排在胶质母细胞瘤、非小细胞肺癌等多个恶性肿瘤中发现，导致激酶持续激活，上调多种下游信号通路，导致细胞持续增殖生。此外，ROS基因还与多个基因发生融合突变。参考文献：[1] Robert, Jacques. Textbook of Cell Signalling in Cancer [M]. Springer International Publishing, 2015.[2]  Wagener C , Stocking C , O. Müller. Cancer Signaling - From Molecular Biology to Targeted Therapy[M]. 2017.[3] Amanda H . Cancer cell signalling[M]. Wiley Blackwell, 2014.部分信息图片来源于网络，侵权联系后台删除。下期预告第三期：MAPK通路；第三期：PI3K通路；感谢支持，欢迎“分享”和“点赞”

-- Breadth of presentations, including one oral and two flash talks, showcase Blueprint Medicines' leadership role in advancing care for patients with systemic mastocytosis -- CAMBRIDGE, Mass. , June 12, 2025 /PRNewswire/ -- Blueprint Medicines Corporation (Nasdaq: BPMC) today announced data presentations reflecting over a decade of collaboration with clinical experts and patient advocates to transform the treatment of systemic mastocytosis (SM). Key results continue to position AYVAKIT®/AYVAKYT® (avapritinib) as the durable standard of care across indolent and advanced SM, and highlight the real-world burden of the disease, reinforcing the importance of treating with a therapy that addresses the root cause of SM. These data will be reported at the 2025 European Hematology Association (EHA2025) Hybrid Congress , being held June 12 to 15 in Milan, Italy , and the European Academy of Allergy and Clinical Immunology (EAACI) Congress 2025, being held June 13 to 16 in Glasgow, United Kingdom . "Our presentations feature large patient populations from the PIONEER, PATHFINDER and EXPLORER trials, with follow-up reaching up to five years in ISM and up to 6.5 years in advanced SM, reflecting both the favorable long-term benefits of AYVAKIT and the unprecedented datasets we have amassed over time," said Becker Hewes , M.D., Chief Medical Officer at Blueprint Medicines . "AYVAKIT has shown transformative clinical outcomes for patients across the spectrum of SM, including sustained disease control in ISM and prolonged survival in advanced SM. These compelling results have translated into real-world practice, with clinicians expanding their view of who is an appropriate candidate for disease-modifying therapy after positive AYVAKIT experiences, and treatment durations trending toward multiple years." PIONEER Three-Year Data: Durable Clinical Benefits and Consistent Safety Profile with Long-Term AYVAKIT Use in ISM As previously presented,1 AYVAKIT demonstrated robust improvements through 144 weeks in overall symptom and symptom domain measures (skin, gastrointestinal, neurocognitive) representative of real-world patient impacts. AYVAKIT showed a well-tolerated safety profile and a low discontinuation rate due to treatment-related adverse events (TRAEs; 3 percent) with a median of three years of exposure, and some patients out to five years on therapy. Common TRAEs included low-grade edemas, headache and nausea. In newly reported data, AYVAKIT showed sustained clinical benefits across quality-of-life measures that reflect general health status and are broadly recognized by allergists/immunologists, validating previously presented results from the disease-specific, Mastocytosis Quality of Life (MC-QoL) questionnaire. This data presentation follows the May 2025 online publication of PIONEER two-year efficacy and safety data in The Journal of Allergy and Clinical Immunology : In Practice. PATHFINDER/EXPLORER Multi-Year Data: Long-Term Survival Benefits of AYVAKIT in Advanced SM AYVAKIT showed prolonged overall survival (OS) in PATHFINDER and EXPLORER, when indirectly compared to real-world data for midostaurin from the German Registry on Disorders of Eosinophils and Mast Cells (GREM). AYVAKIT led to meaningful survival benefits in patients across all prognostic categories (low, intermediate and high risk), per the Revised Mutation-Adjusted Risk Score (MARS-R) – a new OS risk assessment tool for advanced SM. Conducted in collaboration with University Hospital Mannheim, the analyses validate the MARS-R tool's ability to assess OS risks in advanced SM patients treated with AYVAKIT or midostaurin, using clinical and genetic parameters. The MARS-R was developed to inform physician care decisions based on individual patient needs. PRISM Data: Substantial Disease Burden Across Broad Population of Patients with ISM PRISM is one of the largest studies characterizing the impact of SM from both patient and clinical perspectives. Across the spectrum of disease severity, patients with ISM experienced physical, social and emotional challenges that caused meaningful disruption to their daily lives. Patients reported a broad constellation of disease-related impacts, including limitations to physical activities, work/college and relationships; problems with pain/discomfort and anxiety/depression; and adjustments in their daily lives to avoid certain foods, extended sun exposure and smells. Data Presentations EHA2025 Congress Oral Presentation: The Revised Mutation-Adjusted Risk Score (MARS-R) for Predicting Overall Survival in Patients with Advanced Systemic Mastocytosis Treated with Midostaurin or Avapritinib (Abstract S216) Poster Presentation: Blood-Based Proteomics for Deeper Insights Into Indolent Systemic Mastocytosis: The PIONEER Trial Experience (Abstract PS1838) Poster Presentation: High Accuracy of Peripheral Blood Testing Using Machine Learning–Derived Predictive Models to Distinguish Advanced from Indolent Systemic Mastocytosis: Analysis of Avapritinib and Elenestinib Trial Data (Abstract PF1310) Publication-Only Abstract: Phase 2/3 HARBOR Study of Elenestinib in ISM: A Trial-in-Progress Update of Novel Endpoints and Biomarkers Aimed at Evaluating Disease Modification (Abstract PB3108) EAACI Congress 2025 Flash Talk Presentation: Favorable Benefit-Risk Profile of Avapritinib in Indolent Systemic Mastocytosis Is Maintained After 3 Years of Therapy: Longer-Term Analysis of the PIONEER Study (Abstract 000621) Flash Talk Presentation: The Socio-Emotional Impact of Indolent Systemic Mastocytosis: Insights from the PRISM Survey (Abstract 000488) Poster Presentation: The Phase 2/3 Study of Elenestinib, a Highly Potent and Selective Tyrosine Kinase Inhibitor, in Patients with Indolent Systemic Mastocytosis (Abstract 001121) Data presentations are being made available in the "Science―Publications and Presentations" section of the company's website at www.blueprintmedicines.com. 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, pruritus, 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 AYVAKIT (avapritinib) is the first and only medicine approved by the U.S. Food and Drug Administration (FDA) to treat the root cause of SM. It was FDA approved for the treatment of advanced SM in June 2021 and ISM in May 2023. It now is indicated in 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. The medicine is approved in the EU as AYVAKYT for the treatment of adults with ISM with moderate to severe symptoms inadequately controlled on symptomatic treatment, adults with ASM, SM-AHN or 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). Globally, the medicine is approved for one or more indications in 16 countries, including China where it is marketed by CStone Pharmaceuticals, paying tiered percentage royalties on sales. 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. 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. If contraception requires estrogen, limit ethinyl estradiol to ≤20 mcg unless a higher dose is necessary. To report suspected adverse reactions, contact Blueprint Medicines Corporation at 1-888-258-7768 or the FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. AYVAKIT is available in 25-mg, 50-mg, 100-mg and 200-mg tablets. Please click here to see the full U.S. 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 SM in the U.S. and Europe. Leveraging our established research, development, and commercial capability and infrastructure, we 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 and 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 Blueprint Medicines' leadership role and its ability to transform treatment across the spectrum of SM, including sustained disease control in ISM and prolonged survival in advanced SM; AYVAKIT/AYVAKYT's position as the durable standard of care and clinicians' view of appropriate candidates and treatment duration; plans and expectations for Blueprint Medicines' current or future approved drugs and drug candidates; the potential benefits of any of Blueprint Medicines' current or future approved drugs or drug candidates in treating patients; and Blueprint Medicines' strategy, goals, business plans and focus. The words "aim," "may," "will," "could," "would," "should," "expect," "plan," "anticipate," "intend," "believe," "estimate," "predict," "project," "potential," "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 Blueprint Medicines' ability and plans in continuing to build out and expand a commercial infrastructure, and successfully launching, marketing and selling current or future approved products; Blueprint Medicines' ability to successfully expand the approved indications for AYVAKIT/AYVAKYT or obtain marketing approval for AYVAKIT/AYVAKYT in additional geographies in the future; the delay of any current or planned clinical trials or the development of Blueprint Medicines' current or future drug candidates; Blueprint Medicines' advancement of multiple early-stage efforts; Blueprint Medicines' 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 preclinical and clinical results for Blueprint Medicines' drug candidates, which 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 patient enrollment rates; actions of regulatory agencies, which may affect the initiation, timing and progress of clinical trials; Blueprint Medicines' ability to obtain, maintain and enforce patent and other intellectual property protection for AYVAKIT/AYVAKYT or any drug candidates it is developing; Blueprint Medicines' ability to successfully expand its operations, research platform and portfolio of therapeutic candidates, and the timing and costs thereof; the success of Blueprint Medicines' current and future collaborations, financing arrangements, partnerships or licensing arrangements; and the ability of the parties to consummate the proposed merger between Blueprint Medicines and Sanofi on the timeline anticipated or at all, including the occurrence of any event, change or other circumstance that could give rise to the termination of the merger. 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 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 Blueprint Medicines' 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, Blueprint Medicines explicitly disclaims any obligation to update any forward-looking statements. Footnote 1 Reported at the 2025 American Academy of Allergy, Asthma & Immunology (AAAAI) / World Allergy Organization (WAO) Joint Congress Trademarks Blueprint Medicines , AYVAKIT, AYVAKYT and associated logos are trademarks of Blueprint Medicines Corporation. View original content to download multimedia:https://www.prnewswire.com/news-releases/blueprint-medicines-announces-data-reinforcing-sustained-clinical-efficacy-and-well-tolerated-safety-profile-of-long-term-ayvakitayvakyt-avapritinib-treatment-at-2025-eha-and-eaaci-congresses-302480690.html SOURCE Blueprint Medicines Corporation Media Contact, Andrew Law, +1 (617) 844-8205, media@blueprintmedicines.com; Investor Contact: Jenna Cohen, +1 (857) 209-3147, ir@blueprintmedicines.com