On July 18, 2025, Sanofi officially finalized its $9.1 billion acquisition of Blueprint Medicines, a deal aimed at expanding its immunology portfolio and strengthening its position in precision therapies for rare and immune-related diseases.
Under the agreement, Sanofi gains global rights to AYVAKIT® (avapritinib), a treatment for rare immunological diseases approved in both the U.S. and EU. The company will also gain access to elenestinib, an experimental oral drug being tested to treat a rare blood disorder called systemic mastocytosis, and BLU-808, another early-stage treatment designed to target inflammation caused by overactive immune cells known as mast cells.
Beyond expanding its rare immunology pipeline, the acquisition also reflects the company’s strategy to diversify revenue sources beyond DUPIXENT® (dupilumab), its top-selling immunology product. This comes amid the company’s projected loss from Dupixent’s impending market exclusivity expiration in 2031. With this acquisition, Sanofi reinforces its long-term growth strategy by securing high-value assets aligned with its R&D priorities.
Why Blueprint Medicines?
Founded in 2011, Blueprint Medicines is a global biopharmaceutical company specializing in the development of targeted therapies in allergy, inflammation, oncology, and hematology. Its expertise in developing treatments for systemic mastocytosis supports progress in therapies for rare immunological disorders, amid growing interest in the broader immunology market.
Industry forecasts estimate that the global immunology market was valued at $108.4 billion in 2024 and projected to reach $286.38 billion by 2034, with a CAGR of 10.20% from 2025 to 2034. With Sanofi’s goal of improving their immunology R&D and becoming a leading immunology company, this market outlook reinforces the strategic rationale behind its acquisition of Blueprint Medicines.
The role of Ayvakit in Blueprint’s portfolio
AYVAKIT (avapritinib) is a specialized medicine designed to treat certain rare diseases, including gastrointestinal stromal tumors (GIST) and a blood disorder called systemic mastocytosis (SM). It is the first and only FDA-approved treatment for both aggressive and milder forms of SM, offering patients a therapy that can change the course of the disease rather than just managing symptoms.
As of the first quarter of 2025, Ayvakit generated $149.4 million in net product revenues, marking a 62% increase from 2024. With global sales projected to reach $2 billion by 2030, Ayvakit® is positioned as a commercial asset in Blueprint Medicines’ rare immunology portfolio, which is now under Sanofi’s ownership following the acquisition.
In this article, we will explore Blueprint Medicines’ patenting activity and highlight filings related to its precision oncology programs, including KIT inhibitors and RET-targeted therapies.
Blueprint Medicines: Patenting Activity
Blueprint Medicines’ global patent activity rose sharply in 2019, coinciding with the launch of its “2020 Blueprint” strategic plan. The two-year strategy aimed to transition the company from a single-asset biotech into a fully integrated global commercial business. In line with the goal of producing two marketed drugs and submitting four marketing applications, Blueprint significantly expanded its clinical programs, accelerated late-stage development, and strengthened its intellectual property portfolio. These efforts led to regulatory milestones, including FDA accelerated approval for Ayvakit® and breakthrough therapy designation for BLU-667 (now Gavreto®).
The peak in Blueprint’s patent filings in 2021 was then driven by the commercialization of these products as the company sought to extend their market exclusivity through patents on new formulations, dosing regimes, and international filings. The acquisition of Lengo Therapeutics further contributed to this surge by adding novel pipeline assets to the company, such as LNG-451, which prompted additional filings to secure IP rights.
Blueprint Medicines: Top Jurisdictions
The majority of Blueprint Medicines’ patent activity is filed under the PCT system, reflecting a strong international IP protection strategy. This approach aligns with the growing international demand for effective cancer treatments, as the global oncology market is projected to reach $803.81 billion by 2034. This is followed closely by patent filings in the United States, highlighting the importance of securing IP protection in the world’s largest pharmaceutical market and the major center for drug approval and market entry.
Meanwhile, as the largest pharmaceutical market in the Asia-Pacific region and the second largest globally, China follows as the next most active jurisdiction for patent filings. The European Patent Office (EPO) follows closely, reinforcing the company’s commitment to securing protection across major global markets.
Blueprint Medicines: Top Law Firms
Blueprint Medicines maintains a strong international presence through a diverse network of law firms that manage its patent filings across key regions. This includes prominent representation in China (King & Wood Mallesons), Europe (Mathys & Squire), Israel (Reinhold Cohn & Partners), United States (McCarter & English) and Canada (Marks & Clerk). Notably, most of Blueprint’s patent filings in China have been handled by Chen Wenping of King & Wood Mallesons. In addition, the company’s legal representation in Japan is primarily handled by Miyamae Toru, Yamamoto Osamu, Matsuo Junichi, and Kunieda Yukiko from Yuasa & Hara.
Blueprint Medicines: Top Technology Areas
Blueprint Medicines’ patent portfolio reflects a strong focus on pharmaceutical and chemical innovation, which are primarily centered on heterocyclic compounds (C07D). This is closely followed by classifications related to therapeutic applications (A61P) and preparations for medical, dental, or toiletry use (A61K), highlighting a commitment to drug development and healthcare solutions. Additional filings in general organic chemistry methods and equipment (C07B), as well as acyclic or carbocyclic compounds (C07C), point to broader chemical synthesis capabilities that support the company’s therapeutic pipeline and expansion into novel treatment areas.
Core Patents driving KIT and RET-Targeted therapies
Blueprint Medicines has secured key patents around its targeted cancer therapies, focusing on innovations in KIT and RET inhibition. These filings protect the company’s core drug designs and play a major role in supporting its lead products and long-term strategy in precision oncology.
Patent-protected solid forms of avapritinib
U.S. Patent No. 12,060,354 protects several stable crystalline forms of avapritinib, a drug developed by Blueprint Medicines to treat rare cancers caused by genetic mutations, such as gastrointestinal stromal tumors (GIST) and systemic mastocytosis. These forms enhance the drug’s stability, manufacturability, and dosing consistency, which are important for treating patients whose genetic alterations in cancer cells make them resistant to standard therapies.
To support large-scale and dependable drug production, the patent describes solid forms of avapritinib that are designed for pharmaceutical use. One version, called Form A, is especially important because it is stable and has clear, consistent physical traits, such as a sharp melting point and a unique crystal pattern. These qualities make it a good choice for making reliable cancer medications that can be stored long-term and perform consistently in patient treatments.
The patent, titled “Crystalline forms of (S)-1-(4-fluorophenyl)-1-(2-(4-(6-(1-methyl-1H-pyrazol-4-yl)pyrrolo[2,1-f][1,2,4]triazin-4-yl)piperazinyl)-pyrimidin-5-yl)ethan-1-amine and methods of making”, was filed on January 20, 2021, and was granted on August 13, 2024. The inventors are Joshua Waetzig, and Gordon Wilkie, while legal representation was provided by David Conlin, Basam Nabulsi, Thomas Hoover, et al. from McCarter & English.
Targeted dosing regimen for indolent systemic mastocytosis
Indolent systemic mastocytosis is the most common subtype of SM, accounting for 90% of total recorded cases. However, effective treatment remains a challenge due to the high prevalence of KIT D816V mutation in the mast cells, making the disease more resistant to many existing therapies.
U.S. Patent No. 12,252,494 focuses on the safe and effective oral administration of avapritinib to treat indolent systemic mastocytosis (ISM). The regimen includes once-daily dosing between 25 mg and 400 mg, with preferred doses of 200–300 mg being the most effective and well-tolerated amounts. While the treatment is primarily intended for ISM, this dosing strategy could also help treat other forms of the disease linked to the KIT D816V gene mutation.
The patent, titled “Dosing regimens of (S)-1-(4-fluorophenyl)-1-(2-(4-(6-(1-methyl-1H-pyrazol-4-yl)pyrrolo[2,1-f][1,2,4]triazin-4-yl)piperazinyl)-pyrimidin-5-yl)ethan-1-amine for treatment of indolent systemic mastocytosis”, was filed on December 8, 2022, and was granted on March 18, 2025. The inventors are Brenton Mar, Anthony L. Boral, Hui-Min Lin, and Hongliang Shi, and they were represented by David Conlin, Basam Nabulsi, Thomas Hoover, et al. from McCarter & English.
Improved RET inhibition with reduced toxicity and resistance
Studies have identified RET gene fusions as key drivers of tumor growth, prompting the development of targeted therapies designed to block RET signaling. However, existing RET inhibitors often cannot be administered at high enough doses to fully suppress cancer activity due to safety concerns. In many cases, tumors eventually develop resistance through the reactivation of cancer-related pathways, posing a major challenge to achieving long-term treatment success.
U.S. Patent No. 10,202,365 addresses this by introducing a new group of drug compounds designed to block RET, a gene linked to certain types of cancer. These compounds are made to target RET proteins precisely, including its genetic variants that become resistant to current treatments. At the same time, they avoid affecting other proteins in the body that could cause harmful side effects. This makes it possible to give higher doses of the drug safely, improving its overall effectiveness and helping patients with RET-related cancers benefit more and for longer durations.
The patent, titled “2-(pyridin-3-yl)-pyrimidine derivatives as RET inhibitors”, was filed on February 5, 2016, and published on February 12, 2019. The inventors are Natasja Brooijmans, Lucian DiPietro, Paul Fleming, Joseph Kim, Steven Wenglowsky, and Yulian Zhang. This filing was represented by Mark Abate, Marta Delsignore, Kevin Canning, et al. from Goodwin Procter.
What lies ahead for Blueprint?
With Ayvakit® experiencing rapid commercial growth, and BLU-808 advancing in development, 2025 is shaping up to be Blueprint Medicines’ most significant year since its foundation. To sustain this momentum, the company is preparing to initiate the Phase 3 HARBOR trial of elenestinib as a step to further expand its systemic mastocytosis franchise.
At the same time, Blueprint is also prioritizing the investments for its CDK franchise, which facilitates the progression of CDK2 and CDK4-targeting degraders for the treatment of breast cancer and additional solid tumor indications in line with strong preclinical progress. With these initiatives, Blueprint is building a strong foundation for continued growth and expanding its impact across a broader range of cancer indications.
