Day One Biopharmaceuticals and Merck KGaA Enter Global License Agreement to Co-Develop and Commercialize MEK Inhibitor Pimasertib

Compiled by Fan Dongdong

Day One Biopharmaceuticals Announces Global License Agreement with Merck to Co-Develop and Commercialize Pimasertib and MSC2015103B

Pimasertib and MSC2015103B are oral, highly selective small-molecule allosteric inhibitors of MEK 1/2 (key enzymes in the MAPK signaling pathway). Dysregulation of the MAPK pathway has been proven to play a critical role in many cancers. Day One Biopharmaceuticals has entered into an exclusive licensing agreement with Merck KGaA for these two drugs, thereby expanding Day One’s pipeline of clinical-stage targeted cancer therapies.

Day One Biopharmaceuticals, a pharmaceutical startup based in South San Francisco, was co-founded by Dr. Samuel Blackman, a pediatric oncologist who serves as the company’s Chief Medical Officer. The company collaborates with clinical oncologists and scientists to develop innovative cancer therapies, primarily for the treatment of pediatric tumors. Last May, the company secured $60 million in Series A financing, with investors including Canaan Partners, Atlas Venture, and Access Biotechnology.

According to the collaboration agreement between the two companies, Day One Biopharmaceuticals will pay Merck an upfront payment, plus additional regulatory, approval, and sales-based milestone payments. Merck will also receive sales royalties from the potential net sales of Pimasertib and MSC2015103B. The specific financial details of this collaboration were not disclosed publicly.

Previously, pimasertib has been evaluated in more than 10 Phase 1/2 clinical trials involving approximately 900 patients with various tumor types. Day One Biopharmaceuticals plans to further advance Phase 1/2 studies of pimasertib in combination with DAY101, assessing the safety, tolerability, and preliminary efficacy of this regimen in patients aged ≥12 years with recurrent, progressive, or refractory solid tumors harboring MAPK pathway alterations. Blackman stated, “DAY101 monotherapy has demonstrated encouraging antitumor activity in pediatric low-grade gliomas, and we believe that the combination of pimasertib and DAY101, owing to its broader applicability across heterogeneous tumors, will also be well-suited for adult patients with solid tumors.”

DAY101 is a potential, best-in-class, brain-penetrant, highly selective Type II pan-RAF kinase inhibitor under Day One Biopharmaceuticals. This drug is also the first development project of Day One, previously known as TAK-580, and is a targeted therapy for pediatric brain tumors. DAY101 is an oral medication taken once weekly with a unique mechanism of action. This therapy can target cancers with BRAF mutations (the gene located on human chromosome 7 that encodes serine or threonine protein kinases of the RAF family) as well as tumors harboring BRAF wild-type fusion proteins.

It is worth noting that a significant proportion of pediatric tumors are driven by BRAF wild-type fusion proteins rather than BRAF mutations. Previously, DAY101 has undergone clinical testing in more than 250 patients, including children with recurrent glioma. Day One Biopharmaceuticals stated that data on the safety and efficacy of DAY101 will be released this year or next year.

Source: Day One Expands Clinical-Stage Oncology Pipeline; Announces Global License Agreement with Merck KGaA, Darmstadt, Germany to Develop and Commercialize MEK Inhibitor Pimasertib