Day One Licenses Merck KGaA’s MEK Inhibitor Pimasertib, Expands Pipeline

Rare Daily Staff

Cancer therapeutics developer Day One Biopharmaceuticals said it has entered into a global licensing agreement with Merck KGaA for its MEK inhibitor pimasertib, as well as a second compound.

Under the terms of the agreement, Day One will make an upfront payment to Merck KGaA, plus additional regulatory, approval and sales-based milestone payments. Merck KGaA, will also receive royalties on potential net sales of pimasertib and the second compound, MSC2015103B. Specific financial details are not disclosed.

“Day One is purpose-built to accelerate innovative targeted therapies designed to help both children and adults with cancer,” said Jeremy Bender, CEO of Day One. “This license agreement with Merck KGaA, Darmstadt, Germany, exemplifies our core strategy to identify investigational potential treatment options such as pimasertib and leverage our expertise to rapidly advance them in patients who we believe will benefit the most.”

Pimasertib and MSC2015103B are oral, highly-selective small molecule allosteric inhibitors of MEK 1/2, a key enzyme in the MAPK signaling pathway. Dysregulation of the MAPK pathway has been shown to occur in many cancers.

Pimasertib has been studied in more than 10 phase 1/2 clinical trials in approximately 900 patients with various tumor types and has demonstrated a safety and efficacy profile comparable to other MEK inhibitors.

Day One plans to initiate a phase 1/2 study to evaluate the safety, tolerability, and preliminary efficacy of combining pimasertib with DAY101, the company’s potential first-in-class, oral, brain-penetrant, highly selective type II pan-RAF kinase inhibitor, in patients 12 years of age and older with recurrent, progressive, or refractory solid tumors with MAPK pathway aberrations.

“There is strong scientific and clinical rationale for targeting multiple nodes of the MAPK signaling pathway to drive deeper and more durable tumor responses,” said Samuel Blackman, co-founder and chief medical officer of Day One.

He noted that DAY101 demonstrated encouraging single agent anti-tumor activity in pediatric low-grade glioma, and said the company believes the combination of pimasertib and DAY101 will be well-suited for adult patients with solid tumors given their greater heterogeneity. Data have shown that DAY101 selectively inhibits both RAF monomers and dimers, which may broaden its potential clinical application in combination with MEK inhibition in solid tumors driven by non-BRAF V600 mutations and RAF fusions.

Photo: Jeremy Bender, CEO of Day One