Day One acquires MabCare's first ADC for $55M

Day One Biopharmaceuticals has made a notable addition to its oncology pipeline following its first FDA approval. The California-based company has entered the highly discussed field of antibody-drug conjugates (ADCs) by licensing rights to MTX-13, a PTK7-targeting ADC, from MabCare Therapeutics, excluding China. This candidate, now renamed DAY301, is scheduled to enter a Phase I trial for solid tumors by early 2025. MabCare Therapeutics will receive an upfront payment of $55 million and potential milestone payments totaling up to $1.15 billion, along with low-to-mid single-digit royalties.

Day One's interest in the PTK7 target is noteworthy because PTK7 is a catalytically inactive transmembrane protein that is highly expressed in multiple solid tumors but minimally expressed in healthy tissues. Despite its potential, a PTK7-targeting ADC has yet to achieve clinical success. Previously, AbbVie and Pfizer collaborated on developing a PTK7-targeting ADC named cofetuzumab pelidotin, but they discontinued the project last year.

Currently, Genmab appears to be the only company with a PTK7-directed ADC in clinical trials. In April, Genmab acquired PRO1107, which is undergoing a Phase I/II study for solid tumors, through its acquisition of ProfoundBio for $1.8 billion. Samuel Blackman, the head of R&D at Day One, expressed the company's confidence that DAY301's linker-payload technology will overcome the limitations of previous PTK7-targeted ADCs, potentially making it a first-in-class drug against this clinically-validated target.

This new agreement adds to Day One's growing cancer program portfolio. In April, the FDA approved the company's pan-RAF kinase inhibitor Ojemda (tovorafenib) for treating relapsed or refractory low-grade glioma with a BRAF alteration. Additionally, Day One's pipeline includes pimasertib, a MEK 1/2 inhibitor in a Phase I/II trial for solid tumors with MAPK pathway aberrations, and a preclinical VRK1 inhibitor acquired from Sprint Bio last year for $3 million upfront.

In summary, Day One Biopharmaceuticals is expanding its oncology portfolio by entering the ADC space with the acquisition of MTX-13, now DAY301, from MabCare Therapeutics. With a diverse and promising pipeline, the company is poised to make significant strides in cancer treatment.