Day One targets ADC market with MabCare acquisition

Day One Biopharmaceuticals has entered the field of antibody-drug conjugates (ADCs) through an exclusive licensing agreement with MabCare Therapeutics for MTX-13, a novel ADC targeting protein-tyrosine kinase 7 (PTK7). The biotech company, based in Brisbane, California, is investing $55 million upfront for this acquisition. Under the terms of the agreement, Day One will develop, manufacture, and commercialize MTX-13 globally, excluding Greater China. MabCare stands to earn an additional $1.15 billion in milestone payments, plus royalties on net sales outside of Greater China, ranging from low to mid-single digits.

The US Food and Drug Administration (FDA) approved the investigational new drug application for MTX-13, which has been renamed DAY301, in April 2024. The companies have reported that DAY301 has demonstrated anti-tumor activity in various solid tumors during preclinical studies. The first patient is expected to receive a dose in a Phase I clinical trial by the end of this year or early 2025.

Day One Biopharmaceuticals had previously secured FDA approval for Ojemda (tovorafenib) in April 2024. Ojemda is an oral, brain-penetrant, type II RAF kinase inhibitor designed to treat pediatric brain tumors. Following this approval, Day One sold a priority review voucher for $108 million, though the buyer's identity was not disclosed.

The entry of Day One into the ADC market places it among a growing list of biotechs making significant moves in this area. In April 2024, Genmab announced its acquisition of ProfoundBio for $1.8 million, gaining access to its PTK7-targeted ADC. Similarly, Ispen signed a global licensing agreement with Sutro Biopharma in the same month to develop ADCs, a deal valued at up to $900 million. Other pharmaceutical giants like Bristol Myers Squibb, Johnson and Johnson, and Pfizer have also been active in the ADC domain, with Pfizer's acquisition of Seagen for $43 billion in December 2023 standing out as the largest deal in this sector to date.

Day One’s co-founder, Samuel Blackman, expressed his optimism about the acquisition, stating: “We believe the linker-payload technology embodied in DAY301 will overcome the limitations of earlier PTK7-targeted ADCs, giving us a potential first-in-class drug against a clinically validated target. We are excited to add this program to Day One and will look to enter the clinic in the coming months.”

Through this strategic move, Day One Biopharmaceuticals aims to enhance their portfolio and make significant strides in the treatment of various solid tumors. The upcoming Phase I clinical trial for DAY301 will be a crucial step in determining the ADC's efficacy and potential as a first-in-class treatment option. With significant financial commitments and a promising pipeline, Day One is poised to make a substantial impact in the field of oncology.