NextCure, LegoChem join big-league rivals in antibody-drug conjugate race

NextCure has found a new use for its anti-B7-H4 antibody NC762. By partnering with Korea’s LegoChem Biosciences, the biotech plans to aim an antibody-drug conjugate (ADC) at the oncology target and join an R&D race featuring AstraZeneca, Mersana Therapeutics and Seagen.

B7-H4 is abnormally expressed by a range of solid tumors and plays a role in key processes such as cell proliferation and metastasis that support the development and spread of cancers. Because of its limited expression in healthy tissues, multiple companies have identified the cell-surface glycoprotein as a good target for ADCs that deliver cytotoxic payloads to cells with certain markers. 

AstraZeneca began a phase 1/2 clinical trial of its B7-H4-directed ADC, AZD8205, 13 months ago. Seagen followed close behind, pushing SGN-B7H4V into a solid tumor study in January, and Mersana joined the party in August. Genmab and Pfizer have CD3xB7-H4 bispecifics in the clinic, too.

Faced with that wall of rivals, NextCure set out to carve out a space for its anti-B7-H4 antibody NC762, following in the footsteps of Five Prime Therapeutics, now part of Amgen, by moving a monoclonal into the clinic in the summer of 2021. A recent look at data from the study revealed “a few stable diseases beyond six months” and encouraged NextCure to push ahead with the finalization of its phase 2 dose. 

In parallel, NextCure has partnered with LegoChem to use its anti-B7-H4 antibody in an ADC. The deal will see the partners combine their resources, with LegoChem contributing its ConjuAll ADC technology, and split the costs of developing the candidate. The deal features options for the collaborators to add two additional targets for ADC development. 

“We are excited to work with LCB, and apply ConjuAll, a leading ADC technology, to add a new treatment modality to our B7-H4 program,” Timothy Mayer, NextCure’s chief operating officer, said in a statement. “We remain committed to developing novel immunomedicines using multiple modalities to address the significant unmet needs of cancer patients not adequately addressed by available therapies.”