Zai Lab finds latest target in Regeneron?s bispecific, paying up to $190M for Chinese rights

Nine months after hinting they might have bispecific antibodies in the works, Shanghai-based Zai Lab has signed on to help commercialize one of biotech?s most promising candidates.

Zai Lab and Regeneron have signed a deal to develop and commercialize REGN1979, their CD20XCD30 bispecific now being tested in a range of blood cancers, in mainland China, Hong Kong, Taiwan and Macau. Zai Lab will pay Regeneron $30 million and up to $160 million in developmental and sales milestones.

The deal represents the prominent Chinese biotech?s first foray into the increasingly heated race to develop bispecific antibodies ? molecules that grab immune cells and a tumor to smash them together ? as a next step in immunotherapy.

REGN1979 made a huge splash at the American Society for Hematology meeting two years ago, when the New York biotech announced that its Phase I proof-of-concept study had led to a 100% response rate and an 80% complete response rate across 10 patients with relapsed or refractory B-cell non-Hodgkin?s lymphoma. Subsequent results have muddied the picture ? including with the revelation last year that in one trial, two patients died from from cytokine release syndrome ? but broadly pointed to an immunotherapy that could be effective in several blood cancers, and even shows activity in patients whose cancers progressed after CAR-T therapy.

The latest data, unveiled at ASH?s European rival last June, showed 13 responses and 10 complete responses in 14 patients with follicular lymphoma and 4 responses out of 7 patients with diffuse large b-cell lymphoma, although all 4 were complete responses.

?The follicular lymphoma data don?t look as stellar as the prior data cut but the DLBCL data improve,? Baird?s Brian Skorney wrote in response to the June data. ?We think this bispecific program looks like a strong next-gen B-cell lymphoma therapy that could yield a fairly significant market opportunity.?

Zai Lab has made a nearly $4 billion biotech in large part by in-licensing the right experimental drugs from top American biotechs. They grabbed Chinese rights for?niraparib from Tesaro months before its US approval, and last June signed on to a?Deciphera kinase inhibitor for solid tumors, before getting rights to an Incyte PD-1 the following month.

They?re planning to test the latter in several new combinations, including with margetuximab, a HER2-targeting drug licensed from Macrogenics.

Regeneron has offered little timeline for filing with the FDA, but 2020 was shaping up to be a big year for bispecific antibodies. Amgen and Bristol Myers Squibb have each posted promising early batches, and appeared likely to give further updates. Already, in March, Astellas promised Cytomx up to $1.6 billion in a deal centered largely around bispecific antibodies.