Bispecific antibody builder Abpro postpones $69M IPO

Abpro plans to begin clinical testing of two bispecific antibodies in cancer and vascular eye diseases in the first half of next year. (Pixabay/dimitrisvetsikas1969)(Pixabay / dimitrisvetsikas1969)

The early-stage biotech Abpro has postponed its $69 million IPO, according to a report from Renaissance Capital, delaying a capital infusion it hoped would support the first clinical trials of its lead product candidates over the next year. Shares were scheduled to begin trading May 11.

The Woburn, Massachusetts-based biotech, pursuing a handful immuno-oncology and ophthalmology agents in the discovery and preclinical phases, had filed in April to offer 4 million shares between $14 and $16 under the Nasdaq symbol ABP. Abpro has not responded to a request for comment.

During its filing, Abpro said it planned to begin phase 1 testing in the first half of 2019, starting with studies of ABP-100 in breast, gastric and endometrial cancer, and ABP-201 in vascular eye diseases including wet age-related macular degeneration.

Abpro’s prospectus said it had not yet filed investigational new drug applications for FDA permission to begin clinical trials, instead touting results from mouse models.

The company described the two products as next-generation, dual-targeting antibodies: ABP-100, licensed from Memorial Sloan Kettering Cancer Center, binds to both HER2 on cancer cells and CD3 on T cells to launch an antitumor response. ABP-201, meanwhile, simultaneously targets VEGF and angiopoietin-2, two growth factors that play roles in the early and late stages of blood vessel formation.

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In 2016, Abpro signed a $3.5 million deal with Chinese biotech Essex Bio to co-develop monoclonal antibodies. The Chinese biotech Essex specializes in recombinant DNA technology. Essex would retain commercial rights in China, while Abpro would hold them for the rest of the world.

Later that year, Abpro teamed up with AstraZeneca’s MedImmune to research Ang2-VEGF targeting antibodies, like ABP-201, under a new subsidiary named AbMed. The companies planned to explore several potential therapeutic areas.

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Last month saw two other biotechs pull the plug on their IPOs, including Alzheon’s $81 million filing and Mereo BioPharma’s $80 million plans, both on the verge of phase 3 testing.

Novartis-backed Mereo cited “challenging” stock market conditions as it planned to launch clinical studies of its brittle bone disease drug setrusumab. Alzheon, meanwhile, hopes to begin trials of its beta amyloid blocker tramiprosate, acquired in 2013 from Bellus Health, formerly known as Neurochem.