Abpro files $69M IPO to take bispecific antibodies into the clinic

Preclinical-stage biotech Abpro Therapeutics has filed a $69 million IPO that it hopes will fund clinical trials of its lead antibody drugs for cancer and vascular eye disease due to start next year.

The Woburn, Massachusetts-based company says in its filing prospectus that it intends to start testing ABP-100—a four-headed antibody targeting two sites apiece for HER2 and CD3—in the first half of 2019. The first trial will be run in patients with HER2-positive solid tumors, focusing on orphan indications.

The immuno-oncology antibody is licensed from Memorial Sloan-Kettering Cancer Center and is designed to latch onto HER2-epressing cancer cells and redirect cytotoxic T lymphocytes to the tumor through its CD3 binding site. According to the company, it has shown “strong and, in some cases, curative antitumor activity in mouse models of HER2+ breast, gastric and endometrial cancer.”

Abpro also reckons its antibody could improve on current HER2 drugs such as Roche’s Herceptin, Perjeta and Kadcyla—which together made $10 billion-plus in sales last year—by expanding the eligible patient population and reducing side effects.

Later in 2019, Abpro plans to start trials of ABP-201, which takes the same tetravalent approach targeting a pair of binding sites for both VEGF and Ang-2, in diabetic macular edema (DME). Following behind are discovery-stage antibodies for various solid tumors and hematological cancers, as well as autoimmune diseases.

Abpro has been quietly plying its trade since 2004, using its antibody discovery and engineering platforms to develop candidates for biopharma companies and research groups, and recorded around $2 million in sales last year.

Lately, it has started to focus on its own development projects, an effort that gathered momentum in in 2016 when it formed an alliance with AstraZeneca unit Medimmune on the VEGF/Ang2 project. ABP-201 is the lead candidate from that collaboration and is being developed by Abpro’s subsidiary AbMed, along with a second preclinical candidate (ABP-200) in preclinical development for cancer. Medimmune has a minority stake in Abmed.

Ultimately, the intention is to grow the company into a “fully integrated discovery-to-commercial antibody therapeutics company,” says the IPO prospectus.

UBS Investment Bank and Wells Fargo Securities are the joint underwriters for the IPO.