Compass Therapeutics Announces Preclinical Data on Lead Antibody Program and NK Cell Engager Platform to be Presented at the Society for Immunotherapy of Cancer Annual Meeting

CAMBRIDGE, Mass.--(BUSINESS WIRE)-- Compass Therapeutics, a biotechnology company committed to the ambitious goal of comprehensively drugging the human immune system, today announced that preclinical data on CTX-471, a fully human monoclonal antibody that potently induces immune-mediated destruction of solid tumors, will be presented at the Society for Immunotherapy of Cancer (SITC) 2018 Annual Meeting, which is being held this week in Washington, D.C. Preclinical data from the company’s novel NK cell engager platform will also be presented.

“To our knowledge, CTX-471’s preclinical efficacy as a monotherapy in a very large tumor model is unprecedented for an immuno-oncology antibody. These data support our plans to advance our lead therapeutic candidate into the clinic in the first quarter of 2019,” said Thomas Schuetz, M.D., Ph.D., the company’s co-founder and chief executive officer. “In addition, the data on our NK cell engager platform are very exciting. Our preclinical results underscore the power of our StitchMabs™ technology and our empirical approach to identifying novel combinations of therapeutic candidates that can engage the innate and adaptive immune system in unique and novel ways to eradicate tumors.”

CTX-471, a CD137 Agonist

CTX-471 is a fully human monoclonal antibody that binds and stimulates a novel epitope on CD137, also known as 4-1BB — a member of the tumor necrosis factor receptor superfamily. Targeting of this unique epitope, combined with other characteristics of this antibody, give CTX-471 a very different profile compared to other antibodies targeting CD137.

IND-enabling studies for CTX-471 are complete and a Phase 1 clinical trial is planned for Q1 2019. Preclinical data to be presented at SITC suggest that CTX-471 has the potential to become a best-in-class CD137 agonist with strong efficacy both as a monotherapy and in combination with tumor antigen-targeted antibodies and checkpoint inhibitors.

Compass will present data showing that CTX-471 potently induces immune-mediated tumor killing, including complete responses that are associated with the generation of long-term, functional immunological memory in multiple in vivo models and across a broad range of doses. Compass will also present data supporting the future clinical testing of CTX-471 in combination with multiple different therapeutics, including tumor-targeted antibodies and checkpoint inhibitors. These data sets will be presented in two posters:

Poster #407, titled “CTX-471, a novel agonistic antibody targeting CD137, eradicates very large tumors in vivo by selectively reprogramming the tumor microenvironment without causing hepatic toxicity,” on display in Hall E. Presentation hours are Friday, Nov. 9, from 12:45 – 2:15 p.m. and 6:30 – 8 p.m.

Poster #386, titled “CTX-471, a novel agonistic antibody targeting CD137, enhances the anti-tumor activity of tumor antigen-targeted antibodies and immune checkpoint inhibitors when used in combination,” on display in Hall E. Presentation hours are Saturday, Nov. 10 from 12:20 – 1:50 p.m. and 7:00 – 8:30 p.m.

NK Cell Engager Platform

Compass will present data on a novel class of antibodies targeting NK cells, which lowers the threshold for NK cell activation and induces potent tumor cell killing in vitro. As an example, CTX-4419, a first-in-class NKp30 x BCMA bispecific, induces NK cell activation and potent killing of tumor cells expressing high, medium and even low levels of antigen. The data further show that CTX-4419 activates NK cells only in the presence of tumor cells and does not require NK cell priming.

“We are excited about the potential applications of this platform. In addition to its activity across a broad range of antigen expression levels, CTX-4419 productively engages, but does not require, CD16A activation for its superior activity,” said Piotr Bobrowicz, Compass’s chief scientific officer. “This unique characteristic is expected to overcome the reduction or loss of activity connected with CD16A polymorphism, receptor shedding or downregulation in the tumor microenvironment that can render CD16A-based therapeutic approaches ineffective.”

The data will be presented in Poster #P530, titled “A novel class of NK cell engagers overcomes CD16A deficiency,” which will be on display in Hall E on Saturday, Nov. 10 from 12:20 – 1:50 p.m. and 7:00 – 8:30 p.m.

About Compass Therapeutics

Compass Therapeutics has multiple antibody, antibody combination and bispecific programs advancing through preclinical development, targeting multiple pathways of significance for the immune system. The company’s offices and labs are based in Kendall Square in Cambridge, Mass. Compass currently has approximately 80 full-time employees.

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