Kleo Pharmaceuticals

Kleo Pharmaceuticals was a private New Haven, Connecticut biotechnology company developing targeted immunotherapies based on small-molecule and chemically conjugated bispecific approaches derived from Yale University research. The company focused on platform technologies designed to redirect, enhance, or replace antibodies, including Antibody Recruiting Molecules (ARM), Multi-targeted Antibody Therapy Enhancer (MATE), and Synthetic Antibody Mimics (SyAM). Its lead disclosed programs included CD38-directed candidates for multiple myeloma and a CD20 x CD3 bispecific molecule built on rituximab. In January 2021, Biohaven acquired the remaining equity in Kleo and used its assets and Yale-licensed technologies to form Biohaven Labs. As a result, Kleo is best viewed as an acquired, no-longer-independent platform immunotherapy company with preclinical assets and discovery-stage partnerships.