The companies have announced preliminary data from their Phase 1 trial evaluating the first-in-class bispecific antibody, ALG.APV-527, as monotherapy for the treatment of multiple solid tumor types likely to express tumor antigen 5T4. These data indicate that trial endpoints of adequate exposure, safety, tolerability and biological activity were met.

“The interim results from Phase 1 trials of ALG.APV-527 are showing encouraging outcomes, particularly in terms of safety and disease stability in the trial patients who were refractory to multiple previous therapies. Among evaluable patients, 56% (9/16) achieved stable disease in this monotherapy trial. A colon cancer patient remained on study with stable disease for more than six months as well as a breast cancer patient who remained stable for over 11 months. Importantly, there were no instances of serious liver toxicity, a notable outcome given the relatively high incidence of this side effect associated with other treatments targeting 4-1BB. By leveraging a novel bispecific approach, ALG.APV-527 aims to enhance anti-tumor immunity while avoiding the systemic toxicities that previously have hampered the 4-1BB immune receptor pathway. These findings underscore the drug’s potential as a viable option for patients with solid tumors,” says Thomas Marron, MD, PhD, Professor of Immunology & Immunotherapy and Hematology/Oncology at the Icahn School of Medicine at Mount Sinai, and a leading investigator in the trial.