Five Prime Therapeutics has submitted an Investigational New Drug (IND) application for FPA150, a first-in-class immuno-oncology antibody that targets B7-H4. 

FPA150 was discovered using the company’s protein therapeutics platform and anticipates initiating a Phase 1 trial of FPA150 during the first half of 2018.

FPA150 is a high affinity, afucosylated monoclonal antibody designed with a dual mechanism of action: blocking a T cell checkpoint pathway and delivering enhanced antibody-dependent cell-mediated cytotoxicity (ADCC) against tumor cells expressing B7-H4. B7-H4 expression is seen in tumor types such as breast, ovarian and endometrial cancer, and has been correlated with poor prognosis in some studies. 

“We are excited to expand our clinical pipeline with the addition of FPA150, which offers a differentiated approach to existing immunotherapies,” said Bryan Irving, Ph.D., senior vice president of Research at Five Prime. “B7-H4 represents a T cell checkpoint ligand that is not currently targeted by other immuno-oncology agents and is also expressed in several solid tumor types not typically associated with elevated PD-L1 expression.”

Five Prime designed the planned Phase 1 trial with a standard 3+3 dose escalation phase in patients with solid tumors, followed by dose expansion in pre-specified cohorts in tumor types based on B7-H4 expression levels. The initial targeted tumors are advanced or metastatic breast, ovarian, endometrial and urothelial carcinomas.