Orphan drug designation granted for HPN217, a BCMA-targeting trispecific T-cell engager for MM

The U.S. Food and Drug Administration (FDA) has granted an orphan drug designation for HPN217 for the treatment of adults with multiple myeloma (MM).¹ HPN217 is a trispecific T-cell engager² recombinant protein construct that targets B-cell maturation antigen (BCMA). It has albumin-binding domains for half-life extension and CD3 for T-cell engagement.

HPN217 is currently being evaluated in a phase I/II clinical trial (HPN217-3001, NCT04184050) in patients with relapsed/refractory MM. The focus of this study is to ascertain the safety, tolerability, and pharmacokinetics of HPN217 as primary endpoints. Overall response rate, progression-free survival, overall survival, and duration of response are the secondary endpoints. The first patient has been dosed with HPN217 and so far, the treatment has been well tolerated with no dose-limiting toxicities reported.³

While the interim results of this trial are expected later in 2021, a poster was presented at the 62nd American Society of Hematology (ASH) Annual Meeting and Exposition, demonstrating the structure of HPN217, its mode of action, and the ongoing trial design.⁴ HPN217 has been shown to have potent tumor killing action in vitro and in vivo models in the presence of T cells.