Phanes Therapeutics has announced that the US Food and Drug Administration (FDA) has granted Fast Track designation to PT217 for the treatment of patients with metastatic de novo or treatment-emergent neuroendocrine prostate cancer (NEPC).

This is the second Fast Track Designation granted to PT217 by the FDA. Earlier this year, PT217 was granted Fast Track designation for extensive-stage small cell lung cancer (ES-SCLC) with disease progression following platinum chemotherapy with or without a checkpoint inhibitor by the agency.

PT217, a first-in-class native IgG-like bispecific antibody (bsAb) targeting DLL3 and CD47, is being developed for the treatment of patients with small cell lung cancer (SCLC) and neuroendocrine carcinoma, including neuroendocrine prostate cancer (NEPC).

In addition to Fast Track designation, PT217 was also granted orphan drug designations for the treatment of small cell lung cancer and neuroendocrine carcinoma (NEC), respectively.

The multi-center Phase I/II clinical trial of PT217 (NCT05652686), known as the SKYBRIDGE study, is currently evaluating the safety, tolerability, pharmacokinetics and preliminary efficacy of PT217 in patients with advanced or refractory cancers expressing DLL3.

A Phase I clinical trial of PT217 is also ongoing in China (CTR20242720). Earlier this year, Phanes entered into a clinical supply agreement with Roche to study PT217 in combination with Roche's anti-PD-L1 therapy, atezolizumab.