Clinical-stage biopharmaceutical company Vir Biotechnology Inc (Nasdaq:VIR) announced on Thursday that the US Food and Drug Administration (FDA) has granted Fast Track designation to VIR-5500, a PSMA-targeted PRO-XTEN dual-masked T-cell engager, for late-line metastatic castration-resistant prostate cancer.

VIR-5500 is being co-developed by Vir Biotechnology and Astellas Pharma (TYO:4503) under a global strategic collaboration.

The therapy is being evaluated in a Phase 1 study across six dose-expansion cohorts, including monotherapy and combination regimens targeting different stages and treatment settings of prostate cancer.

Earlier Phase 1 data showed that VIR-5500 was generally well tolerated and demonstrated promising anti-tumour activity in patients with metastatic castration-resistant prostate cancer.

Fast Track designation is intended to facilitate and expedite development and review of treatments for serious conditions with unmet medical needs.

Phase 3 trials for VIR-5500 are anticipated to begin in 2027.