Vir Biotechnology, Inc. announced on October 8, 2026, that the U.S. Food and Drug Administration (FDA) has granted Fast Track designation to VIR-5500. The designation applies to the treatment of late-line metastatic castration-resistant prostate cancer (mCRPC).
VIR-5500 is a PSMA-targeted PRO-XTEN dual-masked T-cell engager (TCE). The drug is being co-developed by Vir Biotechnology and Astellas Pharma Inc. through a global strategic collaboration.
The company stated that the Fast Track designation is intended to facilitate and expedite the development and review of drugs that address serious conditions and fill an unmet need. VIR-5500 is currently being evaluated in a Phase 1 study across six dose-expansion cohorts. These cohorts include monotherapy and combination regimens targeting patients with various stages of prostate cancer, including those who are taxane-naïve or have been exposed to radioligand therapy.
Phase 1 data reported earlier this year indicated that VIR-5500 was generally well tolerated and exhibited promising anti-tumor activity. The company anticipates that Phase 3 trials will begin in 2027.
