Vir's Prostate Cancer Drug VIR-5500 Gets FDA Fast Track Status, With Phase 3 Planned For 2027
The designation covers late-line metastatic castration-resistant prostate cancer; Vir and Astellas co-develop the drug.
The FDA has granted Fast Track designation to Vir Biotechnology's VIR-5500 for late-line metastatic castration-resistant prostate cancer, according to an 8-K the company filed Thursday. The company says it expects to begin Phase 3 trials in 2027.
What the 8-K says
The filing carries a press release as an exhibit. It describes VIR-5500 as a PSMA-targeted, dual-masked T-cell engager, a drug built to steer the immune system's T-cells against cancer cells. Astellas Pharma and Vir are co-developing it under a global strategic collaboration.
The release defines Fast Track as a designation meant to facilitate and speed the development and review of drugs for serious conditions that fill an unmet need. It cites a 5-year survival rate of approximately 30% for patients with metastatic castration-resistant prostate cancer.
Vir CEO Marianne De Backer said the designation reflects the drug's potential in an area of "serious unmet need" as the companies "prepare to enter pivotal Phase 3 development in 2027." Moitreyee Chatterjee-Kishore, Executive Vice President and Head of Oncology Development at Astellas, said the designation "reinforces the importance of advancing VIR-5500 with urgency."
Where the drug stands
VIR-5500 is in a Phase 1 study with six dose-expansion cohorts. Three test it alone, in patients whose disease is taxane naïve, radioligand therapy naïve or radioligand therapy exposed.
Three test combinations: with enzalutamide in early-line mCRPC, with docetaxel in early-line mCRPC, and with darolutamide in metastatic hormone sensitive prostate cancer.
Phase 1 data reported earlier this year showed the drug was generally well tolerated, with promising anti-tumor activity in mCRPC patients. The release warns that early-stage results may not match later-stage trials and do not ensure approval.
The company's stock closed at $11.52 at Wednesday's close, before the filing.
What to watch
Vir and Astellas anticipate starting pivotal Phase 3 trials in 2027. Enrollment in the Phase 1 expansion cohorts is ongoing.
The 8-K gives no Phase 3 start date beyond 2027, and the release's own risk language lists enrollment rates, regulatory timing and safety data as factors that could change the plan.
