Vir Biotechnology, Inc. (VIR) saw its stock plummet 9.46% on Thursday, February 27th in the intraday trading session following the release of its Q4 2024 earnings and business update. The steep decline reflects investors' concerns over the company's pipeline progress, despite some promising early data.

A key disappointment for investors was Vir's announcement that it would only advance its hepatitis B program with a development and commercialization partner. While the company expects to share functional cure data for this program in Q2 2025, the need for a partner indicates a longer runway to potential commercialization.

On a more positive note, Vir reported encouraging early data from its T-cell engager programs in oncology. VIR-5818, a HER2-targeted T-cell engager, showed promising activity in heavily pre-treated colorectal cancer patients, with a 33% confirmed partial response rate at doses of 400 micrograms per kilogram and above. Similarly, VIR-5500, a PSMA-targeted T-cell engager for prostate cancer, demonstrated impressive PSA declines in the ongoing Phase 1 dose escalation study.

However, these oncology programs are still in early stages of clinical development, with significant work remaining before potential regulatory submissions. Additionally, Vir plans to initiate a Phase 1 study for VIR-5525, an EGFR-targeted T-cell engager, in the first half of 2025.

Vir's hepatitis delta program, which combines tobevibart and elebsiran, is set to enter Phase 3 trials (ECLIPSE program) in the first half of 2025. While the company highlighted impressive virologic responses from the Phase 2 SOLSTICE study, Phase 3 trials are lengthy and challenging, particularly in this underserved disease area.