Vir Biotechnology surges on prostate cancer data, Astellas deal
Analysts raise price targets to $19 after Phase 1 results show 82% PSA50 response rate
Vir Biotechnology shares surged in Tuesday trading after multiple investment firms raised their price targets and upgraded their ratings, citing encouraging Phase 1 clinical data for the company's prostate cancer treatment and a substantial partnership with Astellas Pharma.
The stock jumped to $9.25, representing a significant increase, as analysts from Needham, Raymond James, and Evercore ISI responded to the company's latest trial results and strategic collaboration. The rally brought shares near the upper end of their recent trading range, though not yet reaching the 52-week high of $9.84 set previously according to market data.
The optimism centers on VIR-5500, a PSMA-targeting, PRO-XTEN® dual-masked T-cell engager designed to treat metastatic castration-resistant prostate cancer (mCRPC). Updated Phase 1 dose-escalation data presented Tuesday showed "dose-dependent anti-tumor activity," with particularly strong responses in patients receiving doses of 3,000 µg/kg or higher administered every three weeks, according to the company's announcement.
In these higher-dose cohorts, 82% of PSA-evaluable patients achieved a PSA50 response, defined as a 50% or greater decline in prostate-specific antigen levels. Additionally, 53% of these patients experienced PSA90 responses, indicating a 90% or greater reduction in the biomarker, company data show.
Perhaps most notably, the objective response rate among RECIST-evaluable patients in the higher-dose groups reached 45%, with four of five responders already confirmed and one awaiting confirmation. The company reported that tumor shrinkage was observed across multiple lesions, including visceral metastases, as confirmed by PSMA-PET reductions according to the clinical results.
The safety profile appeared favorable, with no dose-limiting toxicities observed across all 58 patients in the trial. Grade 3 or higher treatment-related adverse events occurred in 12% of patients and were described as manageable. Cytokine release syndrome (CRS) was observed in 50% of patients but was generally limited to Grade 1 (fever only), and prophylactic steroids were not required except in a small exploratory cohort the company stated.
"These results are impressive given that patients were heavily pre-treated with a median of four prior lines of therapy, and nearly half had visceral metastases," the company noted in its presentation available via investor materials.
Bolstering the clinical data announcement, Vir simultaneously revealed a strategic collaboration with Astellas Pharma valued at up to $1.7 billion. The deal includes $335 million in upfront and near-term payments, consisting of $240 million in cash, a $75 million equity investment by Astellas at a 50% premium to the market price, and a $20 million near-term milestone payment, according to the partnership announcement.
Astellas will lead commercialization in the United States, with Vir retaining an option to co-promote and share profits and losses equally. Outside the U.S., Astellas will have exclusive commercialization rights. Global development costs will be split 60-40 between Astellas and Vir, respectively, the companies disclosed.
"The collaboration with Astellas is a significant validation of our PRO-XTEN technology and the potential of VIR-5500 to address unmet needs in prostate cancer," Vir Biotechnology stated.
Analysts responded swiftly to the dual announcements. Raymond James upgraded the stock to "Strong Buy" from "Outperform" and raised its price target to $19 from $12, according to analyst reports. Needham increased its price target to $18 from $14 while maintaining a "Buy" rating, market reports indicated. Evercore ISI also lifted its target to $18 from $12, reiterating its "Outperform" rating, according to analyst commentary.
The analyst actions bring consensus targets above the current market price of $9.25, with an average target of $16.56 according to current market data analysts summarized. The consensus remains overwhelmingly positive, with 4 strong buy ratings and 6 buy ratings among covering analysts, and no hold, sell, or strong sell recommendations market data showed.
The Phase 1 data will be formally presented at the 2026 American Society of Clinical Oncology (ASCO) Genitourinary Cancers Symposium, providing an opportunity for broader oncology community review, the company noted. Next steps include continued dose optimization and expansion cohorts as Vir and Astellas work together to advance VIR-5500 through later-stage trials.