Vir Biotechnology NASDAQ: VIR reported first-quarter 2026 financial results and provided pipeline updates, highlighting progress across its oncology programs and its registrational hepatitis delta virus (HDV) effort. Management also discussed the closing of a global collaboration with Astellas focused on VIR-5500, the company’s PSMA-targeted T-cell engager in prostate cancer.
Astellas collaboration closes, VIR-5500 development expands
CEO Marianne De Backer said Vir has remained focused on executing across oncology and HDV programs since the company’s prior update in February. She began by reviewing the Astellas partnership, which she described as “a deal valued at up to $1.7 billion,” and noted the transaction “successfully closed on April 15.” Under the agreement, Vir and Astellas will co-develop and co-commercialize VIR-5500, a “PRO-XTEN dual masked PSMA-targeted T-cell engager,” with U.S. commercial profits split 50/50 and an option for Vir to co-promote.
De Backer emphasized the rationale for partnering, citing Astellas’ presence in prostate cancer and “decade-long track record” co-developing therapies such as XTANDI. She framed metastatic castration-resistant prostate cancer (mCRPC) as an area of high unmet need, referencing a “five-year survival rate of only 30%.”
Discussing previously presented phase I data, De Backer said VIR-5500 showed a “favorable safety and tolerability profile with no observed dose-limiting toxicities.” At dose levels of 3,000 mcg/kg and above, she said the company saw “mostly grade 1 cytokine release syndrome” and “did not observe any grade 3 CRS at this dose.” She highlighted the absence of mandatory steroid pre-medication in the protocol, which she called a “meaningful differentiator,” and suggested steroid sparing could preserve T-cell function and simplify administration.
De Backer said the safety profile could support outpatient administration and potentially allow use across settings “both the pre as well as post radioligand therapy (RLT).” On efficacy, she said the company observed “depth of PSA and RECIST responses,” with several patients sustaining responses “for up to 27 weeks,” and noted “emerging signs of durability up to eight and 12 months” in extended follow-up cases. She also pointed to activity in heavily pretreated patients, including those with liver metastases, and referenced a complete response in a patient who had relapsed after an actinium-based PSMA radioligand.
The company has now dosed the first patient in phase I dose expansion cohorts for VIR-5500 monotherapy in late-line mCRPC. In expansion, Vir is evaluating a “Q3 week, 800, 2,000, 3,500 mcg/kg step-up dosing” approach in patients refractory after multiple prior lines, including at least one second-generation androgen receptor pathway inhibitor and one taxane regimen. The expansion includes cohorts for patients who are RLT-naïve and those who previously received RLT.
De Backer also said dose escalation continues for VIR-5500 in combination with enzalutamide in earlier-line mCRPC, and that the company anticipates dosing the first patient in combination dose expansion cohorts “in both early-line mCRPC and metastatic hormone-sensitive prostate cancer over the coming months.” Vir continues to target initiation of a registrational phase III program for VIR-5500 in 2027, pending data.
During Q&A, De Backer said the decision to move into phase III will be based on “the totality of the data,” including “PSA, RECIST, our PFS,” and that the monotherapy expansion is intended to deepen the pre- and post-RLT data set. Asked about durability expectations, she said there was not a single threshold but that the company will look for “durability more consistency across the entire expansion cohort.”
Broader oncology pipeline: HER2 and EGFR T-cell engagers
Beyond VIR-5500, De Backer provided updates on Vir’s other PRO-XTEN T-cell engager programs. VIR-5818 is the company’s masked HER2-targeted T-cell engager being studied in a basket trial design across multiple tumor types. Vir expects to report preliminary response data for VIR-5818 monotherapy and in combination with pembrolizumab in the second half of 2026. De Backer characterized the study as “signal-seeking,” intended to inform dose and identify HER2-expressing populations that may warrant further study.
In response to a question on potential development in HER2-positive breast cancer, De Backer said the “bar is high” given available therapies, but added that there remains opportunity to improve treatment outcomes. She said Vir would provide additional guidance after the second-half data update.
On VIR-5525, a dual-masked EGFR-targeted T-cell engager, De Backer said phase I enrollment is progressing as expected, with a design incorporating learnings from VIR-5818 and VIR-5500. The study includes both monotherapy and pembrolizumab combination arms across multiple EGFR-expressing tumor types, including non-small cell lung cancer, colorectal cancer, head and neck squamous cell carcinoma, and cutaneous squamous cell carcinoma.
Asked about another company discontinuing an EGFR T-cell engager, De Backer said the “surprising” element was musculoskeletal issues being cited as dose-limiting toxicity, which she said Vir will monitor. She argued Vir’s masking approach is differentiated, saying the company uses steric hindrance and applies “the same PRO-XTEN mask across all of our clinical programs,” enabling dosing flexibility. She added that based on experience with VIR-5500, the masking technology “allows you to dose much higher,” which she linked to potential improvements in therapeutic index.
Hepatitis delta: SOLSTICE results, regulatory momentum, and ECLIPSE timelines
De Backer said the HDV community remains underserved and estimated “approximately 180,000 actively viremic patients across the United States, U.K., and E.U.” She described Vir’s regimen—tobevibart (a neutralizing monoclonal antibody) plus elebsiran (a small interfering RNA)—as positioned with two key advantages versus competitors: potential best-in-class efficacy and a strong safety profile, along with monthly subcutaneous dosing that may enable both at-home and in-office administration.
De Backer emphasized “target not detected (TND)” as the “gold standard measure” of viral clearance and cited peer-reviewed evidence linking undetectable virus with improved long-term outcomes. She reviewed a subset of phase II SOLSTICE data at 96 weeks that Vir reported in January, stating that 88% of evaluable participants on the combination achieved undetectable virus versus 46% on tobevibart monotherapy. She also cited 41% undetectable virus at 24 weeks, describing a rapid onset and a time-dependent increase in viral suppression with combination therapy. She added that efficacy appeared similar in cirrhotic patients, which she expects to be a significant cohort at launch because of delayed diagnosis.
On safety, De Backer said the combination was well-tolerated with “no grade 3 or higher treatment-related adverse events and discontinuations.” She also reiterated the administration profile: “monthly,” consisting of “two subcutaneous injections to be administered at the same time,” compared with competitive regimens that require daily or weekly injections.
Vir plans to present the complete 96-week SOLSTICE phase II data in an oral presentation at EASL 2026 on May 29 in Barcelona, and a poster on a 48-week subgroup analysis focused on BMI and ALT normalization after viral control.
For the registrational program, De Backer said all three ECLIPSE studies are on track:
- ECLIPSE 1: Enrollment complete at approximately 120 participants randomized 2:1 (combination therapy vs deferred treatment). Primary endpoint is a composite of TND plus ALT normalization at week 48. Vir expects top-line data in the fourth quarter of 2026.
- ECLIPSE 2: Enrollment ongoing across European sites; approximately 150 patients randomized 2:1 to evaluate switching to the combination in patients with inadequate response to bulevirtide. Primary endpoint is TND at week 24.
- ECLIPSE 3: Enrollment complete at approximately 100 patients randomized 2:1 in a head-to-head comparison versus bulevirtide. Primary endpoint is TND at week 48.
During Q&A, De Backer said Vir’s “guidance is that we would need a combination of ECLIPSE 1 and ECLIPSE 2 for filing,” with ECLIPSE 1 in the fourth quarter and ECLIPSE 2 expected in the first quarter of next year.
She also discussed the competitive backdrop, calling Gilead’s expected U.S. launch of bulevirtide a positive for market development, including increased awareness and screening. De Backer said Vir estimates about 61,000 actively viremic patients in the U.S., with only “about 10%–15%” currently diagnosed. She pointed to potential improvements from streamlined testing such as reflex testing after a positive hepatitis B result.
On pricing, De Backer said HDV is an orphan disease and referenced bulevirtide pricing outside the U.S., citing Europe prices “somewhere between $60,000 and $165,000” and Canada at “$115,000.” She added that analyst estimates she has seen range from “$150,000 to $250,000,” which she said Vir views as “very adequate” for a severe orphan disease.
Financial results and cash runway
CFO Jason O’Byrne reported that Vir ended the first quarter with approximately $809.3 million in cash, cash equivalents, and investments, including proceeds from a February follow-on equity offering that generated gross proceeds of about $172.5 million before fees and expenses. He said the proceeds are intended to fund Vir’s share of VIR-5500 development costs, support the broader T-cell engager platform, and provide working capital.
O’Byrne noted that the Astellas collaboration closed after quarter end and that the $315 million in proceeds from that transaction were not reflected in the March 31 cash balance. He said the company received a $75 million cash payment tied to Astellas’ equity investment upon closing and expects a $240 million upfront payment within 30 days of closing. Vir is also eligible for a $20 million manufacturing tech transfer milestone in 2027, and the companies will share global development costs 40% (Vir) and 60% (Astellas). Vir is eligible for up to $1.37 billion in additional development, regulatory, and ex-U.S. sales milestones, as well as tiered double-digit royalties on ex-U.S. net sales, with a portion of certain proceeds shared with Sanofi under an existing license agreement.
For the quarter, Vir reported R&D expense of $108.9 million (including $6 million of stock-based compensation) versus $118.6 million a year ago, and SG&A expense of $23.3 million (including $6.1 million of stock-based compensation) versus $23.9 million a year ago. Operating expenses totaled $132.3 million, down $10.3 million year over year. Net loss was $125.7 million, compared with a net loss of $121 million in the prior-year quarter.
O’Byrne said that, based on the current operating plan and including the net effects of the Astellas agreement and capital raise, Vir expects its cash runway to extend into the second half of 2028.
Management outlook
In closing remarks, De Backer said that since December 2025, collaborations with Norgine and Astellas, along with financing activity, have generated “over a half of a billion dollars in capital,” strengthening Vir’s balance sheet. She said Vir is advancing seven preclinical T-cell engager assets using the PRO-XTEN platform and highlighted upcoming catalysts across both oncology and HDV programs, with priorities focused on rapid clinical execution, advancing expansion and registrational-enabling studies, and disciplined capital deployment.
About Vir Biotechnology NASDAQ: VIR
Vir Biotechnology, Inc is a clinical‐stage immunology company dedicated to developing therapies that prevent and treat serious infectious diseases. The company leverages a suite of proprietary technology platforms—ranging from antibody isolation and screening tools to cell‐based assays and bioinformatics—to identify and advance antiviral and antibacterial candidates. Its scientific approach centers on harnessing the human immune system through monoclonal antibodies and immunomodulatory agents.
The company's pipeline includes product candidates targeting influenza A, COVID‐19, HIV, hepatitis B, and tuberculosis.
Further Reading
This instant news alert was generated by narrative science technology and financial data from MarketBeat in order to provide readers with the fastest reporting and unbiased coverage. Please send any questions or comments about this story to contact@marketbeat.com.
Before you consider Vir Biotechnology, you'll want to hear this.
MarketBeat keeps track of Wall Street's top-rated and best performing research analysts and the stocks they recommend to their clients on a daily basis. MarketBeat has identified the five stocks that top analysts are quietly whispering to their clients to buy now before the broader market catches on... and Vir Biotechnology wasn't on the list.
While Vir Biotechnology currently has a Moderate Buy rating among analysts, top-rated analysts believe these five stocks are better buys.
View The Five Stocks Here
SpaceX has quietly filed to go public later this year. Ahead of what's expected to be the largest IPO of all time, there are seven space stocks that you can buy today that are positioned to benefit from accelerating space commercialization in 2026.
These seven companies are shaping the next phase of the space economy—from launch leaders and satellite networks to data, defense, and in-space infrastructure.
Get This Free Report
