(MENAFN- AsiaNet News)

• Phase 2 trial showed 66% of patients achieved undetectable hepatitis delta virus RNA with Vir's tobevibart-elebsiran combo, with no serious safety issues reported.
• Gilead's rival therapy bulevirtide remains the only approved hepatitis delta treatment in Europe but showed lower long-term response rates in earlier studies.
• VIR trended on Stocktwits as traders highlighted strong efficacy, Gates Foundation backing, and potential for a future head-to-head Phase 3 matchup with Gilead.

Vir Biotechnology drew heightened retail attention on Sunday after unveiling new Phase 2 data showing its tobevibart-elebsiran combination achieved high rates of undetectable hepatitis delta virus (HDV) RNA, positioning the therapy as a potential rival to Gilead Sciences' bulevirtide, which is currently the only approved HDV treatment in Europe.

Vir's Combination Delivers Strong 48-Week Results

Vir said 66% of participants in its Phase 2 SOLSTICE trial receiving monthly doses of tobevibart and elebsiran achieved undetectable HDV RNA at Week 48, while 90% showed reductions in hepatitis B surface antigen below 10 IU/mL, a marker of suppressed viral replication. Alanine aminotransferase levels normalized in more than half of the participants.

The dual regimen was well-tolerated, with no grade 3 or higher treatment-related adverse events or discontinuations. The company said results were consistent even in patients with cirrhosis and high baseline viral load.

“Achieving undetectable HDV RNA is a key endpoint in clinical trials, and HDV RNA undetectability is associated with better outcomes for people living with chronic hepatitis delta,” said Tarik Asselah, of the University of Paris-Cité, who presented the data at AASLD's The Liver Meeting in Washington, D.C.

Eclipse Registration Program Advances

Vir said the combination is now being evaluated in its Eclipse global Phase 3 program, comprising three randomized, controlled trials. Eclipse-1 has completed enrollment ahead of schedule, with topline results from Eclipse-1, -2 and -3 expected in the first quarter of 2027.

CEO Marianne De Backer said the new 48-week data“reinforce our confidence that a monthly dose of tobevibart and elebsiran can deliver meaningful patient benefit with convenient dosing.”

According to the company, the combination offers the potential to eliminate the virus by tackling the viral lifecycle through multiple mechanisms.

Gilead's Bulevirtide Demonstrates Durable Off-Treatment Control

In May, Gilead Sciences reported final results from its pivotal Phase 3 MYR301 study showing that 36% of adults treated with bulevirtide maintained virologic suppression for almost two years after stopping therapy. Participants who remained undetectable for one year post-treatment experienced no relapses in the second year of follow-up.

Among those with prolonged viral clearance at 96 weeks or later, 90% remained undetectable off-treatment.

Gilead said the data underscore bulevirtide's durability after treatment cessation and the importance of sustained viral suppression during therapy. Bulevirtide 2 mg is the only approved HDV therapy in the EEA, UK, Switzerland, and Australia and is not approved in the U.S.

Stocktwits Traders See 'Phenomenal' Data

On Stocktwits, retail sentiment was 'extremely bullish' amid 'extremely high' message volume, placing it among the top ten trending stocks on the platform.

VIR sentiment and message volume as of November 9 | Source: Stocktwits

One user noted that they were encouraged by the company's strong trial results and high-profile early backers, including the Gates Foundation and Cathie Wood's ARK Invest, calling the data“phenomenal” and suggesting pre-market trading could reflect the momentum.

Another investor commented that the trial outcomes appeared“extremely strong,” adding that those who entered the stock before the weekend“may reap rewards” depending on market reaction.

A third user compared the 66% undetectable HDV RNA rate achieved with Vir's monthly regimen to what they said was roughly 16% efficacy for Gilead's bulevirtide, which requires daily injections, describing the results as“good news” ahead of eventual head-to-head Phase 3 testing.

Vir Biotechnology's stock has declined 30% so far in 2025.

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