Ionis Hits 52-Week High as Hepatitis B Drug Succeeds in Phase 3
Shares surge after the GSK-partnered drug, bepirovirsen, demonstrates a functional cure, paving the way for regulatory filings in early 2026.
Ionis Pharmaceuticals Inc. (NASDAQ: IONS) shares climbed to a new 52-week high on Wednesday after the company and its partner GSK announced positive topline results from two pivotal Phase 3 trials for their investigational treatment for chronic hepatitis B (CHB).
The stock jumped significantly in morning trading, reaching an intraday high of $85.64 as investors reacted to news that the drug, bepirovirsen, met its primary endpoint. The successful trials position the partners to seek regulatory approval, potentially introducing the first treatment to offer a "functional cure" for a virus affecting nearly 300 million people worldwide.
According to an official company announcement, the B-Well 1 and B-Well 2 studies both demonstrated that bepirovirsen led to a statistically significant and clinically meaningful clearance of the hepatitis B virus from the blood. This outcome, known as a functional cure, is the ultimate goal of CHB therapy, which currently focuses on long-term viral suppression rather than eradication.
"These results are a significant step forward for patients," the company stated. GSK confirmed it plans to move forward with global regulatory filings, with submissions anticipated in the first quarter of 2026.
The market's enthusiastic response reflects the massive commercial opportunity for an effective CHB treatment. The current standard of care involves lifelong antiviral therapy, which can control the virus but rarely cures it. A finite treatment course that clears the virus would represent a paradigm shift in patient care and a substantial revenue driver.
Wall Street analysts moved quickly to update their models following the news. RBC Capital raised its price target on Ionis to $95, reiterating an "Outperform" rating. TD Cowen also maintained its "Buy" rating with a $99 price target, signaling strong confidence in the drug's prospects and its value to Ionis's pipeline.
Developed using Ionis's proprietary antisense technology, bepirovirsen is designed to recognize and destroy the viral RNA that the hepatitis B virus uses to replicate and produce the antigens that prevent the body's immune system from clearing the infection. The partnership with GSK provides Ionis with a global pharmaceutical giant's resources for manufacturing, regulatory affairs, and commercialization.
Ionis Pharmaceuticals, with a market capitalization now exceeding $12.9 billion, specializes in RNA-targeted therapies. The success of bepirovirsen provides a crucial validation for its technology platform and a significant boost to a pipeline that addresses neurological, cardiovascular, and other complex diseases.
Looking ahead, investors and patients will be watching for the detailed data from the B-Well studies, which GSK plans to present at an upcoming scientific conference. The subsequent regulatory submissions and review processes by the FDA and other global health authorities will be the next major catalysts for the program.