Regulatory status: Approved; NDA submitted in the first quarter of 2026 and approved October 2026

“In Q1, the US FDA accepted for priority review a New Drug Application (NDA) for bepirovirsen and set 26 October 2026 as the decision goal date.” (opens the source at this quote in a new tab)
“lower spend on bepirovirsen which was filed in the quarter” (opens the source at this quote in a new tab)

“Growth was partly offset by lower spend on bepirovirsen which was filed in Q1 2026.” (opens the source at this quote in a new tab)

Field	Quoted record
Drug name	“Hibsago”
Active ingredient	“bepirovirsen”
Approval date	“10/20/2026”

Launch: Anticipated before the end of 2026

“Hibsago should be made available to U.S. patients before the end of the year, a GSK spokesperson told Fierce” (opens the source at this quote in a new tab)

“GSK anticipates the first regulatory decisions in Q3 2026 and launch preparations are underway.” (opens the source at this quote in a new tab)

FDA approval on 20 October 2026

“The U.S. Food and Drug Administration today approved Hibsago (bepirovirsen) injection, in combination with existing antiviral therapy, to treat chronic hepatitis B virus (HBV) infection in certain adults without cirrhosis.” (opens the source at this quote in a new tab)

“Initial U.S. Approval: 2026” (opens the prescribing information at this quote)

Expedited programs named at approval

“The FDA granted Hibsago Fast Track and Breakthrough Therapy designations as well as Priority Review.” (opens the source at this quote in a new tab)

“The approval was granted under FDA priority review and Breakthrough Therapy Designation, recognising significant improvement of bepirovirsen and nucleos(t)ide analogue therapy over existing standard of care.” (opens the source at this quote in a new tab)

Evidence supporting approval

“Researchers studied Hibsago in two clinical trials that compared it with a placebo, an inactive treatment.” (opens the source at this quote in a new tab)
“Across the two trials, 24% of patients who received Hibsago met the requirements to stop their existing medicine, compared with none who received placebo.” (opens the source at this quote in a new tab)

“The approval was supported by results from the B-WELL phase III trials showing functional cure rates of 19% in adults with ≤3000 IU/ml HBsAg, compared to current standard of care alone, which typically achieves less than 1% functional cure rate after one year of treatment.” (opens the source at this quote in a new tab)

Priority review and PDUFA goal date, April 2026

“GSK plc (LSE/NYSE: GSK) today announced that the US Food and Drug Administration (FDA) has accepted for priority review a New Drug Application (NDA) for bepirovirsen, an investigational antisense oligonucleotide (ASO), for the treatment of adults with chronic hepatitis B (CHB).” (opens the source at this quote in a new tab)
“The FDA has assigned 26 October 2026 as the Prescription Drug User Fee Act (PDUFA) goal date.” (opens the source at this quote in a new tab)

“Regulatory review is ongoing in the US with a decision expected from the FDA by 26 October 2026.” (opens the source at this quote in a new tab)

Breakthrough therapy designation, first quarter of 2026

“Bepirovirsen has also received Breakthrough Therapy Designation (BTD), which is reserved for investigational medicines where preliminary clinical evidence indicates the potential for substantial improvement over available therapies.” (opens the source at this quote in a new tab)
“The BTD for bepirovirsen builds on the Fast Track Designation also provided by the US FDA in February 2024.” (opens the source at this quote in a new tab)

“In Q1, bepirovirsen also received FDA Breakthrough Therapy Designation which is reserved for investigational medicines where preliminary clinical evidence indicates the potential for substantial improvement over available therapies.” (opens the source at this quote in a new tab)

Fast track designation, February 2024

“GSK plc (LSE/NYSE: GSK) announced today that the US Food and Drug Administration (FDA) has granted Fast Track designation for bepirovirsen, an investigational antisense oligonucleotide (ASO) for the treatment of chronic hepatitis B (CHB).” (opens the source at this quote in a new tab)
“Data from the phase IIb trials B-Clear and B-Sure, which evaluated the efficacy, safety and durability of response of bepirovirsen in people with CHB, were submitted in support of the application.” (opens the source at this quote in a new tab)

Phase 3 B-Well trials: initiation in February 2023

“Ionis Pharmaceuticals, Inc. (Nasdaq: IONS) today announced that GSK has initiated two randomized, double-blind, placebo-controlled Phase 3 studies evaluating the safety and efficacy of bepirovirsen (formerly IONIS-HBVRx), an investigational antisense medicine for the treatment of patients with chronic hepatitis B infection (CHB).” (opens the source at this quote in a new tab)
“Ionis earned a $15 million milestone payment from GSK associated with the progression of bepirovirsen into the Phase 3 clinical studies.” (opens the source at this quote in a new tab)

Phase 3 B-Well trials: topline results in January 2026

“Primary endpoint met in both trials” (opens the source at this quote in a new tab)
“Global regulatory filings planned from Q1 2026” (opens the source at this quote in a new tab)

Japan: application accepted in February 2026

“First regulatory filing globally, with SENKU designation enabling expedited review” (opens the source at this quote in a new tab)
“GSK plc (LSE/NYSE: GSK) today announced that Japan’s Ministry of Health, Labour and Welfare (MHLW) has accepted for review a new drug application (NDA) for bepirovirsen, an investigational antisense oligonucleotide (ASO), for the treatment of adults with chronic hepatitis B (CHB).” (opens the source at this quote in a new tab)

Japan: SENKU designation, August 2024

“GSK plc (LSE/NYSE: GSK) today announced that the Japanese Ministry of Health, Labour and Welfare (MHLW) has granted SENKU (formerly known as SAKIGAKE) designation for bepirovirsen, an investigational antisense oligonucleotide (ASO) for the treatment of chronic hepatitis B (CHB).” (opens the source at this quote in a new tab)
“The goal of SENKU designation is to increase early patient access to innovative medicines through an expedited review process to treat serious conditions and fill an unmet medical need.” (opens the source at this quote in a new tab)

Japan: approval on 24 August 2026

“First global approval for Hibsago” (opens the source at this quote in a new tab)
“This is the first global approval for bepirovirsen, and the first and only functional cure treatment for CHB approved in Japan.” (opens the source at this quote in a new tab)
“This approval was accelerated by SENKU designation, granted to innovative medicines with potential to address high unmet medical need.” (opens the source at this quote in a new tab)

European Union: marketing authorisation application accepted in March 2026

“GSK plc (LSE/NYSE: GSK) today announced that the European Medicines Agency (EMA) has accepted for review the marketing authorisation application (MAA) for the use of bepirovirsen, an investigational antisense oligonucleotide (ASO), in the treatment of adults with chronic hepatitis B (CHB).” (opens the source at this quote in a new tab)

China: application accepted in March 2026

“GSK plc (LSE/NYSE: GSK) today announced that the China National Medical Products Administration (NMPA) has accepted for review a new drug application (NDA) for bepirovirsen, an investigational antisense oligonucleotide (ASO), for the treatment of adults with chronic hepatitis B (CHB).” (opens the source at this quote in a new tab)

China: breakthrough therapy designation in August 2021 and priority review in April 2026

“Bepirovirsen was granted Breakthrough Therapy designation in China in August 2021 and accepted for Priority Review in April 2026.” (opens the source at this quote in a new tab)

Anticipated regulatory decisions outside the United States

“Reviews are also underway in Japan, China and the EU with further submissions to take place throughout 2026.” (opens the source at this quote in a new tab)

Anticipated pipeline milestone	Event	Timing
United States and Japan	“Regulatory decision (US, JP)”	“H2 2026”
European Union and China	“Regulatory decision (EU, CN)”	“H1 2027”

“GSK continues to advance regulatory submissions for bepirovirsen across multiple geographies with key regulatory decisions anticipated in the coming months.” (opens the source at this quote in a new tab)
“Bepirovirsen is approved in Japan and the US.” (opens the source at this quote in a new tab)

Licensing from Ionis Pharmaceuticals, August 2019

“Ionis Pharmaceuticals, Inc. (Nasdaq: IONS), the leader in RNA-targeted therapeutics, announced today that GSK exercised its option to license Ionis' antisense medicines for people with chronic hepatitis B virus (CHB) infection following positive Phase 2 results.” (opens the source at this quote in a new tab)
“As a part of the licensing agreement, Ionis is eligible to receive license fees and milestone payments up to $262 million, including a $25 million license fee.” (opens the source at this quote in a new tab)
“GSK is now responsible for all development, regulatory and commercialization activities and costs.” (opens the source at this quote in a new tab)

“GSK licensed bepirovirsen from Ionis in 2019 under a collaborative development and licensing agreement.” (opens the source at this quote in a new tab)