GSK plc (LSE/NYSE: GSK) shares edged lower in early Monday trading, even as the pharmaceutical company announced two significant regulatory developments across its oncology and hepatology pipelines.
The US Food and Drug Administration accepted for priority review a supplemental Biologics License Application for Jemperli (dostarlimab) in previously untreated stage II and III dMMR/MSI-H locally advanced rectal cancer.
The FDA has set a PDUFA action date of February 2027 for the application, which was submitted under the agency’s Project Orbis scheme for coordinated international review.
The submission is also eligible for expedited assessment through the National Priority Voucher programme, adding another potential pathway to accelerate the drug’s regulatory journey.
Data backing the application came from the phase II AZUR-1 trial, which enrolled 154 participants and showed a meaningful proportion remained free of detectable cancer a year or more after treatment.
If approved, Jemperli could become the first immunotherapy capable of sparing certain rectal cancer patients from chemotherapy, radiation, and surgery, representing a significant shift in treatment standards.
On a separate front, GSK secured its first global approval for Hibsago (bepirovirsen), after Japan’s Ministry of Health, Labour and Welfare cleared the antisense oligonucleotide as a functional cure for chronic hepatitis B.
The Japanese approval, accelerated through the country’s SENKU designation, applies to adults who have completed at least six months of prior nucleoside analogue therapy.
Phase III B-Well data underpinning the Hibsago approval demonstrated a 19% functional cure rate compared to roughly 1% for standard care alone, a result GSK’s Chief Scientific Officer Tony Wood described as “a major advance” for hepatitis B management.
GSK said US and other regulatory decisions on Hibsago are expected in the coming months, potentially opening the drug to a far larger global patient population.
Despite positive momentum across two therapeutic areas and progress on multiple regulatory fronts, investors responded with caution, with GSK shares trading marginally lower on the day of the announcements.
The muted market reaction suggests investors may be adopting a wait-and-see approach ahead of the February 2027 PDUFA date for Jemperli and the anticipated international regulatory verdicts for Hibsago.
