GSK’s potential ‘functional cure’ for hepatitis B drug has performed strongly in a pair of hotly anticipated phase 3 studies, setting up the pharma for a push to the FDA.
The British drugmaker had been evaluating the Ionis Pharmaceuticals-partnered antisense oligonucleotide, called bepirovirsen, in a pair of late-stage studies for chronic hepatitis B (CHB) spanning more than 1,800 patients in 29 countries.
The trials, dubbed B-Well 1 and B-Well 2, met their primary endpoints by demonstrating a statistically significant and clinically meaningful higher functional cure rate for bepirovirsen and the current standard of care of nucleos(t)ide analogues versus standard of care alone among patients with baseline hepatitis B surface antigen (HBsAg) of less than 3,000 IU/ml.
‘Functional cure’ in the context of the studies was defined as HBsAg loss and undetectable HBV DNA for at least 24 weeks after the treatment.
The results were statistically significant across all ranked endpoints, explained GSK, which singled out patients with HBsAg below 1,000 IU/ml, where ‘an even greater effect was demonstrated.’
GSK is holding back the detailed data for an upcoming conference but said it is planning an approval push to regulators in the first quarter of this year.
If successful, bepirovirsen—which the pharma licensed from Ionis for $25 million upfront in 2019—could become the “first finite, six-month therapeutic option for CHB and to serve as a backbone for future sequential treatment strategies,” the company said.
