The approval of Hibsago has created a new market for a handful of biopharmas, including Gilead, Arrowhead, and Vir, to fill in.
The approval of GSK and Ionis Pharmaceuticals’ Hibsago for chronic hepatitis B virus infection has pushed open the flood gates for a handful of followers also hoping to offer a comparable or better options for patients with the intractable disease.
Hibsago (bepirovirsen) is the first antisense oligonucleotide to receive an FDA nod for the indication. The therapy will offer a “functional cure,” meaning levels of the virus are pushed so low as to be undetectable. While partners GSK and Ionis may be the first, they won’t be the last, according to H.C. Wainwright analysts.
“The first FDA approval of an antisense oligonucleotide for chronic hepatitis B increases our confidence in the emerging functional cure market,” the firm wrote in a Thursday morning investor note. “We view approval as an important advance for the field: uncertainty over whether a finite regimen could generate sufficient sustained off-treatment responses to support FDA approval has now been resolved for bepi’s selected population.”
Behind GSK and Ionis are about 16 companies, ranging from large caps like Gilead Sciences to smaller biotechs like Arrowhead Pharmaceuticals and Aligos Therapeutics. There are also a few privately held companies like Argo Biopharmaceuticals and Tune Therapeutics in the mix.
Many of these companies will present data at the American Association for the Study of Liver Diseases (AASLD) meeting in November.
The approval of Hibsago “establishes a starting point for a multi-product market, in our view,” H.C. Wainwright wrote.
The FDA granted Hibsago approval for a fairly complex indication. The drug can be used in combination with nucleos(t)ide analogue reverse transcriptase inhibitor (NRTI) therapy in adults with chronic hepatitis B infection who do not have liver damage. They must have been on the NRTI therapy for at least six months, have suppressed HBV DNA and have levels of hepatitis B virus (HBV) surface antigen below a certain threshold. The therapy was approved with a companion diagnostic from Roche to test for HBV surface antigen.
With such a specific population, H.C. Wainwright points out that there are plenty of patients who do not fit the exact mold. “We believe higher-antigen patients and patients who do not achieve sustained responses remain substantial opportunities for subsequent regimens.”
Aligos is one biotech that could offer such an option. The company is developing the oral capsid assembly modulator pevifoscorvir sodium (pevy) for patients with chronic infection who have a higher antigen burden. An abstract from AASLD shows a reduction in HBV surface antigen that H.C. Wainwright believes supports further exploration of whether the therapy could offer a functional cure for these patients.
Investors will have to wait until the third quarter of 2027 for a more robust Phase 2 readout from the B-SUPREME trial, which H.C. Wainwright said is “the principal pevy efficacy checkpoint.”
Precision Biosciences will also present at AASLD, showcasing Phase 1 results from the ELIMINATE-B program for the gene therapy PBGENE-HBV. While the data are early, H.C. Wainwright will be watching for details on the duration of pgRNA loss, which is the biomarker Precision is tracking to look for the elimination of the stable viral genomes that give rise to new HBV infections.
GSK and Ionis will also have a showing at AASLD. H.C. Wainwright expects the presentation to help physicians understand how to select and manage patients.
Arrowhead is another company that could benefit from the new market established by Ionis and GSK. The biotech’s siRNA daplusiran/tomligisiran is being tested by GSK in the Phase 2b B-UNITED trial along with Hibsago.
Assembly Biosciences, which is developing the oral hepatitis D virus (HDV) entry inhibitor ABI-6250, is a “partnering opportunity,” according to H.C. Wainwright.
Other names with early assets include Vir Biotechnology’s elebsiran and tobevibart combo and Mirum Pharmaceuticals’ monoclonal antibody brelovitug. “We would not transfer bepi’s HBV approval directly into higher efficacy assumptions for those programs,” H.C. Wainwright said.
