After J&J limbo, Arrowhead finds a new (old) partner for hep B program: GSK

Arrowhead Pharmaceuticals finally knows the future of its hepatitis B med: Johnson & Johnson has offloaded the rights to GSK.

Earlier this year, J&J’s Janssen unit began shrinking its infectious disease and vaccine portfolio, leaving several partners, including Arrowhead, unclear on the future of their partnerships. Arrowhead had been working with Janssen since 2018 on the hepatitis B medicine JNJ-3989.

Now, GSK has been revealed as Arrowhead’s new partner for the program—although the two have an existing licensing deal. The U.K. pharma is paying a total of $1 billion in upfront and milestone-based payments to both Arrowhead and Janssen for the rights to JNJ-3989. GSK will also owe Arrowhead all remaining financial obligations under the original deal that pertain to the single candidate. The original deal between J&J and Arrowhead totaled $3.7 billion in upfront and milestone payments for the hep B med and up to three targets.

Janssen will continue to be responsible for ongoing clinical trials of JNJ-3989, which is currently in phase 2 testing.

GSK is happy to pick up the licensing deal from Janssen, with immediate plans to pair JNJ-3989 with its own candidate bepirovirsen to try to achieve better functional cure rates. GSK said the combo could move into a phase 2 trial in 2024.

“We are excited to build on promising results already demonstrated with bepirovirsen to investigate a novel sequential regimen with JNJ-3989. We believe this approach could redefine the treatment paradigm for chronic hepatitis B by helping even more patients achieve functional cure,” said GSK Chief Scientific Officer Tony Wood, Ph.D., in the Tuesday release.

Arrowhead and GSK signed a deal in 2021 to work on the oligonucleotide therapeutic GSK4532990 (ARO-HSD) for patients with alcohol-related and non-alcohol-related liver diseases. GSK snagged rights to develop the candidate outside of greater China.

GSK has doubled down on the bepirovirsen program, which is partnered with Ionis Pharmaceuticals. The therapy is being tested in a pair of phase 3 studies as a potential “functional cure” for hepatitis B virus infection.

But the pharma also has a larger oligonucleotide strategy and has been collecting partnerships to go deeper into the field. It signed a research collaboration with Elsie Biotechnologies in July to discover even more oligonucleotide therapeutics. Prior to that, Wave Life Sciences was offered $170 million upfront for a license to a preclinical RNA editing therapy and up to eight programs from the biotech’s oligonucleotide platform.

“GSK has a global reach, a clear commitment to help those living with chronic hepatitis B, and a promising strategy for clinical studies designed to improve functional cure rates,” said Arrowhead CEO Chris Anzalone, Ph.D., in a statement. “We have great confidence in the team at GSK and look forward to seeing this program progress towards the goal of potentially helping the millions of patients with chronic hepatitis B worldwide without adequate treatment options.”