AbbVie bought ex-China rights to two NaV1.8 sodium channel pain inhibitors from Beijing-based Haisco Pharmaceutical for up to $745 million. The structure: $30 million upfront, $10 million in near-term milestones, $705 million in additional milestone payments, and tiered royalties in the high-single-digit percentages on net sales.
What does AbbVie actually get? Two assets: HSK55718, an IV formulation in Phase 1 trials in China, and HSK51155, an oral candidate still in preclinical. Both target NaV1.8, a sodium channel in pain-sensing nerve cells that transmit pain signals to the brain. They don’t carry the addiction risk that opioids do, and are designed to block pain at the source by limiting abnormal nerve firing. AbbVie will fund certain R&D costs through clinical proof of concept.
The closest comparable is Eli Lilly’s deal for SiteOne Therapeutics, which included a NaV1.8 inhibitor in a package worth up to $1 billion. Vertex Pharmaceuticals holds the first-mover position. Journavx, approved in early 2025, generated $59.6 million in revenue last year. Vertex’s next-gen NaV1.8 candidate failed Phase II, though, and Vertex dropped it.
At $30 million down for two pre-Phase 2 assets, it’s cheap optionality. If either program clears clinical hurdles, $705 million in milestones starts moving. For Haisco, it’s the second sizable licensing deal in 2026, after its $955 million biobucks lung disease deal with AirNexis Therapeutics in January.
No close date was disclosed.
Diana Kowalski