Nektar’s next cytokine hope follows bempe towards the bin

After the abandonment of bempegaldesleukin last year, Nektar really needed rezpegaldesleukin to work, if only to justify the group’s ongoing work with cytokines. But the project’s failure in a phase 2 systemic lupus erythematosus trial suggests that the follow-on IL-2 asset, which had been engineered to stimulate regulatory T cells, is similarly ill-fated. None of the doses tested in the Island-SLE study met the primary endpoint, and neither was there a dose-response with the middle dose performing best, though still missing significance. True, lupus’s reputation as a tough disease to treat is justified, but Lilly, Nektar's partner on rezpegaldesleukin, has already decided to walk away from the indication; last year, it dropped the asset in ulcerative colitis. The partners are to discuss rezpegaldesleukin’s future but without Lilly’s commitment Nektar said it would not push on alone in lupus; the biotech is sitting on around $500m in cash but is already supporting other projects. Analysts from both SVB and Mizuho state that Lilly might hand back rights completely. Nektar’s shares dropped 46% at the open, leaving it with a market cap of less than $300m.