Nothing is going to grow from AnaptysBio’s ACORN. One year after flunking a palmoplantar pustulosis (PPP) trial, the anti-IL-36R antibody imsidolimab has come up short in a phase 2 acne study.
The ACORN study randomized 123 moderate to severe acne patients to receive placebo or one of two doses of imsidolimab. After 12 weeks, participants in the low- and high-dose cohorts had respectively experienced 21% and 27% declines in facial inflammatory lesions. The problem? Participants on placebo experienced a 38% reduction. Placebo outperformed the study drug at three other time points, too.
Imsidolimab also failed to beat placebo against a secondary endpoint that looked at the proportion of patients who had a facial investigator global assessment of clear or almost clear with at least a two-point decrease from baseline. No patients on the low dose of imsidolimab met the criteria, compared to 12% of their peers in the high-dose arm and 14% of participants on placebo.
AnaptysBio responded by stopping development in acne. Investors responded by sending AnaptysBio’s stock down 10% to around $25.
The big question for AnaptysBio now is whether imsidolimab will be once, twice, three times a failure. While the biotech has suffered back-to-back setbacks in PPP and acne, it is forging ahead with a phase 3 clinical trial in generalized pustular psoriasis (GPP). AnaptysBio moved into phase 3 on the strength of data on eight subjects enrolled in a midphase trial.
In GPP, AnaptysBio is going up against Boehringer Ingelheim, which received priority review at the FDA for its IL-36R drug spesolimab late last year. AnaptysBio initiated its phase 3 trial in December, putting it some way behind Boehringer. The next data drop on imsidolimab is scheduled for the second half of the year, when AnaptysBio expects to post top-line results from a phase 2 trial in moderate to severe forms of the skin lump condition hidradenitis suppurativa.