Shares of AnaptysBio, Inc. (ANAB) plunged 15% to $19.70 in after-hours on Wednesday, following disappointing topline results of the HARP study.
HARP is a phase II study evaluating Imsidolimab for the treatment of moderate-to-severe Hidradenitis Suppurativa (HS) in 149 patients.
Patients received subcutaneous monthly doses of Imsidolimab 400 mg/200mg, Imsidolimab 200 mg/100mg, or placebo for a 16-week period followed by an extension period of 16 weeks.
The primary endpoint was the mean change in inflammatory nodule and abscess (AN) lesion count from baseline at week 16. The secondary endpoint was the Hidradenitis Suppurativa Clinical Response (HiSCR) measure.
Imsidolimab did not demonstrate improvement over placebo in the primary or the secondary endpoints.
The mean baseline total inflammatory nodule and abscess (AN) lesion count for the Imsidolimab high dose, the low dose, and the placebo arm were 14.0, 11.9, and 12.1, respectively.
The company plans to discontinue Imsidolimab clinical development in HS.
Imsidolimab previously demonstrated efficacy and safety in the GALLOP Phase 2 trial in generalized pustular psoriasis, a life-threatening inflammatory disease in which Imsidolimab has been granted Orphan Disease Designation.
A phase III trial evaluating Imsidolimab for the treatment of Generalized Pustular Psoriasis, dubbed GEMINI-1 GPP is ongoing, with top-line data anticipated in Q4 2023.
ANAB has traded in a range of $18.20 to $37.89 in the last 52 weeks. The stock closed Wednesday's trading at $23.22, down 2.27%.
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April 24, 2026 15:15 ET Economics news flow was relatively light this week even as the conflict in the Middle East continued, raising concerns for policymakers. In the U.S., spending data, initial jobless claims and pending home sales were the highlights. Business confidence in the biggest euro area economy was in focus in Europe. Inflation data from Japan gained attention in Asia.