AnaptysBio's Imsidolimab Fails To Separate From Placebo In Skin Blistering Disorder Study

AnaptysBio Inc (NASDAQ: ANAB) reports disappointing top-line data from its Phase 2 (POPLAR) trial of imsidolimab for palmoplantar pustulosis (PPP).

• The study failed to meet its primary endpoint of improvement on disease severity index from baseline at week 16, compared to placebo.
• PPP is an autoimmune disorder characterized by blister-like sores on the palms of hands and feet' soles.
• Improvement in disease severity index at week 16 was 6.1 for imsidolimab-treated patients, compared to 6.3 in the placebo group.
• The mean change in disease severity from baseline was 5.78 or 38% improvement in the Imsidolimab arm, versus 6.78 or 33% improvement on the placebo.
• Nine patients achieved 50% improvement, and four patients achieved 75% improvement in the imsidolimab arm at week 16, compared to 12 and 3 responders in the placebo arm, respectively.
• Five imsidolimab-treated patients achieved almost clear skin at week 16 relative to 3 on placebo.
• Further development in PPP is not currently anticipated, but the company will continue developing imsidolimab in five other immuno-dermatological indications.
• Phase 3 study in generalized pustular psoriasis will start during mid-2021.
• Imsidolimab was generally well-tolerated with a similar frequency of adverse events between treatment groups, and no severe or serious adverse events were observed in the imsidolimab arm. 
• Price Action: ANAB shares trading has been halted, set to resume at 8:30 am EST.