Kezar Life's Lead Asset Fails To Top Placebo In Muscle Inflammation Disease

Kezar Life Sciences Inc KZR announced topline results from the PRESIDIO Phase 2 trial of zetomipzomib (KZR-616) in patients with dermatomyositis (DM) and polymyositis (PM), chronic inflammatory diseases of muscle.
Topline results showed that most DM and PM patients saw clinically meaningful improvements in Total Improvement Score (TIS), but zetomipzomib demonstrated no significant differentiation from placebo.
At Week 16, the zetomipzomib 45 mg subcutaneously weekly group achieved a mean TIS of 25.5 versus the control group's mean TIS of 25.
Related: Small-cap Biopharma Kezar Life Sciences Is Soaring, Here's Why.
Following crossover, at week 32, the arm receiving zetomipzomib beginning at Week 16 achieved a mean TIS of 32.5 versus the control group's mean TIS of 31.3.
Zetomipzomib was well tolerated. Adverse events were generally mild-to-moderate, and the most common treatment-emergent adverse events were injection site reactions, which were transient and manageable.
One subject withdrew from the study following an injection site reaction.
There were three Grade 3 serious adverse events in the zetomipzomib arms, including one patient who experienced a mechanical fall and syncope and another patient who had a retinal detachment. All deemed unrelated to zetomipzomib.
Price Action: KZR shares closed 24.1% lower at $9.35 during after-hours trading on Tuesday.