Case Status
Case Caption
Aramouni v. Acelyrin, Inc., et al.
Co-Lead Counsel
Practice Areas
U.S. District Court for the Central District of California
Judge Assigned
Fernando M. Olguin
Case Number
Acelyrin, Inc.
Shao-Lee Lin
Mardi C. Dier
Bruce C. Cozadd
Dan Becker
Alan B. Colowick
Henry O. Gosebruch
Patrick Machado
Beth Seidenberg
Dawn Svoronos
Stock Symbol
File Date
Class Period
Lead Plaintiff Deadline

The litigation focuses on Acelyrin’s disclosures about its lead product candidate (izokibep), intended to treat patients with moderate to severe Hidradenitis Suppurativa (“HS”).

During the Class Period, Acelyrin said that evidence “continues to support the hypothesis that the high potency and small molecular size of izokibep can lead to clinically meaningful, differentiated benefits for patients[.]”  

The complaint alleges that Acelyrin mispresented and omitted to disclose that: (1) izokibep was less effective in treating HS than the company had led investors to believe; (2) accordingly, Acelyrin overstated izokibep’s clinical and/or commercial prospects; and (3) as a result, Acelyrin had overstated its business prospects.

Investors learned the truth on Sept. 11, 2023, when Acelyrin announced disappointing top-line results from Part B of the Phase 2b/3 trial evaluating izokibep for the treatment of moderate to severe HS. The company said izokibep failed to show statistically significant reduction in abscesses and inflammatory nodules in patients as compared to placebo.

This news drove the price of Acelyrin shares plummeting $17.19 lower during the two trading days ended Sept. 13, 2023.


First Amended Complaint is Filed
Hagens Berman is appointed Co-Lead Counsel

Complaint is Filed

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