Case Summary



Case Details

  • Aramouni v. Acelyrin, Inc., et al.
  • Class Period:May 04, 2023 - September 11, 2023
  • Date Filed:November 15, 2023
  • Jurisdiction:U.S. District Court, Central District of California
  • Docket Number: 2:23-cv-09672
  • Lead Plaintiff Deadline: January 16, 2024
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A class action lawsuit captioned Aramouni v. Acelyrin, Inc., et al. has been filed against Acelyrin, Inc. (“Acelyrin” or the “Company”) (NASDAQ: SLRN) and certain of the Company’s top executive officers alleging that they violated the federal securities laws. The lawsuit seeks to represent all persons and entities who purchased or otherwise acquired Acelyrin’s securities between May 4, 2023, and September 11, 2023, both dates inclusive (the “Class Period”).

Acelyrin is a clinical biopharma company that focuses on developing and commercializing transformative medicines. The Company’s lead product candidate is izokibep, a small protein therapeutic designed to inhibit IL-17A with purportedly high potency, which is currently in Part B of a Phase 2b/3 clinical trial for use in the treatment of moderate to severe Hidradenitis Suppurativa (“HS”).

On April 13, 2023, Acelyrin filed a registration statement on Form S-1 with the United States Securities and Exchange Commission (“SEC”) in connection with the Company’s Initial Public Offering (“IPO”), which, after several amendments, was declared effective by the SEC on May 4, 2023 (the “Registration Statement”). On May 4, 2023, pursuant to the Registration Statement, Acelyrin’s common stock began publicly trading on the Nasdaq Global Select Market under the trading symbol “SLRN”. On May 5, 2023, Acelyrin filed a prospectus on Form 424B4 with the SEC in connection with the IPO, which incorporated and formed part of the Registration Statement (collectively with the Registration Statement, the “Offering Documents”) Pursuant to the Offering Documents, Acelyrin issued 30 million shares of its common stock to the public at the Offering price of $18.00 per share for proceeds to the Company of $502.2 million after applicable underwriting discounts and commissions.

The complaint alleges that throughout the Class Period, Defendants made materially false and misleading statements regarding the Company’s business, operations, and prospects. Specifically, Defendants made false and/or misleading statements and/or failed to disclose that: (i) izokibep was less effective in treating HS than Defendants had led investors to believe; (ii) accordingly, Acelyrin overstated izokibep’s clinical and/or commercial prospects; (iii) as a result, Acelyrin also overstated the Company’s business prospects post-IPO; and (iv) as a result, the Company’s public statements were materially false and misleading at all relevant times.

On September 11, 2023, after the markets closed, 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. Specifically, izokibep failed to show statistically significant reduction in abscesses and inflammatory nodules in patients as compared to placebo. On this news, Acelyrin’s stock price fell $17.19 per share, or 61.61%, over the following two trading sessions, to close at $10.71 per share on September 13, 2023.

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If you purchased or otherwise acquired Acelyrin’s securities between May 4, 2023, and September 11, 2023, both dates inclusive, and suffered substantial losses, and you wish to serve as lead plaintiff in this lawsuit, we encourage you to submit your information to DiCello Levitt LLP via the form on this page. 

You can also contact DiCello Levitt partner Brian O’Mara by calling (888) 287-9005 or at 

The deadline to apply to the Court to serve as a lead plaintiff in the Acelyrin lawsuit is January 16, 2024.

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