The Class Period commences on May 4, 2023, when ACELYRIN, INC.'s initial public offering was completed and Acelyrin’s common stock began publicly trading on the NASDAQ. The complaint alleges that throughout the Class Period, the defendants touted izokibep’s effectiveness in treating HS.

However, the truth was revealed on September 11, 2023, after the markets closed, when Acelyrin issued a press release entitled “ACELYRIN, INC. Announces Top-Line Results from Placebo-Controlled Clinical Trial of Izokibep for Moderate-to-Severe Hidradenitis Suppurativa,” which stated that the “primary endpoint of HiSCR75 at week 16 did not meet statistical significance.”

Following 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.

According to the complaint and throughout the Class Period, the defendants 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; and (iii) as a result, Acelyrin also overstated the company’s business prospects post-IPO.

Investors who purchased or acquired Acelyrin securities between May 4, 2023 and September 11, 2023 may no later than January 16, 2024, seek to be appointed as a lead plaintiff representative of the class.