Alumis and Acelyrin file a definitive proxy statement for proposed merger

Alumis and Acelyrin have filed a definitive proxy statement/prospectus with the US Securities and Exchange Commission for the proposed merger of the companies.

According to a joint statement from the company, each company will hold a respective special meeting of stockholders on Tuesday, May 13, 2025. Stockholders of record as of the close of business on April 1, 2025, will be entitled to vote at the respective special meetings of stockholders. Acelyrin stockholders will receive 0.4274 shares of Alumis common stock for each share of Acelyrin common stock owned. Upon close, Alumis stockholders will own ~55% of the combined company, and Acelyrin stockholders will own ~45% of the combined company.

The companies stated that by combining assets, resources, and talent, including members of Acelyrin’s lonigutamab program, the combined company will be well positioned to maximize the value of its pipeline. Lonigutamab is a subcutaneously delivered monoclonal antibody targeting IGF-1R being investigated for the treatment of thyroid eye disease.

Pending approval, the companies stated that the merging of the two companies will “create a late-stage clinical biopharma company dedicated to innovating, developing, and commercializing transformative therapies for immune-mediated diseases.”

The transaction is expected to close in Q2 of 2025, subject to approval by the stockholders of both companies and satisfaction of other customary closing conditions.

References:

1. Alumis and ACELYRIN file joint definitive proxy statement for proposed merger. Published April 4, 2025. Accessed April 7, 2025. https://investors.alumis.com/news-releases/news-release-details/alumis-and-acelyrin-file-joint-definitive-proxy-statement