Alumis Raises $300 Million in Public Offering Following Planned ACELYRIN Merger
Key Insights
Alumis completed an upsized public offering of 17.65 million shares at $17 per share, raising approximately $300 million in gross proceeds to fund its clinical-stage pipeline.
The company is simultaneously pursuing a merger with ACELYRIN that would create a combined entity with approximately $737 million in pro forma cash and runway into 2027.
The merged company will focus on immune-mediated diseases with key milestones including Phase 3 data for ESK-001 in psoriasis expected in Q1 2026 and Phase 2b lupus data in 2026.
Alumis Inc., a clinical-stage biopharmaceutical company developing targeted therapies for immune-mediated diseases, announced the pricing of an upsized public offering that raised approximately $300 million in gross proceeds. The offering of 17.65 million shares at $17 per share closed on January 9, 2026, providing the company with additional capital as it advances its pipeline of oral tyrosine kinase 2 inhibitors.
The timing of the capital raise coincides with Alumis's planned merger with ACELYRIN, which is expected to close in the second quarter of 2025 following stockholder approval. The transaction will create a late-stage clinical biopharma company with a differentiated pipeline and strong financial position.
Strategic Merger Creates Combined Entity
Under the merger agreement, ACELYRIN stockholders will receive 0.4274 shares of Alumis common stock for each share of ACELYRIN common stock owned. Upon completion, Alumis stockholders will own approximately 55% of the combined company and ACELYRIN stockholders will own approximately 45% on a fully diluted basis.
The combined entity will have pro forma cash of approximately $737 million as of December 31, 2024, providing runway into 2027 and extending beyond multiple expected clinical readouts. Both companies' boards of directors have unanimously recommended that their respective stockholders vote in favor of the proposed merger.
Pipeline Focused on Immune-Mediated Diseases
Alumis's lead program, envudeucitinib (ESK-001), is an oral, highly selective, small molecule allosteric inhibitor of TYK2 (search) currently being evaluated in moderate-to-severe plaque psoriasis (search) and systemic lupus erythematosus (search). The company expects topline data from Phase 3 ONWARD trials in psoriasis in Q1 2026, with Phase 2b LUMUS trial data in lupus on track for readout in 2026.
The pipeline also includes A-005, a clinical-stage, CNS-penetrant allosteric TYK2 (search) inhibitor for neuroinflammatory and neurodegenerative diseases (search), with Phase 2 clinical trial initiation planned for multiple sclerosis (search). Additionally, the merger will add lonigutamab, a subcutaneously delivered anti-insulin-like growth factor 1 receptor therapy for thyroid eye disease (search), with committed capital for clinical development.
Financial Structure and Leadership
Morgan Stanley (search), Leerink Partners (search), Cantor, and Wells Fargo Securities served as joint book-running managers for the public offering, with Baird and Oppenheimer & Co. acting as co-lead managers. The underwriters received a 30-day option to purchase up to an additional 2.65 million shares.
The combined company will benefit from leadership teams with proven track records in developing innovative therapies and maintaining operational discipline. By combining assets, resources, and talent, including members of ACELYRIN's lonigutamab program, the merged entity aims to maximize the value of its pipeline through capital efficiency and strategic focus.
Regulatory and Development Timeline
Special meetings for both companies' stockholders are scheduled for May 13, 2025, with stockholders of record as of April 1, 2025, entitled to vote. The transaction is subject to approval by stockholders of both companies and satisfaction of customary closing conditions.
Alumis leverages its proprietary precision data analytics platform to identify and develop molecules with potential to address immune-mediated diseases as monotherapy or combination therapies. The company's precision approach aims to optimize clinical outcomes and significantly improve patient health across its target indications.