Alumis Inc. (Nasdaq: ALMS) and ACELYRIN, Inc. (Nasdaq: SLRN) today announced a definitive merger agreement, creating a powerhouse in immunology-focused biopharmaceutical innovation. This all-stock transaction strengthens the combined company’s financial position, extends its operating runway into 2027, and positions it for multiple anticipated clinical milestones.

Key Highlights of the Merger:

• Robust Late-Stage Pipeline – Alumis’ TYK2 inhibitor, ESK-001, advancing in Phase 3 for moderate-to-severe plaque psoriasis (ONWARD trials) and Phase 2b for systemic lupus erythematosus (LUMUS trial), with topline data readouts expected in 2026.
• Lonigutamab Development Underway – ACELYRIN’s best-in-class anti-IGF-1R therapy for thyroid eye disease (TED) to be evaluated for differentiation and optimized within the broader Alumis pipeline.
• Strong Financial Foundation – A pro forma cash position of ~$737 million as of Dec. 31, 2024, supporting continued development and commercial readiness through multiple clinical readouts.
• Balanced Ownership Structure – Alumis stockholders to own ~55% and ACELYRIN stockholders ~45% of the combined company.
• Unified Leadership & Operational Focus – The combined entity will operate under the Alumis name, led by the current Alumis executive team, with headquarters in South San Francisco.

CEO Perspectives on the Strategic Vision

"This merger unites two companies committed to advancing precision medicine for immune-mediated diseases. Alumis will now have the financial flexibility to progress its pipeline, accelerate commercial readiness, and expand the potential of ESK-001 across multiple indications," said Martin Babler, President, CEO, and Chairman of Alumis. “As we move forward, we remain focused on disciplined capital allocation and maximizing the value of our differentiated late-stage portfolio.”

Bruce Cozadd, Chair of ACELYRIN’s Board of Directors, added: “Following a rigorous strategic review, we are confident Alumis is the right partner to optimize the development of lonigutamab and drive long-term value for stockholders.”

Mina Kim, CEO of ACELYRIN, stated: “This merger strengthens our mission to develop transformative immunology therapies. By combining our expertise and resources, we are better positioned to advance our pipeline and expand treatment options for patients in need.”

Advancing a Best-in-Class Immunology Pipeline

The merger brings together two complementary pipelines focused on precision medicine for immune-mediated diseases:

• ESK-001 (Oral TYK2 Inhibitor) – Currently in Phase 3 for moderate-to-severe plaque psoriasis (PsO) and Phase 2b for systemic lupus erythematosus (SLE), with potential expansion into additional indications.
• A-005 (CNS-Penetrant TYK2 Inhibitor) – A first-in-class therapy for neuroinflammatory and neurodegenerative diseases such as multiple sclerosis (MS) and Parkinson’s Disease, with a Phase 2 trial in MS expected to initiate in H2 2025.
• Lonigutamab (Anti-IGF-1R Therapy) – The first subcutaneous anti-IGF-1R therapy for thyroid eye disease (TED), with efficacy comparable to IV-administered standard of care. Ongoing assessment will optimize its development strategy.

Financial and Transaction Details

• ACELYRIN stockholders will receive 0.4274 shares of Alumis common stock per ACELYRIN share owned.
• The transaction has been unanimously approved by both companies’ Boards and is expected to close in Q2 2025, pending stockholder and regulatory approvals.
• Stockholders representing ~62% of Alumis’ voting common stock and ~24% of ACELYRIN’s common stock have entered into voting agreements supporting the transaction.