ACELYRIN (SLRN) M&A Announcement summary

Deal rationale and strategic fit

• Merger creates a differentiated late-stage biopharma focused on immune-mediated diseases, combining complementary pipelines, expertise, and proprietary data analytics for R&D.

• Strategic review by both companies determined this path maximizes value for shareholders and patients, leveraging combined resources.

• Combined entity aims to accelerate development and commercialization of transformative immunology therapies.

• Expanded portfolio includes lonigutamab for thyroid eye disease and a TYK2 inhibitor, broadening therapeutic options.

Financial terms and conditions

• All-stock transaction: ACELYRIN stockholders receive 0.4274 Alumis shares per ACELYRIN share, resulting in a 55%/45% pro forma ownership split between Alumis and ACELYRIN stockholders.

• Pro forma cash position of $737 million at end of 2024, providing runway into 2027 and supporting key clinical milestones.

• Alumis will issue approximately 44.7 million shares to ACELYRIN shareholders, with just under 55 million shares outstanding post-merger.

Synergies and expected cost savings

• Early synergies expected from eliminating duplicative public company infrastructure and pooling resources for late-stage clinical development.

• Enhanced financial strength enables pursuit of multiple programs and milestone readouts.

• Combined R&D and commercial expertise expected to drive value and operational efficiency.