Form 4: ACELYRIN Director's Stock Options Converted Following Alumis Merger Completion

A recent SEC Form 4 filing reveals the conversion of Director Bruce C. Cozadd's stock options in ACELYRIN, Inc. into Alumis, Inc. shares following the successful merger of the two companies.

Summary

• Bruce C. Cozadd, a Director of ACELYRIN, Inc. (SLRN), filed a Form 4 reporting changes in his beneficial ownership of derivative securities.
• The changes are a direct result of the merger between ACELYRIN, Inc. and Alumis, Inc. (Parent), which became effective on May 21, 2025.
• Pursuant to the Merger Agreement, ACELYRIN, Inc. merged with and into Arrow Merger Sub, Inc., a wholly owned subsidiary of Alumis, Inc., with ACELYRIN surviving as a wholly owned subsidiary of Alumis.
• At the effective time of the merger, each share of ACELYRIN common stock was converted into the right to receive 0.4814 shares of Alumis voting common stock.
• Outstanding and unexercised ACELYRIN stock options with an exercise price of $18.00 or less were assumed by Alumis and converted.
• The number of shares subject to the converted options is calculated by multiplying the original number of shares by the 0.4814 Exchange Ratio, rounded down.
• The exercise price of the converted options is calculated by dividing the original exercise price by the 0.4814 Exchange Ratio, rounded up to the nearest whole cent.
• Mr. Cozadd's three tranches of Director Stock Options, with original exercise prices of $4.0426, $18.00, and $4.46, and original share counts of 183,434, 23,243, and 92,158 respectively, are now beneficially owned as Alumis options (reported as 0 ACELYRIN options remaining).

Sentiment

Score: 7

Explanation: The filing reports the successful completion of a previously announced merger, indicating a planned corporate action has been executed, which is generally a positive sign of operational execution.

Positives

• The successful completion of the merger between ACELYRIN, Inc. and Alumis, Inc. indicates a significant corporate strategic objective has been achieved.
• Director stock options were appropriately converted into options for the acquiring entity, Alumis, Inc., ensuring continuity of incentive for the director.

Future Outlook

No specific forward-looking statements or guidance regarding the combined entity's future performance or strategy are provided in this filing, which reports a completed transaction.

Industry Context

This filing reflects a completed merger within the biotechnology or pharmaceutical industry, a common strategic move for companies seeking to consolidate assets, expand pipelines, or achieve greater scale.

Stakeholder Impact

• Shareholders of ACELYRIN, Inc. have had their shares converted into shares of Alumis, Inc., impacting their ownership structure and future investment performance.
• Holders of ACELYRIN stock options, including Director Bruce C. Cozadd, have had their options converted into options to purchase Alumis, Inc. common stock, maintaining their equity incentives within the new corporate structure.

Next Steps

• The converted stock options will now be subject to the terms and conditions of Alumis, Inc.'s equity plans, with vesting schedules continuing as per the original agreements, adjusted for the merger terms.

Key Dates

Keywords

SEC Form 4, ACELYRIN, SLRN, Alumis, Merger, Stock Options, Beneficial Ownership, Director, Corporate Action, Equity Conversion