Form 4: ACELYRIN Chief Medical Officer Reports Full Conversion of Holdings Following Alumis Merger

ACELYRIN, Inc.'s Chief Medical Officer, Shephard Mpofu, has reported the conversion of all his common stock and employee stock options into securities of Alumis, Inc. following the completion of their merger.

Summary

• Shephard Mpofu, Chief Medical Officer of ACELYRIN, Inc., filed a Form 4 reporting changes in his beneficial ownership of ACELYRIN securities.
• The changes occurred on May 21, 2025, as a direct result of the merger between ACELYRIN, Inc. and Alumis, Inc. (Parent), where ACELYRIN became 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.
• Mr. Mpofu disposed of 121,789 shares of ACELYRIN Common Stock, resulting in zero beneficial ownership of ACELYRIN common stock post-transaction.
• Outstanding and unvested Restricted Stock Units (RSUs) were assumed by Alumis and converted into Alumis RSU awards based on the 0.4814 exchange ratio.
• Outstanding and vested RSUs were cancelled and converted into the right to receive Alumis common stock based on the 0.4814 exchange ratio.
• All outstanding and unexercised employee stock options with an exercise price of $18.00 or less were assumed by Alumis and converted into options to purchase Alumis common stock.
• The conversion of options involved multiplying the number of shares subject to the option by the 0.4814 exchange ratio and dividing the exercise price by the same ratio.
• Mr. Mpofu disposed of three tranches of employee stock options: 328,860 options (exercise price $4.22), 142,586 options (exercise price $7.68), and 118,858 options (exercise price $10.17), resulting in zero beneficial ownership of ACELYRIN options post-transaction.

Sentiment

Score: 5

Explanation: The document is a factual report of a completed corporate transaction and insider ownership changes, providing no explicit positive or negative sentiment regarding company performance or outlook.

Positives

• The completion of the merger signifies a strategic consolidation for ACELYRIN, now operating as a wholly-owned subsidiary of Alumis, Inc.
• The reporting person's equity holdings (common stock and stock options) were successfully converted into the acquiring entity's securities, preserving their value and continuity of interest.

Future Outlook

This Form 4 primarily reports a completed transaction (merger and subsequent conversion of securities) and does not provide forward-looking statements or guidance regarding the future performance or strategic direction of the combined entity, Alumis, Inc.

Industry Context

This filing reflects a specific corporate acquisition within the biotechnology or pharmaceutical sector, where ACELYRIN, Inc. has been acquired by Alumis, Inc. Such mergers are common in the industry for strategic growth, pipeline consolidation, or market expansion, leading to changes in corporate structure and insider holdings.

Corporate Governance

Stakeholder Impact

• Shareholders of ACELYRIN, Inc. had their common stock converted into shares of Alumis, Inc. at a fixed exchange ratio, impacting their ownership structure and future investment in the combined entity.
• Employees of ACELYRIN, Inc., particularly those with equity compensation like the Chief Medical Officer, had their stock options and restricted stock units converted into equivalent awards in Alumis, Inc., ensuring continuity of their equity incentives under the new parent company.

Key Dates

Keywords

ACELYRIN, SLRN, Alumis, Merger, Form 4, Insider Transaction, Beneficial Ownership, Stock Options, Common Stock, Corporate Acquisition, Chief Medical Officer