Form 4: ACELYRIN Director's Holdings Converted Following Merger with Alumis

A recent SEC Form 4 filing reveals that ACELYRIN, Inc. Director Henry O. Gosebruch's common stock and stock options were converted into Alumis, Inc. shares and options following the completion of the merger on May 21, 2025.

Summary

• ACELYRIN, Inc. (SLRN) completed its merger with Alumis, Inc. (Parent) on May 21, 2025, with ACELYRIN surviving as a wholly owned subsidiary of Alumis.
• Director Henry O. Gosebruch disposed of 50,000 shares of ACELYRIN Common Stock, resulting in zero direct beneficial ownership post-merger.
• Two tranches of Director Stock Options, totaling 92,158 shares (exercise price $4.46) and 155,450 shares (exercise price $7.4345), were also disposed of and subsequently converted into options to purchase Alumis Common Stock.
• Each share of ACELYRIN common stock was converted into the right to receive 0.4814 shares of Alumis voting common stock (the "Exchange Ratio"), plus cash for any fractional shares.
• Outstanding and unexercised stock options with a per share exercise price of $18.00 or less were assumed by Alumis and converted based on the Exchange Ratio, with adjusted exercise prices.

Sentiment

Score: 7

Explanation: The document reports the successful completion of a merger, which is generally a positive strategic event for the companies involved, providing clarity and a path forward. The conversion of shares and options is a procedural outcome of this positive event.

Positives

• The successful completion of the merger provides a clear strategic path forward for ACELYRIN as a wholly-owned subsidiary of Alumis.
• ACELYRIN shareholders received Alumis common stock, providing liquidity and continued equity participation in the combined entity.
• Existing stock options held by the director were assumed and converted by Alumis, ensuring continuity of incentive for key personnel.

Future Outlook

The document indicates the successful completion of the merger, with ACELYRIN, Inc. now operating as a wholly owned subsidiary of Alumis, Inc. This suggests a consolidated future under the Alumis corporate structure.

Industry Context

This filing reflects a common occurrence in the biotechnology and pharmaceutical sectors, where smaller companies are acquired by larger entities to consolidate pipelines, expand market reach, or achieve synergies. The merger of ACELYRIN into Alumis is consistent with ongoing M&A trends in the life sciences industry.

Stakeholder Impact

• Shareholders of ACELYRIN, Inc. had their common stock converted into shares of Alumis, Inc., impacting their equity holdings and future investment exposure.
• Holders of ACELYRIN stock options, including Director Henry O. Gosebruch, had their options assumed and converted by Alumis, preserving their potential equity upside in the new entity.

Next Steps

• ACELYRIN, Inc. will continue operations as a wholly owned subsidiary of Alumis, Inc.
• The converted stock options will continue to vest according to their original schedules, subject to the reporting person's continued service as a director of the surviving entity or parent.

Key Dates

Keywords

ACELYRIN, SLRN, Alumis, Merger, Form 4, Insider Transaction, Stock Option Conversion, Beneficial Ownership, Corporate Acquisition, Biotechnology