Form 4: Y-mAbs Therapeutics Acquired for $8.60/Share

Y-mAbs Therapeutics, Inc. completed its merger, becoming an indirect wholly-owned subsidiary of Perseus BidCo US, Inc., with shareholders receiving $8.60 per share in cash.

Summary

• Y-mAbs Therapeutics, Inc. (YMAB) completed its merger on September 16, 2025, following a tender offer by Yosemite Merger Sub, Inc., a subsidiary of Perseus BidCo US, Inc.
• The company now operates as an indirect wholly-owned subsidiary of Perseus BidCo US, Inc.
• Shareholders received $8.60 per share in cash for their common stock, without interest and subject to applicable tax withholding.
• Restricted Stock Units (RSUs) held by the Reporting Person were cancelled and converted into a cash payment equal to the number of shares issuable multiplied by the $8.60 merger consideration.
• Stock options held by the Reporting Person were cancelled and converted into a cash payment equal to the number of shares subject to the option multiplied by the excess of the $8.60 merger consideration over the option's exercise price.
• Stock options with an exercise price equal to or exceeding the $8.60 merger consideration were cancelled for no consideration.

Sentiment

Score: 7

Explanation: The filing reports the successful completion of a merger, resulting in a cash payout for shareholders and option/RSU holders, which is generally a positive outcome for those stakeholders.

Positives

• Shareholders of Y-mAbs Therapeutics, Inc. received a cash payout of $8.60 per share for their common stock.
• Holders of Restricted Stock Units (RSUs) received a cash payment for their units.
• Holders of in-the-money employee stock options received a cash payment for their options.

Negatives

• Y-mAbs Therapeutics, Inc. ceased to be an independent publicly traded company.
• Employee stock options with an exercise price equal to or exceeding the $8.60 merger consideration were cancelled for no value.

Future Outlook

Y-mAbs Therapeutics, Inc. is now an indirect wholly-owned subsidiary of Perseus BidCo US, Inc., and as such, no independent future outlook or guidance is provided in this filing.

Industry Context

This filing reports the completion of an acquisition, which is a common occurrence in the biotechnology and pharmaceutical industries as larger entities seek to expand their pipelines or market presence through strategic mergers and acquisitions.

Corporate Governance

Stakeholder Impact

• Shareholders: Received $8.60 per share in cash for their common stock.
• Employees (with RSUs/Options): Received cash for their RSUs and in-the-money stock options, while out-of-the-money options were cancelled for no value.

Next Steps

• Y-mAbs Therapeutics, Inc. will continue operations as an indirect wholly-owned subsidiary of Perseus BidCo US, Inc., no longer trading publicly.

Key Dates

Keywords

Y-mAbs Therapeutics, YMAB, Merger, Acquisition, Tender Offer, Form 4, Insider Transaction, James Healy, Sofinnova, Common Stock, Restricted Stock Units, Stock Options