Form 4: Y-mAbs Executive Converts Equity Post-Merger

Y-mAbs Therapeutics SVP John LaRocca converted restricted stock units and stock options into cash following the company's merger with Yosemite Merger Sub, Inc.

Summary

• The merger of Y-mAbs Therapeutics, Inc. (the "Issuer") with Yosemite Merger Sub, Inc. ("Purchaser") was completed on September 16, 2025, following a tender offer for shares of the Issuer's common stock.
• Y-mAbs Therapeutics, Inc. now operates as the surviving corporation and an indirect wholly owned subsidiary of Perseus BidCo US, Inc. and Stark International Lux.
• John LaRocca, SVP, General Counsel & Secretary of Y-mAbs Therapeutics, Inc., reported the conversion of his equity awards due to the merger.
• LaRocca's 21,500 Restricted Stock Units (RSUs) were cancelled and converted into a cash payment of $8.60 per share.
• His 42,900 employee stock options with an exercise price of $6.16 were cancelled and converted into cash, calculated as the difference between the $8.60 merger consideration and the exercise price.
• His 142,600 employee stock options with an exercise price of $9.83 were cancelled for no consideration, as their exercise price exceeded the $8.60 merger consideration.

Sentiment

Score: 7

Explanation: The reporting person received a cash payout for their vested and unvested RSUs and in-the-money stock options as a result of the merger, indicating a successful liquidity event for their equity holdings. However, out-of-the-money options were cancelled for no consideration.

Positives

• The reporting person received a cash payout for their 21,500 Restricted Stock Units (RSUs) at $8.60 per share, totaling $184,900.
• The reporting person received a cash payout for 42,900 in-the-money employee stock options, totaling $104,676, representing a liquidity event for these equity holdings.

Negatives

• 142,600 employee stock options with an exercise price of $9.83 per share were cancelled for no consideration, as their exercise price exceeded the $8.60 merger consideration.
• Y-mAbs Therapeutics, Inc. ceased to be an independent publicly traded company, becoming an indirect wholly owned subsidiary.

Risks

• NA

Future Outlook

NA

Industry Context

The acquisition of Y-mAbs Therapeutics, Inc. by Perseus BidCo US, Inc. and Stark International Lux reflects a common trend in the biotechnology and pharmaceutical sectors where smaller, innovative companies are acquired by larger entities, often providing a strategic exit for existing shareholders and management.

Management Changes

Corporate Governance

Legal Proceedings

• NA

Related Party Transactions

• NA

Stakeholder Impact

• Shareholders: Public shareholders of Y-mAbs Therapeutics, Inc. received $8.60 per share in cash as part of the merger consideration.
• Employees (including the reporting person): Equity awards were converted to cash, providing liquidity for their holdings.
• Company: Y-mAbs Therapeutics, Inc. is no longer an independent publicly traded entity, operating as a subsidiary under new ownership.

Next Steps

• NA

Key Dates

Keywords

Y-mAbs Therapeutics, YMAB, Merger, Tender Offer, Insider Transaction, Form 4, Stock Options, RSU, Equity Conversion, John LaRocca