Abiopharma

🔍 Lowinger Timothy B (Executive)

Company: Mersana Therapeutics, Inc. (MRSN)

Report Date: 2026-01-06

Detailed Transactions and Holdings:

• Sold 10,466 shares of Common Stock (Direct)
  Date: 2026-01-06 | Code: U | equity_swap_involved: 0 | transaction_form_type: 4 | Footnotes: F1, F3, F1
• Sold 3,047 shares of Stock Option (right to buy) at $16.0125 per share (Derivative)
  Date: 2026-01-06 | Code: D | equity_swap_involved: 0 | transaction_form_type: 4 | Footnotes: F4, F4, F4
• Sold 6,702 shares of Stock Option (right to buy) at $16.0125 per share (Derivative)
  Date: 2026-01-06 | Code: D | equity_swap_involved: 0 | transaction_form_type: 4 | Footnotes: F4, F4, F4
• Sold 696 shares of Stock Option (right to buy) at $355.75 per share (Derivative)
  Date: 2026-01-06 | Code: D | equity_swap_involved: 0 | transaction_form_type: 4 | Footnotes: F5, F5, F5
• Sold 1,578 shares of Stock Option (right to buy) at $355.75 per share (Derivative)
  Date: 2026-01-06 | Code: D | equity_swap_involved: 0 | transaction_form_type: 4 | Footnotes: F5, F5, F5
• Sold 713 shares of Stock Option (right to buy) at $87.75 per share (Derivative)
  Date: 2026-01-06 | Code: D | equity_swap_involved: 0 | transaction_form_type: 4 | Footnotes: F5, F5, F5
• Sold 419 shares of Stock Option (right to buy) at $87.75 per share (Derivative)
  Date: 2026-01-06 | Code: D | equity_swap_involved: 0 | transaction_form_type: 4 | Footnotes: F5, F5, F5
• Sold 920 shares of Stock Option (right to buy) at $154.0 per share (Derivative)
  Date: 2026-01-06 | Code: D | equity_swap_involved: 0 | transaction_form_type: 4 | Footnotes: F5, F5, F5
• Sold 3,090 shares of Stock Option (right to buy) at $154.0 per share (Derivative)
  Date: 2026-01-06 | Code: D | equity_swap_involved: 0 | transaction_form_type: 4 | Footnotes: F5, F5, F5
• Sold 275 shares of Stock Option (right to buy) at $527.25 per share (Derivative)
  Date: 2026-01-06 | Code: D | equity_swap_involved: 0 | transaction_form_type: 4 | Footnotes: F5, F5, F5
• Sold 4,974 shares of Stock Option (right to buy) at $527.25 per share (Derivative)
  Date: 2026-01-06 | Code: D | equity_swap_involved: 0 | transaction_form_type: 4 | Footnotes: F5, F5, F5
• Sold 215 shares of Stock Option (right to buy) at $157.0 per share (Derivative)
  Date: 2026-01-06 | Code: D | equity_swap_involved: 0 | transaction_form_type: 4 | Footnotes: F5, F5, F5
• Sold 3,234 shares of Stock Option (right to buy) at $157.0 per share (Derivative)
  Date: 2026-01-06 | Code: D | equity_swap_involved: 0 | transaction_form_type: 4 | Footnotes: F5, F5, F5
• Sold 858 shares of Stock Option (right to buy) at $151.5 per share (Derivative)
  Date: 2026-01-06 | Code: D | equity_swap_involved: 0 | transaction_form_type: 4 | Footnotes: F5, F5, F5
• Sold 5,891 shares of Stock Option (right to buy) at $151.5 per share (Derivative)
  Date: 2026-01-06 | Code: D | equity_swap_involved: 0 | transaction_form_type: 4 | Footnotes: F5, F5, F5
• Sold 1,040 shares of Stock Option (right to buy) at $75.5 per share (Derivative)
  Date: 2026-01-06 | Code: D | equity_swap_involved: 0 | transaction_form_type: 4 | Footnotes: F5, F5, F5
• Sold 7,959 shares of Stock Option (right to buy) at $75.5 per share (Derivative)
  Date: 2026-01-06 | Code: D | equity_swap_involved: 0 | transaction_form_type: 4 | Footnotes: F5, F5, F5
• Sold 1,834 shares of Stock Option (right to buy) at $102.5 per share (Derivative)
  Date: 2026-01-06 | Code: D | equity_swap_involved: 0 | transaction_form_type: 4 | Footnotes: F5, F5, F5
• Sold 192 shares of Restricted Stock Units (Derivative)
  Date: 2026-01-06 | Code: D | equity_swap_involved: 0 | transaction_form_type: 4 | Footnotes: F6, F6, F6
• Sold 750 shares of Restricted Stock Units (Derivative)
  Date: 2026-01-06 | Code: D | equity_swap_involved: 0 | transaction_form_type: 4 | Footnotes: F6, F6, F6
• Sold 1,500 shares of Restricted Stock Units (Derivative)
  Date: 2026-01-06 | Code: D | equity_swap_involved: 0 | transaction_form_type: 4 | Footnotes: F6, F6, F6
• Sold 2,166 shares of Restricted Stock Units (Derivative)
  Date: 2026-01-06 | Code: D | equity_swap_involved: 0 | transaction_form_type: 4 | Footnotes: F6, F6, F6

Footnotes:

• F1: Pursuant to the terms of that certain Agreement and Plan of Merger (the "Merger Agreement"), by and among the Issuer, Day One Biopharmaceuticals, Inc. ("Parent") and Parent's direct wholly-owned subsidiary, Emerald Merger Sub, Inc. ("Purchaser"), dated as of November 12, 2025, the shares (the "Shares") of common stock, par value $0.0001 per share, of the Issuer (the "Common Stock") that were tendered to Purchaser prior to the expiration time of the Offer were exchanged for: (i) $25.00 per Share, net to the stockholder in cash, without interest and less any applicable tax withholding (the "Upfront Cash Consideration"), plus (ii) one non-tradeable contingent value right per Share (each, a "CVR"),
• F2: (continued from footnote 1) which represents the right to receive certain contingent milestone payments of up to an aggregate of $30.25 per CVR in cash, without interest and less any applicable tax withholding, upon the achievement of certain specified milestones in accordance with the terms and subject to the conditions of a contingent value rights agreement entered into by Parent and the rights agent (the Upfront Cash Consideration plus one CVR, collectively, the "Offer Price"). After completion of the tender offer, pursuant to the terms of the Merger Agreement, Purchaser merged with and into the Issuer, effective as of January 6, 2026 (the "Effective Time"), with the Issuer continuing as the surviving corporation and a wholly owned subsidiary of Parent.
• F3: Includes 160 shares of Common Stock acquired by the Reporting Person in June 2025 through the Issuer's employee stock purchase plan.
• F4: Pursuant to the terms of the Merger Agreement, effective as of immediately prior to the Effective Time, each option to purchase shares of Common Stock ("Issuer Option") that was outstanding and unexercised as of immediately prior to the Effective Time and had an exercise price per Share that was less than the Upfront Cash Consideration (each, a "Cash-Out Option"), became fully vested and was automatically cancelled and converted into the right to receive, without interest and subject to deduction for any required tax withholding, (i) the Offer Price minus (ii) the exercise price payable per share of Common Stock underlying such Cash-Out Option.
• F5: Pursuant to the terms of the Merger Agreement, effective as of 10 business days prior to the closing of the Merger (the "Acceleration Date"), each Issuer Option then outstanding and unexercised that had an exercise price per Share that was equal to or greater than the Upfront Cash Consideration (each, an "OTM Option"), became fully vested and exercisable up to and through the closing of regular trading on the Nasdaq Stock Market on the fifth business day following the Acceleration Date (the "Last Exercise Date"). OTM Options not exercised on or prior to the Last Exercise Date were cancelled and ceased to exist as of the Effective Time, and no consideration was delivered in exchange for such OTM Option.
• F6: Pursuant to the terms of the Merger Agreement, effective as of immediately prior to the Effective Time, each Company restricted stock unit award, which represented the right to receive one share of Common Stock, that was then outstanding was automatically cancelled and converted into the right to receive, without interest and subject to deduction for any required tax withholding, the Offer Price.