A Form 4 filed on August 17, 2026, disclosed that Douglas Kerr, Chief Medical Officer of Dyne Therapeutics, Inc. (NASDAQ:DYN), sold 1,556 shares of common stock on August 13, 2026, to satisfy tax withholding obligations tied to vesting restricted stock units.

Key Highlights

  • Reporting person: Douglas Kerr, Chief Medical Officer of Dyne Therapeutics, Inc.
  • Transaction: 1,556 shares of common stock disposed of (transaction code S) on August 13, 2026.
  • Weighted average price: $26.28 per share, with individual sales ranging from $26.17 to $26.39, inclusive.
  • Purpose: Shares were automatically sold to satisfy tax withholding obligations on vesting restricted stock units granted February 12, 2026.
  • Post-transaction ownership: 167,599 shares of common stock beneficially owned directly, including 140,001 unvested RSUs.
  • Rule 10b5-1 plan: The sale was made pursuant to a binding contract consistent with the affirmative defense conditions of Rule 10b5-1(c) and was not a discretionary trade.

Dyne Therapeutics CMO Share Sale: Tax Withholding on RSU Vesting

According to the filing, Douglas Kerr, serving as Chief Medical Officer of Dyne Therapeutics, Inc., disposed of 1,556 shares of common stock on August 13, 2026, at a weighted average price of $26.28 per share. The shares were sold in multiple transactions at prices within the range of $26.17 to $26.39, inclusive. The filing notes that Kerr undertakes to provide full information regarding the number of shares sold at each separate price within that range upon request by the issuer, any security holder, or SEC staff.

The filing states that the sale "represents shares automatically sold by the Reporting Person to satisfy tax withholding obligations in connection with the vesting of restricted stock units granted to the Reporting Person on February 12, 2026." The filing further states that "the automatic sale of the Reporting Person's shares is provided for in a restricted stock unit agreement constituting a 'binding contract' consistent with the affirmative defense to liability under Rule 10b5-1 and the sale does not represent a discretionary trade by the Reporting Person."

Following the reported transaction, Kerr directly beneficially owned 167,599 shares of common stock, a figure that, according to the filing, includes 140,001 unvested RSUs. The Form 4 was signed by Dan Wilson as Attorney-in-Fact on August 17, 2026.

What Was Disclosed

Dyne Therapeutics' Chief Medical Officer Douglas Kerr sold 1,556 shares of common stock on August 13, 2026, at a weighted average of $26.28 per share, solely to cover tax obligations upon RSU vesting, leaving him with 167,599 shares beneficially owned directly.