Director David R. Brennan filed a Form 4 with the SEC on September 11, 2026, disclosing the sale of 25,000 shares of Insmed Inc common stock on September 9, 2026.

Key Highlights

  • Shares sold: David R. Brennan disposed of 25,000 shares of Insmed Inc common stock on September 9, 2026.
  • Sale price: The transaction was executed at $124 per share.
  • Transaction code: The sale was coded "S" (open-market sale) in the filing.
  • Direct holdings after transaction: Brennan directly holds 39,238 shares of common stock following the reported transaction.
  • Indirect holdings: An additional 60,000 shares are held indirectly by a spouse revocable trust.
  • Role: Brennan is identified in the filing as a Director of Insmed Inc (NASDAQ:INSM).

Brennan's Share Sale and Remaining Ownership in Insmed

According to the Form 4 filed on September 11, 2026, David R. Brennan, a director of Insmed Inc, sold 25,000 shares of the company's common stock on September 9, 2026, at a price of $124 per share. The transaction is recorded with code "S" in the filing, indicating an open-market sale. The filing was signed by Michael A. Smith as attorney-in-fact on behalf of Brennan.

Following the reported sale, the filing discloses that Brennan directly owns 39,238 shares of Insmed common stock. In addition, 60,000 shares are reported as indirectly beneficially owned through a spouse revocable trust. No derivative securities transactions were reported in Table II of the filing.

The filing does not indicate whether the transaction was made pursuant to a Rule 10b5-1 trading plan, as the corresponding checkbox on the form is not checked. Brennan's address is listed as 700 US Highway 202/206, Bridgewater, New Jersey 08807. The filing covers only non-derivative securities, and no amendment date is listed, indicating this is an original filing.

What Was Disclosed

The filing reports a single open-market sale of 25,000 Insmed common shares by director David R. Brennan at $124 per share on September 9, 2026, leaving him with 39,238 shares held directly and 60,000 shares held indirectly through a spouse revocable trust.