Welcome to our dedicated page for INSMED SEC filings (Ticker: INSM), a comprehensive resource for investors and traders seeking official regulatory documents including 10-K annual reports, 10-Q quarterly earnings, 8-K material events, and insider trading forms.
Insmed Incorporated filings document formal disclosures for its commercial biopharmaceutical portfolio and respiratory and inflammatory pipeline. Recent Form 8-K reports furnish financial results, investor presentations, Regulation FD materials, clinical-study updates for ARIKAYCE and brensocatib, regulatory approval announcements for BRINSUPRI, and portfolio additions such as INS1148.
The company’s proxy materials describe board elections, executive compensation, equity awards, shareholder voting matters and governance practices. Other current reports document compensatory arrangements, director-transition disclosures, exhibits and Inline XBRL cover-page data tied to Insmed’s Nasdaq-listed common stock.
Insmed Inc.'s Chief Medical Officer, Martina Flammer, M.D., reported a series of equity transactions in company stock. On January 6, 2026, she exercised a stock option for 8,570 shares of common stock at an exercise price of $26.43 per share, converting a derivative position into directly held stock. That same day, she reported open-market sales of common stock, including 4,783 shares at a weighted average price of $173.47, 2,830 shares at $174.21, and 957 shares at $175.01.
Additional sales included 1,615 shares at $173.33 on January 6, 1,434 shares at a weighted average of $175.84 on January 7, and on January 8, 1,660 shares at a weighted average of $173.87 and 3,251 shares at $174.17. A portion of the shares sold was specifically to satisfy tax withholding obligations upon vesting of restricted stock units and related broker fees. After these transactions, she directly held 86,794 shares of Insmed common stock. All trades noted as (1) were effected under a Rule 10b5-1 trading plan adopted on February 27, 2025.
Insmed Chair and CEO William Lewis reported three sales of Insmed common stock on January 6–8, 2026. He sold 4,096 shares on January 6 at $173.33, 2,357 shares on January 7 at $175.07, and 3,223 shares on January 8 at $174.17, all reported as open market sales.
According to the filing, these shares were sold to satisfy tax withholding obligations upon the vesting of Restricted Stock Units and to cover related broker fees. After these transactions, Lewis directly held 315,407 shares of Insmed common stock. He also had indirect beneficial ownership of 233,924 shares held by the Katie Procter Dynasty Trust and 50,500 shares held by the William Lewis Family Legacy Trust.
Insmed's chief legal officer reports small share sales tied to tax withholding. Michael Alexander Smith, Chief Legal Officer of Insmed Inc., reported three sales of common stock on January 6–8, 2026. He sold 1,396 shares at $173.33, 709 shares at $175.07, and 1,053 shares at $174.17. After these transactions, he directly beneficially owned 57,037 shares of Insmed common stock. A footnote explains that the shares were sold to satisfy tax withholding obligations upon the vesting of restricted stock units and to cover related broker fees, indicating the sales were driven by tax requirements rather than discretionary trading.
INSM received a Rule 144 notice covering a planned sale of 1,053 shares of its common stock through Merrill Lynch on 01/08/2026, with an aggregate market value of 183401 and listing on NASDAQ. These shares were acquired on 01/06/2026 through stock plan activity from the issuer. The notice reports that 213,273,469 shares of common stock were outstanding. Over the prior three months, Michael Smith reported separate sales of 709, 1,396, and 27,130 common shares with gross proceeds of 124124, 241968, and 4985054, respectively.
INSM insider William Lewis has filed a notice to sell additional common shares under Rule 144. The filing covers 3223 common shares to be sold through Merrill Lynch at an aggregate market value of 561349, with 213273469 shares of the issuer’s common stock outstanding and the shares listed on NASDAQ.
These 3223 shares were acquired on 01/06/2026 via stock plan activity from the issuer, with payment completed the same day. Over the past three months, Lewis has also sold common shares of the issuer in several transactions, including 10699 shares for gross proceeds of 1786437 on 12/18/2025 and 10699 shares for 2199583 on 12/04/2025. By signing the notice, he represents that he is not aware of any material adverse information about the issuer’s current or prospective operations that has not been publicly disclosed.
Roger Adsett filed a notice of proposed sale of 802 shares of common stock of the issuer through Merrill Lynch on NASDAQ, with an aggregate market value of 140406 and 213273469 shares outstanding. The shares were acquired on 01/05/2026 through stock plan activity from the issuer, with the same date listed for payment. The notice also reports that over the past three months, Adsett sold 1,429 common shares on 01/06/2026 for gross proceeds of 247688.
An insider has filed a Rule 144 notice to sell 709 shares of common stock through broker Merrill Lynch on or about 01/07/2026, to be traded on NASDAQ. These 709 shares were acquired on 01/05/2026 through stock plan activity with the issuer. The notice also lists prior sales over the last three months by the same seller, including 1,396 common shares sold on 01/06/2026 for gross proceeds of 241968, and 27,130 common shares sold on 11/03/2025 for gross proceeds of 4985054. By signing, the seller represents that they are not aware of undisclosed material adverse information about the issuer.
A company insider filed a Rule 144 notice to sell 2357 shares of common stock through Merrill Lynch on the NASDAQ, with an approximate sale date of 01/07/2026. These 2357 shares of common stock were acquired on 01/05/2026 through stock plan activity from the issuer.
Over the past three months, the same seller, William Lewis, has already sold additional common shares of the issuer. These sales included 4096 shares on 01/06/2026 for gross proceeds of 709959, and two earlier sales of 10699 shares each on 12/18/2025 and 12/04/2025 for gross proceeds of 1786437 and 2199583, respectively.
An insider has filed a notice to sell 1,678 common shares of the issuer through Merrill Lynch on or about 01/07/2026 on the NASDAQ. The filing lists an aggregate market value of 293,935 for these planned sales, compared with 213,273,469 shares outstanding for the issuer.
The shares to be sold were acquired on 01/05/2026 as stock plan activity from the issuer. The notice also discloses that Sara Bonstein sold 1,517 common shares on 01/06/2026, generating gross proceeds of 262,941 over the past three months.
Insmed investor Martina Flammer filed a Form 144 notice indicating an intention to sell 1,434 shares of common stock through Merrill Lynch on the NASDAQ, with an aggregate market value of 252154. The shares to be sold were acquired on 01/05/2026 through stock plan activity with the issuer.
As context, the same seller reported prior sales of Insmed common stock over the past three months, including 10,185 shares on 01/06/2026 for gross proceeds of 1770153 and 12,303 shares on 01/05/2026 for gross proceeds of 2108459. Additional sales were disclosed on 12/01/2025 and 11/11/2025. The filing also notes that the issuer had 213,273,469 shares of common stock outstanding.