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.
INSM notice of proposed sale under Form 144 reporting planned dispositions of Common Stock by Michael Smith. The filing lists three recent sale entries dated 05/13/2026, 03/30/2026, and 02/24/2026
INSMED Inc Chief Legal Officer Michael Alexander Smith reported an open-market sale of 6,149 shares of common stock at $108.47 per share. The transaction was made under a pre-arranged Rule 10b5-1 trading plan adopted on November 7, 2025. Following this sale, he directly holds 41,613 company shares.
INSMED Inc Chair and CEO William Lewis reported a mix of stock sales and option exercises in company common stock. On May 18, 2026, he sold a total of 25,564 shares in three open-market transactions at weighted average prices in the $105–$107 per share range, executed under a preset Rule 10b5-1 trading plan adopted on September 4, 2025.
On the same date, Lewis also exercised 10,699 stock options to acquire common shares, with exercise prices of $17.16 and $30.46 per share. The filing shows both direct holdings and additional shares held indirectly through a trust, indicating he retains a substantial ownership interest after these transactions.
INSM filed a Form 144 reporting proposed sales of Common Stock by William Lewis. The notice lists multiple proposed dispositions with trade dates and share counts, for example 13,283 shares on 05/13/2026 and 10,699 shares on 05/04/2026. The entries also show large associated position figures on each line.
Insmed Incorporated filed a shelf registration on May 15, 2026 on Form S-3 to register common stock and debt securities for offer and sale from time to time after the registration statement becomes effective. The prospectus describes that offerings may be by the company or by selling securityholders and that specific terms will be set forth in prospectus supplements.
The prospectus lists authorized common stock of 500,000,000 shares and states there were 216,521,841 shares outstanding as of March 31, 2026. It also discloses the Nasdaq listing symbol INSM and the last reported sale price of $115.62 on May 14, 2026. The document states that net proceeds usage will be described in each supplement and that the company will not receive proceeds from selling securityholders unless stated in a supplement.
INSMED Inc ownership update: a Schedule 13G/A amendment reports that certain related reporting persons together hold sizable positions in Common Stock. Darwin Global Management, Ltd. and related parties report 16,805,184 shares (representing 7.8%) and Darwin Global Master Fund, Ltd. reports 14,182,375 shares (representing 6.6%), using an outstanding share base of 215,852,149 shares as of March 6, 2026. The filing attributes shared voting and dispositive power and is signed by authorized representatives.
INSMED Inc Chief Financial Officer Sara Bonstein reported an open-market sale of 8,272 shares of common stock on May 13, 2026 at an average price of $116.18 per share. According to the filing, the shares were sold to satisfy tax withholding obligations and related broker fees arising from the vesting of Restricted Stock Units. After this transaction, Bonstein directly holds 71,486 shares of INSMED common stock, so the sale represents a relatively small portion of her overall reported holdings and is tied to compensation-related tax requirements rather than a discretionary portfolio change.
SCHAFER CAROL reported acquisition or exercise transactions in this Form 4 filing.
INSMED Inc director Carol Schafer received an equity award of 3,305 Restricted Stock Units (RSUs) on May 13, 2026. Each RSU represents a contingent right to receive one share of common stock, granted for no cash consideration as part of director compensation.
The RSUs vest in full on the first anniversary of the grant date if she remains on the Board through the earlier of that date or the company’s annual shareholder meeting in that year, and attends at least 75% of Board meetings during the period. After this grant, she holds 66,622 shares of common stock directly.
INSMED Inc Chief Operating Officer Roger Adsett reported a small share sale primarily tied to taxes on equity compensation. He sold 5,837 shares of common stock at an average price of $116.18 per share. A footnote explains the shares were sold to satisfy tax withholding obligations upon the vesting of Restricted Stock Units and to cover related broker fees, rather than as a discretionary portfolio move. After the transaction, he directly holds 100,973 shares of INSMED common stock.
ANDERSON ELIZABETH M reported acquisition or exercise transactions in this Form 4 filing.
INSMED Inc director Elizabeth M. Anderson received a grant of 3,305 Restricted Stock Units (RSUs), each representing one share of common stock. The award was granted for no cash consideration.
The RSUs vest in full on the first anniversary of the May 13, 2026 grant date if she remains on the Board and attends at least 75% of Board meetings. Following the grant, she directly holds 62,034 shares.