INSM SEC Filing News — Insmed Incorporated

Latest SEC filings for Insmed Incorporated (INSM) explained in plain English. Covers insider buying and selling (Form 4), proposed insider sales (Form 144), material company events (8-K), and quarterly & annual reports (10-Q / 10-K). StrongBuyAnalytics provides navigation and brief excerpts or summaries; original filings remain at the SEC/source links and were authored by their filers, not StrongBuyAnalytics. Filing dates shown are source dates. Coverage and detection can be delayed or incomplete because of SEC availability, amendments, parsing, caching, or outages. Latest source filing date shown: 2026-10-05.

Insmed Incorporated develops and commercializes therapies for patients with serious and rare diseases in the United States, Europe, Japan, and internationally. The company offers ARIKAYCE for the treatment of refractory nontuberculous mycobacterial lung infections, as well as is in phase 3 clinical trial for the treatment of mycobacterium avium complex lung disease as part of a combination antibacterial drug regimen for adult patients. It also develops brensocatib, an oral reversible inhibitor o…
Sector: Healthcare Industry: Biotechnology Market Cap: $20.8B
20
Total Filings
0
Bullish Classifications
9
Bearish Classifications
8
Insider Transactions
3
Material Events (8-K)
1
Periodic Reports
Rule-based classifications for INSM currently lean bearish. Of the 20 filing records displayed, 9 carry bearish classifications (such as insider sales or negative 8-K disclosures) versus 0 bullish. This does not necessarily signal fundamental deterioration — insiders sell for many reasons — but it is worth monitoring alongside the company's core financial metrics.
INSM Filing Activity Snapshot 2026-06-25 — 2026-10-05
Insider Transactions (Form 4)
0 buys vs 8 sells
Net insider selling in this period — insiders sell for many reasons beyond conviction.
Largest Form 144 Filing
$31.96M
Adsett Roger (Chief Operating Officer) · 2026-08-12
239,850 shares · Form 4
Form 144 Notices
8
Proposed insider sales filed — Form 144 is a notice of intent, not a confirmed transaction. Actual sales are confirmed via Form 4.
Insider Transactions 8 · Forms 3, 4 and 5

A Form 4 is filed within two business days of a company insider — an officer, a director, or a holder of more than ten percent of the stock — changing their position in the shares. All 8 filings in this group are Form 4s for Insmed Incorporated.

The difficulty with reading these filings as a group is that a single form type covers transactions that mean entirely different things. An executive spending their own money to buy stock and an executive having shares withheld to pay tax on a vesting grant both appear as a Form 4. Every filing below is therefore tagged with the nature of the underlying transaction, taken from the transaction code reported on the form itself.

Across the 8 insider filings shown, the breakdown is 8 open-market sale. 8 of them involved a discretionary open-market trade; the rest are compensation and administrative mechanics.

What each transaction type means

Open-market sale ×8
The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.
Form 4 Open-market sale Insider Selling 2026-09-11

INSM insider Brennan David R (Director) sold 25,000 shares (~$3.10M)

Brennan David R, listed as Director at INSMED Inc, reported an open-market sale of 25,000 INSM shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.

The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Transactions reported on this filing
Code Nature Shares Price Value
S Open-market sale 25,000 $124.00 $3.10M
Filing: Form 4 (Insider Transaction) Insider: Brennan David R (Director) Shares: 25,000 Est. Value: $3.10M
View on SEC EDGAR → Open Filing Document →
Form 4 Open-market sale Insider Selling 2026-08-19

INSM insider SHAROKY MELVIN MD (Director) sold 5,000 shares (~$637.6K)

SHAROKY MELVIN MD, listed as Director at INSMED Inc, reported an open-market sale of 5,000 INSM shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.

The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Transactions reported on this filing
Code Nature Shares Price Value
S Open-market sale 5,000 $127.53 $637.6K
Filing: Form 4 (Insider Transaction) Insider: SHAROKY MELVIN MD (Director) Shares: 5,000 Est. Value: $637.6K
View on SEC EDGAR → Open Filing Document →
Form 4 Open-market sale Insider Selling 2026-08-12

INSM insider Adsett Roger (Chief Operating Officer) sold 239,850 shares (~$31.96M)

Adsett Roger, listed as Chief Operating Officer at INSMED Inc, reported an open-market sale of 239,850 INSM shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.

The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Transactions reported on this filing
Code Nature Shares Price Value
M Option exercise 82,280 $13.67 $1.12M
M Option exercise 76,600 $17.16 $1.31M
M Option exercise 80,970 $30.46 $2.47M
S Open-market sale 239,850 $133.27 $31.96M
M Option exercise derivative · Stock Option (right to buy) 82,280 — —
M Option exercise derivative · Stock Option (right to buy) 76,600 — —
M Option exercise derivative · Stock Option (right to buy) 80,970 — —
Filing: Form 4 (Insider Transaction) Insider: Adsett Roger (Chief Operating Officer) Shares: 239,850 Est. Value: $31.96M
View on SEC EDGAR → Open Filing Document →
Form 4 Open-market sale Insider Selling 2026-08-07

INSM insider Flammer Martina M.D. (Chief Medical Officer) sold 27,173 shares (~$3.49M)

Flammer Martina M.D., listed as Chief Medical Officer at INSMED Inc, reported an open-market sale of 27,173 INSM shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.

The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Transactions reported on this filing
Code Nature Shares Price Value
M Option exercise 18,278 $18.95 $346.4K
M Option exercise 8,895 $25.83 $229.8K
S Open-market sale 8,895 $127.00 $1.13M
S Open-market sale 18,278 $129.40 $2.37M
M Option exercise derivative · Stock Option (right to buy) 18,278 — —
M Option exercise derivative · Stock Option (right to buy) 8,895 — —
Filing: Form 4 (Insider Transaction) Insider: Flammer Martina M.D. (Chief Medical Officer) Shares: 27,173 Est. Value: $3.49M
View on SEC EDGAR → Open Filing Document →
Form 4 Open-market sale Insider Selling 2026-07-24

INSM insider Lewis William (Director, Chair and CEO) sold 10,700 shares (~$1.13M)

Lewis William, listed as Director, Chair and CEO at INSMED Inc, reported an open-market sale of 10,700 INSM shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.

The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Transactions reported on this filing
Code Nature Shares Price Value
M Option exercise 6,260 $30.46 $190.7K
M Option exercise 4,440 $17.16 $76.2K
S Open-market sale 4,828 $105.62 $509.9K
S Open-market sale 5,872 $106.43 $625.0K
M Option exercise derivative · Stock Option (right to buy) 6,260 — —
M Option exercise derivative · Stock Option (right to buy) 4,440 — —
Filing: Form 4 (Insider Transaction) Insider: Lewis William (Director, Chair and CEO) Shares: 10,700 Est. Value: $1.13M
View on SEC EDGAR → Open Filing Document →
Form 4 Open-market sale Insider Selling 2026-07-10

INSM insider Lewis William (Director, Chair and CEO) sold 10,699 shares (~$1.26M)

Lewis William, listed as Director, Chair and CEO at INSMED Inc, reported an open-market sale of 10,699 INSM shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.

The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Transactions reported on this filing
Code Nature Shares Price Value
M Option exercise 6,259 $30.46 $190.6K
M Option exercise 4,440 $17.16 $76.2K
S Open-market sale 5,005 $116.55 $583.3K
S Open-market sale 2,335 $117.62 $274.6K
S Open-market sale 3,359 $118.52 $398.1K
M Option exercise derivative · Stock Option (right to buy) 6,259 — —
M Option exercise derivative · Stock Option (right to buy) 4,440 — —
Filing: Form 4 (Insider Transaction) Insider: Lewis William (Director, Chair and CEO) Shares: 10,699 Est. Value: $1.26M
View on SEC EDGAR → Open Filing Document →
Form 4 Open-market sale Insider Selling 2026-07-08

INSM insider Flammer Martina M.D. (Chief Medical Officer) sold 12,302 shares (~$1.35M)

Flammer Martina M.D., listed as Chief Medical Officer at INSMED Inc, reported an open-market sale of 12,302 INSM shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.

The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Transactions reported on this filing
Code Nature Shares Price Value
M Option exercise 7,945 $29.13 $231.4K
M Option exercise 4,357 $19.74 $86.0K
S Open-market sale 4,854 $109.02 $529.2K
S Open-market sale 7,448 $110.60 $823.7K
M Option exercise derivative · Stock Option (right to buy) 7,945 — —
M Option exercise derivative · Stock Option (right to buy) 4,357 — —
Filing: Form 4 (Insider Transaction) Insider: Flammer Martina M.D. (Chief Medical Officer) Shares: 12,302 Est. Value: $1.35M
View on SEC EDGAR → Open Filing Document →
Form 4 Open-market sale Insider Selling 2026-06-26

INSM insider Lewis William (Director, Chair and CEO) sold 21,398 shares (~$2.21M)

Lewis William, listed as Director, Chair and CEO at INSMED Inc, reported an open-market sale of 21,398 INSM shares in a Form 4 filing. This is a confirmed insider sale, not just a proposed sale notice.

The insider sold shares on the open market. Sales may be discretionary or executed automatically under a pre-arranged Rule 10b5-1 trading plan, and a Form 4 does not always make clear which applies.

Transactions reported on this filing
Code Nature Shares Price Value
M Option exercise 12,518 $30.46 $381.3K
M Option exercise 8,880 $17.16 $152.4K
S Open-market sale 12,091 $102.34 $1.24M
S Open-market sale 1,836 $103.10 $189.3K
S Open-market sale 3,723 $104.28 $388.2K
S Open-market sale 2,456 $105.27 $258.5K
S Open-market sale 1,292 $106.27 $137.3K
M Option exercise derivative · Stock Option (right to buy) 12,518 — —
M Option exercise derivative · Stock Option (right to buy) 8,880 — —
Filing: Form 4 (Insider Transaction) Insider: Lewis William (Director, Chair and CEO) Shares: 21,398 Est. Value: $2.21M
View on SEC EDGAR → Open Filing Document →
Proposed Insider Sales 8 · Form 144

A Form 144 is a notice of intent to sell restricted or control securities. It is not a record that anything was sold. Insmed Incorporated has 8 such notices in this period.

The distinction matters because a Form 144 is frequently reported as though it were a completed insider sale. The filer may sell all of the shares covered, some of them, or none at all, and there is no obligation to update the notice either way. A sale that is actually executed by an officer or director shows up separately on a Form 4, which is the filing to check before treating a proposed sale as a real one.

Form 144 Proposed Insider Sale 2026-09-10

INSM Form 144 filed for proposed insider sale by Brennan David R (25,000 shares) ~$3.10M

Brennan David R filed a Form 144 with the SEC indicating intent to sell INSM (INSMED Inc) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: Brennan David R Shares: 25,000 Est. Value: $3.10M
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2026-08-17

INSM Form 144 filed for proposed insider sale by MELVIN SHAROKY (5,000 shares) ~$637.6K

MELVIN SHAROKY filed a Form 144 with the SEC indicating intent to sell INSM (INSMED Inc) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: MELVIN SHAROKY Shares: 5,000 Est. Value: $637.6K
View on SEC EDGAR → Open Filing Document →
Form 144 Large Proposed Insider Sale 2026-08-10

INSM Form 144 filed for proposed insider sale by Roger Adsett (239,850 shares) ~$31.96M

Roger Adsett filed a Form 144 with the SEC indicating intent to sell INSM (INSMED Inc) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4. The proposed dollar value is large enough to merit attention.

Filing: Form 144 (Proposed Sale Notice) Insider: Roger Adsett Shares: 239,850 Est. Value: $31.96M
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2026-08-06

INSM Form 144 filed for proposed insider sale by Martina Flammer (27,173 shares) ~$3.49M

Martina Flammer filed a Form 144 with the SEC indicating intent to sell INSM (INSMED Inc) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: Martina Flammer Shares: 27,173 Est. Value: $3.49M
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2026-07-23

INSM Form 144 filed for proposed insider sale by William Lewis (10,700 shares) ~$1.13M

William Lewis filed a Form 144 with the SEC indicating intent to sell INSM (INSMED Inc) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: William Lewis Shares: 10,700 Est. Value: $1.13M
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2026-07-09

INSM Form 144 filed for proposed insider sale by William Lewis (10,699 shares) ~$1.26M

William Lewis filed a Form 144 with the SEC indicating intent to sell INSM (INSMED Inc) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: William Lewis Shares: 10,699 Est. Value: $1.26M
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2026-07-06

INSM Form 144 filed for proposed insider sale by Martina Flammer (12,302 shares) ~$1.35M

Martina Flammer filed a Form 144 with the SEC indicating intent to sell INSM (INSMED Inc) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: Martina Flammer Shares: 12,302 Est. Value: $1.35M
View on SEC EDGAR → Open Filing Document →
Form 144 Proposed Insider Sale 2026-06-25

INSM Form 144 filed for proposed insider sale by William Lewis (21,398 shares) ~$2.21M

William Lewis filed a Form 144 with the SEC indicating intent to sell INSM (INSMED Inc) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: William Lewis Shares: 21,398 Est. Value: $2.21M
View on SEC EDGAR → Open Filing Document →
Material Events 3 · Form 8-K

An 8-K reports a material event in the window between scheduled reports. There are 3 in this period for Insmed Incorporated. Each 8-K names the item number it is filed under, and that number is the fastest way to tell a routine disclosure from a consequential one.

Item 2.02 is an earnings release, Item 5.02 is a change of directors or officers, and Item 1.01 or 2.01 covers a material agreement or a completed acquisition. Item 7.01 and Item 8.01 are the general-purpose disclosure items and carry no fixed meaning on their own.

Form 8-K Material Company Update 2026-10-05

INSM filed 8-K — material company event

INSMED Inc filed an 8-K with the SEC reporting a material event. Summary unavailable — view the original SEC filing for the full text.

Filing: 8-K (Material Event)
View on SEC EDGAR → Open Filing Document →
Form 8-K Material Company Update 2026-08-06

INSM filed 8-K — material company event

INSMED Inc filed an 8-K with the SEC reporting a material event. Summary unavailable — view the original SEC filing for the full text.

Filing: 8-K (Material Event)
View on SEC EDGAR → Open Filing Document →
Form 8-K Material Company Update 2026-07-16

INSM filed 8-K — material company event

INSMED Inc filed an 8-K with the SEC reporting a material event. Summary unavailable — view the original SEC filing for the full text.

Filing: 8-K (Material Event)
View on SEC EDGAR → Open Filing Document →
Periodic Reports 1 · Forms 10-K and 10-Q

The periodic reports are where the audited and reviewed financial statements live. This period contains 1 quarterly report (10-Q) for Insmed Incorporated.

The two are not equivalent in weight. A 10-K is audited by an external firm and includes the full risk factor disclosure, business description and management discussion; a 10-Q is unaudited, reviewed rather than examined, and much shorter. When a figure in a quarterly report is later revised, the annual report is usually where the correction appears.

An amended report — 10-K/A or 10-Q/A — restates or corrects something in the original filing, and is worth reading against the version it replaces.

Form 10-Q Quarterly Report 2026-08-06

INSM filed Quarterly Report (10-Q)

INSMED Inc filed its quarterly report with the SEC. This report includes unaudited financial statements and management discussion for the quarter.

Filing: 10-Q (Quarterly Report)
View on SEC EDGAR → Open Filing Document →

How we classify Insmed Incorporated's filings

Straight from EDGAR

Each displayed record links to an original source document. StrongBuyAnalytics provides navigation and brief excerpts or summaries, not the filing itself. Parsing may omit context or contain errors, so read the original document in full.

Transaction codes, not guesswork

The nature shown on each insider filing comes from the transaction code the filer entered on the form itself — P for an open-market purchase, A for a compensation award, F for shares withheld to pay tax, M for an option exercise. Where one filing contains several codes, the transaction table lists them line by line.

Why the distinction matters

Insider activity is routinely summarised as buying or selling, which flattens together decisions that mean very different things. Shares withheld for tax on a vesting grant are an automatic administrative step; shares bought on the open market are someone committing their own money at the current price.

What this page does not tell you

A filing records what happened, not why. Form 4 does not always disclose whether a sale was executed under a pre-arranged Rule 10b5-1 plan, and no single filing is a basis for a decision on INSM. Read these alongside the fundamentals rather than in isolation.

Frequently Asked Questions — INSM SEC Filings

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Publisher, sources & limitations — September 15, 2026. StrongBuyAnalytics provides navigation and brief excerpts or summaries for educational use. Original filings remain at SEC EDGAR or other displayed source links; StrongBuyAnalytics does not author them. Filing dates are source dates, not publication dates for this page. Coverage can be delayed, incomplete, amended, or unavailable because of SEC/source availability, parsing, caching, or outages. Verify every material statement in the original filing.
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