INSM's three largest insider shareholders as of August 29, 2026 are Steinar J Engelsen (Director, 320.80K shares), William Lewis (Chair And Ceo, 259.06K shares), Melvin Md Sharoky (Director, 246.08K shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Steinar J Engelsen | Director | 320,802 | 0 | 320,802 | 18.5% | 03 Nov, 2021 |
| 2 | William Lewis | Chair And Ceo | 259,058 | 0 | 259,058 | 14.9% | 10 Jul, 2026 |
| 3 | Melvin Md Sharoky | Director | 246,081 | 0 | 246,081 | 14.2% | 15 May, 2026 |
| 4 | John Drayton Wise | Chief Commercial Officer | 236,999 | 0 | 236,999 | 13.6% | 07 Feb, 2025 |
| 5 | Roger Adsett | Chief Operating Officer | 98,603 | 0 | 98,603 | 5.7% | 05 Jun, 2026 |
| 6 | Clarissa Desjardins | Director | 70,312 | 0 | 70,312 | 4.0% | 15 May, 2026 |
| 7 | Alfred Altomari | Director | 69,495 | 0 | 69,495 | 4.0% | 15 May, 2024 |
| 8 | Sara Bonstein | Chief Financial Officer | 69,082 | 0 | 69,082 | 4.0% | 05 Jun, 2026 |
| 9 | David R Brennan | Director | 64,238 | 0 | 64,238 | 3.7% | 15 May, 2026 |
| 10 | Elizabeth M Anderson | Director | 62,034 | 0 | 62,034 | 3.6% | 15 May, 2026 |
| 11 | Martina M.D. Flammer | Chief Medical Officer | 60,486 | 0 | 60,486 | 3.5% | 07 Aug, 2026 |
| 12 | Leo Lee | Director | 57,971 | 0 | 57,971 | 3.3% | 15 May, 2026 |
| 13 | Orlov S Nicole Schaeffer | Chief People Strategy Officer | 41,754 | 0 | 41,754 | 2.4% | 06 Jan, 2026 |
| 14 | Michael Alexander Smith | Chief Legal Officer | 37,648 | 0 | 37,648 | 2.2% | 24 Jun, 2026 |
| 15 | John Soriano | Chief Compliance Officer | 35,204 | 0 | 35,204 | 2.0% | 09 Sep, 2021 |
| 16 | Samuele Butera | Svp, Gm, Global Respiratory | 7,342 | 0 | 7,342 | 0.4% | 24 Jun, 2026 |
Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.
| Date | Insider | Position | Transaction | Shares | Price | Value | Shares Held After | Ownership |
|---|---|---|---|---|---|---|---|---|
| 17 Aug, 2026 | Melvin Md Sharoky | Director | Disposed S | 5,000 | $127.53 | $637.65K | 0 | Indirect |
| 06 Aug, 2026 | Martina M.D. Flammer | Chief Medical Officer | Acquired M | 18,278 | $18.95 | $346.37K | 78,764 | Direct |
| 06 Aug, 2026 | Martina M.D. Flammer | Chief Medical Officer | Acquired M | 8,895 | $25.83 | $229.76K | 87,659 | Direct |
| 06 Aug, 2026 | Martina M.D. Flammer | Chief Medical Officer | Disposed S | 8,895 | $127.00 | $1.13Mn | 78,764 | Direct |
| 06 Aug, 2026 | Martina M.D. Flammer | Chief Medical Officer | Disposed S | 18,278 | $129.40 | $2.37Mn | 60,486 | Direct |
| 06 Aug, 2026 | Martina M.D. Flammer | Chief Medical Officer | Disposed M | 18,278 | $0.00 | $0 | 36,555 | Direct |
| 06 Aug, 2026 | Martina M.D. Flammer | Chief Medical Officer | Disposed M | 8,895 | $0.00 | $0 | 35,580 | Direct |
| 09 Jul, 2026 | William Lewis | Chair And Ceo | Acquired M | 6,259 | $30.46 | $190.65K | 265,317 | Direct |
| 09 Jul, 2026 | William Lewis | Chair And Ceo | Acquired M | 4,440 | $17.16 | $76.19K | 269,757 | Direct |
| 09 Jul, 2026 | William Lewis | Chair And Ceo | Disposed S | 5,005 | $116.55 | $583.33K | 264,752 | Direct |
| 09 Jul, 2026 | William Lewis | Chair And Ceo | Disposed S | 2,335 | $117.62 | $274.64K | 262,417 | Direct |
| 09 Jul, 2026 | William Lewis | Chair And Ceo | Disposed S | 3,359 | $118.52 | $398.11K | 259,058 | Direct |
| 09 Jul, 2026 | William Lewis | Chair And Ceo | Disposed M | 6,259 | $0.00 | $0 | 6,260 | Direct |
| 09 Jul, 2026 | William Lewis | Chair And Ceo | Disposed M | 4,440 | $0.00 | $0 | 4,440 | Direct |
| 06 Jul, 2026 | Martina M.D. Flammer | Chief Medical Officer | Acquired M | 7,945 | $29.13 | $231.44K | 68,431 | Direct |
| 06 Jul, 2026 | Martina M.D. Flammer | Chief Medical Officer | Acquired M | 4,357 | $19.74 | $86.01K | 72,788 | Direct |
| 06 Jul, 2026 | Martina M.D. Flammer | Chief Medical Officer | Disposed S | 4,854 | $109.02 | $529.18K | 67,934 | Direct |
| 06 Jul, 2026 | Martina M.D. Flammer | Chief Medical Officer | Disposed S | 7,448 | $110.60 | $823.75K | 60,486 | Direct |
| 06 Jul, 2026 | Martina M.D. Flammer | Chief Medical Officer | Disposed M | 7,945 | $0.00 | $0 | 23,835 | Direct |
| 06 Jul, 2026 | Martina M.D. Flammer | Chief Medical Officer | Disposed M | 4,357 | $0.00 | $0 | 4,358 | Direct |