Sarissa Capital Management LP — 13F Holdings & Portfolio
CIK 1577524 · latest 13F-HR filed 2026-08-14
Sarissa Capital Management LP manages $177.9M in 13F-reported U.S. long-equity assets across 10 reported positions as of its 2026-06-30 13F-HR filing. Its largest disclosed positions are INVA (24.14%), IRWD (21.75%), AMRN (15.00%). Quarter over quarter (versus its 2026-03-31 filing) the fund opened 1 new position and exited 0; 6 existing positions rose in reported value and 2 fell.
AUM is the long-equity portion reported on Form 13F-HR. Excludes short positions, cash, foreign holdings, and non-13F assets. For informational purposes only — not investment advice.
Long-equity book
Distinct positions
Filed 2026-08-14
vs 2026-03-31
Portfolio charts
Latest quarter's book, what changed, and how the portfolio has evolved across filings.
Portfolio map
Q2 26Box size = position value; colour = change in share count vs the prior quarter (green added, red trimmed, blue new). Rows split across managers or share classes are combined. Click a box for the stock.
Sector mix
% of 13F valueSectors from each company's SIC code; funds and ETFs grouped separately.
Biggest buys and sells
Q1 26 → Q2 26Estimated from the change in shares held × the quarter-end price, so price moves alone don't count as buying. New and exited positions are included.
13F assets and positions
4 quartersTotal reported 13F value (bars) and number of positions (line) each quarter. Value changes include market moves.
Top positions over time
reported valueThe eight largest current positions, valued at each quarter end.
Concentration
top 10 = 100%Cumulative share of the portfolio held in the largest N positions.
As of the firm’s regulatory filing dated Jul 8, 2026.
SUITE 400
GREENWICH, CT 06830
| Name | Title / Status | Ownership | Type |
|---|---|---|---|
| DENNER, ALEXANDER, JOHN Control | CHIEF EXECUTIVE OFFICER/CHIEF INVESTMENT OFFICER since Apr 2013 | 75% or more | Individual |
| SARISSA CAPITAL MANAGEMENT GP LLC Control | GENERAL PARTNER since Apr 2013 | Less than 5% | Domestic Entity |
| SCHNAIDT, LAURA, TUCKER | CHIEF COMPLIANCE OFFICER & GENERAL COUNSEL since Jun 2026 | Less than 5% | Individual |
| DENNER, ALEXANDER, JOHN Control Indirect owner via SARISSA CAPITAL MANAGEMENT GP LLC | MANAGING MEMBER since Apr 2013 | 75% or more | Individual |
Ownership & leadership changes · 7 filings with changes since Apr 2, 2013
From the firm’s regulatory filings, newest first. Dates are filing dates: a filing that no longer lists someone does not say when they left.
- No longer listedBONFIGLIO, PATRICE, EADON · CHIEF COMPLIANCE OFFICER · Less than 5% · control person · listed since Jan 2023
- AddedSCHNAIDT, LAURA, TUCKER · CHIEF COMPLIANCE OFFICER & GENERAL COUNSEL · Less than 5%
- No longer listedDIPAOLO, MARK, ANTHONY · CHIEF LEGAL OFFICER/GENERAL COUNSEL · Less than 5% · control person · listed since Apr 2013
- ChangedBONFIGLIO, PATRICE, EADON · title CHIEF FINANCIAL OFFICER/CHIEF COMPLIANCE OFFICER → CHIEF COMPLIANCE OFFICER
- No longer listedVINCENT, ERIC, NELSON · PRESIDENT · Less than 5% · control person · listed since Apr 2019
- AddedVINCENT, ERIC, NELSON · PRESIDENT · Less than 5% · control person
- No longer listedMULLIGAN, RICHARD, CHARLES · SENIOR MANAGING DIRECTOR · Less than 5% · control person · listed since Apr 2013
- No longer listedSRISKANDARAJAH, MAYURAN · MANAGING DIRECTOR · Less than 5% · control person · listed since Apr 2013
- ChangedBONFIGLIO, PATRICE, EADON · title CHIEF FINANCIAL OFFICER → CHIEF FINANCIAL OFFICER/CHIEF COMPLIANCE OFFICER
- ChangedDIPAOLO, MARK, ANTHONY · title CHIEF COMPLIANCE OFFICER/CHIEF LEGAL OFFICER/GENERAL COUNSEL → CHIEF LEGAL OFFICER/GENERAL COUNSEL
- No longer listedPLATT, SETH, PHILLIP · CHIEF COMPLIANCE OFFICER/CHIEF OPERATING OFFICER · Less than 5% · control person · listed since Apr 2013
- AddedBONFIGLIO, PATRICE, EADON · CHIEF FINANCIAL OFFICER · Less than 5% · control person
- ChangedDENNER, ALEXANDER, JOHN · title CHIEF INVESTMENT OFFICER → CHIEF EXECUTIVE OFFICER/CHIEF INVESTMENT OFFICER
- ChangedDIPAOLO, MARK, ANTHONY · title GENERAL COUNSEL/CHIEF LEGAL OFFICER → CHIEF COMPLIANCE OFFICER/CHIEF LEGAL OFFICER/GENERAL COUNSEL
- ListedDENNER, ALEXANDER, JOHN · CHIEF INVESTMENT OFFICER · 75% or more · control person
- ListedDENNER, ALEXANDER, JOHN · MANAGING MEMBER · 75% or more · indirect via SARISSA CAPITAL MANAGEMENT GP LLC · control person
- ListedDIPAOLO, MARK, ANTHONY · GENERAL COUNSEL/CHIEF LEGAL OFFICER · Less than 5% · control person
- ListedMULLIGAN, RICHARD, CHARLES · SENIOR MANAGING DIRECTOR · Less than 5% · control person
- ListedPLATT, SETH, PHILLIP · CHIEF COMPLIANCE OFFICER/CHIEF OPERATING OFFICER · Less than 5% · control person
- ListedSARISSA CAPITAL MANAGEMENT GP LLC · GENERAL PARTNER · Less than 5% · control person
- ListedSRISKANDARAJAH, MAYURAN · MANAGING DIRECTOR · Less than 5% · control person
Quarter-over-quarter changes
Changes in reported position value vs the prior 13F, so price moves count too, not just shares bought or sold.
Top Adds (vs prior quarter)
- IRONWOOD PHARMACEUTICALS INC$6.4M +19.9%
- LANTHEUS HLDGS INC$5.9M +46.3%
- CYTOKINETICS INC$4.4M +29.3%
- NEUROCRINE BIOSCIENCES INC$4.3M +27.9%
- BIOHAVEN LTD$3.9M +81.9%
Sarissa Capital Management LP Holdings (2026-06-30)
Rows tagged Call or Put are options positions, not stock. Per SEC Form 13F-HR, Value shows the notional value of the underlying (shares covered × underlying price), not the option premium. Shares is the number of underlying shares covered (divide by 100 for contract count).
| # | Issuer | Symbol | CUSIP | Value | Weight | Shares | Type |
|---|---|---|---|---|---|---|---|
| 1 | INNOVIVA INC | INVA | 45781M101 | $42.9M | 24.14% | 1,890,604 | SH |
| 2 | IRONWOOD PHARMACEUTICALS INC | IRWD | 46333X108 | $38.7M | 21.75% | 9,188,635 | SH |
| 3 | AMARIN CORP PLC | AMRN | 023111404 | $26.7M | 15.00% | 1,673,395 | SH |
| 4 | NEUROCRINE BIOSCIENCES INC | NBIX | 64125C109 | $19.6M | 11.04% | 116,533 | SH |
| 5 | CYTOKINETICS INC | CYTK | 23282W605 | $19.5M | 10.95% | 228,623 | SH |
| 6 | LANTHEUS HLDGS INC | LNTH | 516544103 | $18.5M | 10.41% | 166,919 | SH |
| 7 | BIOHAVEN LTD | BHVN | G1110E107 | $8.7M | 4.87% | 582,312 | SH |
| 8 | REGENERON PHARMACEUTICALS | REGN | 75886F107 | $2.6M | 1.47% | 4,190 | SH |
| 9 | VOR BIOPHARMA INC | VOR | 929033207 | $467.6K | 0.26% | 25,399 | SH |
| 10 | BIOGEN INC | BIIB | 09062X103 | $205.3K | 0.12% | 950 | SH |
| Period | Filed | AUM | Holdings | Accession |
|---|---|---|---|---|
| 2026-06-30 | 2026-08-14 | $177.9M | 10 | 0000899140-26-000879 |
| 2026-03-31 | 2026-05-15 | $157.6M | 9 | 0000899140-26-000574 |
| 2025-12-31 | 2026-02-17 | $222.9M | 9 | 0000899140-26-000256 |
| 2025-09-30 | 2025-11-14 | $180.4M | 8 | 0000899140-25-001320 |
GREENWICH, CT 06830