MPM BioImpact LLC — 13F Holdings & Portfolio
CIK 1687078 · latest 13F-HR filed 2026-08-14
MPM BioImpact LLC manages $1.64B in 13F-reported U.S. long-equity assets across 37 reported positions as of its 2026-06-30 13F-HR filing. Its largest disclosed positions are CGEM (10.81%), AKTS (9.50%), LQDA (6.74%). Quarter over quarter (versus its 2026-03-31 filing) the fund opened 7 new positions, exited 11, added to 20, and trimmed 10.
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.
$1.64B
Long-equity book
37
Distinct positions
2026-06-30
Filed 2026-08-14
+7 / −11 / ↑20 / ↓10
vs 2026-03-31
Portfolio charts
Latest quarter's book, what changed, and how the portfolio has evolved across filings.
| Name | Title / Status | Ownership | Type |
|---|
Quarter-over-quarter changes
Share-count changes vs the prior 13F.
Top Adds (vs prior quarter)
- Aktis Oncology, Inc.$69.3M +80.2%
- Cullinan Therapeutics, Inc.$68.5M +63.1%
- Liquidia Corporation$57.5M +108.4%
- Revolution Medicines, Inc.$42.9M +87.1%
- Uniqure NV$34.1M +152.2%
Top Trims
- DBV Technologies S A-$48.8M -44.8%
- Context Therapeutics Inc-$27.3M -97.4%
- Forte Biosciences, Inc.-$4.9M -19.0%
- Tarsus Pharmaceuticals Inc-$2.9M -12.4%
- Oric Pharmaceuticals Inc-$2.5M -10.8%
New Positions
- Ultragenyx Pharmaceuticals, Inc.$47.4M
- BIOAGE Labs Inc$40.9M
- Taysha Gene Therapies, Inc.$30.6M
- Zura Bio Ltd.$26.4M
- Adlai Nortye Ltd$22.3M
Exited Positions
- Agios Pharmaceuticals Inc$44.2M
- Xenon Pharmaceuticals Inc$34.2M
- Evommune Inc$33.5M
- Cytokinetics Inc$33.0M
- Corvus Pharmaceuticals Inc$24.5M
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 | Cullinan Therapeutics, Inc. | CGEM | 230031106 | $177.2M | 10.81% | 9,731,341 | SH |
| 2 | Aktis Oncology, Inc. | AKTS | 01021M104 | $155.9M | 9.50% | 4,835,872 | SH |
| 3 | Liquidia Corporation | LQDA | 53635D202 | $110.5M | 6.74% | 1,386,174 | SH |
| 4 | Revolution Medicines, Inc. | RVMD | 76155X100 | $92.2M | 5.62% | 492,483 | SH |
| 5 | Corcept Therapeutics, Inc. | CORT | 218352102 | $67.0M | 4.09% | 771,028 | SH |
| 6 | Edgewise Therapeutics Inc | EWTX | 28036F105 | $65.9M | 4.02% | 1,620,780 | SH |
| 7 | Travere Therapeutics Inc | TVTX | 89422G107 | $63.8M | 3.89% | 1,122,731 | SH |
| 8 | DBV Technologies S A | DBVT | 23306J309 | $60.1M | 3.67% | 3,666,284 | SH |
| 9 | Trevi Therapeutics Inc | TRVI | 89532M101 | $57.3M | 3.50% | 3,073,577 | SH |
| 10 | Alumis Inc | ALMS | 022307102 | $56.8M | 3.46% | 2,019,020 | SH |
| 11 | Uniqure NV | QURE | N90064101 | $56.5M | 3.44% | 1,225,855 | SH |
| 12 | Ultragenyx Pharmaceuticals, Inc. | RARE | 90400D108 | $47.4M | 2.89% | 1,418,215 | SH |
| 13 | Relay Therapeutics Inc. | RLAY | 75943R102 | $45.2M | 2.76% | 2,415,672 | SH |
| 14 | Abivax SA | ABVX | 00370M103 | $44.8M | 2.73% | 336,347 | SH |
| 15 | Dyne Therapeutics, Inc. | DYN | 26818M108 | $42.7M | 2.60% | 1,922,093 | SH |
| 16 | Dianthus Therapeutics Inc | DNTH | 252828108 | $40.9M | 2.50% | 420,002 | SH |
| 17 | BIOAGE Labs Inc | BIOA | 09077V100 | $40.9M | 2.49% | 1,667,661 | SH |
| 18 | Urogen Pharma Ltd | URGN | M96088105 | $34.3M | 2.09% | 933,415 | SH |
| 19 | MoonLake Immunotherapeutics | MLTX | 61559X104 | $31.3M | 1.91% | 1,606,967 | SH |
| 20 | Palvella Therapeutics Inc | PVLA | 697947109 | $31.2M | 1.90% | 204,027 | SH |
| 21 | Taysha Gene Therapies, Inc. | TSHA | 877619106 | $30.6M | 1.87% | 4,500,000 | SH |
| 22 | Syndax Pharmaceuticals Inc | SNDX | 87164F105 | $29.2M | 1.78% | 1,333,523 | SH |
| 23 | Monte Rosa Therapeutics Inc | GLUE | 61225M102 | $28.1M | 1.71% | 1,161,081 | SH |
| 24 | Zura Bio Ltd. | ZURA | G9TY5A101 | $26.4M | 1.61% | 4,472,843 | SH |
| 25 | Natera Inc | NTRA | 632307104 | $25.1M | 1.53% | 92,638 | SH |
| 26 | Stoke Therapeutics Inc | STOK | 86150R107 | $23.7M | 1.44% | 723,314 | SH |
| 27 | Adlai Nortye Ltd | ANL | 00704R109 | $22.3M | 1.36% | 1,936,291 | SH |
| 28 | Belite Bio Inc | BLTE | 07782B104 | $21.1M | 1.29% | 137,208 | SH |
| 29 | Forte Biosciences, Inc. | FBRX | 34962G208 | $21.0M | 1.28% | 987,448 | SH |
| 30 | Oric Pharmaceuticals Inc | ORIC | 68622P109 | $20.4M | 1.24% | 1,882,162 | SH |
| 31 | Tarsus Pharmaceuticals Inc | TARS | 87650L103 | $20.3M | 1.24% | 322,007 | SH |
| 32 | Annexon Inc | ANNX | 03589W102 | $20.2M | 1.23% | 3,544,354 | SH |
| 33 | Bright Minds Biosciences Inc | DRUG | 10919W405 | $14.2M | 0.87% | 202,114 | SH |
| 34 | Entrada Therapeutics, Inc. | TRDA | 29384C108 | $9.2M | 0.56% | 1,253,053 | SH |
| 35 | Aclaris Therapeutics Inc | ACRS | 00461U105 | $5.5M | 0.34% | 1,042,467 | SH |
| 36 | Context Therapeutics Inc | CNTX | 21077P108 | $719.5K | 0.04% | 1,299,046 | SH |
| 37 | Werewolf Therapeutics, Inc. | HOWL | 95075A107 | $28.9K | 0.00% | 80,142 | SH |
| Period | Filed | AUM | Holdings | Accession |
|---|---|---|---|---|
| 2026-06-30 | 2026-08-14 | $1.64B | 37 | 0001193125-26-352199 |
| 2026-03-31 | 2026-05-15 | $1.29B | 41 | 0001193125-26-226995 |
| 2025-12-31 | 2026-02-17 | $874.0M | 38 | 0001193125-26-054813 |
| 2025-09-30 | 2025-11-14 | $610.9M | 40 | 0001193125-25-283112 |
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