MPM BioImpact LLC

CIK 1687078 · last filed 2025-04-30

MPM BioImpact LLC is a corporate insider who has filed 16 SEC Form 4 insider transactions across 5 companies since 2017. The most recent filing, for HOWL, was dated Apr 30, 2025. Across all open-market trades the lifetime net is −$43.4M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $167.3M across reported positions. The firm reports its address in Boston, MA. 66 SEC filings were submitted jointly with Oncology Impact Fund (Cayman) Management L.P.

"Disclosed insider exposure" sums this person's most-recently-reported share counts across each company they're an insider in, multiplied by the current underlying price. It is not net worth — it misses retail holdings, private investments, real estate, index funds, and any company where the person isn't an SEC-reporting insider. For informational purposes only.

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Disclosed Exposure

$167.26M

Companies

5

Total Filings

16

Lifetime Open-Market Net

-$43.42M

Filer Profile

Reported Address
399 BOYLSTON STREET, SUITE 1100
BOSTON, MA 02116
Phone
(617) 425-9200
State of Incorporation
DE
Formerly Known As
BioImpact Capital LLC (2021–2023)
MPM Oncology Impact Management LP (2017–2021)
Related Filers
Oncology Impact Fund (Cayman) Management L.P. — 66 joint filings, latest 2025-12-04
UBS Oncology Impact Fund L.P. — 66 joint filings, latest 2025-12-04
ANSBERT GADICKE — 46 joint filings, latest 2025-12-04
MPM Oncology Impact Management GP LLC — 32 joint filings, latest 2021-08-25
MPM ONCOLOGY INNOVATIONS FUND LP — 12 joint filings, latest 2025-12-04
MPM Oncology Innovations Fund GP LLC — 12 joint filings, latest 2025-12-04
MPM ASSET MANAGEMENT LLC — 10 joint filings, latest 2025-12-04
Profile details as reported on the filer's SEC submissions — for individual insiders the address is often in care of the issuer. Related filers are identified from jointly filed SEC submissions and shared reported addresses. View filings on SEC EDGAR.

Holdings By Company

Latest on-record share count from this person's most recent non-derivative Form 4 transaction in each company. Disclosed exposure = shares × current underlying price.
Symbol Role Shares Price Disclosed Exposure Lifetime OM Net Filings Latest Filed
HOWL 10%+ Owner 6,718,670 $0.99 $6.64M -$32.2K 1 2025-04-30
iTeos Therapeutics, Inc. (ITOS) Delisted 10%+ Owner 4,943,551 $10.15 $50.18M -$24.60M 7 2021-12-02
CGEM 10%+ Owner 7,648,268 $21.00 $160.61M -$12.62M 5 2021-09-20
Harpoon Therapeutics, Inc. (HARP) Delisted 10%+ Owner 637,490 $23.01 $14.67M -$7.08M 2 2021-06-02
Viracta Therapeutics, Inc. (SNSS) Delisted 10%+ Owner 951,857 $18.62 $17.72M $904.0K 1 2017-11-06

Recent Filings

16 filings
Insider activity across all companies, newest first. Form 4 rows are post-trade confirmations (buys, sells, grants, exercises). Notice (144) rows are pre-trade notices of intent to sell restricted or control stock under Rule 144 — they may not all execute. Compare adjacent dates to see which notices became actual sales.
Filed Symbol Action Net Shares Net $ Link
2025-04-30 HOWL Mixed +325,409 -$187 EDGAR
2021-12-02 iTeos Therapeutics, Inc. (ITOS) Delisted Sell (S) −559,092 -$19.27M EDGAR
2021-11-30 iTeos Therapeutics, Inc. (ITOS) Delisted Sell (S) −154,264 -$5.43M EDGAR
2021-10-14 iTeos Therapeutics, Inc. (ITOS) Delisted Sell (S) −380,008 -$10.34M EDGAR
2021-10-05 iTeos Therapeutics, Inc. (ITOS) Delisted Sell (S) −184,520 -$4.99M EDGAR
2021-09-20 CGEM Sell (S) −9,372 -$272.4K EDGAR
2021-09-16 iTeos Therapeutics, Inc. (ITOS) Delisted Sell (S) −305,668 -$8.47M EDGAR
2021-09-13 CGEM Sell (S) −69,759 -$2.04M EDGAR
2021-09-08 CGEM Sell (S) −145,920 -$4.26M EDGAR
2021-09-02 CGEM Sell (S) −72,927 -$2.15M EDGAR
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Form 4 codes: P = open-market purchase · S = open-market sale · A = grant/award · M = option exercise · F = tax withholding at vest · G = bona-fide gift · D = disposition to issuer · J = other (see filing footnote). Only P / S codes carry directional signal.
Notice (144 / 144/A): Form 144 is a notice of intent to sell restricted/control stock under Rule 144, filed before the sale; 144/A is an amendment. Many notices are pre-scheduled under Rule 10b5-1 plans. A Form 4 with code S typically follows within a few days when the planned sale executes; missing follow-up Form 4s suggest the notice was cancelled or modified.