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X4 Pharmaceuticals, Inc (0001501697)
SIC: 2836 - Biological Products, (No Diagnostic Substances)
State location: MA | State of Inc.: DE | Fiscal Year End: 1231
formerly: Arsanis, Inc. (until 2019-03-13)
Business Address
61 NORTH BEACON STREET
4TH FLOOR
BOSTON MA 02134
857-529-8300
Mailing Address
61 NORTH BEACON STREET
4TH FLOOR
BOSTON MA 02134
Ownership Reports from: (Click on owner name to see other issuer holdings for the owner, or CIK for owner filings.)

Owner Filings Transaction Date Type of Owner
Woods Keith 0001996804 2023-10-16 director
Arbet-Engels Christophe 0001802615 2023-08-16 officer: Chief Medical Officer
Baldry Mark 0001644137 2022-11-03 officer: Chief Commercial Officer
de Craecker Francoise 0001887843 2021-10-14 director
DiBiase Mary 0001880179 2021-09-08 officer: Chief Operating Officer
Cadavid Diego 0001778713 2020-12-14 officer: Chief Medical Officer
Taveras Arthur 0001830901 2020-11-02 officer: Chief Scientific Officer
Lawton Alison Frances 0001542650 2020-10-05 director
Skerlj Renato 0001814632 2020-06-10 officer: Chief Scientific Officer
Meisner Derek M 0001752461 2019-11-04 officer: General Counsel
Aliski William 0001598426 2019-09-18 director
Kelley Lynne E 0001667584 2019-04-24 officer: See Remarks
Stewart Murray 0001723450 2019-03-29 director
BLECH ISAAC 0000905536 2019-03-13 director
WYZGA MICHAEL S 0001201256 2019-03-13 director
Bridger Gary 0001600049 2019-03-13 director
Mostafa Adam S. 0001738081 2019-03-13 officer: See Remarks
Ragan Paula 0001769914 2019-03-13 director, officer: President and CEO
Behbahani Ali 0001613867 2018-06-01 10 percent owner
Chang Carmen 0001746342 2018-06-01 10 percent owner
BARRIS PETER J 0001005561 2017-11-20 10 percent owner
MOTT DAVID M 0001219871 2017-11-20 10 percent owner
SANDELL SCOTT D 0001237289 2017-11-20 10 percent owner
BASKETT FOREST 0001277631 2017-11-20 10 percent owner
Viswanathan Ravi 0001479386 2017-11-20 10 percent owner
Sonsini Peter W. 0001559807 2017-11-20 10 percent owner
Florence Anthony A. Jr. 0001559827 2017-11-20 10 percent owner
Sakoda Jon 0001589961 2017-11-20 10 percent owner
Makhzoumi Mohamad 0001630226 2017-11-20 10 percent owner
New Enterprise Associates 16, L.P. 0001694560 2017-11-20 10 percent owner
Puttagunta Chetan 0001695859 2017-11-20 10 percent owner
NEA Partners 16, L.P. 0001712881 2017-11-20 10 percent owner
NEA 16 GP, LLC 0001712882 2017-11-20 10 percent owner
ISALY SAMUEL D 0001055949 2017-11-15 10 percent owner
ORBIMED ADVISORS LLC 0001055951 2017-11-15 10 percent owner
MCGUIRE TERRANCE 0001117003 2017-11-15 director, 10 percent owner
MCGIRR DAVID W J 0001219023 2017-11-15 director
Ross Michael Jay 0001254452 2017-11-15 director, 10 percent owner
GRAY MICHAEL 0001271411 2017-11-15 director, officer: See Remarks
GORDON CARL L 0001282930 2017-11-15 director, 10 percent owner
STEVENS ANTHONY CHRIS 0001284788 2017-11-15 officer: Chief Medical Officer
Flint Jonathan A 0001295676 2017-11-15 10 percent owner
Clark William D 0001355415 2017-11-15 director
SCHULMAN AMY W 0001438226 2017-11-15 director
Polaris Venture Partners Special Founders' Fund V, L.P. 0001439586 2017-11-15 10 percent owner
Polaris Venture Partners Entrepreneurs' Fund V, L.P. 0001439587 2017-11-15 10 percent owner
Polaris Venture Partners Founders' Fund V, L.P. 0001439588 2017-11-15 10 percent owner
Polaris Venture Management Co. V, L.L.C. 0001439589 2017-11-15 10 percent owner
Polaris Venture Partners V, L.P. 0001439590 2017-11-15 10 percent owner
SV LIFE SCIENCES FUND V LP 0001460732 2017-11-15 10 percent owner
SV Life Sciences Fund V Strategic Partners, L.P. 0001482194 2017-11-15 10 percent owner
OrbiMed Capital GP IV LLC 0001502240 2017-11-15 10 percent owner
SV Life Sciences Fund VI, L.P. 0001642251 2017-11-15 10 percent owner
SVLSF V, LLC 0001644160 2017-11-15 10 percent owner
Muhlenbeck Frank 0001646114 2017-11-15 10 percent owner
Alphabet Inc. 0001652044 2017-11-15 10 percent owner
Bill & Melinda Gates Foundation 0001663801 2017-11-15 10 percent owner
SV Life Sciences Fund VI Strategic Partners, L.P. 0001667605 2017-11-15 10 percent owner
Section 32 Fund 1, LP 0001691436 2017-11-15 10 percent owner
Section 32 GP 1, LLC 0001691437 2017-11-15 10 percent owner
SVLSF VI, LLC 0001717728 2017-11-15 10 percent owner
GV 2016, L.P. 0001721789 2017-11-15 10 percent owner
Mantus David 0001721863 2017-11-15 officer: Chief Development Officer
NeoMed Innovation V L.P. 0001721884 2017-11-15 10 percent owner
Alexandria Venture Investments, LLC 0001722024 2017-11-15 10 percent owner
Nessi Claudio 0001722050 2017-11-15 director, 10 percent owner
Nagy Eszter 0001722056 2017-11-15 10 percent owner, officer: Chief Scientific Officer
Gerngross Tillman U. 0001722061 2017-11-15 director, 10 percent owner
Russo Rene 0001722066 2017-11-15 director, 10 percent owner, officer: See Remarks
GV 2016 GP, L.L.C. 0001722201 2017-11-15 10 percent owner
GV 2016 GP, L.P. 0001722204 2017-11-15 10 percent owner
Maris William J 0001722210 2017-11-15 10 percent owner
Herr Stefan 0001722440 2017-11-15 10 percent owner
Adams Jan 0001722536 2017-11-15 10 percent owner
Anna-Maria & Stephen Kellen Foundation, Inc. 0001722602 2017-11-15 10 percent owner
EMBL Ventures Verwaltungs GmbH 0001722603 2017-11-15 10 percent owner
EMBL Technology Fund II GmbH & Co. KG 0001722607 2017-11-15 10 percent owner
NeoMed Management (Jersey) Ltd 0001722665 2017-11-15 10 percent owner
NeoMed Innovation V Ltd 0001722666 2017-11-15 10 percent owner


Items 1 - 80

The information presented below contains only portions of the information presented in the referenced filing or filings.
You should consult the original filing for complete information. Hyperlinks to the forms are provided for your convenience.

Acquistion or Disposition Transaction Date Deemed Execution Date Reporting Owner Form Transaction Type Direct or Indirect Ownership Number of Securities Transacted Number of Securities Owned Line Number Owner CIK Security Name
A 2025-02-12   Arbet-Engels Christophe 4 A-Award --D 850000.0000 864207.0000 1 0001802615 Common Stock
A 2025-02-12   Mostafa Adam S. 4 A-Award --D 850000.0000 850000.0000 1 0001738081 Common Stock
A 2025-02-12   Ragan Paula 4 A-Award --D 2250000.0000 3337386.0000 1 0001769914 Common Stock
A 2025-02-12   Baldry Mark 4 A-Award --D 600000.0000 729173.0000 3 0001644137 Common Stock
A 2025-02-12   DiBiase Mary 4 A-Award --D 650000.0000 1140980.0000 1 0001880179 Common Stock
D 2025-01-24   Ragan Paula 4 S-Sale --D 76473.0000 1087386.0000 2 0001769914 Common Stock
D 2025-01-24   Mostafa Adam S. 4 S-Sale --D 74773.0000 0.0000 2 0001738081 Common Stock
D 2025-01-24   Baldry Mark 4 S-Sale --D 29159.0000 94123.0000 2 0001644137 Common Stock
D 2025-01-24   DiBiase Mary 4 S-Sale --D 22258.0000 490980.0000 2 0001880179 Common Stock
D 2025-01-24   Arbet-Engels Christophe 4 S-Sale --D 11624.0000 14207.0000 2 0001802615 Common Stock
A 2025-01-23   Ragan Paula 4 A-Award --D 169940.0000 1163859.0000 1 0001769914 Common Stock
A 2025-01-23   Mostafa Adam S. 4 A-Award --D 74773.0000 74773.0000 1 0001738081 Common Stock
A 2025-01-23   Baldry Mark 4 A-Award --D 74773.0000 123282.0000 1 0001644137 Common Stock
A 2025-01-23   DiBiase Mary 4 A-Award --D 61178.0000 513238.0000 1 0001880179 Common Stock
A 2025-01-23   Arbet-Engels Christophe 4 A-Award --D 25831.0000 25831.0000 1 0001802615 Common Stock
A 2024-11-15   Baldry Mark 4 P-Purchase --D 13404.0000 129173.0000 2 0001644137 Common Stock
D 2024-11-15   Ragan Paula 4 S-Sale --D 31897.0000 993919.0000 1 0001769914 Common Stock
D 2024-10-15   Ragan Paula 4 S-Sale --D 31897.0000 1025816.0000 1 0001769914 Common Stock
D 2024-10-07   Mostafa Adam S. 4 S-Sale --D 230645.0000 0.0000 2 0001738081 Common Stock
D 2024-10-07   Baldry Mark 4 S-Sale --D 11127.0000 48509.0000 2 0001644137 Common Stock
D 2024-10-07   Ragan Paula 4 S-Sale --D 239436.0000 1057713.0000 2 0001769914 Common Stock
D 2024-10-07   DiBiase Mary 4 S-Sale --D 67695.0000 452060.0000 2 0001880179 Common Stock
D 2024-10-07   Taveras Arthur 4 S-Sale --D 76920.0000 388026.0000 2 0001830901 Common Stock
A 2024-10-04   Mostafa Adam S. 4 A-Award --D 230645.0000 230645.0000 1 0001738081 Common Stock
A 2024-10-04   Baldry Mark 4 A-Award --D 34946.0000 59636.0000 1 0001644137 Common Stock
A 2024-10-04   Ragan Paula 4 A-Award --D 532081.0000 1297149.0000 1 0001769914 Common Stock
A 2024-10-04   DiBiase Mary 4 A-Award --D 230645.0000 519755.0000 1 0001880179 Common Stock
A 2024-10-04   Taveras Arthur 4 A-Award --D 230645.0000 464946.0000 1 0001830901 Common Stock
D 2024-09-09   DiBiase Mary 4 S-Sale --D 2642.0000 289110.0000 1 0001880179 Common Stock
A 2024-06-10   de Craecker Francoise 4 A-Award --D 45000.0000 96667.0000 1 0001887843 Common Stock
A 2024-06-10   Aliski William 4 A-Award --D 45000.0000 96667.0000 1 0001598426 Common Stock
A 2024-06-10   MCGIRR DAVID W J 4 A-Award --D 45000.0000 96667.0000 1 0001219023 Common Stock
A 2024-06-10   Stewart Murray 4 A-Award --D 45000.0000 191504.0000 1 0001723450 Common Stock
A 2024-06-10   Bridger Gary 4 A-Award --D 45000.0000 96667.0000 1 0001600049 Common Stock
A 2024-06-10   Woods Keith 4 A-Award --D 45000.0000 135000.0000 1 0001996804 Common Stock
A 2024-06-10   Lawton Alison Frances 4 A-Award --D 45000.0000 96667.0000 1 0001542650 Common Stock
A 2024-06-10   WYZGA MICHAEL S 4 A-Award --D 45000.0000 121667.0000 1 0001201256 Common Stock
A 2024-05-17   Baldry Mark 4 P-Purchase --D 21646.0000 115769.0000 1 0001644137 Common Stock
D 2024-03-11   Taveras Arthur 4 S-Sale --D 14235.0000 234301.0000 1 0001830901 Common Stock
D 2024-03-11   Ragan Paula 4 S-Sale --D 49678.0000 765068.0000 1 0001769914 Common Stock
D 2024-03-11   Mostafa Adam S. 4 S-Sale --D 52500.0000 0.0000 1 0001738081 Common Stock
D 2024-03-11   DiBiase Mary 4 S-Sale --D 15409.0000 291752.0000 1 0001880179 Common Stock
A 2024-02-13   Arbet-Engels Christophe 4/A A-Award --D 180816.0000 180816.0000 1 0001802615 Stock Appreciation Right
A 2024-02-13   Arbet-Engels Christophe 4 A-Award --D 475831.0000 475831.0000 1 0001802615 Stock Appreciation Right
A 2024-02-13   Mostafa Adam S. 4 A-Award --D 523414.0000 523414.0000 1 0001738081 Stock Appreciation Right
A 2024-02-13   DiBiase Mary 4 A-Award --D 428248.0000 428248.0000 1 0001880179 Stock Appreciation Right
A 2024-02-13   Ragan Paula 4 A-Award --D 1189578.0000 1189578.0000 1 0001769914 Stock Appreciation Right
A 2024-02-13   Baldry Mark 4 A-Award --D 523414.0000 523414.0000 1 0001644137 Stock Appreciation Right
A 2024-02-13   Taveras Arthur 4 A-Award --D 428248.0000 428248.0000 1 0001830901 Stock Appreciation Right
D 2024-02-12   DiBiase Mary 4 S-Sale --D 3683.0000 307161.0000 1 0001880179 Common Stock
D 2024-02-12   Taveras Arthur 4 S-Sale --D 787.0000 248536.0000 1 0001830901 Common Stock
D 2024-02-12   Ragan Paula 4 S-Sale --D 21695.0000 814746.0000 1 0001769914 Common Stock
D 2024-02-12   Mostafa Adam S. 4 S-Sale --D 27721.0000 52500.0000 1 0001738081 Common Stock
D 2023-11-03   Ragan Paula 4 S-Sale --D 39906.0000 836441.0000 2 0001769914 Common Stock
D 2023-11-01   Ragan Paula 4 S-Sale --D 199531.0000 876347.0000 1 0001769914 Common Stock
D 2023-11-01   Mostafa Adam S. 4 S-Sale --D 230645.0000 80221.0000 1 0001738081 Common Stock
D 2023-11-01   DiBiase Mary 4 S-Sale --D 67695.0000 310844.0000 1 0001880179 Common Stock
D 2023-11-01   Baldry Mark 4 S-Sale --D 10257.0000 24690.0000 1 0001644137 Common Stock
D 2023-11-01   Taveras Arthur 4 S-Sale --D 67695.0000 249323.0000 1 0001830901 Common Stock
A 2023-10-31   Mostafa Adam S. 4 A-Award --D 230645.0000 310866.0000 1 0001738081 Common Stock
A 2023-10-31   Baldry Mark 4 A-Award --D 34947.0000 34947.0000 1 0001644137 Common Stock
A 2023-10-31   Taveras Arthur 4 A-Award --D 230645.0000 317018.0000 1 0001830901 Common Stock
A 2023-10-31   Ragan Paula 4 A-Award --D 532081.0000 1075878.0000 1 0001769914 Common Stock
A 2023-10-31   DiBiase Mary 4 A-Award --D 230645.0000 378539.0000 1 0001880179 Common Stock
A 2023-10-16   Woods Keith 4 A-Award --D 90000.0000 90000.0000 1 0001996804 Common Stock
D 2023-09-08   DiBiase Mary 4 S-Sale --D 2642.0000 147894.0000 1 0001880179 Common Stock
A 2023-08-31   Arbet-Engels Christophe 4 A-Award --D 1250000.0000 1250000.0000 1 0001802615 Stock Option (right to buy)
A 2023-08-18   WYZGA MICHAEL S 4 P-Purchase --D 25000.0000 76667.0000 1 0001201256 Common Stock
D 2023-08-10   Stewart Murray 4 S-Sale --D 130056.0000 146504.0000 2 0001723450 Common Stock
A 2023-08-09   Stewart Murray 4 A-Award --D 269893.0000 276560.0000 1 0001723450 Common Stock
D 2023-06-30   DiBiase Mary 4 S-Sale --D 464.0000 150536.0000 1 0001880179 Common Stock
D 2023-06-30   Mostafa Adam S. 4 S-Sale --D 2641.0000 80221.0000 1 0001738081 Common Stock
D 2023-06-23   DiBiase Mary 4 S-Sale --D 857.0000 151000.0000 1 0001880179 Common Stock
D 2023-06-23   Mostafa Adam S. 4 S-Sale --D 5417.0000 82862.0000 1 0001738081 Common Stock
D 2023-06-23   Ragan Paula 4 S-Sale --D 6724.0000 543797.0000 1 0001769914 Common Stock
D 2023-06-15   DiBiase Mary 4 S-Sale --D 857.0000 151857.0000 1 0001880179 Common Stock
D 2023-06-15   Mostafa Adam S. 4 S-Sale --D 5417.0000 88279.0000 1 0001738081 Common Stock
D 2023-06-15   Ragan Paula 4 S-Sale --D 6724.0000 550521.0000 1 0001769914 Common Stock
A 2023-06-13   Aliski William 4 A-Award --D 45000.0000 51667.0000 1 0001598426 Common Stock
A 2023-06-13   Bridger Gary 4 A-Award --D 45000.0000 51667.0000 1 0001600049 Common Stock

http://www.sec.gov/cgi-bin/own-disp


Modified: 04/22/2016