Investor Rock Springs Capital Management LP
13D/G Filings

This page shows a list of all the recent 13D/G filings made by Rock Springs Capital Management LP . Schedule 13D is commonly referred to as a “beneficial ownership report.” The term "beneficial owner" is defined under SEC rules. It includes any person who directly or indirectly shares voting power or investment power (the power to sell the security).

When a person or group of persons acquires beneficial ownership of more than 5% of a voting class of a company’s equity securities, they are required to file a Schedule 13D within ten days after the purchase. Click the link icon to see the full transaction history.

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Date Form Target Prev
Shares		 Current
Shares		 Change
(Percent)		 Ownership
(Percent)		 Change
(Percent)
2025-09-12 13G TLPH / Talphera, Inc. 3,589,186
2025-08-13 13G/A SPRB / Spruce Biosciences, Inc. 2,609,125 0
2025-08-13 13G/A INZY / Inozyme Pharma, Inc. 3,681,174 0
2025-05-15 13G/A XLO / Xilio Therapeutics, Inc. 3,003,259 0
2025-05-15 13G/A TVTX / Travere Therapeutics, Inc. 4,973,649 2,921,196
2025-05-15 13G/A MREO / Mereo BioPharma Group plc - Depositary Receipt (Common Stock) 47,670,850 33,421,235
2025-05-15 13G/A ACRS / Aclaris Therapeutics, Inc. 6,761,861 5,046,309
2025-02-14 13G/A TVTX / Travere Therapeutics, Inc. 4,411,983 4,973,649
2024-11-22 13G ACRS / Aclaris Therapeutics, Inc. 2,998,495 6,761,861
2024-11-12 13G/A XLO / Xilio Therapeutics, Inc. 3,003,259 3,003,259
2024-11-12 13G/A MREO / Mereo BioPharma Group plc - Depositary Receipt (Common Stock) 39,919,255 47,670,850
2024-11-12 13G/A IMCR / Immunocore Holdings plc - Depositary Receipt (Common Stock) 2,661,507 0
2024-05-01 13G TVTX / Travere Therapeutics, Inc. 4,411,983
2024-04-05 13G/A XLO / Xilio Therapeutics, Inc. 1,440,759 3,003,259
2024-02-14 13G XLO / Xilio Therapeutics, Inc. 1,440,759
2024-02-14 13G/A TPST / Tempest Therapeutics, Inc. 823,654 0
2024-02-14 13G/A MREO / Mereo BioPharma Group plc - Depositary Receipt (Common Stock) 31,224,485 39,919,255
2024-02-14 13G/A MREO / Mereo BioPharma Group plc - Depositary Receipt (Common Stock) 31,224,485 39,919,255
2024-02-14 13G/A SPRB / Spruce Biosciences, Inc. 1,622,689 2,609,125
2024-02-14 13G/A IMCR / Immunocore Holdings plc - Depositary Receipt (Common Stock) 3,321,066 2,661,507
2024-02-14 13G/A INZY / Inozyme Pharma, Inc. 3,086,027 3,681,174
2024-02-14 13G/A GMDAQ / Gamida Cell Ltd. 0
2024-02-14 13G/A SYRE / Spyre Therapeutics, Inc. 0
2024-02-14 13G/A AGIO / Agios Pharmaceuticals, Inc. 2,996,592 2,152,173
2024-02-14 13G/A ACRS / Aclaris Therapeutics, Inc. 3,961,249 2,998,495
2023-02-14 13G/A SRRA / Sierra Oncology Inc 1,184,793 0
2023-02-14 13G/A MIRM / Mirum Pharmaceuticals, Inc. 1,538,814 1,795,733
2023-02-14 13G/A PHASQ / PhaseBio Pharmaceuticals, Inc. 2,581,299 0
2023-02-14 13G/A TPST / Tempest Therapeutics, Inc. 823,654 823,654
2023-02-14 13G/A CMPX / Compass Therapeutics, Inc. 5,328,088 5,333,188
2023-02-14 13G/A MREO / Mereo BioPharma Group plc - Depositary Receipt (Common Stock) 5,585,621 31,224,485
2023-02-14 13G/A SPRB / Spruce Biosciences, Inc. 1,622,689 1,622,689
2023-02-14 13G/A INZY / Inozyme Pharma, Inc. 2,452,637 3,086,027
2023-02-14 13G/A IMCR / Immunocore Holdings plc - Depositary Receipt (Common Stock) 2,471,555 3,321,066
2023-02-14 13G AGIO / Agios Pharmaceuticals, Inc. 2,996,592
2023-02-14 13G AGLE / Aeglea BioTherapeutics Inc 3,413,906
2023-02-14 13G/A ACRS / Aclaris Therapeutics, Inc. 3,861,347 3,961,249
2022-04-25 13G INZY / Inozyme Pharma, Inc. 2,452,637
2022-02-15 13G MREO / Mereo BioPharma Group plc - Depositary Receipt (Common Stock) 5,585,621
2022-02-15 13G/A US33830X1046 / Five Prime Therapeutics Inc 3,041,559 0
2022-02-15 13G/A CMPX / Compass Therapeutics, Inc. 5,324,017 5,328,088
2022-02-15 13G/A ACRS / Aclaris Therapeutics, Inc. 2,676,100 3,861,347
2022-02-15 13G/A MIRM / Mirum Pharmaceuticals, Inc. 1,496,525 1,538,814
2022-02-15 13G/A IMCR / Immunocore Holdings plc - Depositary Receipt (Common Stock) 2,329,785 2,471,555
2022-02-15 13G/A PHAS / PhaseBio Pharmaceuticals Inc 1,314,374 2,581,299
2022-02-15 13G/A ARDX / Ardelyx, Inc. 5,148,112 0
2022-02-15 13G/A SPRB / Spruce Biosciences, Inc. 1,631,000 1,622,689
2022-02-15 13G/A SRRA / Sierra Oncology Inc 567,358 1,184,793
2022-02-15 13G/A US16706W1027 / Chiasma Inc 3,243,600 0
2022-02-15 13G/A FSTX / F-star Therapeutics Inc 1,054,232 751,889
2022-02-15 13G/A TARA / Protara Therapeutics, Inc. 643,200 0
2022-01-03 13G TPST / Tempest Therapeutics, Inc. 310,161 823,654
2021-12-30 13G CMPX / Compass Therapeutics, Inc. 5,324,017
2021-07-15 13G/A TPST / Tempest Therapeutics, Inc. 642,155 310,161
2021-07-08 13G TPST / Tempest Therapeutics, Inc. 642,155
2021-06-24 13G US16706W1027 / Chiasma Inc 3,243,600
2021-05-17 13G FSTX / F-star Therapeutics Inc 1,054,232
2021-04-19 13G IMCR / Immunocore Holdings plc - Depositary Receipt (Common Stock) 2,329,785
2021-03-01 13G US33830X1046 / Five Prime Therapeutics Inc 3,041,559
2021-02-16 13G/A ARDX / Ardelyx, Inc. 4,990,187 5,148,112
2021-02-16 13G/A SRRA / Sierra Oncology Inc 555,077 567,358
2021-02-16 13G/A SPRB / Spruce Biosciences, Inc. 1,708,673 1,631,000
2021-02-16 13G/A TARA / Protara Therapeutics, Inc. 643,622 643,200
2021-02-16 13G/A PHAS / PhaseBio Pharmaceuticals Inc 1,651,874 1,314,374
2021-02-16 13G/A ACRS / Aclaris Therapeutics, Inc. 2,213,856 2,676,100
2021-02-16 13G/A MIRM / Mirum Pharmaceuticals, Inc. 1,245,000 1,496,525
2020-11-16 13G PHAS / PhaseBio Pharmaceuticals Inc 1,125,000 1,651,874
2020-10-26 13G ACRS / Aclaris Therapeutics, Inc. 1,600,000 2,213,856
2020-10-19 13G SRRA / Sierra Oncology Inc 555,077
2020-10-19 13G SPRB / Spruce Biosciences, Inc. 1,708,673
2020-10-02 13G TARA / Protara Therapeutics, Inc. 643,622
2020-02-14 13G/A ACRS / Aclaris Therapeutics, Inc. 2,100,000 1,600,000
2020-02-14 13G/A ARDX / Ardelyx, Inc. 3,182,797 4,990,187
2020-02-14 13G/A ASMB / Assembly Biosciences, Inc. 1,300,000 1,500,000
2020-02-14 13G/A PHAS / PhaseBio Pharmaceuticals Inc 1,450,000 1,125,000
2020-02-14 13G/A MIRM / Mirum Pharmaceuticals, Inc. 1,400,000 1,245,000
2019-12-16 13G MIRM / Mirum Pharmaceuticals, Inc. 1,400,000
2019-10-07 13G ASMB / Assembly Biosciences, Inc. 1,300,000
2019-09-27 13G ARDX / Ardelyx, Inc. 2,140,187 3,182,797
2019-07-29 13G ACRS / Aclaris Therapeutics, Inc. 2,100,000
2019-04-22 13G PHAS / PhaseBio Pharmaceuticals Inc 1,450,000
2019-02-14 13G/A ARDX / Ardelyx, Inc. 2,415,744 2,140,187
2019-02-14 13G/A COLL / Collegium Pharmaceutical, Inc. 1,915,729 1,605,105
2019-02-14 13G/A MRSN / Mersana Therapeutics, Inc. 1,326,800 1,000,000
2018-02-14 13G/A MRSN / Mersana Therapeutics, Inc. 1,326,800
2018-02-14 13G/A ARDX / Ardelyx, Inc. 2,390,187 2,415,744
2018-02-14 13G/A COLL / Collegium Pharmaceutical, Inc. 1,600,000 1,915,729
2017-11-02 13G ARDX / Ardelyx, Inc. 2,390,187
2017-07-07 13G MRSN / Mersana Therapeutics, Inc. 1,527,893
2017-02-14 13G/A CLSD / Clearside Biomedical, Inc. 1,300,000 935,000
2017-02-14 13G/A COLL / Collegium Pharmaceutical, Inc. 1,201,400 1,600,000
2017-02-14 13G/A CRME / Cardiome Pharma Corp. 1,190,000 1,200,000
2016-06-10 13G CLSD / Clearside Biomedical, Inc. 1,300,000
2016-05-16 13G COLL / Collegium Pharmaceutical, Inc. 1,145,000 1,201,400
2016-02-16 13G/A ALBO / Albireo Pharma Inc 4,000,000 0
2016-02-16 13G/A ALBO / Albireo Pharma Inc 0
2015-08-04 13G CRME / Cardiome Pharma Corp. 1,190,000
2015-04-23 13G ALBO / Albireo Pharma Inc 4,000,000