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Bain Capital Life Sciences Investors, LLC

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13F filer, CIK 1703031, Boston, MA

Bain Capital Life Sciences Investors, LLC reported $1,506,676,329 across 21 holdings for the quarter ended 2025-09-30, in a 13F-HR filed 2025-11-14. Its ten largest share positions make up 92.72% of the portfolio.

Filed (acceptance time not in the bulk data set), ingested 13F-HR 0001193125-25-283094

Period
2025-09-30
Reported value
$1.51B
Holdings
21
Top 10 weight
92.72%
New
2
Sold out
4

Part of the filer group Bain Capital Life Sciences Investors, LLC

How groups are built

Largest buys vs the previous quarter

SecurityShares changeApprox. value
HTFLnew+12,448,158$419M
CDTXadded+520,310$49.8M
XFORadded+1,872,729$6.4M
MERSANA THERAPEUTICS INCnew+346,545$2.69M

Ranked by the share change valued at this quarter's implied price (value over shares in the 13F). A position sold out is valued at the previous quarter's price, its last report.

Largest sells vs the previous quarter

SecurityShares changeApprox. value
NUVLexited-1,447,267-$110M
DNTHreduced-1,166,358-$45.9M
IRONexited-583,500-$30.9M
PHVSreduced-122,106-$3.05M
Mersana Therapeutics Incexited-8,663,673-$2.56M

Ranked by the share change valued at this quarter's implied price (value over shares in the 13F). A position sold out is valued at the previous quarter's price, its last report.

Holdings, Q3 2025

Share positions as resolved from 13F-HR 0001193125-25-283094, largest first. % of portfolio is the value over $1,506,676,328, the sum of the share positions whose value is usable for ratios (method).

SecurityHistorySharesValue% of portfolioChangeLatest eventTimeline
HTFLHEARTFLOW INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: 12,448,158 shares 12,448,158$419M27.81%newTimeline
NAMSNEWAMSTERDAM PHARMA COMPANYQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 10,473,913 shares; 2024Q4: 10,719,110 shares; 2025Q1: 10,719,110 shares; 2025Q2: 10,719,110 shares; 2025Q3: 10,719,110 shares 10,719,110$305M20.23%0Timeline
CDTXCIDARA THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 703,080 shares; 2024Q4: 703,080 shares; 2025Q1: 703,080 shares; 2025Q2: 2,500,680 shares; 2025Q3: 3,020,990 shares 3,020,990$289M19.2%+520,310Timeline
PHVSPHARVARIS N VQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 3,303,381 shares; 2024Q4: 3,303,381 shares; 2025Q1: 3,303,381 shares; 2025Q2: 3,303,381 shares; 2025Q3: 3,181,275 shares 3,181,275$79.4M5.27%-122,106Timeline
OLMAOLEMA PHARMACEUTICALS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: 7,470,214 shares; 2025Q1: 6,843,954 shares; 2025Q2: 6,843,954 shares; 2025Q3: 6,843,954 shares 6,843,954$67M4.45%0Timeline
SVRASAVARA INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 14,565,457 shares; 2024Q4: 14,565,457 shares; 2025Q1: 17,600,621 shares; 2025Q2: 17,600,621 shares; 2025Q3: 17,600,621 shares 17,600,621$62.8M4.17%0Timeline
DNTHDIANTHUS THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 3,013,423 shares; 2024Q4: 2,689,707 shares; 2025Q1: 2,689,707 shares; 2025Q2: 2,482,250 shares; 2025Q3: 1,315,892 shares 1,315,892$51.8M3.44%-1,166,358Timeline
SLDBSOLID BIOSCIENCES INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 4,034,582 shares; 2024Q4: 4,034,582 shares; 2025Q1: 7,911,669 shares; 2025Q2: 7,911,669 shares; 2025Q3: 7,911,669 shares 7,911,669$48.8M3.24%0Timeline
UPBUPSTREAM BIO INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: 2,295,322 shares; 2025Q1: 2,295,322 shares; 2025Q2: 2,439,538 shares; 2025Q3: 2,439,538 shares 2,439,538$45.9M3.05%0Timeline
RPIDRAPID MICRO BIOSYSTEMS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 8,434,560 shares; 2024Q4: 8,434,560 shares; 2025Q1: 8,434,560 shares; 2025Q2: 8,434,560 shares; 2025Q3: 8,434,560 shares 8,434,560$28.2M1.87%0Timeline
TNGXTANGO THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 2,712,008 shares; 2024Q4: 2,712,008 shares; 2025Q1: 2,712,008 shares; 2025Q2: 2,712,008 shares; 2025Q3: 2,712,008 shares 2,712,008$22.8M1.51%0Timeline
CABACABALETTA BIO INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 2,760,888 shares; 2024Q4: 2,760,888 shares; 2025Q1: 2,760,888 shares; 2025Q2: 9,677,125 shares; 2025Q3: 9,677,125 shares 9,677,125$22.6M1.5%0Timeline
KYTXKYVERNA THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 3,368,370 shares; 2024Q4: 3,368,370 shares; 2025Q1: 3,368,370 shares; 2025Q2: 3,368,370 shares; 2025Q3: 3,368,370 shares 3,368,370$20.2M1.34%0Timeline
ANNXANNEXON INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 8,449,748 shares; 2024Q4: 5,249,069 shares; 2025Q1: 5,249,069 shares; 2025Q2: 5,249,069 shares; 2025Q3: 5,249,069 shares 5,249,069$16M1.06%0Timeline
XFORX4 PHARMACEUTICALS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: 563,859 shares; 2025Q3: 2,436,588 shares 2,436,588$8.33M0.55%+1,872,729Timeline
AVIRATEA PHARMACEUTICALS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 2,485,638 shares; 2024Q4: 2,485,638 shares; 2025Q1: 2,485,638 shares; 2025Q2: 2,485,638 shares; 2025Q3: 2,485,638 shares 2,485,638$7.21M0.48%0Timeline
XLOXilio Therapeutics Inc.Quarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 4,566,817 shares; 2024Q4: 4,566,817 shares; 2025Q1: 4,566,817 shares; 2025Q2: 4,566,817 shares; 2025Q3: 4,566,817 shares 4,566,817$3.85M0.26%0Timeline
MERSANA THERAPEUTICS INCMERSANA THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: not reported; 2024Q4: not reported; 2025Q1: not reported; 2025Q2: not reported; 2025Q3: 346,545 shares 346,545$2.69M0.18%new
CCCCC4 THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 1,111,910 shares; 2024Q4: 1,111,910 shares; 2025Q1: 1,111,910 shares; 2025Q2: 1,111,910 shares; 2025Q3: 1,111,910 shares 1,111,910$2.47M0.16%0Timeline
IPSCCENTURY THERAPEUTICS INCQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 5,410,361 shares; 2024Q4: 5,410,361 shares; 2025Q1: 5,410,361 shares; 2025Q2: 5,410,361 shares; 2025Q3: 3,538,609 shares 3,538,609$1.76M0.12%-1,871,752Timeline
NAMSWNEWAMSTERDAM PHARMA COMPANYQuarterly shares; oldest to newest; scale is this security's eight-quarter maximum; 2023Q4: restricted; 2024Q1: restricted; 2024Q2: restricted; 2024Q3: 100,000 shares; 2024Q4: 100,000 shares; 2025Q1: 100,000 shares; 2025Q2: 100,000 shares; 2025Q3: 100,000 shares 100,000$1.71M0.11%0Timeline

Sold out in Q3 2025

Positions in the previous quarter's report that this quarter's report no longer lists.

SecurityShares beforeValue beforeType
NUVLNUVALENT INC1,447,267$110Mshares
IRONDISC MEDICINE INC583,500$30.9Mshares
Mersana Therapeutics IncMersana Therapeutics Inc8,663,673$2.56Mshares
IVVDINVIVYD INC1,799,595$1.29Mshares

How Q3 2025 was built

Available 13F filings of this filer for the quarter and their roles: the base report is the latest original or restatement, NEW HOLDINGS amendments filed after it are added (method).

FilingRoleAmendmentFiledAcceptedIngested
13F-HR 0001193125-25-283094 base2025-11-14acceptance time not in the bulk data set