Bain Capital Life Sciences Investors, LLC Long-Term Concentrated

Name: Bain Capital Life Sciences Investors, LLC Q1 2026 13F Filing | 13F Explorer
Creator: Bain Capital Life Sciences Investors, LLC
Published: 2026-05-15

Location: Boston, MA

CIK: 0001703031 · Show all filings

Period: Q1 2026 (← Previous)

Filing Date: May 15, 2026

Total Value: $1.109B (100.0% shares, 0.0% debt)

Holdings (20)

New Positions (4)

CNTA CENTESSA PHARMACEUTICALS 2.3%

Value $25.22M Shares 635,000 Est. Cost $39.72 Unrealized —

ALKS ALKERMES PLC 1.9%

Value $21.57M Shares 610,000 Est. Cost $32.34 Unrealized 0.0%

IRON DISC MEDICINE INC 0.8%

Value $9.031M Shares 141,234 Est. Cost $74.04 Unrealized 0.0%

XLO XILIO THERAPEUTICS INC 0.5%

Value $5.584M Shares 664,021 Est. Cost $8.41 Unrealized —

Ticker	Issuer	Shares	Value	%	Est. Cost	Unrealized	Class	CUSIP
CNTA	CENTESSA PHARMACEUTICALS	635,000	$25.22M	2.3%	$39.72	—	SPONSORED ADS	152309100
ALKS	ALKERMES PLC	610,000	$21.57M	1.9%	$32.34	0.0%	SHS	G01767105
IRON	DISC MEDICINE INC	141,234	$9.031M	0.8%	$74.04	0.0%	COM	254604101
XLO	XILIO THERAPEUTICS INC	664,021	$5.584M	0.5%	$8.41	—	COM	98422T209

Increased Positions (1)

SLDB SOLID BIOSCIENCES INC 6.4%

Value $70.62M (+58.3%) Shares 9,808,819 (+24.0%) Est. Cost $5.82 Unrealized +4.0%

Ticker	Issuer	Shares	Value	%	Est. Cost	Unrealized	Class	CUSIP
SLDB	SOLID BIOSCIENCES INC	9,808,819 (+24.0%)	$70.62M (+58.3%)	6.4%	$5.82	+4.0%	COM NEW	83422E204

Exited Positions (3)

— MERSANA THERAPEUTICS INC 0.9%

Value $10.03M Shares 346,545 Est. Cost $7.76 Unrealized —

TNGX TANGO THERAPEUTICS INC 0.5%

Value $5.79M Shares 653,493 Est. Cost $10.01 Unrealized +18.9%

XLO XILIO THERAPEUTICS INC 0.4%

Value $4.72M Shares 7,372,686 Est. Cost $7.01 Unrealized -91.4%

Ticker	Issuer	Shares	Value	%	Est. Cost	Unrealized	Class	CUSIP
—	MERSANA THERAPEUTICS INC	346,545	$10.03M	0.9%	$7.76	—	—	59045L205
TNGX	TANGO THERAPEUTICS INC	653,493	$5.79M	0.5%	$10.01	+18.9%	—	87583X109
XLO	XILIO THERAPEUTICS INC	7,372,686	$4.72M	0.4%	$7.01	-91.4%	—	98422T100

Decreased Positions (6)

HTFL HEARTFLOW INC 22.9%

Value $254M (-29.9%) Shares 10,448,158 (-16.1%) Est. Cost $32.24 Unrealized -10.1%

OLMA OLEMA PHARMACEUTICALS INC 10.0%

Value $111M (-47.6%) Shares 7,473,238 (-12.2%) Est. Cost $11.52 Unrealized +121.1%

UPB UPSTREAM BIO INC 0.7%

Value $7.805M (-78.4%) Shares 867,211 (-34.8%) Est. Cost $21.55 Unrealized +9.9%

AVIR ATEA PHARMACEUTICALS INC 1.1%

Value $12.7M (+43.1%) Shares 2,360,638 (-5.0%) Est. Cost $32.23 Unrealized -87.6%

PHVS PHARVARIS N V 6.8%

Value $75.58M (-2.8%) Shares 2,675,509 (-4.5%) Est. Cost $23.89 Unrealized +11.9%

DNTH DIANTHUS THERAPEUTICS INC 2.7%

Value $30.42M (-0.7%) Shares 362,470 (-51.3%) Est. Cost $21.73 Unrealized +118.9%

Ticker	Issuer	Shares	Value	%	Est. Cost	Unrealized	Class	CUSIP
HTFL	HEARTFLOW INC	10,448,158 (-16.1%)	$254M (-29.9%)	22.9%	$32.24	-10.1%	COM	42238D107
OLMA	OLEMA PHARMACEUTICALS INC	7,473,238 (-12.2%)	$111M (-47.6%)	10.0%	$11.52	+121.1%	COM	68062P106
UPB	UPSTREAM BIO INC	867,211 (-34.8%)	$7.805M (-78.4%)	0.7%	$21.55	+9.9%	COM	91678A107
AVIR	ATEA PHARMACEUTICALS INC	2,360,638 (-5.0%)	$12.7M (+43.1%)	1.1%	$32.23	-87.6%	COM	04683R106
PHVS	PHARVARIS N V	2,675,509 (-4.5%)	$75.58M (-2.8%)	6.8%	$23.89	+11.9%	COM	N69605108
DNTH	DIANTHUS THERAPEUTICS INC	362,470 (-51.3%)	$30.42M (-0.7%)	2.7%	$21.73	+118.9%	COM	252828108

Unchanged Positions (9)

NAMS NEWAMSTERDAM PHARMA COMPANY 21.1%

Value $234M Shares 7,306,566 Est. Cost $10.88 Unrealized +210.1%

SVRA SAVARA INC 8.7%

Value $96.1M Shares 17,600,621 Est. Cost $2.08 Unrealized +173.9%

RPID RAPID MICRO BIOSYSTEMS INC 1.7%

Value $19.15M Shares 8,434,560 Est. Cost $20.66 Unrealized -81.0%

CCCC C4 THERAPEUTICS INC 1.7%

Value $18.86M Shares 7,171,910 Est. Cost $6.50 Unrealized -67.9%

CABA CABALETTA BIO INC 2.3%

Value $26.03M Shares 9,677,125 Est. Cost $3.63 Unrealized -28.0%

ANNX ANNEXON INC 2.6%

Value $28.88M Shares 5,212,674 Est. Cost $11.24 Unrealized -48.9%

KYTX KYVERNA THERAPEUTICS INC 2.4%

Value $26.84M Shares 3,110,000 Est. Cost $27.08 Unrealized -69.3%

XFOR X4 PHARMACEUTICALS INC 3.0%

Value $32.91M Shares 7,967,454 Est. Cost $3.42 Unrealized +6.4%

NAMSW NEWAMSTERDAM PHARMA COMPANY 0.2%

Value $2.004M Shares 99,999 Est. Cost $0.86 Unrealized —

Ticker	Issuer	Shares	Value	%	Est. Cost	Unrealized	Class	CUSIP
NAMS	NEWAMSTERDAM PHARMA COMPANY	7,306,566	$234M	21.1%	$10.88	+210.1%	ORDINARY SHARES	N62509109
SVRA	SAVARA INC	17,600,621	$96.1M	8.7%	$2.08	+173.9%	COM	805111101
RPID	RAPID MICRO BIOSYSTEMS INC	8,434,560	$19.15M	1.7%	$20.66	-81.0%	CLASS A COM	75340L104
CCCC	C4 THERAPEUTICS INC	7,171,910	$18.86M	1.7%	$6.50	-67.9%	COM STK	12529R107
CABA	CABALETTA BIO INC	9,677,125	$26.03M	2.3%	$3.63	-28.0%	COM	12674W109
ANNX	ANNEXON INC	5,212,674	$28.88M	2.6%	$11.24	-48.9%	COM	03589W102
KYTX	KYVERNA THERAPEUTICS INC	3,110,000	$26.84M	2.4%	$27.08	-69.3%	COM	501976104
XFOR	X4 PHARMACEUTICALS INC	7,967,454	$32.91M	3.0%	$3.42	+6.4%	COM NEW	98420X202
NAMSW	NEWAMSTERDAM PHARMA COMPANY	99,999	$2.004M	0.2%	$0.86	—	*W EXP 99/99/999	N62509117