Atlas Venture Life Science Advisors, LLC Long-Term Concentrated

Location: CAMBRIDGE, MA

CIK: 0001917529 · Show all filings

Period: Q1 2026 (← Previous)

Filing Date: May 14, 2026

Total Value ($000): $790,032 (100.0% shares, 0.0% debt)

Holdings (6)

Exited Positions (2)

DAWN Day One Biopharmaceuticals, Inc. 7.6%

Value ($000) $59,765 Shares 6,412,560 Est. Cost $19.68 Unrealized -44.0%

— Generation Bio, Co. 0.6%

Value ($000) $4,703 Shares 827,946 Est. Cost $5.68 Unrealized —

Ticker	Issuer	Shares	Value ($000)	%	Est. Cost	Unrealized	Class	CUSIP
DAWN	Day One Biopharmaceuticals, Inc.	6,412,560	$59,765	7.6%	$19.68	-44.0%	—	23954D109
—	Generation Bio, Co.	827,946	$4,703	0.6%	$5.68	—	—	37148K209

Decreased Positions (1)

KYMR Kymera Therapeutics, Inc. 48.3%

Value ($000) $381,302 (+5.2%) Shares 4,578,008 (-1.8%) Est. Cost $58.25 Unrealized +33.2%

Ticker	Issuer	Shares	Value ($000)	%	Est. Cost	Unrealized	Class	CUSIP
KYMR	Kymera Therapeutics, Inc.	4,578,008 (-1.8%)	$381,302 (+5.2%)	48.3%	$58.25	+33.2%	Common Stock	501575104

Unchanged Positions (5)

IRON Disc Medicine, Inc. 12.3%

Value ($000) $96,797 Shares 1,513,875 Est. Cost $48.39 Unrealized +53.0%

DYN Dyne Therapeutics, Inc. 21.0%

Value ($000) $165,535 Shares 9,130,465 Est. Cost $13.88 Unrealized +23.3%

QTTB Q32 Bio, Inc. 1.7%

Value ($000) $13,431 Shares 2,092,106 Est. Cost $13.78 Unrealized -71.4%

KRRO Korro Bio, Inc. 1.6%

Value ($000) $12,873 Shares 1,137,149 Est. Cost $33.30 Unrealized -67.6%

SION Sionna Therapeutics, Inc. 15.2%

Value ($000) $120,094 Shares 2,995,602 Est. Cost $16.34 Unrealized +140.2%

Ticker	Issuer	Shares	Value ($000)	%	Est. Cost	Unrealized	Class	CUSIP
IRON	Disc Medicine, Inc.	1,513,875	$96,797	12.3%	$48.39	+53.0%	Common Stock	254604101
DYN	Dyne Therapeutics, Inc.	9,130,465	$165,535	21.0%	$13.88	+23.3%	Common Stock	26818M108
QTTB	Q32 Bio, Inc.	2,092,106	$13,431	1.7%	$13.78	-71.4%	Common Stock	746964105
KRRO	Korro Bio, Inc.	1,137,149	$12,873	1.6%	$33.30	-67.6%	Common Stock	500946108
SION	Sionna Therapeutics, Inc.	2,995,602	$120,094	15.2%	$16.34	+140.2%	Common Stock	829401108