Atlas Venture Life Science Advisors, LLC Long-Term Concentrated

Name: Atlas Venture Life Science Advisors, LLC Q2 2026 13F Filing | 13F Explorer
Creator: Atlas Venture Life Science Advisors, LLC
Published: 2026-08-13

Location: Cambridge, MA

CIK: 0001917529 · Show all filings

Period: Q2 2026 (← Previous)

Filing Date: Aug 13, 2026

Total Value: $881M (100.0% shares, 0.0% debt)

Holdings (7)

New Positions (1)

KLRA Kailera Therapeutics, Inc. 12.9%

Value $114M Shares 5,171,282 Est. Cost — Unrealized —

Ticker	Issuer	Shares	Value	%	Est. Cost	Unrealized	Class	CUSIP
KLRA	Kailera Therapeutics, Inc.	5,171,282	$114M	12.9%	—	—	Common Stock	482931102

Increased Positions (1)

QTTB Q32 Bio, Inc. 3.9%

Value $34.62M (+157.7%) Shares 2,717,106 (+29.9%) Est. Cost — Unrealized —

Ticker	Issuer	Shares	Value	%	Est. Cost	Unrealized	Class	CUSIP
QTTB	Q32 Bio, Inc.	2,717,106 (+29.9%)	$34.62M (+157.7%)	3.9%	—	—	Common Stock	746964105

Decreased Positions (3)

KYMR Kymera Therapeutics, Inc. 37.1%

Value $327M (-14.4%) Shares 2,847,541 (-37.8%) Est. Cost — Unrealized —

DYN Dyne Therapeutics, Inc. 17.1%

Value $151M (-8.8%) Shares 6,800,099 (-25.5%) Est. Cost — Unrealized —

KRRO Korro Bio, Inc. 1.4%

Value $12.69M (-1.4%) Shares 962,884 (-15.3%) Est. Cost — Unrealized —

Ticker	Issuer	Shares	Value	%	Est. Cost	Unrealized	Class	CUSIP
KYMR	Kymera Therapeutics, Inc.	2,847,541 (-37.8%)	$327M (-14.4%)	37.1%	—	—	Common Stock	501575104
DYN	Dyne Therapeutics, Inc.	6,800,099 (-25.5%)	$151M (-8.8%)	17.1%	—	—	Common Stock	26818M108
KRRO	Korro Bio, Inc.	962,884 (-15.3%)	$12.69M (-1.4%)	1.4%	—	—	Common Stock	500946108

Unchanged Positions (2)

IRON Disc Medicine, Inc. 12.6%

Value $111M Shares 1,513,875 Est. Cost — Unrealized —

SION Sionna Therapeutics, Inc. 15.0%

Value $132M Shares 2,995,602 Est. Cost — Unrealized —

Ticker	Issuer	Shares	Value	%	Est. Cost	Unrealized	Class	CUSIP
IRON	Disc Medicine, Inc.	1,513,875	$111M	12.6%	—	—	Common Stock	254604101
SION	Sionna Therapeutics, Inc.	2,995,602	$132M	15.0%	—	—	Common Stock	829401108