LNS8801 by Linnaeus Therapeutics: status and timeline

LNS8801

Once-daily oral GPER agonist that preserves physical and cognitive function by activating aging-related pathways. Prior phase 1/2 in cancer patients; now testing in healthy older adults.

PilotStage 3 of 5

Phase 1/2 complete in cancer (100+ patients). PROSPR healthspan trial enrolling.

Updated Feb 2026Checked 10 Oct0 updates this week

Milestones

Next · PROSPR healthspan trial enrollment ongoing

Linnaeus founded as Penn spinout2016Complete.
Phase 1/2 cancer trial initiated2017Complete.
Over 100 cancer patients treated, good safety profile2025Complete.
FDA grants orphan drug designation for metastatic cutaneous melanoma2023Complete.
ARPA-H PROSPR award announcedFeb 2026Complete.
PROSPR healthspan trial enrollment ongoingTarget 2026Current milestone.
PROSPR trial expected to completeTarget 2027Not yet reached.

Most important updates

Upcoming

2026PROSPR healthspan trial enrollment ongoing (next)
2027PROSPR trial expected to complete
2027PROSPR interim results

Current obstacles

Proving healthspan benefit in humansPROSPR trial must show LNS8801 preserves physical and cognitive independence in healthy older adults.
Safety in long-term, preventive useHealthy people taking a drug for decades need near-zero side-effect burden. Cancer tolerance is higher than for health maintenance.

Physics limits

Aging has multiple causesAddressing one receptor and one signaling pathway will not reverse all aging. Genetic, epigenetic, metabolic and environmental factors drive aging; a single drug cannot fix all.
Cellular senescence is hard to reverseSenescent cells accumulate with age and secrete harmful factors. A drug that activates one receptor may slow senescence but not clear existing senescent cells.

How it works

4 parts

Target

Activate GPER estrogen receptor

Binds selectively to GPER, a G protein-coupled receptor found throughout the body that regulates aging.

Signaling

Restore protective signaling

Activation triggers cascades that reduce inflammation, maintain muscle, strengthen bone and protect cognition.

Specificity

Avoid nuclear estrogen receptors

Targets GPER only, not nuclear ERα/ERβ receptors, avoiding cancer and feminization risks of HRT.

Breadth

One drug, many aging systems

GPER is expressed across tissues, allowing one drug to target muscle, bone, heart, vasculature and brain.

Spec sheet

Spec	LNS8801
Dosing	Once-daily oral^R (reported)
Cancer patients treated (phase 1/2)	100+^R (reported)
First-in-human cancer indication	Orphan drug designation^R (reported)
ARPA-H PROSPR grant	$22 million (up to)^R (reported)

^R reported by the company

Update log

2 updates

Feb 2026

Major: ARPA-H awards Linnaeus $22M to test LNS8801 for healthspan preservation in the PROSPR trialRegulatorFunding

2025

Major: LNS8801 demonstrates exceptional safety in phase 1/2 cancer trials with 100+ patients treatedPressTest

About Linnaeus Therapeutics

The team behind LNS8801

Linnaeus Therapeutics

LNS8801, GPER agonist, aging, healthspan

Linnaeus Therapeutics develops small-molecule drugs targeting aging and disease. The company was founded in 2016 by scientists from the University of Pennsylvania and is advancing LNS8801, a selective estrogen-receptor agonist, for healthspan preservation in older adults.

Linnaeus is a Penn spinout founded in 2016. LNS8801 activates estrogen receptor to preserve physical and cognitive aging.
100+ cancer patients treated in phase 1/2 with good safety. ARPA-H awarded $22M for PROSPR healthspan trial.

linnaeusbio.com (opens linnaeusbio.com)Company profile →

Founded: 201610 yrs
Headquarters: United States
Status: Private
Valuation: private
Raised: $38M3 rounds
Last round: ARPA-H PROSPR grant · $22MFeb 2026
Works in: LongevityAnti-aging drugs
Coverage: 1 program · 5 updateslatest 1 Feb 2026checked 10 Oct
Lead investors: Kairos Ventures
Partners: University of Pennsylvania (opens upenn.edu)Merck (opens merck.com)
Investors: Kairos Ventures (opens kairosventures.com)Penn Medicine Co-Investment Fund (opens upenn.edu)
People: Todd Ridky (opens med.upenn.edu)Co-founderChristopher Natale (opens linnaeusbio.com)Co-founder & Chief Scientific Officer

Spec

LNS8801

Dosing

Once-daily oral^R (reported)

Cancer patients treated (phase 1/2)

100+^R (reported)

First-in-human cancer indication

Orphan drug designation^R (reported)

ARPA-H PROSPR grant

$22 million (up to)^R (reported)