UKidney by United Therapeutics: status and timeline

Milestones

Next · UKidney clinical trial enrollment begins (target mid-2025)

UKidney gene design finalized2023Complete.
FDA expanded access granted for first UKidney transplantNov 2024Complete.
World's first UKidney transplant into Towana Looney25 Nov 2024Complete.
FDA IND clearance for UKidney clinical trialFeb 2025Complete.
UKidney clinical trial enrollment begins (target mid-2025)Target Q2 2025Current milestone.
Expansion to up to 50 trial participantsTarget Q4 2025Not yet reached.

Most important updates

Upcoming

Q2 2025UKidney clinical trial enrollment begins (target mid-2025) (next)
Q4 2025Expansion to up to 50 trial participants
2027BLA submission target for UKidney

Current obstacles

Long-term immune toleranceThe first UKidney recipient showed early promise, but years-long function without severe rejection or chronic vasculopathy has not yet been demonstrated.
Antibody reboundPatients with high pre-transplant antibody levels (like the first recipient, who donated a kidney to her mother) may see antibody rebound, requiring monitoring.
Immunosuppression regimen optimizationThe right balance of immunosuppression to prevent rejection while minimizing infection and malignancy risk in xenotransplant recipients is not yet established.

Physics limits

Genetic variability in pigsPig genetics vary like human genetics; even with identical intended edits, functional outcomes may differ across pig lineages or recipients.
Coagulation mismatchPig coagulation cascade proteins are fundamentally different from human. Complete hemostatic compatibility cannot be achieved by gene editing alone and requires ongoing immunosuppression.

How it works

3 parts

Human immune regulators

Six human transgenes manage rejection

Human genes suppress complement and regulate inflammation, allowing immune tolerance.

Pig rejection targets removed

Four critical pig genes knocked out

Three rejection genes inactivated; growth hormone knocked out to prevent organ enlargement.

SPF breeding

Designated pathogen-free pigs

SPF pigs minimize zoonotic infection risk and ensure consistent genetic background.

Spec sheet

Spec	UKidney
Total gene edits	10 edits^R (reported)
Human transgenes inserted	6^R (reported)
Porcine genes knocked out	4^R (reported)
First recipient age	53 years^R (reported)
Initial trial cohort	6 patients^R (reported)
Expanded trial enrollment target	Up to 50 patients^R (reported)
Christiansburg SPF facility capacity	~125 organs per year^R (reported)

^R reported by the company

Papers & demos

1 item

Nov 2024demo
World's first UKidney xenotransplant under FDA expanded access (opens businesswire.com)First demonstration of a 10-gene-edit pig kidney in a living recipient, opening clinical trial pathway.

Update log

2 updates

Feb 2025

Major: FDA clears IND application for UKidney xenotransplant clinical trialPressRegulatory

Nov 2024

Major: Revivicor performs world's first UKidney xenotransplant under FDA expanded accessPressTest

About United Therapeutics

The team behind UKidney

United Therapeutics

Xenotransplant, gene-edited pig organs, UKidney UHeart, Revivicor

United Therapeutics develops pig-organ xenotransplants via Revivicor for end-stage renal and cardiac disease. Programs include UKidney, UHeart, and UThymoKidney.

United Therapeutics acquired xenotransplant pioneer Revivicor in 2011.
December 2024: First UKidney transplant performed under FDA compassionate-use authorization.
Three programs: UKidney and UHeart (10 edits each), UThymoKidney (single-gene); trials planned 2025–2026.

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

Founded: 199630 yrs
Headquarters: United States
Status: Public
Listed: UTHR (opens google.com)NASDAQ
Valuation: $24Best. market capOct 2026estimate
Last round: Founded1996
Works in: BiotechCell & organ therapies
Coverage: 3 programs · 5 updateslatest 1 Feb 2025checked 10 Oct
Partners: NYU Langone Health (opens nyulangone.org)FDA (opens fda.gov)Revivicor, Inc. (opens revivicor.com)
People: Martine Rothblatt (opens en.wikipedia.org)Founder, Chairperson, and Chief Executive Officer

Spec

UKidney

Total gene edits

10 edits^R (reported)

Human transgenes inserted

6^R (reported)

Porcine genes knocked out

4^R (reported)

First recipient age

53 years^R (reported)

Initial trial cohort

6 patients^R (reported)

Expanded trial enrollment target

Up to 50 patients^R (reported)

Christiansburg SPF facility capacity

~125 organs per year^R (reported)