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Pig kidneys bridge first patients to human transplants

Pig kidneys bridge first patients to human transplants

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eGenesis reports five patients treated with engineered pig kidneys; two went on to receive human donor organs

September 4th, 2026: eGenesis reports five patients treated; two bridged to human transplants

Overview

Updated 5 days ago

Tim Andrews went 271 days without dialysis after receiving a genetically engineered pig kidney in January 2025. In January 2026, he received a human donor kidney — the first time a pig organ has bridged a patient to a human transplant.

eGenesis reported on September 4 that five patients have received its EGEN-2784 pig kidneys since March 2024. Three have sustained kidney function beyond eight months, and two have transitioned to human donor kidneys. The company plans a 33-patient trial starting in early 2027.

Why it matters

If pig kidneys can keep patients off dialysis while they wait for human organs, it could change how 800,000 Americans with kidney failure are treated.

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Key Indicators

5
Patients who received pig kidney transplants
Since March 2024 under FDA Expanded Access at Mass General Brigham.
271
Days Andrews lived without dialysis on pig kidney
Longest dialysis-free survival after porcine kidney xenotransplant in a living human.
2
Patients bridged to human donor transplants
First reported transitions from xenotransplantation to allotransplantation.
28,000
Kidney transplants performed in US in 2024
Against more than 800,000 Americans with end-stage kidney disease.
60%
Five-year mortality rate on dialysis
Higher than mortality rates for the most common cancers.

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People Involved

Organizations Involved

Timeline

March 2024 September 2026

5 events Latest: September 4th, 2026 · 1 week ago
Tap a bar to jump to that date
  1. eGenesis reports five patients treated; two bridged to human transplants

    Latest Clinical update

    eGenesis announced that five patients received EGEN-2784 kidneys since March 2024. Three sustained function beyond eight months; two transitioned to human donor kidneys. The Lancet published Andrews' case. FDA cleared the 33-patient RESTORE trial.

  2. Andrews receives human donor kidney

    Procedure

    Andrews received a deceased-donor human kidney with immediate graft function and no evidence of sensitization during follow-up.

  3. Andrews' pig kidney removed after 271 days

    Medical event

    The xenotransplant developed microvascular injury and inflammation after immunosuppression was reduced. The kidney was removed; Andrews went on dialysis for 82 days.

  4. Tim Andrews receives engineered pig kidney

    Procedure

    Andrews received an EGEN-2784 pig kidney under an FDA Expanded Access Investigational New Drug application. The kidney functioned immediately.

  5. First pig kidney xenotransplant to living human

    Medical milestone

    Massachusetts General Hospital performed the world's first porcine kidney xenotransplant to a living human. The patient survived 52 days before death from cardiac causes unrelated to the transplant.

Scenarios

1

RESTORE trial confirms pig kidneys as viable bridge therapy

Likely Resolves by End of 2029

Discussed by: eGenesis, Mass General Brigham researchers

The 33-patient RESTORE trial, expected to start in Q1 2027, will test EGEN-2784 in patients waitlisted for human kidneys. If results match the Expanded Access experience, pig kidneys could become a standard bridge therapy for patients awaiting human organs.

2

Late graft failure emerges as recurring obstacle

Possible Resolves by Q2 2028

Discussed by: Mass General Brigham researchers (Riella et al.)

Andrews' pig kidney developed microvascular injury and inflammation after immunosuppression was reduced. If this pattern repeats in other patients, xenotransplants may be limited to short-term bridging rather than destination therapy. The Lancet paper explicitly flags implications for immunosuppressive strategies and donor genetic engineering.

3

Cost and access barriers slow xenotransplant adoption

Possible Resolves by End of 2028

Discussed by: New Scientist, Monica Willicombe

The procedure is experimental and costly. New Scientist notes that costs could be a barrier to widespread adoption, and researchers suggest artificial kidneys and organ regeneration should also be pursued. Riella said pig kidneys might compete with human kidney transplants within 15 years, but not yet.

Historical Context

3 moments from history that rhyme with this story — and how they unfolded.

December 1954

First successful kidney transplant (1954)

Joseph Murray transplanted a kidney between identical twins at Peter Bent Brigham Hospital in Boston, now part of Mass General Brigham. The recipient, Richard Herrick, lived eight more years.

Then

The success proved organ transplantation was possible, leading to the development of immunosuppressive drugs.

Now

Kidney transplantation became the gold standard for end-stage kidney disease, but donor shortages persist.

Why this matters now

The same institution that pioneered human kidney transplantation is now testing pig kidneys as a bridge to human transplants.

December 1967

First human heart transplant (1967)

Christiaan Barnard transplanted a human heart into Louis Washkansky in Cape Town, South Africa. Washkansky lived 18 days before dying of pneumonia.

Then

The procedure sparked global interest, but early survival rates were poor.

Now

Heart transplantation became standard treatment over the following decades, with one-year survival now above 90%.

Why this matters now

Early xenotransplants face similar skepticism and technical challenges to early heart transplants, which took years to become routine.

December 1982

Jarvik-7 artificial heart (1982)

Barney Clark, a 61-year-old dentist, received the Jarvik-7 artificial heart at the University of Utah. He lived 112 days with the device, which was powered by an external air compressor.

Then

Clark died from multiple organ failure, but the device proved mechanical hearts could sustain life.

Now

The Jarvik-7 was later used as a bridge to transplant, and ventricular assist devices became standard for patients awaiting heart transplants.

Why this matters now

Like the Jarvik-7, pig kidneys are being tested as a bridge to human transplantation, with the open question of whether they can become destination therapy.

Sources

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