Second Pig Kidney Patient Now Passes 285 Days Without Dialysis, Breaking Prior Record

A woman being treated at Massachusetts General Hospital has now lived 285 days with a genetically modified pig kidney and zero dialysis, according to Cambridge, Massachusetts-based biotech eGenesis. That beats the previous record of 271 days set by 67-year-old Tim Andrews of New Hampshire, whose case is the subject of a study published Thursday in The Lancet medical journal.

The woman is the fifth patient to receive an eGenesis pig kidney through the FDA's expanded access pathway, a program that lets patients with serious or life-threatening conditions try experimental treatments when there's no good alternative. Her kidney, according to eGenesis, remains fully functional.

Andrews' Case: The Bridge That Worked

Andrews had end-stage kidney disease from type 2 diabetes. He received a kidney from Wilma, a Yucatan miniature pig, on January 25, 2025, at Mass General Brigham. The organ started working immediately.

According to The Lancet, Andrews had only a 9% chance of getting a human kidney within five years and faced better than a 40% risk of dying or being pulled from the transplant list before one arrived. "I was alive, and I hadn't been in a long time," Andrews told The Guardian, describing the transplant as a "miracle" that let him cook, vacuum, and walk his dog Cupcake again.

The kidney functioned for 271 days before doctors detected damage. Ground News reported the Lancet paper pins the failure on thrombotic microangiopathy, tiny blood clots that formed in the organ's vessels and progressed to full failure. Andrews returned to dialysis for 82 days, then received a human donor kidney in January 2026. That kidney is working well, according to the BBC.

Dr. Leonardo Riella of Mass General Brigham's Center for Transplantation Sciences, the study's lead author, called organ shortage "the greatest crisis we have right now in transplantation." He said the goal is for pig kidneys to serve first as a bridge to a human organ and eventually, if long-term safety holds up, as a standalone "destination therapy."

The New Record Holder

The BBC, The Guardian, and a wire story from the Press Association running in the Ilford Recorder and Irvine Times all framed Andrews' 271 days as the headline record, without noting that a second patient has already surpassed it. Wired and Ground News reported the fuller timeline: the woman received her pig kidney on November 22, 2025, and as of Thursday, September 3, 2026, has passed 285 days without dialysis, making her the current record holder.

eGenesis CEO Mike Curtis told Wired the company used CRISPR gene editing to strip out pig genes that trigger immune rejection and insert human genes to help the organ evade the immune system. "What we saw with Mr. Andrews was a radical improvement in his overall health while he was on the pig kidney versus if he had stayed on chronic dialysis," Curtis said. eGenesis also confirmed a separate, third patient successfully received a human transplant after living with a pig kidney for eight months.

69 Genetic Edits, One Dead Pig Named Wilma

Wilma underwent 69 genomic modifications before her kidney was harvested, per the Guardian and BBC. Some edits removed pig cell markers the human immune system attacks on sight. Others inserted human DNA to help the organ hide from immune detection. A separate set of edits disabled dormant viruses embedded in pig DNA to reduce infection risk. Researchers told Sky News no pig viruses or pathogens were detected in Andrews at any point during his 271 days.

The first attempt at a living-person pig kidney transplant, done at Massachusetts General Hospital in 2024, ended after 52 days when the patient died of heart problems doctors said were unrelated to the transplant.

The Scale of the Problem

Nearly 100,000 Americans are waiting for a kidney, according to the BBC, while only about 25,000 transplants happen each year. In the UK, more than 7,000 people are on the kidney transplant waiting list. Dr. Rommel Ravanan, chief medical officer for NHS Blood and Transplant, told the Press Association that the US and China have carried out several similar pig kidney transplants since 2022, but the UK currently has no clinical trials underway, even though regulators have examined how such a program might work.

Every pig kidney transplanted so far has eventually failed or been removed. None has lasted a full year, and the sample size is five patients under expanded access plus a small number of earlier cases. The evidence shows promising short-term bridge data, with no proof yet of long-term viability as a standalone therapy.

The FDA has authorized eGenesis to run a formal trial enrolling up to 33 kidney failure patients starting in 2027, aimed at establishing whether pig kidneys can work as permanent replacements rather than temporary bridges. Whether the current 285-day case eventually needs replacement, and how long the next cohort of patients can go before rejection sets in, remains the open question the 2027 trial is designed to answer.