Breakthrough Xenotransplant: Man Survives Nine Months with a Pig Kidney

When Tim Andrews turned 66, a double whammy of diabetes and high blood pressure left his kidneys in ruins. Two heart attacks, a dwindling appetite and the inability to walk left him feeling, in his own words, “I was dying.”

He was one of roughly 90,000 people on the U.S. kidney‑waiting list, a roster where, on average, 11 patients die each day. And because his blood type was rare, the odds of finding a compatible human kidney were painfully slim.

Instead of sitting on the list, Andrews opted for an experimental route at Mass General Brigham: a pig kidney that had been extensively edited to mute rejection‑triggering genes and deactivate lurking viruses. “If I’m going to die, I might as well do something for humanity,” he said, a sentiment that resonated with the team leading the study.

The transplant took place in January 2025. The organ performed surprisingly well, delivering enough function to keep Andrews alive and out of dialysis for the better part of a year. He did have setbacks—hospital stays, occasional clots, and the inevitable wear that comes with a foreign organ—but the pig kidney bought him precious time.

By the end of September, the graft began to fail; blood clots had damaged its vessels beyond repair. The organ was removed, dialysis was briefly reinstated, and shortly thereafter a human kidney from a matching donor arrived. Andrews now spends his days paddling a kayak on a pond near his cabin, a quiet celebration of a second chance.

Dr. Leonardo V. Riella, lead author of the Lancet paper describing the case, called the pig kidney a “bridge” that spares patients the relentless toll of dialysis, which can make them too frail for a transplant later on. “Life on dialysis is no life,” he explained, echoing the desperation many patients feel.

eGenesis, the biotech firm that produced the pig and helped fund the study, reported that the pig kidney did not seem to prime the immune system against a later human organ. “Right now we don’t think there’s any downside of having a pig kidney followed by a human kidney,” said CEO Mike Curtis, noting that this was an unexpected but welcome finding.

Five patients have so far received eGenesis pig kidneys through an FDA‑expanded access program, three of them—including Andrews—lasting more than eight months. A formal clinical trial with 33 participants is slated to begin next year, building on earlier milestones such as the first gene‑edited pig kidney transplant in March 2024 and earlier pig‑heart attempts.

The story is still unfolding, but for Andrews and countless others waiting on the transplant list, the experiment offers a glimpse of a future where organ scarcity might finally meet a viable, life‑saving solution.