Pig Kidney Survives Over Nine Months in a Human Patient, Setting a New Record

On November 22, 2025, a 58‑year‑old woman stepped onto the operating table at Massachusetts General Hospital with a very unusual donor organ in the wings—a kidney harvested from a genetically engineered pig. Nine months later, the organ is still doing its job, and she hasn’t needed a single dialysis session since the surgery.

The transplant was made possible by eGenesis, a biotech company that uses CRISPR to snip out pig genes that would normally trigger a fierce immune attack, and to insert a handful of human genes that help the organ blend in. The result is a kidney that looks, size‑wise and function‑wise, like a human one, but without the immediate rejection that would otherwise shut it down within days.

According to eGenesis, the kidney has now functioned for 285 days – a new benchmark that eclipses the previous high of 271 days set by a man named Tim Andrews. Andrews, who received his pig kidney in early 2025, eventually saw it fail because of tiny clots forming inside the organ, a condition doctors call thrombotic microangiopathy. That lesson has already shaped how the current team tweaks immunosuppressant dosages for newer patients.

Why does this matter? In the United States, more than 95,000 people are waiting for a kidney, yet only about 28,000 transplants happen each year. Most patients spend three to five years on dialysis, a grueling routine of three four‑hour sessions a week that wears on veins, the heart and overall health. “Their health deteriorates faster than the transplant pipeline can keep up,” says Mike Curtis, CEO of eGenesis.

The woman’s case is the fifth to come through an FDA “expanded access” pathway, a regulatory loophole that lets seriously ill patients try experimental therapies when no approved options exist. The agency has now cleared eGenesis for a more formal trial involving up to 33 kidney‑failure patients aged 50‑70, slated to start in 2027. In the meantime, the company plans to keep offering transplants under the expanded‑access route, hoping to push the durability mark toward a full year.

Each successful transplant teaches scientists something new. The recent Lancet paper describing Andrews’s experience pinpoints where the organ’s blood vessels gave way, informing the next generation of gene edits and drug regimens. It’s a careful, step‑by‑step dance, but the momentum feels unmistakable.

For the woman, the clock keeps ticking, and each day without dialysis feels like a small victory against a system that has long struggled to meet demand. If her kidney continues to work, it could be the first real proof that pig‑derived organs can serve as a reliable bridge—maybe even a long‑term solution—for the millions awaiting a human donor.