A small but closely watched clinical trial has given transplant medicine something it rarely gets in this area: a real signal that a few patients may be able to live without long-term anti-rejection medication. In the study, published April 17 in Nature Communications, researchers reported that three living-donor liver transplant recipients stayed off all immunosuppressive drugs for more than three years after receiving an experimental cell therapy before surgery.
That matters because anti-rejection drugs, while lifesaving, come with a heavy price. Patients often need them for life, and the trade-off can be brutal: higher risks of infection, kidney damage, diabetes, certain cancers, and other long-term complications. The hope behind the new approach is pretty straightforward even if the science is not — retrain the recipient’s immune system to treat the donated organ less like an invader and more like accepted tissue.
The treatment uses donor-derived regulatory dendritic cells, or ddDCregs. These cells were made from the liver donor’s white blood cells and infused into the recipient seven days before transplant surgery. After the transplant, patients still received standard immunosuppressive drugs at first. Only later, beginning about a year after surgery and only if biopsies looked calm and “permissive,” did doctors begin tapering medication.
So the headline result is encouraging, but it needs context. This was not a case of all transplant patients suddenly going drug-free. The trial involved 15 prospective living-donor liver recipients, and 13 were included in the final analysis after two were excluded for reasons unrelated to the study. Of those 13, 8 were considered eligible to try withdrawing immunosuppressive drugs. Four came completely off them, and three remained drug-free through the end of follow-up, averaging about three years without immunosuppression.
The safety picture, at least in this early-stage trial, looked reassuring. Researchers reported that donor cell collection was well tolerated, there were no infusion reactions or infusion-related adverse events, and complication rates at 12 months did not appear meaningfully worse than those in a matched standard-care group. The one grade 4 adverse event noted in the paper was a patient death more than four years after transplant following a traumatic head injury, which investigators said was unrelated to the therapy itself.
Still, not everyone benefited. Four of the eight patients who were eligible for withdrawal failed the tapering process and returned to baseline immunosuppression. Another patient did come fully off medication, but later resumed treatment after suspected immune reactivation and rejection two weeks after a COVID-19 vaccination, according to the paper. That detail is striking, though it should not be overread from a sample this small.
Researchers were careful not to oversell what they had found. The paper describes the study as a first-in-human phase I/IIa trial designed mainly to test feasibility and safety, with only preliminary signals on efficacy. The authors also note that the trial was small, single-center, open-label, and limited to low-risk living-donor liver transplantation, which means the results cannot simply be applied to all liver transplants, let alone kidney, heart, or lung transplants.
Even so, transplant specialists have been chasing this goal for years because the upside is enormous. The idea is sometimes called operational tolerance — the transplanted organ keeps working even after immunosuppressive drugs are stopped. That outcome is rare in adult liver transplantation when drug withdrawal is attempted in conventional care, which is exactly why these results have drawn attention. The paper says historical success rates for complete withdrawal in eligible adult liver recipients have been around 13% to 16%, depending on the setting and timing.
There is also a wider story here. Other groups, particularly in Japan and the United States, are exploring cell-based ways to reduce or eliminate lifelong immunosuppression in transplant recipients. Juntendo University, for instance, has highlighted parallel work on immune-tolerance therapies in liver transplantation and a push toward broader clinical development. That does not validate this trial by itself, but it does show the field is moving beyond theory and into human testing.
For patients and families, the message is hopeful, but not yet practice-changing. This is not a green light for transplant recipients to alter medication on their own. It is, though, one of the clearer signs yet that the immune system may be coached — carefully, selectively, and with a lot of monitoring — to accept a donated liver with far less drug exposure than has long been assumed necessary. That’s a big deal. But for now, it remains an early one.
