A Phase I Study Evaluating Safety and Tolerability of Viral‐Specific T Cells Against BK‐Virus in Adult Kidney Transplant Recipients

BK polyomavirus (BKPyV) poses a significant threat to kidney transplant recipients (KTR). Current management primarily involves reducing immunosuppression, which increases the risk of rejection. Cell-based immunotherapy with virus-specific T cells (VST) has emerged as an alternative approach for treating BKPyV in KTRs. This single-center phase I, open-label trial enrolled KTRs with persistent BKPyV-DNAemia and BKPyV nephropathy (BKPyVAN) (NCT05042076) despite being on lower immunosuppression. BK-specific T cells were isolated from leukapheresis products from compatible donors. Patients were treated with VST therapy and followed for 52 weeks. Safety and tolerability were the primary focus of this trial. Three patients completed the trial. No grade III or IV adverse events, acute rejections, or graft versus host disease were reported. All patients tolerated the therapy well, with no significant safety concerns observed during the follow-up period. BK-VST demonstrated promising safety and tolerability profiles in this small cohort of kidney transplant recipients with severe BK infections. These findings suggest that VST therapy may offer a safe adjunctive treatment option for BKPyV infections post-transplantation. Larger studies are needed to confirm these preliminary results and assess long-term efficacy in treating BKPyV infections and preserving graft function in kidney transplant recipients.