Study of Posoleucel (Formerly Known as ALVR105; Viralym-M) in Kidney Transplant Patients With BK Viremia

Inclusion Criteria: * Patients who had a kidney transplant performed greater than or equal to 28 days prior to enrollment * At least 1 identified, suitably matched Posoleucel (ALVR105) cell line for infusion is available. * Capable of giving signed informed consent which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in the protocol. * Contraceptive use by men and women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies. Exclusion Criteria: * Undergone allogeneic hematopoietic cell transplantation * Evidence or history of graft versus host disease (GVHD) or cytokine release syndrome (CRS). * Uncontrolled or progressive bacterial or fungal infections * Known or presumed pneumonia * Ongoing therapy with high-dose systemic corticosteroids (ie, prednisone dose \>0.5 mg/kg/day or equivalent). * Pregnant or lactating or planning to become pregnant. * Weight \<40 kg. * Patients who received, or planned to receive abatacept or belatacept, within 3 months of screening