Key Points: Posoleucel was generally safe, well tolerated, and associated with a greater reduction of BK viremia compared with placebo. BK viremia reduction occurred coincident with an increase in the circulating frequency of BK virus–specific T cells in posoleucel recipients. The presence and persistence of posoleucel was confirmed by T-cell receptor variable β sequencing. Background: Kidney transplant recipients with BK virus infection are at risk of developing BK virus–associated nephropathy, allograft rejection, and subsequent graft loss. There are no approved treatments for BK virus infection. Posoleucel is an off-the-shelf, allogeneic, multivirus-specific T-cell investigational therapy targeting BK virus, as well as five other opportunistic viruses: adenovirus, cytomegalovirus, Epstein–Barr virus, human herpesvirus 6, and John Cunningham virus. Methods: In this phase 2, double-blind study, kidney transplant recipients with BK viremia were randomized 1:1:1 to receive posoleucel weekly for 3 weeks and then every 14 days (bi-weekly dosing) or every 28 days (monthly dosing) or placebo for 12 weeks. Participants were followed for 12 weeks after completing treatment. The primary objective was safety; the secondary objective was plasma BK viral load reduction. Results: Sixty-one participants were randomized and dosed. Baseline characteristics were similar across groups. No deaths, graft-versus-host disease, or cytokine release syndrome occurred. The proportion of patients who had adverse events (AEs) judged by the investigators to be treatment-related was slightly lower in recipients of posoleucel: 20% (4 of 20 patients) and 18% (4 of 22) in those infused on a bi-weekly and monthly schedule, respectively, and 26% (5 of 19) in placebo recipients. None of the grade 3–4 AEs or serious AEs in any group were deemed treatment-related. No deaths, graft-versus-host disease, or cytokine release syndrome occurred. Three participants had allograft rejection, but none were deemed treatment-related by investigators. In posoleucel recipients, BK viremia reduction was associated with an increase in the circulating frequency of BK virus–specific T cells, and the presence and persistence of posoleucel was confirmed by T-cell receptor sequencing. Conclusions: Posoleucel was generally safe, well tolerated, and associated with a larger reduction of BK viremia compared with placebo. Limitations of this study include the relatively short duration of follow-up and lack of power to detect significant differences in clinical outcomes. Clinical Trial registry name and registration number: Study of Posoleucel (Formerly Known as ALVR105; Viralym-M) in Kidney Transplant Patients With BK Viremia, NCT04605484.

The risk of cancer increases after transplantation. However, the consensus on immunosuppression (IS) adjustment after diagnosis of malignancy is lacking. Our study aims to assess the impact of IS adjustment on mortality of post-kidney transplant patients and allograft outcomes. We retrospectively reviewed the data in our center of 110 subjects. Our results showed IS dose adjustment was not statistically associated with mortality risk (HR 1.94, 95%CI 0.85–4.41, p = 0.12), and chemotherapy was the only factor that was significantly related to mortality (HR 2.3, 95%CI 1.21–4.35, p = 0.01). IS reduction was not statistically associated with worsening graft function (OR 3.8, 95%CI 0.77–18.71, p = 0.10), nor with graft survival (SHR 4.46, 95%CI 0.58–34.48, p = 0.15) after variables adjustment. Creatinine at cancer diagnosis and history of rejection were both negatively associated with graft survival (SHR 1.72, 95%CI 1.28–2.30, p < 0.01 and SHR 3.44, 95%CI 1.25–9.49, p = 0.02). Reduction of both mycophenolate and calcineurin inhibitors was associated with worsening graft function and lower graft survival in subgroup analysis (OR 6.14, 95%CI 1.14–33.15, p = 0.04; HR 17.97, 95%CI 1.81–178.78, p = 0.01). In summary, cancer causes high mortality and morbidity in kidney transplant recipients; the importance of cancer screening should be emphasized.

Malignancy is the third major cause of death among transplant recipients. Patient and kidney transplant outcomes after the diagnosis of malignancy are not well described. We reviewed incidences and outcomes of colorectal, lung, PTLD, and renal malignancy after transplant among patients who received a transplant from January 2000 to December 2018 using the UNOS/OPTN database. Incidence of each malignancy was measured at 5 years and 10 years of transplant. The Kaplan–Meier curve was used for time-to-event analysis (graft and patient outcomes). Additionally, we sought to identify the causes of graft failure among these recipients. We found that 12,764 (5.5%) patients suffered malignancy, excluding squamous and basal cell skin carcinoma after transplant. During the first 5 years of transplant, incidence of colorectal, lung, PTLD, and renal malignancies was 2.99, 9.21, 15.61, and 8.55 per 10,000 person-years, respectively. Rates of graft failure were 10.3%, 7.6%, 19.9%, and 18.8%, respectively, among these patients at 5 years. Mortality rate was highest among patients who suffered lung malignancy (84%), followed by colorectal (61.5%), PTLD (49.1%), and renal (35.5%) at 5 years after diagnosis of malignancy. In conclusion, kidney transplant recipients diagnosed with lung malignancy have the lowest graft survival, compared to PTLD, colorectal, and renal malignancy. PTLD has the highest incidence rate in the first 5 years of transplant.