ICIs May be Used as Individualized Therapy in Select Solid Organ Transplant Recipients

Immune checkpoint inhibitors (ICIs) can be used as an individualized therapy in select patients who have undergone solid organ transplantation for metastatic cancer, according to a study published in Cancer.

However, researchers indicated that additional research is necessary to determine the most effective use of these agents to further improve outcomes.

“We believe that the current case series has contributed to the expansion of clinical experience in this area and provides some insight regarding the management of immunosuppression during ICI therapy,” the authors wrote.

Data from patients who received solid organ transplant and ICIs for the treatment of malignancy between January 1, 2016, and September 30, 2019 were retrospectively studied by researchers. Overall, 7 kidney, 8 liver, and 2 heart transplant recipients were identified.

The most common malignancies treated with ICIs in the study cohort were metastatic squamous cell carcinoma (5 patients; 29%) and hepatocellular carcinoma (5 patients; 29%), which were found exclusively among those who had received a liver transplant. The median duration of ICIs was 1.7 months (interquartile range, 0.4-7.6 months).

The cumulative incidence of cancer progression was 50% and 69%, respectively, at 6 months and 12 months. Moreover, 11 patients (65%) died over the median follow-up period of 4.6 months (interquartile range, 1.5-13.2 months) from the time of ICI initiation, with the most common cause of death being cancer progression.

“In competing risk analysis, cancer progression was found to be the earliest and most frequently occurring event leading to premature death,” the authors wrote. “Although the risk of organ complications was found to be only 18% at 6 months, this could have been due to the high rate of patients experiencing cancer progression and subsequent death.”

With regard to safety, 5 patients (29%) experienced adverse events (AEs), including 4 patients (24%) with immune-related AEs, 3 patients (18%) with acute allograft rejections, 1 patient (6%) with autoimmune colitis, and 1 patient who was a heart transplant recipient (6%) with ICI-induced cardiotoxicity.

“To our knowledge, sustainable or replacement therapies in patients with other organ transplants remain nonexistent. Regardless, the use of ICIs after solid organ transplantation should not be discouraged, especially in patients with limited options, and the potential risk of organ complications should not be considered prohibitive,” the authors explained. “A thorough discussion of the risks and benefits of ICIs within the context of cancer-related risks of mortality and morbidity using a multidisciplinary approach needs to take place before immunotherapy is initiated.”

Importantly, this study was limited by its retrospective nature and heterogenous population in terms of cancer type and immunosuppression management. However, to date, this is the largest single-center case series of solid organ transplant recipients who were treated with ICIs.

“Future work, ideally incorporating biomarkers of tumor response and noninvasive monitoring for rejection, are needed to help guide ICI therapies among [solid organ transplant recipients],” the authors concluded.

Reference:

Owoyemi I, Vaughan LE, Costello CM, et al. Clinical Outcomes of Solid Organ Transplant Recipients With Metastatic Cancers Who Are Treated With Immune Checkpoint Inhibitors: A Single-Center Analysis. Cancer. doi: 10.1002/cncr.33134.