SYST-09 IMPACT OF END-STAGE RENAL DISEASE AND CONCOMITANT DIALYSIS ON THE EFFICACY OF IMMUNOTHERAPY IN BRAIN METASTASES PATIENTS: A PROPENSITY-MATCHED SURVIVAL ANALYSIS

INTRODUCTION: Mounting evidence demonstrates the therapeutic promise of immunotherapies (ITs) for brain metastases (BM). However, there is concern that stringent eligibility criteria in these clinical studies have selected against patients with comorbid conditions. As a result, it remains unclear if these results are truly applicable to the general population, particularly in individuals with end-stage renal disease (ESRD) on dialysis. Therefore, we sought to determine the impact of concomitant dialysis treatment and IT on overall survival (OS) of patients with BM. METHODS: Data were collected from TriNetX (TriNetX, Inc., Cambridge, MA), a global research network that aggregates clinical data from 92 healthcare organizations. Independent variables included ‘secondary malignant neoplasm of brain’, ‘ipilimumab’, ‘pembrolizumab’, ‘ESRD’, ‘dependence on renal dialysis’, and ‘dialysis services and procedures’. Patients with BM receiving IT were dichotomized by dialysis use. Cohorts were propensity matched on age, gender, and race. Kaplan-Meier analyses and log rank tests were conducted to assess overall survival (OS) and survival probability over a five-year period. RESULTS: Of the 14,368 confirmed BM patients treated with IT, 95 (0.6%) began dialysis within three months of IT initiation. Propensity matching established 95 patients in each cohort. The dialyzed cohort had a median OS of 277 days with a survival probability of 11.6%, compared to the non-dialyzed group with a median OS of 419 days and survival probability of 40.29% (p=0.109; hazard ratio 1.422, 95% confidence interval, 0.923-2.191, p=0.891). A separate comparison cohort was created to compare ESRD diagnosis with or without dialysis (n=56 and n=106 respectively). The comparison cohorts did not show a difference in median OS and survival probability (p=0.49). CONCLUSION: Despite their health complexities, individuals with ESRD, with or without dependence on dialysis, may nonetheless derive a similar survival benefit from ITs. Therefore, we advocate for greater inclusion of patients with advanced comorbidities in clinical trials to assess for real-world safety and efficacy outcomes.