Abstract
BACKGROUND
Survival benefit with immune checkpoints inhibitors in patients with metastatic NSCLC and Melanoma has been demonstrated. However, the published results do not describe the incidence of brain metastasis as a site of recurrence in these patients. We sought to determine the incidence of central nervous system (CNS) relapse/progression relative to systemic response in patients with NSCLC or Melanoma treated with a PD-1 inhibitor.
METHODS
We retrospectively identified 217 patients (145 with metastatic NSCLC, 72 with metastatic Melanoma) treated with Pembrolizumab or Nivolumab, between 2009 and 2016. Demographic and clinical variable were assessed to determine CNS and systemic response using descriptive statistics.
RESULTS
The median age of the cohort was 65 years (22–93), with a median of 1 (0–6) treatment prior to PD-1 inhibitor therapy and median follow-up of 344 days. Of the 217 patients, 213 received monotherapy with either Nivolumab (99) or Pembrolizumab (114). Four patients received Nivolumab combined with Bevacizumab. The median time on therapy was 113 days for Nivolumab (14–1598) and 149 for Pembrolizumab (21–1099). Forty patients had brain metastases at the time of initiation of treatment, and 28 of these patients received treatment for at least one brain metastasis prior to immunotherapy. Thirty-two patients (15%) had CNS disease progression during immunotherapy treatment: 15 patients (7%) developed new CNS disease and 17 (8%) had progression of pre-existing CNS metastasis (7/17 received prior CNS directed treatment). In these 32 patients, concomitant systemic disease progression was observed in 27, and 5 patients progressed only in the CNS.
CONCLUSION
This retrospective analysis showed that development/progression of CNS metastasis in patients on treatment with a PD-1 inhibitor has good concordance with systemic disease status. The incidence of CNS disease in patients on this therapy is comparable to historic cohorts treated with conventional chemotherapy.