A Multicenter Analysis of Immune Checkpoint Inhibitors as Adjuvant Therapy Following Treatment of Isolated Brain Metastasis

Abstract

Background: The objective of this work was to characterize outcomes of patients with isolated brain metastases managed with local therapy followed by immune checkpoint inhibitor (ICI) therapy. Materials and Methods: Patients from four medical centers were included if they presented with isolated brain metastases treated with local therapy and received adjuvant treatment with ICIs. Results: Eleven patients with median size of largest brain metastasis of 3.9 cm, treated with surgical resection (n = 8) and/or stereotactic radiosurgery (SRS; n = 6), were included. Ipilimumab/nivolumab was the adjuvant ICI used in four patients, of whom one recurred (25%) and none died, compared with three of seven (43%) who recurred and two of seven (29%) who died following adjuvant treatment with ICI monotherapy. All recurrences were intracranial. Conclusion: Patients with isolated brain metastases treated with surgery or SRS appeared to benefit from adjuvant ICI therapy, particularly with combination therapy. Recurrences in this setting appear to largely occur intracranially.