Durability of CNS disease control in NSCLC patients with brain metastases treated with immune checkpoint inhibitors plus cranial radiotherapy

Background: Immune checkpoint inhibitors (ICIs) have excellent systemic activity and are standard first line treatment in EGFR/ALK wild type metastatic non-small cell lung cancer (NSCLC). However, their role in patients with brain metastases, which affects over 20% of patients and cause significant morbidity, is less clear. Methods: We reviewed patients with EGFR/ALK wild-type mNSCLC with CNS metastases. Serial MRIs were reviewed to determine the time to intracranial progression (iPFS). Multivariate regression was performed to adjust for the disease-specific graded prognostic score (ds-GPA). Results: We identified 36 ICI- and 33 chemotherapy-treated patients with baseline CNS metastases and available serial MRIs (average frequency:3.5 months). Baseline radiation was given except for 2 chemotherapy-treated patients with asymptomatic solitary metastasis. The CNS burden of disease was higher in the ICI-treated group (ICI:22% vs. chemotherapy:0% had 50% and 58% in chemotherapy-treated patients (p = 0.03). Conclusions: Remarkable CNS disease control is seen with baseline RT plus ICIs in patients with PD-L1 50%. Strategies for delaying WBRT should be investigated in this subgroup of patients.

Automated summary

ICIs show remarkable efficacy in the treatment of brain metastases in patients with EGFR/ALK wild-type mNSCLC, providing effective disease control. Baseline radiation plus ICIs can be considered as an effective strategy for patients with PD-L1 50% and further investigation is warranted to delay whole brain radiation therapy in this subgroup of patients.