Pembrolizumab Safe, Active for Certain Patients With NSCLC and Brain Metastases
Pembrolizumab is safe and active in certain patients with brain metastases from non–small-cell lung cancer (NSCLC), findings from an open-label clinical trial suggest (Lancet Oncol. 2020 May;21[5]:655-663).
“We did a phase 2 trial of pembrolizumab in patients with [NSCLC] or melanoma with untreated brain metastases to determine the activity of PD-1 blockade in the CNS,” said Sarah B. Goldberg, MD, Department of Medicine (Medical Oncology), Yale School of Medicine, New Haven, Connecticut, and co-investigators, who previously reported interim findings and now report an updated analysis of the full NSCLC cohort.
Between March 31, 2014, and May 21, 2018, a total of 42 patients with stage IV NSCLC and at least 1 brain metastasis 5 mm to 20 mm in size were included in the trial. These patients were previously untreated or had disease progress after previous radiotherapy.
The study comprised of 2 patient cohorts; patients in cohort 1 (n = 37) had PD-L1 expression ≥1% and cohort 2 (n = 5) had patients with PD-L1 expression <1% or unevaluable. All patients were given pembrolizumab 10 mg/kg every 2 weeks and evaluated for response and safety.
The main end point of the trial was the proportion of patients achieving a brain metastasis response (partial response or complete response).
The median follow-up time frame was 8.3 months, and 11 (29.7%; 95% CI, 15.9-47.0) patients in cohort 1 had a brain metastasis response compared with 0 responses in cohort 2.
Treatment-related grade 3-4 adverse events included pneumonitis, constitutional symptoms, colitis, adrenal insufficiency, hyperglycemia, and hypokalemia; no treatment-related deaths were reported.
“Pembrolizumab has activity in brain metastases from NSCLC with PD-L1 expression at least 1% and is safe in selected patients with untreated brain metastases,” Dr Goldberg and colleagues concluded.
“Further investigation of immunotherapy in patients with CNS disease from NSCLC is warranted,” they added.—Hina Porcelli
