A Randomised Open-label Phase III Trial of REduced Frequency Pembrolizumab immuNothErapy for First-line Treatment of Patients With Advanced Non-small Cell Lung Cancer (NSCLC)

REFINE-lung will test whether reduced pembrolizumab dose frequency after 6 months of standard treatment is safe and effective. Patients treated with 1st line pembrolizumab who are progression free and otherwise planning to continue therapy at 6 months will be initially randomised to control 6 weekly versus interventional 12 weekly therapy. If an interim analysis shows that the 12 weekly treatment is no less effective, subsequent patients will also be randomised to 9, 15 and 18 weekly treatment frequency arms. Patients who progress on a reduced frequency arm will be offered re-escalation to standard 6 weekly therapy.