Randomized phase 2 trial of addition of SBRT to standard of care systemic therapy for oligoprogressive breast cancer or NSCLC

Most patients with metastatic cancer eventually develop resistance to systemic therapy, with some having limited disease progression (oligoprogression, five or less progressive lesions on PET-CT or CT). The randomized phase 2 CURB Oligoprogression trial, at Memorial Sloan Kettering Cancer Center and six affiliated regional centers in the states of New York and New Jersey, evaluated addition of SBRT to standard systemic therapy (SOC) for oligoprogressive metastatic breast cancer (mBC) or non-small cell lung cancer (mNSCLC). The median progression-free survival was 7.2 months in the SOC plus SBRT group versus 3.2 months in the SOC only group (HR 0.53; p=0.0035). This mPFS benefit with addition of SBRT was observed only among the mNSCLC patients (10.0 months versus 2.2 months; HR 0.41; p=0.0039) and not among the mBC patients (4.4 months versus 4.2 months; p=0.43). Grade 2 or worse adverse events occurred in 62% of the patients in the SBRT plus SOC group and 41% of patients in the SOC only group. The authors conclude that oligoprogression in patients with mNSCLC could be effectively treated with SBRT plus SOC.