Researchers conducted the MATCH study to assess the clinical benefits of adding low-dose radiotherapy (LDRT) to atezolizumab plus chemotherapy as first-line therapy in patients with extensive-stage small-call lung cancer (ES-SCLC). The single-arm, phase 2 trial was conducted in eight centers, where atezolizumab (1,200 mg IV, D1) plus cisplatin (75 mg/m2 IV, D1)/Carboplatin (AUC=5 IV, D1) pluse etoposide (100 mg/m2 IV, D1-D3) were administered every 21 days for four cycles to patients with measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 at baseline with Eastern Cooperative Oncology Group performance status of 0-1. Concurrent LDRT (15 Gy/5f) was administered during days 1-5 in the first cycle. Participants then continued atezolizumab maintenance therapy until clinical benefit was lost or unacceptable toxicity occurred. The study team used a primary endpoint of objective response rate (ORR) confirmed by them following two consecutive evaluations at least 4 weeks apart. Disease control rate (DCR) and safety were secondary endpoints. Based on the completed first phase of the trial in August 2021, and with a median follow-up of 4 months, the confirmed ORR was 95.2% (95% CI, 76.2-99.9), among which all patients were partial responders. The DCR was 100%, and the safety profile was consistent with previous reports. The most common grade 3-4 adverse events (AEs) were decreased neutrophil count (66.7%), decreased white blood cell count (42.9%), and anemia (38.1%), whereas no grade 5 AEs were observed. “The combination of LDRT and [atezolizumab] plus chemotherapy showed promising benefit and was tolerable in [patients] with ES-SCLC,” wrote the study authors. Phase 2 of the trial is ongoing.
