Toripalimab Plus Chemo Dubbed New Standard First-Line Therapy for ES-SCLC

Adding toripalimab to chemotherapy improves survival in patients with newly diagnosed extensive-stage small cell lung cancer (ES-SCLC), according to research presented at the ESMO Congress 2023.

Both progression-free survival (PFS) and overall survival (OS) were improved with the combination over chemotherapy alone, reported study presenter Ying Liu, MD, of Jilin Cancer Hospital in Changchun, China.

“Toripalimab plus chemotherapy presents a new standard first-line therapy for ES-SCLC,” Dr Liu said.

Dr Liu and colleagues tested the combination in the phase 3 EXTENTORCH trial (ClnicalTrials.gov identifier: NCT04012606). The trial included 442 patients with ES-SCLC who had received no prior systemic therapy.

The patients were randomly assigned to receive toripalimab plus chemotherapy (n=223) or placebo plus chemotherapy (n=219) for 4-6 cycles. This was followed by toripalimab or placebo maintenance until disease progression or treatment intolerance. Chemotherapy consisted of carboplatin or cisplatin plus etoposide.

The median follow-up for PFS, the primary endpoint, was 11.8 months. The median PFS was 5.8 months with toripalimab and 5.6 months with placebo (hazard ratio [HR], 0.667; 95% CI, 0.539-0.824; P =.0002). The 1-year PFS rate was 18.1% in the toripalimab arm and 4.9% in the placebo arm.

The median follow-up for OS was 13.7 months. The median OS was 14.6 months with toripalimab and 13.3 months with placebo (HR, 0.798; 95% CI, 0.648-0.982; P =.0327). The 1-year OS rate was 63.1% in the toripalimab arm and 54.9% in the placebo arm.

A biomarker analysis showed that tumor mutational burden was not associated with PFS or OS. However, mutations in the focal adhesion/integrin pathway were associated with worse PFS and OS among patients treated with toripalimab.

The proportion of patients who went on to receive subsequent systemic therapy was 55.2% in the toripalimab arm and 69.4% in the placebo arm. In both arms, the most common subsequent therapy was chemotherapy (49.3% and 59.4%, respectively), followed by a tyrosine kinase inhibitor (33.6% and 44.3%, respectively).

The rate of treatment-emergent adverse events (AEs) was 99.5% in the toripalimab arm and 100% in the placebo arm. The rate of grade 3 or higher treatment-emergent AEs was 89.6% and 89.4%, respectively. The most common grade 3-4 treatment-emergent AEs in both treatment arms were hematologic events.

Immune-related AEs of grade 3 or higher occurred in 9.9% of patients in the toripalimab arm and 0.9% of patients in the placebo arm. Treatment-emergent AEs led to death in 12 patients in the toripalimab arm and 7 patients in the placebo arm.

Disclosures: This study was supported by Shanghai Junshi Biosciences. The study authors declared no conflicts of interest.

Reference

Cheng Y, Liu Y, Zhang W, et al. EXTENTORCH: A randomized, phase III trial of toripalimab versus placebo, in combination with chemotherapy as a first-line therapy for patients with extensive stage small cell lung cancer (ES-SCLC). Presented at ESMO Congress 2023. Oct. 20-24, 2023. Madrid, Spain. Abstract LBA93.

This article originally appeared on Cancer Therapy Advisor