Dr Singhi on the Rationale for Evaluating Lurbinectedin Plus Atezolizumab in ES-SCLC

“We have to recognize that patients no longer get that chemotherapy break, which is currently our standard of practice. Therefore, [we need to ensure] that we’re managing their toxicity, [that this regimen] is truly tolerable for our patients, and preserving their quality of life while they’re now going to receive what I believe is practice-changing: the addition of chemotherapy to maintenance therapy.”

Eric K. Singhi, MD, an assistant professor in the Department of General Oncology in the Division of Cancer Medicine and in the Department of Thoracic/Head and Neck Medical Oncology at The University of Texas MD Anderson Cancer Center, explained the rationale for evaluating lurbinectedin (Zepzelca) plus atezolizumab (Tecentriq) for the first-line treatment of patients with extensive-stage small cell lung cancer (ES-SCLC).

The phase 3 IMforte trial (NCT05091567) evaluated the efficacy and safety of lurbinectedin plus atezolizumab compared with lurbinectedin alone for the maintenance treatment of patients with ES-SCLC whose disease did not progress after first-line induction therapy with atezolizumab plus carboplatin/etoposide. Of note, the study aimed to assess whether the addition of lurbinectedin to chemotherapy improves outcomes for patients as a maintenance therapy, Singhi began.

Data from the study revealed that the combination of lurbinectedin and atezolizumab improves both progression-free survival (PFS) and overall survival (OS), he explained. Specifically, at a data cutoff of July 29, 2024, the median PFS was 5.4 months (95% CI, 4.2-5.8) vs 2.1 months (95% CI, 1.6-2.7) in the lurbinectedin plus atezolizumab (n = 242) and atezolizumab alone (n = 241) arms, respectively (HR, 0.54; 95% CI, 0.43-0.67; 2-sided P < .0001). The 6- and 12-month independent review facility-assessed PFS rates were 41.2% and 20.5%, respectively, in the lurbinectedin arm compared with 18.7% and 12.0% in the atezolizumab arm, respectively. Furthermore, the median OS was 13.2 months (95% CI, 11.9-16.4) vs 10.6 months (95% CI, 9.5-12.2) in the lurbinectedin and atezolizumab arms, respectively (HR, 0.73; 95% CI, 0.57-0.95; 2-sided P = .0174). Notably, the 12-month OS rates were 56.3% and 44.1% in the lurbinectedin and atezolizumab arms, respectively.

However, in this study, patients no longer receive a chemotherapy break, which is a current standard practice, Singhi emphasized. With this consideration, he noted that it’s essential to manage patients’ toxicity and ensure that the regimen is tolerable and that quality of life is top of mind, he concluded.