1804P - Atezolizumab plus chemotherapy followed by atezolizumab plus anlotinib in the first-line treatment for extensive-stage small cell lung cancer: A multicenter, single-arm, prospective real-world study

Background

Immunotherapy combined with chemotherapy followed by Immunotherapy maintenance has demonstrated clinical activity in extensive-stage SCLC (ES-SCLC). Combining anti-vascular therapy with immunochemotherapy could further improve survival but also increase the incidence of adverse events. It remained unknown whether adding anti-vascular therapy to Immunotherapy in the maintenance phase rather than the induction phase could provide better benefit in treatment-naive patients with ES-SCLC.

Methods

We conducted this multicenter, prospective, single-arm, open-label, real-world trial to evaluate the efficacy of atezolizumab plus chemotherapy followed by atezolizumab plus anlotinib as first-line therapy in patients with ES-SCLC. Patients received atezolizumab + EC for four-six cycles (induction phase), followed by atezolizumab + anlotinib for at least 2 years (maintenance phase). The primary end point was progression-free survival (PFS). Safety was assessed in all patients who received at least 4 cycles of treatment.

Results

Between Jul 1, 2020, and Dec 30, 2023, 53 patients were enrolled to the study. At data cutoff (April 17, 2024), the last enrolled patient had been followed up for about four months. Among 53 patients evaluable for efficacy analysis, 1 (1.8%) patient achieved CR, 41 (77.3%) achieved PR, and 8 (15.0%) achieved SD, resulting in an ORR of 79.2% and DCR of 94.3%. The median PFS was 9 months (95% CI, 8 to 13 months). The incidence of grade 3 or higher treatment-related adverse events was 19.2 %, including neutropenia, anemia, nausea, pneumonia, myocarditis, liver and kidney damage. Deaths related to the regimen occurred in 4 patients (7.5%) (death was due to pneumonia in 2 patients, kidney damage in 1 patient, and myocarditis in 1 patient).

Conclusions

Atezolizumab plus chemotherapy followed by atezolizumab plus anlotinib as first-line treatment for ES-SCLC provided a PFS benefit. Duo to the prophylactic use of rhG-CSF in the real-world, the grade 3 or higher safety profile was superior to that reported.

Clinical trial identification

China Medical Research Registration Number MR-34-22-017378.

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

The “USTC Research Funds of the Double First-Class Initiative” (YD9110002052).

Disclosure

All authors have declared no conflicts of interest.