Abstract 713P
Background
Since September 2019, combination immunotherapy, which combines cytotoxic chemotherapy with immune-checkpoint inhibitors therapy, has been used as the first-line treatment for extensive-stage small cell lung cancer (ES-SCLC). However, factors related to clinical course and prognosis in real-world settings have not been sufficiently investigated.
Methods
We retrospectively examined 101 cases of ES-SCLC treated with combination immunotherapy, at participating institutions between September 2019 and December 31, 2023.
Results
The male/female ratio was 76/25, with a median age of 70 years (range: 26-84 years). Atezolizumab was combined in 57 cases, and durvalumab in 44 cases. First-line treatment was administered in 83 cases, and second-line or later treatment in 13 cases. The response rate (ORR) was 56.4% (95% CI: 46.7%-65.7%), median overall survival (OS) was 9.7 months (range: 0.4-49.8 months), and median progression-free survival (PFS) was 5.1 months (range: 0.4-36.9 months). No differences in OS or PFS were observed between treatment regimens. Immune-related adverse events (irAEs) occurred in 28 cases. Sixteen cases (15.8%) achieved long-term survival of 24 months or more. Performance status (PS) at the start of treatment, hypoalbuminemia, and CRP levels were associated with OS.
Conclusions
The clinical course of combination immunotherapy, for ES-SCLC has become clearer with its approval. PS, albumin, and CRP levels at the start of treatment were confirmed as prognostic factors, as previously reported. While irAEs and changes in CRP and eosinophil counts were examined as potential predictive factors for the efficacy of immune checkpoint inhibitors, as reported in non-small cell lung cancer and renal cell carcinoma, no significant factors were found. ES-SCLC may respond differently compared to non-small cell lung cancer. The number of long-term survivors has increased with the use of immune-checkpoint inhibitors, and identifying predictive factors for their efficacy remains a future challenge.
Clinical trial identification
Juntendo University Hospital Clinical Reserch and Trial Center No:H18-0083.
Editorial acknowledgement
Legal entity responsible for the study
Respiratory Medicine Department, Juntendo University Graduate school of medicine.
Funding
Has not received any funding.
Disclosure
T. Mimori: Financial Interests, Personal, Invited Speaker: AstraZeneca, Chugai pharmaceutical, Daiichi Sankyo pharmaceutical, Bristol Myers Squibb, Taiho pharmaceutical, Eisai, Ono Pharmaceutical; Financial Interests, Institutional, Local PI: AstraZeneca, Amgen, Chugai pharmaceutical, MSD, Janssen pharmaceutical, Syneous Health. T. Shukuya: Financial Interests, Personal and Institutional, Local PI: AstraZeneca, Chugai pharmaceutical, MSD, Novartis; Financial Interests, Personal and Institutional, Speaker’s Bureau: AstraZeneca, Chugai pharmaceutical, Boehringer Ingelheim, Novartis; Financial Interests, Personal and Institutional, Research Funding: Chugai pharmaceutical, Boehringer Ingelheim; Financial Interests, Personal, Speaker’s Bureau: Eli Lilly, Ono Pharmaceutical, Merck, Takeda pharmaceutical, Pfizer, Daiichi Sankyo pharmaceutical, Taiho pharmaceutical, Bristol Myers Squibb, Eisai, Nippon Kayaku, Amgen. K. Takahashi: Financial Interests, Personal, Invited Speaker: AstraZeneca, Chugai pharmaceutical, Boehringer Ingelheim, MSD, Ono Pharmaceutical, Takeda pharmaceutical, Pfizer, Daiichi Sankyo pharmaceutical, Eisai, Nippon Kayaku; Non-Financial Interests, Personal, Advisory Board: Eli Lilly, Novartis, Taiho pharmaceutical, Amgen, Merck. All other authors have declared no conflicts of interest.