Abstract 201P
Background
Extensive Stage Small cell Lung Cancer (ES-SCLC) is an aggressive disease with poor outcomes. Although most patients (pts) initially respond to first-line (1L) treatment, eventually all will relapse. Second-line (2L) therapeutic options have limited efficacy. For pts with platinum-free interval (PFI) ≥90 days, rechallenge with carboplatin-etoposide (CE) is a standard option. A phase 3, randomized trial comparing rechallenge CE vs topotecan in pts with PFI ≥90 days, demonstrated longer progression-free survival (PFS) in the rechallenge group (4.7 m vs 2.7 m; HR=0.57; p=.0041) but similar (7.5 v 7.4 m) overall survival (OS). However, this study pre-dates the use of 1st line chemo-immunotherapy (CT-IO) therefore the efficacy of platinum rechallenge after CT-IO is still unclear. Real-world data could offer valuable insights for this strategy.
Methods
We retrospectively reviewed pts with ES-SCLC who received second-line rechallenge CE after first-line CT-IO between September 2020 and August 2023 in 9 European centres. Demographic and clinical data were collected and analysed.
Results
A total of 93 pts were included. Sixty-six pts (71%) had PFI between 3 and 6 m. Clinical and demographic characteristics stratified by PFI are shown in the table. Consolidation thoracic radiotherapy and prophylactic cranial irradiation had been administered in 31 pts (33.3%) and 20 pts (21.5%), respectively. ORR was 59.1%. Median PFS was 5 m (95% CI, 4.3 – 5.7) and median OS was 7 m (95% CI, 5.7 – 8.3). Notably, PFS and OS were not different according to PFI (3-6 m v > 6 m).
Table: 201P
Demographic and clinical characteristics
| PFI 3-6 months (N = 66) | PFI > 6 months (N = 27) | |
| Sex – no. (%) | ||
| Male | 31 (47.0) | 15 (55.6) |
| Female | 35 (53.0) | 12 (44.4) |
| Median age – years (range) | 65 (43 – 84) | 67 (45 – 81) |
| ECOG – no. (%) | ||
| 0 | 3 (4.5) | 3 (11.1) |
| 1 | 52 (78.8) | 20 (74.1) |
| 2 | 11 (16.7) | 4 (14.8) |
| Smoking status – no. (%) | ||
| Never smoker | 0 (0.0) | 1 (3.7) |
| Former smoker | 34 (51.5) | 10 (37.0) |
| Current smoker | 32 (48.5) | 16 (59.3) |
| Liver metastases – no. (%) | ||
| No | 39 (59.1) | 22 (81.5) |
| Yes | 27 (40.9) | 5 (18.5) |
| Brain metastases – no. (%) | ||
| No | 61 (92.4) | 22 (81.5) |
| Yes | 5 (7.6) | 5 (18.5) |
Conclusions
Rechallenge with CE is a valid 2L option in pts diagnosed with ES-SCLC who progress after 1L CT-IO. Our analysis shows similar results compared to previous studies. Furthermore, outcomes were consistent across pts with different PFIs, confirming its efficacy in pts with PFI > 3 months.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
R. Shah: Financial Interests, Personal, Advisory Board, Advisory board + speaker roles: BMS; Financial Interests, Personal, Advisory Board, Ad board and speaker roles: Boehringer Ingelheim, AstraZeneca, Roche, MSD, Pfizer, Lilly, Novartis, Takeda, Bayer, BeiGene, Guardant, Sanofi, EQRx, Merck; Financial Interests, Personal, Other, specialist advisor: Genesiscare; Non-Financial Interests, Personal, Leadership Role, Steering committee member: BTOG. E. Bria: Financial Interests, Personal, Advisory Board: AZ, Roche, BMS, MSD, Eli Lilly, Amgen, Pfizer, Novartis; Financial Interests, Personal, Invited Speaker: AZ, Roche, BMS, MSD, Eli Lilly, Pfizer, Novartis; Financial Interests, Institutional, Research Grant: AZ, Roche. S. Silva Diaz: Financial Interests, Personal, Invited Speaker: Pfizer, Ipsen. T. Talbot: Financial Interests, Personal, Invited Speaker: Merck, Dohme. T. Newsom-Davis: Financial Interests, Personal, Advisory Role: Amgen, Bayer, AstraZeneca, BMS, Boehringen Ingelheim, Eli Lilly, MSD, Novartis, Pfizer, Roche, Takeda. F. Blackhall: Financial Interests, Personal, Invited Speaker, Educational Symposium lecture: AstraZeneca; Financial Interests, Personal, Advisory Board, NTRK Advisory Board and guidelines for diagnosis: Bayer; Financial Interests, Personal, Other, IDMC Chair: AstraZeneca; Financial Interests, Personal, Advisory Board, Small cell Advisory Board Oct 2020: Amgen; Financial Interests, Personal, Invited Speaker, ESMO Satellite Symposium November 2020: Takeda; Financial Interests, Personal, Other, Consultancy for RETinhibitor development: Blueprint; Financial Interests, Personal, Other, Real world evidence research study design and analysis (EGFR): Janssen; Financial Interests, Institutional, Invited Speaker, Institutional payment for clinical trial activities: Amgen, Pfizer; Financial Interests, Institutional, Invited Speaker, Payment for clinical trial activities: Mirati; Financial Interests, Institutional, Invited Speaker, Clinical trial activities: BMS; Financial Interests, Institutional, Funding, Real world evidence research programme: Roche; Non-Financial Interests, Personal, Advisory Role, Application of genotyping platforms in lung cancer: Guardant Health; Non-Financial Interests, Personal, Advisory Role, Clinical trials of IMPs in lung cancer and translational lung cancer biomarkers: AstraZeneca. R. Califano: Financial Interests, Personal, Advisory Board: AstraZeneca, Boehringer Ingelheim, Roche, Pfizer; Financial Interests, Personal, Advisory Role: MSD, Lilly Oncology, BMS, Takeda, Janssen, Bayer, Novartis. All other authors have declared no conflicts of interest.