Abstract 674P
Background
The addition of platinum-pemetrexed chemotherapy to TKI has improved progression-free survival in treatment-nai¨ve advanced EGFR-mutated NSCLC. However, its role in current practice remains unclear. We describe treatment outcomes in a tertiary cancer centre.
Methods
Patients with advanced EGFR-mutated NSCLC who received first-line TKI plus platinum doublet chemotherapy (1L TKI-chemo) at National Cancer Centre Singapore were identified. Primary endpoints were time to treatment failure (TTF) and overall survival (OS) by Kaplan-Meier method.
Results
Of 2129 patients with advanced EGFR-mutated NSCLC between 11/2003-06/2023, 104 (4.9%) were treated with 1L TKI-chemo. Median age was 59 (range 24-84), 58/104 (55.8%) were female, 86/104 (82.7%) were never-smokers and 100/104 (96.2%) were ECOG 0/1. 49/104 (47.1%) had Ex19del mutations and 41/104 (39.4%) had L858R. Baseline intracranial (CNS) metastases were present in 26/104 (25.0%). 1G TKI was used in 86/104 (82.7%) and 3G in 13/104 (12.5%). Pemetrexed was the most common platinum partner in 61/104 (58.7%) followed by Gemcitabine at 39/104 (37.5%). Median number of platinum doublet cycles received was 6 (range 1-8). At median follow-up of 31 months (m), 4 patients remained on 1G TKI-chemo while 7 remained on 3G TKI-chemo. Partial response was achieved in 83/104 (79.8%). Median TTF was 17m and median OS was 38m. TTF was significantly longer in patients treated with 3G than 1G TKI (median not reached vs 16m, p=0.039). At time of disease progression, CNS failure was observed in 21/74 (28.4%) and 1/6 (16.7%) of those treated with 1G and 3G TKI respectively (p=0.114). Ex19del and L858R had similar median TTF (19m vs 18m, p=0.660) and OS (41m vs 39m, p=0.721). Survival outcomes were comparable between pemetrexed and gemcitabine (median TTF 17m vs 16m, p=0.815; median OS 38m vs 39m, p=0.997).
Conclusions
Our data supports the efficacy of 1L TKI-chemo in a select group of patients, with preliminary activity of 1L osimertinib plus chemotherapy. L858R have similar treatment outcomes to 1L TKI- chemo as Ex19del. Gemcitabine can be considered an alternative platinum partner in pemetrexed-ineligible patients.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Lung Cancer Consortium Singapore.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.