Efficacy of dabrafenib-trametinib combination in BRAF V600E-mutated metastatic non-small cell lung cancer: Results of the IFCT-2004 BLaDE cohort.

9082 Background: BRAF V600E mutations occur up to 2% of advanced non-small cell lung (NSCLC). Dabrafenib-trametinib (D-T) combination was associated with improved OS rates in phase II study and was approved in the 1st-line setting and further. The IFCT-2004 BLaDE study reports the D-T combination efficacy in a large French real-world multicenter cohort of advanced BRAF V600E-mutated NSCLC. Methods: Patients (pts) with advanced NSCLC harboring BRAF V600E mutation diagnosed between 01.01.2016 and 31.12.2019 and treated with D-T combination (D 300 mg + T 2 mg daily) whatever the treatment line were included. Demographic, clinical, pathological data were collected as well as data of efficacy and reason of treatment discontinuation. The primary endpoint was 12 months-OS rate in pts receiving the D-T as 2nd-line or subsequent treatment (L2+). Results: 163 pts were included in 54 centers through 32 national testing labs: 50.3 % were female, 30.2% never-smokers, 95.1 % had adenocarcinoma and PDL1 was > 1% in 78.2%. Median age was 68.3 years. At D-T initiation, 80.8 % of pts were PS 0/1, 93.9 % were stage IIIB/C ineligible for surgery or local therapy and IV, 20.9% had brain metastases and 27% received D+T as 1st line treatment (L1). At the data cutoff (30.06.2021), median (m) follow-up was 27.4 months [95% CI 22.2-31.9] and 47 pts (28.8%) remained on study treatment. 12 months-OS rate in pts receiving D+T in L2+ (n = 119) was 67.4% [95% CI 57.8-75.3] with a median progression-free survival (mPFS) of 10.4 months [95% CI 7.3-13.1]. In the 44 pts receiving D+T in L1, 12 months-OS rate was also 67.4% [95% CI 51.2-79.3] with a mPFS of 18.2 months [95% CI 7.7-21.3]. Objective response rates were 73.8% [95% CI 65.5 - 82.2] and 82.9% [95% CI 71.4 - 94.4], disease progression was observed as best response in 3.7% [95% CI 0.1 - 7.3] and 0% in L2+ and L1, respectively. Other efficacy results are detailed in the table. D-T discontinuation for toxicity was reported in 10.3% of pts. 51.2% and 43.7% of pts received subsequent treatment in L2+ and L1 respectively. For L2+ pts, subsequent treatments were immunotherapy (IO)-based in 37.2 % and chemotherapy in 58.3%. For L1 pts, subsequent treatments were (IO)-based in 42.9% and chemotherapy in 42.7%. Conclusions: Our series confirms significant efficacy of D-T combination in BRAF V600E-mutated metastatic NSCLC. These results in real-world conditions are consistent with registration studies but also support its use in 1st line setting. [Table: see text]