Sequential treatment with targeted and immune checkpoint inhibitor therapies in patients with BRAF positive metastatic melanoma: Real-world data.

e21539 Background: The use of targeted therapies (TT) and checkpoint inhibitors (IT) significantly prolonged survival in patients with metastatic melanoma, especially in patients with BRAF mutation-positive melanoma. Optimal sequence of therapies use is still a matter of debate. The aim of this study was to evaluate real-life practice and outcomes in melanoma patients treated sequentially. Methods: Consecutive patients with BRAF mutation-positive unresectable or metastatic melanoma started treatment with TT (BRAF and MEK inhibitors) and/or IT (anti-PD1) between 1/Oct/2016 and 31/Dec/2020. Clinical factors including age, gender, ECOG performance status, baseline LDH level, and location of metastases, response to treatment and irAEs occurrence were analyzed. Survival analyses were performed using the Kaplan-Meier method, Log-rank and chi-square tests were used for comparison between groups. Data cut-off was 31/Dec/2021. Results: In total 585 patients were enrolled. 170 (29%) patients were treated with IT and 415 (71%) with TT in the first line. 331 patients (56%) received only one line of treatment – 247/415 (59%) patients only TT and 84/170 (49%) patients received only IT (anti-PD1). Disease progression was found in 175 (71%) patients in the only TT group and in 43 (51%) in the only IT group. 254 patients qualified for sequential treatment 168 (29%) patients received TT then IT (TT-IT), 64 (11%) IT then TT (IT-TT), and 22 (4%) IT-IT (anti-PD-1 then anti-CTLA-4). Patients with brain metastases and elevated LDH were statistically more often treated with first line TT and more patients with normal LDH level received IT-IT therapy. No other statistically significant differences in baseline characteristics was found for IT-TT, TT-IT and IT-IT groups. The estimated median OS (mOS) was not reached in patients treated with only one line of IT treatment, while for TT only it was only 11.8 months. Estimated mOS for patients treated in the first line with IT or TT was significantly different (p = 0.02; HR = 0.74, Cl 95% 0.6-0.9) and reached 25.6 and 15.3 months, respectively; although no statistically significant mOS differences was found in the subgroups without brain metastases (p = 0.56) and with normal LDH (p = 0.36). For sequential treatment groups mOS for IT-TT, TT-IT, and IT-IT was 19.6, 19.9 and 35.9 months, respectively. There was no statistically significant difference in OS between IT-TT and TT-IT treated groups (p = 0.56), and between IT-TT, TT-IT and IT-IT groups (p = 0.19). Conclusions: Patients who were treated with IT in the 1st line had better OS than patients treated TT in the 1st line in real-world data but this may be related to better prognostic factors in the IT group. Selected patients receiving IT in the first line achieve long OS, which is a result of a long-term response to IT. Novel predictive biomarkers factors of IT response should be incorporated in prospective trials.