Brain metastases in clinical trial participants with KRAS-mutated advanced non-small cell lung cancer receiving docetaxel: Pooled data analysis

Abstract

Objectives: Limited data are available on central nervous system (CNS) efficacy with standard-of-care therapies for KRAS-mutated (KRASmut) advanced non-small cell lung cancer (NSCLC). The objective of this study was to investigate the incidence and progression of brain metastases in KRASmut advanced NSCLC treated with docetaxel using pooled data from historical clinical trials.

Materials and methods: Data from phase 2/3 trials of docetaxel-containing regimens in advanced NSCLC were sourced from the Medidata platform. Analysis was restricted to stage IIIB-IV KRASmut NSCLC with disease progression after ≥ 1 systemic anticancer therapy. Participants with asymptomatic, treated, and stable brain metastases were included. Endpoints included 12-month CNS disease control rate (CNS-DCR) and CNS progression per Response Evaluation Criteria in Solid Tumors; progression-free survival (PFS); and overall survival (OS). Data were pooled and analyses stratified by baseline brain metastases status.

Results: A total of 595 participants were included in the analysis (62 [10%] with baseline brain metastases and 533 [90 %] without). Among participants with brain metastases, 17 (27.4 %) had CNS progression during docetaxel treatment and 12-month CNS-DCR was 75.8 %; 45 (8.4 %) participants without baseline brain metastases developed brain metastases during treatment. In an analysis restricted to patients with metastatic disease, outcomes with and without baseline brain metastases included: median PFS, 3.3 and 4.9 months (p < 0.005); 12-month PFS, 5 % and 16 %; median OS, 6.9 and 10.4 months (p < 0.005); and 12-month OS, 20 % and 44 %, respectively.

Conclusion: These findings establish CNS progression rates with docetaxel in previously treated KRASmut advanced NSCLC and facilitate interpretation of data from ongoing randomized clinical trials of novel KRAS-targeted therapeutic strategies vs. docetaxel.

Keywords: Brain metastases; Docetaxel; KRAS mutations; KRAS(G12C); Non-small cell lung cancer.