Crizotinib in ROS1-rearranged lung cancer (EUCROSS): Updated overall survival.

9078 Background: ROS1 rearrangements are found in approximately 1% of non-small cell lung cancer (NSCLC) patients. Prospective clinical trials showed high efficacy of crizotinib in this molecular subset. Lately, we reported an overall response rate (ORR) of 70% and a median progression-free survival (PFS) of 19.4 months for patients treated within the EUCROSS trial (Michels et al. Clin Oncol, 37(15_suppl):9066-9066, 2019). Here we present an updated analysis of the overall survival. Methods: EUCROSS is a European multi-centre, single arm phase 2 trial (Clinicaltrial.gov identifier: NCT02183870). Key eligibility criteria were ≥18 years of age, advanced/metastatic lung cancer, centrally confirmed ROS1-rearranged (fluorescence-in situ hybridisation) and no or stable brain metastases at baseline. Crizotinib was given at a dose of 250 mg twice daily. Primary endpoint of the trial was investigator-assessed ORR in the response-evaluable population (Response Evaluation Criteria in Solid Tumors, version 1.1), with secondary endpoints of PFS and overall survival (OS). Results: Of the 34 patients who received at least one dose of crizotinib (intention-to-treat population, ITT), 30 were included the primary efficacy analysis set (PAS). After a median follow-up of 55.9 months, 13 (43%) patients in the PAS and 15 (44%) in the ITT had died. Median OS was not reached in either group (95% CI, 17.1-NR and 20.3-NR, respectively). OS was negatively correlated with the presence of brain metastases (Log-rank p = 0.1805) and TP53 mutations (Log-rank p = 0.015). Detailed listings of the survival rates are depicted in Table. No new safety signals were observed. Owing to the approval of crizotinib by the European Medicines Agency, all patients who were still on treatment by January 24th 2018 (n=8), were prescribed crizotinib outside the trial. Conclusions: Updated OS highlights the efficacy of crizotinib in patients with ROS1-rearranged lung cancer. Patients with co-occurring TP53 mutations or brain metastases had worse outcomes and represent challenging populations. Clinical trial information: NCT02183870. [Table: see text]