Alectinib in ALK-positive, crizotinib-resistant, non-small-cell lung cancer: a single-group, multicentre, phase 2 trial

Abstract

SummaryBackgroundAlectinib, a highly selective, central nervous system (CNS)-active anaplastic lymphoma kinase (ALK) inhibitor, demonstrated promising clinical activity in crizotinib-naïve and crizotinib-resistant ALK-positive non-small-cell lung cancer (NSCLC). This phase 2 study evaluated the safety and efficacy of alectinib in ALK-positive NSCLC patients who progressed on previous crizotinib.MethodsThis ongoing North American study (NCT01871805) enrolled patients with stage IIIB/IV ALK-positive NSCLC, who had progressed following crizotinib. Patients were treated with oral alectinib 600 mg twice daily until progression, death or withdrawal. Primary endpoint was overall response rate (ORR) by independent review committee (IRC) using RECIST v1.1. Secondary endpoints included progression-free survival (PFS), duration of response (DOR), intracranial ORR and DOR, safety, and patient-reported outcomes. The intent-to-treat population was used for efficacy and safety analyses, with the response evaluable population used for response endpoints.FindingsA total of 87 patients were enrolled in the intent-to-treat population. All patients had received prior crizotinib therapy, and 64 patients (74%) had also received prior chemotherapy. Fifty-two patients (60%) had baseline CNS metastases, of whom 18 (35%) had received no prior brain radiation therapy. At the time of primary analysis (median follow-up 4.8 months), ORR by IRC was 48% (95% CI 36–60). Adverse events were predominantly grade 1 or 2, most commonly constipation, fatigue, myalgia and peripheral edema. The most common grade ≥3 AEs were changes in laboratory values, including increased blood creatine phosphokinase (in 8%, n=7), increased alanine aminotransferase (in 6% n=5), and increased aspartate aminotransferase (in 5% n=4).InterpretationAlectinib demonstrated clinical efficacy and was well tolerated in patients with ALK-positive NSCLC who had progressed on crizotinib. Alectinib was active in the CNS, as demonstrated by durable responses in the majority of crizotinib-resistant patients with CNS disease. Therefore, alectinib could be a suitable treatment for patients with ALK-positive disease who have progressed on crizotinib.