RET Inhibitor Shows Activity in Select Patients With Lung Cancer in ARROW Trial
Posted: Wednesday, July 10, 2019
According to results from the registration-enabling ARROW study presented at the 2019 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 9008), the selective RET inhibitor BLU-667 demonstrated antitumor activity for patients with advanced RET fusion–positive non–small cell lung cancer (NSCLC). The inhibitor was also reported to be well tolerated among patients, and enrollment of the expansion trial is ongoing, noted Justin F. Gainor, MD, of Massachusetts General Hospital, Boston, and colleagues.
In this global clinical trial (ClinicalTrials.gov identifier NCT03037385), the authors enrolled 79 patients with advanced RET fusion–positive NSCLC to receive dose escalation of BLU-667 (30–600 mg once or twice daily). The recommended phase II dose was 400 mg daily. The median number of prior therapies among the patients was two and included chemotherapy (76%), immunotherapy (41%, and multikinase inhibitors (27%).
Among the 57 patients who were evaluable for response with measurable disease and at least one follow-up assessment, the overall response rate was 56%. Of the responding patients, 29 of 32 (91%) are still on treatment, and 6 achieved a response duration of at least 6 months. Of the evaluated patients, the authors reported a 91% disease control rate. A majority of patients (80%) treated at the recommended phase II dose remain on treatment.
Treatment-related toxicity—which was generally low-grade and reversible—included increased aspartate transaminase (22%), hypertension (18%), increased alanine aminotransferase (17%), constipation (17%), fatigue (15%), and deceased neutrophils (15%).
Disclosure: The study authors’ disclosure information may be found at coi.asco.org.