We evaluated pulmonary adverse events observed within 7 days after drug initiation in phase 1 to phase 3 studies of the anaplastic lymphoma kinase (ALK) inhibitor brigatinib.

The phase 1/2 study enrolled patients with advanced malignancies (dosage range, 30 mg-300 mg once a day); the phase 2 ALK in Lung Cancer Trial of AP26113 study treated patients with advanced ALK+ NSCLC postcrizotinib at either 90 mg once a day or 90 mg once a day for 7 days followed by 180 mg once a day; and the phase 3 ALK in Lung Cancer Trial of Brigatinib in first Line study treated inhibitor-naive patients with ALK+ NSCLC with brigatinib (180 mg once a day [with 7-day lead-in at 90 mg once a day]) or crizotinib (250 mg twice a day). Early-onset pulmonary events (EOPEs) at least possibly associated with brigatinib were captured.

In the phase 1/2, ALK in Lung Cancer Trial of AP26113, and ALK in Lung Cancer Trial of Brigatinib in first Line studies, 8% (11/137), 6% (14/219), and 3% (4/136) of patients, respectively, had at least possible EOPEs on brigatinib, with frequency appearing to increase with the starting dosage. Across trials, at the 90-mg once-a-day starting dosage (alone or step-up dosing), 4.5% of patients (20/440) had at least possible events (median time to onset, 2 days). A total of 12 patients (3%) had grade 3 or higher events leading to brigatinib discontinuation. Seven patients (1.5%) had grade 1 to grade 2 events and successfully continued brigatinib with or without brigatinib interruption, steroids, or supplemental oxygen. In pooled analysis of these trials, occurrence of EOPEs was significantly associated with continuous 10-year increases in patient age in unadjusted logistic regression analysis, and with Eastern Cooperative Oncology Group performance status and number of previous regimens in multivariate regression.

Clinically apparent EOPEs can occur within days of commencing brigatinib in a subset of patients with NSCLC. Identifying clinical parameters associated with a higher risk of developing such events may help mitigate these events.