This article has been updated with additional information on the IMpower010 trial.
NEW YORK — The US Food and Drug Administration on Friday approved atezolizumab (Genentech's Tecentriq) as an adjuvant treatment following resection and platinum-based chemotherapy for non-small cell lung cancer patients whose tumors express PD-L1 in at least 1 percent of cells.
At the same time, the agency approved the Ventana PD-L1 Assay from Ventana Medical Systems, which like Genentech is part of Roche, as a companion diagnostic device to determine which patients qualify for atezolizumab treatment.
The approval was based on an interim analysis of the Phase III IMpower010 trial, a multicenter, randomized, open-label trial of 1,005 stage IB through stage IIIA NSCLC patients. The patients had all undergone tumor resection and cisplatin adjuvant chemotherapy. In the trial, patients with stage II to IIIA tumors and PD-L1 expression in at least 1 percent of tumor cells had a 34 percent lower risk of disease recurrence or death on atezolizumab compared to those randomized to receive best supportive care. When researchers considered those with PD-L1 expression in more than 50 percent of tumors cells, atezolizumab reduced the risk of death or disease recurrence by 57 percent compared to best supportive care.
In the all-comer population, regardless of biomarker status, atezolizumab reduced the risk of death or disease recurrence by 21 percent versus the comparator arm. Specifically, in the the subset of patients who were PD-L1 negative, the data from IMpower010 showed no clear benefit with atezolizumab over best supportive care.
At the European Society for Medical Oncology Congress last month, experts discussed the right PD-L1 expression cutoff after Genentech released data from IMpower010 on the subset of patients with PD-L1 expression in 1 to 49 percent of tumor cells. In this group, adjuvant atezolizumab reduced the risk of death or disease recurrence by 13 percent compared to best supportive care (hazard ratio .87). At the meeting, experts said they would use other biomarker and clinical information to decide whether to prescribe adjuvant atezolizumab to NSCLC patients with low PD-L1 expression, and most agreed that better predictive biomarkers are needed to predict response to checkpoint inhibitors.
The FDA's approval of adjuvant atezolizumab in the broader NSCLC patient population using the lower PD-L1 cutoff comes six weeks ahead of the agency's goal date.