The US Food and Drug Administration has approved a new indication for the immunotherapy drug atezolizumab (Tecentriq) — the adjuvant treatment following resection and platinum-based chemotherapy in patients with stage II to IIIA non-small cell lung cancer (NSCLC) whose tumors have PD-L1 expression ≥ 1%.
The agency also approved the Ventana PD-L1 (SP263) Assay (Ventana Medical Systems) as the companion diagnostic device for selecting patients with these tumors.
The recommended atezolizumab dose for this indication is 840 mg every 2 weeks, 1200 mg every 3 weeks, or 1680 mg every 4 weeks for up to 1 year. The approval is based on efficacy and safety results from the global, randomized, open-label IMpower010 study in patients with stage IB (tumors ≥ 4 cm) through stage IIIA NSCLC.
Interim results from the trial were presented in June of this year at the American Society of Clinical Oncology (ASCO) 2021 annual meeting, as reported by Medscape Medical News. At that time, study investigator Heather Wakelee, MD, of the Stanford University Medical Center, observed that the standard of care for many stage IB-IIIA NSCLC patients “has not changed for many years.”
Most patients with resected NSCLC receive adjuvant platinum-based chemotherapy, which has been shown to modestly reduce the risk for disease recurrence in those with completely resected disease, she said.
In the IMpower010 study, 1005 patients who had complete tumor resection and cisplatin-based adjuvant chemotherapy were randomly assigned (1:1) to receive atezolizumab 1200 mg every 3 weeks for 16 cycles or best supportive care (BSC).
The primary outcome measure was disease-free survival (DFS) among the 476 patients who had stage II-IIIA NSCLC with PD-L1 ≥ 1%.
The interim results reported at ASCO showed that median DFS was not reached in patients on atezolizumab compared with 35.3 months on best supportive care (hazard ratio [HR], 0.66; P = .004).
In its approval notice, the FDA gave further details. A prespecified secondary subgroup analysis of patients with PD-L1 tumor cell expression ≥ 50%, the DFS hazard ratio was 0.43. In an exploratory subgroup analysis of patients with PD-L1 TC 1-49%, the DFS hazard ratio was 0.87.
Last month at the 2021 World Conference on Lung Cancer, Ichiro Yoshino, MD, PhD, of Chiba University Hospital, Japan, pointed out various trial details that could have affected the results.
He said that patients who underwent lobectomy had a “more evident benefit from atezolizumab,” whereas those who had pneumonectomy “did not benefit” from the drug.
Consequently, “the type of surgery must affect DFS in IMpower010,” Yoshino said.
The type of chemotherapy used may also be influential, he further commented.
All patients in the trial were expected to undergo four cycles of adjuvant chemotherapy; however, the rate of receipt was “very high” with cisplatin–docetaxel but “low” with cisplatin–gemcitabine, Yoshino said. The outcomes were worse in the subset of patients who received gemcitabine.
The FDA noted that the most common (≥ 10%) adverse reactions in patients receiving atezolizumab, including laboratory abnormalities, were increased aspartate aminotransferase, blood creatinine, and alanine aminotransferase; as well as hyperkalemia, rash, cough, hypothyroidism, pyrexia, fatigue/asthenia, musculoskeletal pain, peripheral neuropathy, arthralgia, and pruritus.
This FDA review was conducted under its Project Orbis, which enables concurrent submission of oncology drugs among international partners. For this review, FDA collaborated with the Australian Therapeutic Goods Administration, the Brazilian Health Regulatory Agency, Health Canada, The Swiss Agency for Therapeutic Products (Swissmedic), and the United Kingdom’s Medicines and Healthcare products Regulatory Agency. The application reviews are ongoing at the other regulatory agencies.