IMpower010 Study of Atezolizumab in Resectable NSCLC: Benefits Observed Regardless of Stage, Type of Prior Treatment

In an exploratory analysis of the pivotal phase III IMpower010 trial—which found that adjuvant atezolizumab significantly improved disease-free survival in resectable non–small cell lung cancer (NSCLC)—benefit was shown regardless of the type of surgery or the chemotherapy doublet received by the patient, according to findings reported by Nasser Altorki, MD, and colleagues at a Plenary Session of the International Association for the Study of Lung Cancer (IASLC) 2021 World Conference on Lung Cancer (Abstract PL02.05).

“[We] showed an improved disease-free survival with atezolizumab in PD-L1–expressing [patients with] stage II–IIIA [disease] and in all [randomly assigned patients with] stage II–IIIA [disease], across most disease stages, in patients with nodal involvement, and across most surgery types and chemotherapy regimens,” said Dr. Altorki, of NewYork-Presbyterian Hospital, Weill Cornell Medicine in New York.

Nasser Altorki, MD

The primary results of IMpower010 were presented at the 2021 ASCO Annual Meeting (Abstract 8500). Those results included a significant disease-free survival benefit for adjuvant atezolizumab (after surgery and chemotherapy) vs best supportive care in patients with PD-L1–­expressing (≥ 1%) stage II or IIIA disease and in all randomly assigned patients with stage II or IIIA disease. Median disease-free survival in the primary population of patients with stage II and IIIA disease was not reached in the atezolizumab arm and was 35.3 months in patients given best supportive care (hazard ratio [HR] = 0.66, P = .004). Significant benefit was also observed in all randomly assigned patients with stage II and IIIA disease.

The study enrolled 1,280 patients with resectable NSCLC who were treated with adjuvant cisplatin-based chemotherapy after resection. The 1,005 who met eligibility criteria after completion of chemotherapy were randomly assigned to receive atezolizumab at 1,200 mg every 21 days for up to 16 cycles or best supportive care.

Current Exploratory Analysis

In the presentation at the World Conference on Lung Cancer, investigators examined the impact of therapies prior to adjuvant atezolizumab, including the extent of pulmonary resection, the type of mediastinal nodal assessment, and the particular chemotherapy doublet—parameters that were well balanced between the arms.

In the intent-to-treat population, 78% of patients underwent lobectomy, 16% had pneumonectomy, and 5% had bilobectomy. Mediastinal lymph node dissection or sampling was done in 81% and 18%, respectively.

In both arms, for all chemotherapy regimens, most patients received the planned four cycles of treatment. Chemotherapy regimens included cisplatin/pemetrexed (38%), cisplatin/vinorelbine (30%), cisplatin/gemcitabine (16%), and cisplatin/docetaxel (15%). Median time from surgery to adjuvant atezolizumab was about 5 months for both arms. 

No Association With Surgery or Chemotherapy

“Disease-free survival was better for most disease stages, regardless of the type of surgery or the cisplatin doublet that was used (Table 1). The disease-free survival favored the atezolizumab arm,” Dr. Altorki said.

Table 1: Disease-Free Survival by Prior Treatment in PD-L1–Positive Patients With Stage II and IIIA NSCLC (n = 476)

The same analysis in the 882 randomly assigned patients with stage II and IIIA NSCLC also showed that across most stages, types of surgery, and chemotherapy regimens, disease-free survival favored atezolizumab. As expected, this held true in the intent-to-treat analysis, though Dr. Altorki reminded listeners that statistical significance has not yet been reached in that group. “Patients who participated in the IMpower010 trial, including patients with nodal involvement, saw benefit across disease stages (stage II–IIIA subpopulations),” he concluded.

Disclosure: Dr. Altorki has received research funding from a number of entities and serves on the advisory board of AstraZeneca.