Vienna – Longer follow-up in the so-called IMpower010 trial further solidifies the value of atezolizumab (Tecentriq) in stage II-IIIa non-small cell lung cancer (NSCLC) in patients with tumor cells PD-L1 targets for expressing drugs.
A new analysis by IMpower010 presented at the World Congress on Lung Cancer showed a hazard ratio of 0.71 (95% CI 0.49-1.03) for all patients – Vall d’Hebron University Hospital, Barcelona, Spain Enriqueta Felip, MD, reported that the use of PD-L1-targeting drugs was associated with mortality compared with best supportive care.
With a median follow-up duration of 46 months, the 5-year overall survival (OS) rate was 76.8% with atezolizumab versus 67.5% with supportive care. Median overall survival has not been reached in either group.
These data follow an earlier interim analysis reported last year in which adjuvant atezolizumab significantly prolonged disease-free survival (DFS) in all patients with stage II-IIIa disease (HR 0.79; 95% CI 0.64-0.96) and PD-L1 TC ≥1% (HR 0.66; 95% CI 0.50-0.88, P=0.004). Last October, the FDA deemed the data sufficient to approve the drug as adjuvant therapy after resection and platinum-based chemotherapy in patients with PD-L1 TC ≥1%.
Nonetheless, the data time at the time was insufficient for a meaningful reading of overall survival. The new analysis, with 13 months of follow-up, aims to fill that gap.
The greatest OS benefit was observed in patients with PD-L1 TC ≥50% (HR 0.43; 95% CI 0.24-0.78). When data from all participants in the trial were analyzed, which also included patients with PD-L1 TC levels less than 1%, for patients with stage II-IIIA disease (HR 0.95; 95% CI 0.74-1.24) or in IB- Stage IIIA disease in the intention-to-treat (ITT) population (HR 0.995; 95% CI 0.78-1.28).
“These data support the previously reported positive benefit-risk profile of adjuvant atezolizumab in PD-L1-positive resected NSCLC,” Felip said, noting that OS data are still not fully mature.
The international IMpower10 trial enrolled patients with operable stage Ib-IIIa NSCLC with sufficient tissue for PD-L1 expression analysis. After resection, 1,005 patients were randomly assigned to receive 1,200 mg of atezolizumab every 21 days or best supportive care. DFS was the primary outcome measure and OS was the key secondary endpoint.
Analysis of patients with stage II-IIIa disease and PD-L1 TC ≥1% showed that the analysis was performed in most subgroups except those receiving cisplatin plus gemcitabine . Few changes, no new or unexpected safety signals.
Adverse events occurred in almost twice as many patients assigned to atezolizumab compared to best supportive care (22% vs 11.5%) and resulted in atezolizumab 18.2 % of patients discontinued. Treatment-related fatal adverse events occurred in 0.8% of patients in the atezolizumab group compared with best supportive care.
Commenting on the results, Benjamin Besse, MD, of the Gustave Roussy Cancer Campus in Villejuif, France, listed several pieces of data he is still eager to see related to these results. Specifically, when looking at OS results, Besse said it’s always important to look at crossover data.
“How many patients in the control group received atezolizumab or any other immunotherapy?” Bessie said. “This has not been reported.”
In addition, Besse would like to see more data on other patient subgroups. The presentation did not show a breakdown of survival benefit only for patients with PD-L1 TC 1%-49% or those whose tumors were PD-L1 negative.
“I’m very interested to see if these subgroups in the control group perform well,” Besse said.
IMpower010 will proceed with final DFS analysis and further OS tracking and analysis. Its listing on Clinicaltrials.gov indicates that final completion is expected in 2027.
Leah Lawrence is a freelance health writer and editor living in Delaware.
IMpower010 is supported by Genentech/Roche.
Felip and Besse report conflicts of interest related to various industry entities.