Findings from a recent study demonstrate that the use of atezolizumab, a PD-L1 inhibitor, in combination with carboplatin plus pemetrexed as first-line therapy and pemetrexed as maintenance therapy improves progression free survival (PFS) in patients with Stage IV non-squamous non-small cell lung cancer (NSCLC).
Vassiliki A. Papadimitrakopoulou, M.D., chief of the Section of Thoracic Medical Oncology at MD Anderson Cancer Center, presents these findings today at the International Association for the Study of Lung Cancer’s (IASLC’s) 19th World Conference on Lung Cancer (WCLC) in Toronto, Canada.
IMpower132 is a global, randomized, open-label, Phase III study of 578 chemotherapy-naïve patients with Stage IV non-squamous NSCLC.
Eligibility criteria included measurable disease by Response Evaluation Criteria in Solid Tumours (RECIST) guidelines v1.1 and Eastern Cooperative Oncology Group Performance Status (ECOG PS) 0-1.
Exclusion criteria included tumours known to harbor epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) driver mutations, untreated central nervous system (CNS) metastases, autoimmune disease and prior exposure to immunotherapy.
Patients were randomized 1:1 to receive four or six cycles of carboplatin area under the curve (AUC) 6 mg/mL/min or cisplatin 75 mg/m2 plus pemetrexed 500 mg/m2 Q3W, followed by pemetrexed as maintenance therapy (Arm B), or carboplatin-pemetrexed or cisplatin-pemetrexed plus atezolizumab 1200 mg, followed by pemetrexed plus atezolizumab as maintenance therapy (Arm A).
Results of the study showed that the atezolizumab plus pemetrexed—based chemotherapy (Arm A) resulted in improvement in PFS (median 7.6 months versus 5.2 months for the control group) associated with 40 percent reduction in risk for progression (HR 0.60, 95 CI :0.49, 072) in all patients and across key clinical subgroups, including Asian patients (HR 0.42;95% CI:0.28-0.63), never smokers (HR 0.49; 95% CI 0.28-0.87), current and former smokers (HR 0.61; 95% CI 0.50-0.74.
Also, at this interim OS analysis, this atezolizumab plus pemetrexed-based chemotherapy demonstrated a numerical improvement in OS of 4.5 months over pemetrexed-based chemotherapy alone (HR 0.46; 95% CI :0.22-0.96).
These IMpower132 study results are significant because it further supports the use of atezolizumab plus chemotherapy with or without Avastin (bevacizumab) in chemotherapy-naïve NSCLC.
“The findings from IMpower132 indicate that the addition of atezolizumab to a backbone of carboplatin and pemetrexed chemotherapy provides better clinical efficacy than carboplatin and pemetrexed alone,” said Dr. Papadimitrakopoulou. “By inhibiting the interaction of PD-L1 with its receptors PD-1 and B7.1, atezolizumab restores tumour-specific T-cell immunity, offering a valuable treatment option that prolongs survival for patients with Stage IV non-squamous NSCLC.”