medwireNews: The programmed death-ligand 1 (PD-L1) directed antibody atezolizumab confers an overall survival (OS) advantage relative to docetaxel in previously treated patients with locally advanced or metastatic non-small-cell lung cancer (NSCLC), indicate phase III trial findings.
The improvements were seen regardless of PD-L1 expression levels, presenting author Fabrice Barlesi (Aix Marseille University, France) told the audience at the ESMO 2016 Congress, held in Copenhagen, Denmark.
Median OS was 13.8 months for the 425 patients randomly assigned to receive intravenous atezolizumab 1200 mg every 3 weeks, and 9.3 months for the 425 participants given docetaxel 75 mg/m2 every 3 weeks. This equated to a significant 27% reduction in the risk of death with atezolizumab treatment.
Participants with PD-L1 expression – defined as at least 1% PD-L1–positive tumor or tumor infiltrating cells – benefited from atezolizumab versus docetaxel, but so did individuals categorized as PD-L1–negative, with corresponding median OS durations of 15.7 versus 10.3 months and 12.6 versus 8.9 months. Barlesi pointed out that the hazard ratios (HRs) for both these subgroups – at 0.74 and 0.75, respectively – were similar to that observed in the overall study cohort.
The most pronounced benefit, however, was seen in patients with high PD-L1 expression, defined as at least 50% positive tumor cells or 10% tumor infiltrating cells. In these patients, OS was a median of 20.5 months in the atezolizumab treatment arm, compared with 8.9 months in the docetaxel group, giving a significant HR of 0.41.
Atezolizumab treatment was not associated with an improvement in either progression-free survival or objective response, a scenario that has been observed with other immunotherapeutic agents, said Barlesi.
But the duration of response was “clearly improved” with atezolizumab, at a median of 16.3 versus 6.2 months for docetaxel, he added.
Adverse events of grade 3 or 4 occurred in 15% of atezolizumab-treated patients and 43% of those given docetaxel, with no new safety signals reported in this trial. No deaths in the atezolizumab group were attributed to the study drug, while one death in the comparator group was considered related to docetaxel.
The incidence of immune-related toxicity in the atezolizumab treatment arm was low, with less than 1% of patients experiencing grade 3 or 4 pneumonitis, hepatitis or colitis.
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