Efficacy vs. effectiveness: erlotinib in previously treated non-small-cell lung cancer

A randomized trial carried out by Shepherd et al. in patients with advanced or metastatic non-small-cell lung cancer showed statistically significant benefit of erlotinib over placebo in prolonging overall survival and progression-free survival.

The primary outcome was to compare overall survival of patients treated with erlotinib for non-small-cell lung cancer at Alberta Health Services - Cancer Care to the overall survival seen in the pivotal trial. Secondary outcomes included comparing progression-free survival, overall response rate, and duration of response between the two patient populations.

A retrospective review of charts was conducted for patients with locally advanced or metastatic non-small-cell lung cancer who received erlotinib therapy after failure of at least one prior chemotherapy regimen between 1 August 2006 and 31 July 2009. Survival data was analyzed using the Kaplan-Meier method.

Median overall survival and progression-free survival were 5.19 months and 2.46 months, respectively, in Alberta Health Services - Cancer Care patients. The rate of response was 11% (median duration of response, 6.7 months). The likelihood of a response to erlotinib was higher among nonsmokers (p < 0.0001) and those with response to prior chemotherapy (p = 0.0896). In multivariate analysis, good performance status (p = 0.0109) and response to prior therapy (p < 0.0001) were favorable factors for survival.

In a clinical setting, erlotinib does not perform as well in terms of median overall survival as reported in the pivotal trial (5.19 vs. 6.70 months).