Figure 3

Impact of benefit of erlotinib in one subpopulation vs harm in another: Despite substantial benefit in one subpopulation, a randomized trial may conclude that an agent is ineffective if it causes harm in a different subpopulation. Erlotinib vs placebo were added to chemotherapy in NSCLC, [33] and the curves overlapped suggesting no impact of erlotinib (two center curves, redrawn from Herbst et al. [33]). However, on molecular assessment, erlotinib was associated with potential benefit in the 13% of patients with an EGFR mutation (p=0.09), but was associated with harm in the 21% of patients with KRAS mutations (p=0.03) (curves resynthesized using component parts from Eberhard et al. [34]).