A Randomized, Placebo-Controlled, Multicenter, Biomarker-Selected, Phase 2 Study of Apricoxib in Combination with Erlotinib in Patients with Advanced Non-Small-Cell Lung Cancer

Cyclooxygenase-2 (COX-2) overexpression is associated with a poor prognosis in non-small-cell lung cancer (NSCLC) and may promote resistance to epidermal growth factor receptor inhibitors. This randomized phase 2 trial evaluated apricoxib, a novel COX-2 inhibitor, in combination with erlotinib in biomarker-selected patients. Patients with stage IIIB/IV NSCLC previously treated with platinum-based chemotherapy were randomized (2:1) to 400 mg/day apricoxib plus 150 mg/day erlotinib (AP/E) or placebo plus erlotinib (P/E) in 21-day cycles until disease progression or unacceptable toxicity. The primary endpoint was time to progression (TTP). A decrease of 50% or more from baseline urinary prostaglandin E-2 metabolite after a 5-day, open-label, run-in period was used to select eligible patients. One hundred twenty patients (median age 64 years) were randomized (78 to AP/E and 42 to P/E). Overall median TTP was 1.8 months in the AP/E group and 2.1 months in the P/E group, with a 12% objective response rate in both groups (intent-to-treat analysis). A subgroup analysis in patients aged 65 years or younger demonstrated a statistically significant TTP benefit for AP/E (hazard ratio 0.5 [95% confidence interval: not applicable-0.9]; p=0.018) and overall survival advantage at minimum 1-year follow-up (median 12.2 versus 4.0 months; hazard ratio=0.5; p=0.021). The most common adverse events were rash, diarrhea, fatigue, and nausea. Toxicity contributed to early discontinuations in patients aged more than 65 years treated with AP/E. This is the first randomized placebo-controlled study of a COX-2 inhibitor in NSCLC to use a prospective patient-selection strategy. Although AP/E seemed to improve TTP and overall survival in a subset of patients aged 65 years or younger, the primary endpoint of the trial was not met.