Erlotinib added to carboplatin and paclitaxel as first-line treatment of ovarian cancer: A phase II study based on surgical reassessment

Background: The purpose of this study was to determine whether adding the anti-epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor erlotinib to carboplatin/paclitaxel improved pathologic complete response (pCR) at reassessment surgery in epithelial ovarian, fallopian tube, or primary peritoneal cancers (OFPC). Methods: Patients with stage III-IV OFPC initiated treatment within 12 weeks of initial cytoreductive surgery or, after histologic confirmation of diagnosis, neoadjuvantly. Treatment included paclitaxel (175 mg/m²) and carboplatin (AUC 6) every 3 weeks for up to 6 cycles, plus oral erlotinib 150 mg daily. The primary objective was to determine whether the pCR rate at reassessment surgery was at least 60% after optimal cytoreduction at initial surgery (< 1 cm residual disease), or at least 40% after suboptimal cytoreduction (at least 1 cm residual disease) using a two-stage design (alpha = 0.10, beta = 0.10). Results: The study population included 56 patients with stage III-IV OFPC. EGFR gene amplification was present in 15% of the 20 tumors evaluated. Twenty-eight patients had protocol therapy after optimal cytoreduction (stratum I), 23 had protocol therapy either after suboptimal cytoreduction (stratum II), and 5 received neoadjuvant therapy prior to cytoreduction (stratum III). Pathologic CR was confirmed in 8 patients (29%; 95% confidence intervals 13%, 49%) in stratum I and 3 patients (11%, 95% C.I. 2%, 28%) in stratum II, which did not meet the prespecified efficacy endpoint in either stratum. Conclusions: Among unselected patients, erlotinib plus carboplatin-paclitaxel did not improve pCR rates compared with historical experience with carboplatin-paclitaxel alone in patients with stage III-IV OFPC.