Phase III trial of induction gemcitabine or paclitaxel plus carboplatin followed by paclitaxel consolidation in ovarian cancer.

Objective: The safety and efficacy of gemcitabine plus carboplatin (GC) or paclitaxel plus carboplatin (TC) induction regimens with or without paclitaxel consolidation therapy were assessed in ovarian cancer (OC).

Methods: Patients with stage IC-IV OC were randomized to either GC (gemcitabine 1,000 mg/m(2), days 1 and 8, plus carboplatin area under the curve [AUC] 5, day 1) or TC (paclitaxel 175 mg/m(2) plus carboplatin AUC 6, day 1) every 21 days for up to six cycles. Patients with complete response (CR) were allowed optional consolidation with paclitaxel 135 mg/m(2) every 28 days for ≤ 12 months. Patients without CR received single-agent crossover therapy at induction doses/schedules until CR, disease progression (PD), or unacceptable toxicity. PD or death in 636 patients was required to compare induction arms with 80% statistical power for progression-free survival (PFS), the primary endpoint.

Results: Randomized induction therapy was received by 820 of 919 patients enrolled; 352 patients with CR received paclitaxel consolidation whereas 155 patients without CR received single-agent crossover therapy. PFS was similar for GC and TC (median, 20.0 and 22.2 months, respectively; P=.199). Despite high censoring rates (>52%), overall survival was longer for TC (median, 57.3 versus 43.8 months for GC; P=.013). Controlling for patient characteristics including performance status, residual tumor size, and tumor stage, there was no statistical difference in a multivariate analysis (HR=1.22; 95% CI=0.99-1.52; P=.067).

Conclusions: GC does not improve PFS over TC as first-line induction chemotherapy in OC. Although favoring TC, overall survival analyses were limited by the study design and high censoring rates.