Phase I/II study of weekly topotecan and gefitinib in patients with platinum-resistant ovarian, peritoneal, or fallopian tube cancer.

6059 Background: The epidermal growth factor receptor (EGFR) is expressed in many types of cancer. Fifty to 70% of epithelial ovarian can overexpress EGFR, and its expression has been correlated with poor prognosis features in many cases. While these tumors are chemosensitive to platinum-based therapy, chemoresistance often develops. We conducted a phase I/II trial to examine the efficacy, safety, and toxicity of gefitinib, a tyrosine kinase inhibitor, combined with topotecan in women with recurrent ovarian cancer with EGFR receptor positivity (1+ or greater). Methods: Patients with measurable, recurrent or persistent cancer after treatment with a platinum and paclitaxel-containing regimen were eligible for this study (n = 19). We first used “run-in” dose escalation, in which a conventional 3+3 algorithm was used. Initial treatment was gefitinib 250 mg oral dose daily and topotecan at a dose of 2.0 mg/m2 on days 1, 8, and 15, with cycles repeated every 28 days. Dose escalations were planned for topotecan (Dose Levels 1–3: 2, 3, 4 mg/m2) until the MTD was reached. Next, an additional 10 patients with refractory or progressive ovarian cancer were enrolled in the phase II study. Results: 19 patients received a total of 61 cycles. Median age was 60 years. Histological types of treated patients included 73% serous (n = 14), 12.5% mixed (n = 2), 12.5% transitional (n = 2) and 6.3% clear cell (n = 1). There were 3 patients treated at dose level 1, 3 patients at dose level 2, and 3 patients treated at dose level 3. The maximum tolerated dose was topotecan 4.0mg/m2 IV days 1, 8 and 15, and gefitinib 250mg p.o. QD x28 days. Therefore, dose level 3 was used for the Phase II portion of the trial. Of the 19 patients included in the phase I/II, 3 patients were inevaluable for response to therapy due to toxicity, missed therapy or decline in performance status. Of the 16 patients, 81% patients (n = 13) had progressive disease, 12.5% stable disease (n = 2), and 6% partial response (n = 1). We assessed all 19 patients for adverse events; 60% had treatment-related grade 3 events, primarily blood disorders such as anemia (n = 3, 16%), neutrophil count decrease (n = 4, 21%). Conclusions: This prospective phase I/II clinical trial failed to show sufficient clinical activity of topotecan in combination with gefitinib in patients with EGFR-positive recurrent ovarian, fallopian tube, or peritoneal cancers. The drug combination was relatively well-tolerated in this cohort. As such, the study did not proceed to the next accrual goal secondary to the lack of response. Clinical trial information: NCT00317772.