Phase I evaluation of lenvatinib and weekly paclitaxel in patients with recurrent endometrial, ovarian, fallopian tube, or primary peritoneal Cancer.

OBJECTIVES: To estimate the maximally tolerated dose (MTD) and describe toxicities associated with lenvatinib and weekly paclitaxel in patients with recurrent endometrial and platinum resistant epithelial ovarian cancer. METHODS: Using a 3 + 3 design patients were given weekly paclitaxel 80 mg/m2 IV day 1, 8, 15 and oral levantinib daily on a 28-day cycle. Lenvatinib dose levels were 8 mg, 12 mg, 16 mg, 20 mg. Toxicities were recorded using CTCAE v4.03 and response was determined with imaging after cycle 2, then every 3rd cycle, using RECIST 1.1 criteria. RESULTS: 26 patients were enrolled; 19 with ovarian cancer (14 high grade serous, 1 low grade serous, 2 clear cell, 1 endometrioid, and 1 carcinosarcoma), and 7 with endometrial cancer (3 serous, and 4 endometrioid). The MTD was established at lenvatinib 16 mg and weekly paclitaxel 80 mg/m2. Toxicities (all grades) occurring in ≥25% of patients included anemia, neutropenia, lymphopenia, mucositis, nausea, diarrhea, anorexia, hypertension, fatigue, proteinuria, epistaxis, hoarseness. Twenty-three patients were evaluable for response and PFS; 15 (65%) had a partial response, 7 (30%) stable, 1 (4%) progressive disease with an objective response rate of 65%; 71% in ovarian and 50% in endometrial cancer. Median progression free survival (PFS) is 12.4 months; 14.0 months in endometrial cancer, 7.2 months in ovarian cancer; 54% had a PFS > 6 months. The median duration of response for PR patients (n = 15) was 10.9 months. CONCLUSIONS: The regimen was tolerable with manageable side effects. Encouraging activity was observed in endometrial and ovarian cancer, and warrants further development.