5538 Background: Tivozanib is a potent, selective pan-vascular endothelial growth factor (VEGF) receptor tyrosine kinase inhibitor with a long half-life. This study assessed its activity in patients with recurrent, platinum-resistant ovarian cancer (OC), fallopian tube cancer (FTC) or primary peritoneal cancer (PPC). Methods: This open-label phase II study used a Simon’s two-stage design. Eligible patients had recurrent, platinum-resistant OC, FTC or PPC; ECOG PS of 0-1; normal end organ function; and measurable or detectable disease. There was no limit on the number of prior regimens. Treatment consisted of tivozanib 1.5 mg orally once daily (3 weeks on/1 week off). The primary endpoint was response rate. Secondary endpoints were progression-free survival (PFS), overall survival (OS), and toxicity assessment. If 1 partial response (PR) was observed in stage I [n = 12], enrollment proceeded to stage II. The null hypothesis was rejected for ≥ 4 responses in 30 patients. Results: Thirty-one patients were enrolled, and 30 were treated. Twenty-three had OC [76.67%], 5 FTC [16.67%] and 2 PPC [6.67%]. Twenty-six had measurable [86.67%] and 4 detectable disease [13.37%]. The median age was 60, and median number of prior regimens was 4 [range 1-9]. Four PRs [13.33%] were recorded. Twelve patients had stable disease (SD) [40%]. The clinical benefit rate (PR + SD) was 53%. Seven patients [23.33%] survived progression-free for > 6 mos. One patient continued treatment for > 2 yrs. The median PFS was 4 mos [range 1-25] and median OS was 8 mos [range 1-39]. There were no treatment-related deaths. Grade 3-4 related toxicities were hypertension [8], fatigue [3], fistula [2], hyponatremia [2], intestinal perforation, obstruction, stroke, proteinuria, hypomagnesemia, hypoalbuminemia, portal hypertension, nausea and anemia [1 each]. Frequent grade 1-2 related toxicities included fatigue [19], hypertension [13], anorexia [12], arthralgia [11], diarrhea [11], weight loss [10], hoarseness [8], headache [8] and nausea [7]. Exploratory analyses in tumor samples are ongoing. Conclusions: Tivozanib is active in patients with recurrent OC, FTC or PPC, without substantial toxicity, supporting its further development. Clinical trial information: NCT01853644.
