Phase II study of single-agent cabozantinib in patients with recurrent clear cell ovarian, primary peritoneal or fallopian tube cancer (NRG-GY001).

To evaluate the efficacy and tolerability of cabozantinib in recurrent clear cell ovarian, primary peritoneal or fallopian tube cancer.

Patients with recurrent ovarian, fallopian or primary peritoneal tumors with at least 50% clear cell histomorphology, measurable disease, one or two prior regimens and ECOG performance status 0-2 received cabozantinib 60 mg orally once daily continuously, in 4-week cycles until disease progression or unacceptable toxicity. Primary endpoints were progression-free survival (PFS) at six months and complete or partial tumor response (as assessed by RECIST 1.1). Secondary endpoints included toxicity, PFS, and overall survival (OS).

Over 19 months, 13 patients were accrued. Fifty-four percent of patients were ≥60 years of age. Performance statuses of 0 and 1 comprised 8 and 5 patients. No objective tumor responses were seen. Three (23% [95% CI: 5%, 54%]) of 13 patients had PFS ≥6 months, including one patient who received cabozantinib for 23 cycles and was still on treatment as of the data cut-off date. Median PFS and OS were 3.6 and 8.1 months, respectively. There was one patient with a grade 5 event: a thromboembolic event considered possibly related to study therapy; patient's cause of death was determined to be due to disease and protocol treatment. Four other patients had thromboembolic events (two grade 3 and one each grade 1 and grade 2). Other grade 3 or higher events reported in two or more patients were nausea, vomiting, fatigue, dyspnea, and dehydration.

Cabozantinib demonstrated minimal activity in the second- and third-line treatments of clear cell ovarian, fallopian tube or primary peritoneal carcinoma.