Sequential bevacizumab and oral cyclophosphamide for recurrent ovarian cancer

Test the safety and efficacy of sequentially blocking angiogenesis by adding oral cyclophosphamide to bevacizumab following cancer progression on bevacizumab in patients with recurrent ovarian cancer.

Eligibility included ≤ 2 lines of treatment for recurrence and measurable cancer by RECIST 1.0. Patients received bevacizumab (15 mg/kg every 3 weeks IV) and upon RECIST progression, oral cyclophosphamide (50mg orally daily) was added. Objectives included safety, toxicities, 3- and 6-month PFS rates, response rate, PFS, and OS.

20 patients were enrolled. Overall response rate was 10%, and 65% of patients had confirmed stable disease (SD). Thirteen of 20 patients received oral cyclophosphamide added to bevacizumab upon bevacizumab progression. Of these 13 patients, 1 patient subsequently achieved a PR (this patient had SD as best response during bevacizumab) and 3 patients had a confirmed SD. For all patients, median PFS was 8.41 months, 6 month PFS rate was 65%, duration of response (DOR) was 7.3 months, and median OS was 22.72 months. Median DOR for patients receiving both bevacizumab and cyclophosphamide was 8.4 months. Most toxicities were grades 1 and 2 and manageable. Grades 3 and grade 4 toxicities included 1 myocardial infarction, 1 gastrointestinal perforation (GIP), and 12/20 patients (60%) developed grade 3 HTN.

Addition of oral cyclophosphamide to bevacizumab at the time of cancer progression on bevacizumab appears to have continued anti-cancer effects in a subgroup of patients and appears to be safe. Randomized trials testing combination versus sequential anti-angiogenic therapy for recurrent ovarian cancer are warranted.