369 Clinical benefit of oral metronomic cyclophosphamide administration in heavily pretreated recurrent epithelial ovarian cancer

Introduction/Background* Oral metronomic cyclophosphamide (OMC) consists in the chronic administration of low, usually daily, doses of chemotherapy. The effective reduction of tumor growth, oral administration, low toxicity profile and low cost make this therapeutic choice attractive for women with relapsed ovarian cancer, especially heavily pretreated patients. We retrospectively evaluated the clinical benefit and the objective response in patients treated with OMC for recurrent ovarian cancer. Methodology We included patients treated with OMC (50 mg daily) from 2016 to 2021 at the Academic Department Gynaecology, Mauriziano Hospital, Torino, Italy. Clinical benefit was classified as CA125 response, radiological response and symptomatic improvement as reported by the treating physician. Toxicity profile was assessed using Common Terminology Criteria for Adverse Events version 5.0. Result(s)* Thirty-eight patients were analyzed. Average age was 72 years (range 49-88). 34 (90%) had FIGO stage III and IV disease at diagnosis and 64% had received ≥ 3 previous lines. Before starting OMC, 21% had ECOG 0, 58% ECOG 1 and 21% ECOG 2. 8.6% of patients obtained partial response (PR) and 37% stable disease (SD). Median duration of the response was 7.4 months. After 3 months from starting OMC, 51% of patients experienced symptoms improvement and 69.5% Ca125 reduction or stabilization. Only one patient discontinued for side effects and no G3-4 hematological toxicities were observed, reflecting a low toxicity profile. Only nausea and fatigue G1-G2 were reported in 5 (13%) and 13 (34%) cases, respectively. Conclusion* OMC could be a feasible therapy for recurrent ovarian cancer leading to an acceptable clinical response with a low toxicity profile, even if patients are heavily pretreated and with a suboptimal performance status. We are now prospectively assessing the Patient Reported Outcomes (PROs) in order to objectify the tolerability and the symptoms improvement. All authors have no conflict of interest.