A phase II clinical trial involving the use of low-dose daily oral cyclophosphamide, weekly vinblastine and rofecoxib in patients with advanced solid tumors

Abstract

3137 Background: Preclinical studies indicate the conventional chemotherapeutic agents given continuously at low doses may provide an improved therapeutic index (RS Kerbel et al, Annals of Oncology 13:12–15, 2002). Cyclophosphamide and vinblastine have been best studied in experimental models where tumor growth retardation is achieved, at least in part, through antiangiogenic mechanisms. Methods: 50 with advanced solid tumors were enrolled (26 male and 24 female, median age 63 years - range 24 - 85). 43 patients had received at least one prior chemotherapy regimen. Patients were required to have ECOG performance status < 2, a life expectancy of > 3 months and at least one measurable lesion. All patients received cyclophosphamide 50 mg PO daily, weekly injections of vinblastine 3 mg/m2, and rofecoxib 25 mg PO daily. Results: Of the 45 evaluable patients, there were 2 complete responses (CR) (4%), 4 partial responses (PR) (9%) for an overall objective response rate of 13%. An additional 6 patients achieved disease stabilization (SD) ≥ 6 months (13%). The primary endpoint of clinical benefit (CR + PR + SD ≥ 6 months) was, therefore, 26%. The median progression-free survival for all patients was 105 days, and 240 days for patients experiencing clinical benefit. The incidence of grade 3/4 toxicities were as follows: neutropenia 12/2, anaemia 2/0, and thrombocytopenia 1/0. No patients developed grade 3 or 4 nausea, vomiting, mucositis or alopecia. Conclusions: This low-dose regimen consisting of daily oral cyclophosphamide and weekly vinblastine injections given concurrently with rofecoxib is associated with minimal toxicity and provides significant clinical benefit to patients with advanced solid tumors. These results are particularly encouraging given the nature of the study population, and indicate that this regimen merits further investigation in specific disease site studies. Author Disclosure Employment or Leadership Consultant or Advisory Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration This clinical research was supported only by the Northern Cancer Research Foundation - a non-profit, regional charitable organization. No personal income was included in this support.