Vitamin D Targets Thrombosis in Cancer Patients
Cancer and Thrombosis
A clinical trial of a biologically active metabolite of Vitamin D3 demonstrated an unanticipated reduction of thrombosis in cancer patients. Thrombosis is a serious complication in advanced cancers and affects between 15 and 20 per cent of all cancer patients.
Dr. Peter Venner, medical oncologist at the Alberta Cancer Board's Cross Cancer Institute, presented the finding today at the annual meeting of the American Society of Clinical Oncology (ASCO) in Atlanta, Georgia.
In a randomized trial involving 250 patients with advanced prostate cancer in 48 clinical sites, those receiving high-dose calcitriol (DN-101) along with Docetaxel experienced a significant reduction in both venous and arterial thromboses compared to patients receiving a placebo and Docetaxel. Calcitriol is a naturally occurring hormone and the biologically active form of Vitamin D.
While the clinical trial involved patients with advanced stages of prostate cancer, in vitro studies of myelogenous leukemia cells, monocytes and osteoblasts and observation in mice hold promise for improved safety in a wide range of cancers.
"This is a serendipitous outcome," says Dr. Venner. "It wasn't what we were looking for, but it offers an avenue of investigation that could result in a new class of anticoagulants, which could, in turn, significantly improve outcomes for cancer patients."
The study was primarily looking at the effects of DN-101 on PSA responses in patients with advanced prostate cancer and secondarily on survival rates. As part of the analysis of the data, its impact on reducing chemotherapy side effects was detected. The drug demonstrated a positive outcome on both survival and reduction of side effects. The effect on thrombosis that unexpectedly emerged from the study will be tested and confirmed in a recently activated phase III clinical trial.
The study was chaired by Dr. Tomasz M. Beer of Oregon Health and Science University and involved researchers from the United States and Canada. DN-101 is produced by Novacea Inc. South San Francisco, CA.