ASH 2015
Dalteparin thromboprophylaxis in cancer patients at high risk for venous thromboembolism
Prof Alok Khorana - Cleveland Clinic, Cleveland, USA
Cancer patients who are at high risk of thrombosis can be given primary preventive treatment. But you’ve been looking into this experimentally, what did you find? What did you do, indeed?
Yes, so today at ASH we reported results of a randomised clinical trial taking high risk patients and patients being high risk for getting blood clots. We know they’re high risk based on a risk score that my colleagues and I developed about seven years ago. If they have a score of 3 or higher they are at really high risk for getting clots. We took the high risk patients and randomised them to receive dalteparin, which is a low molecular weight heparin, given 5,000 units once a day for twelve weeks or to observation. We found two things: one, we were screening these patients before they even started on the study drug and we found a very high rate of baseline blood clots, about 9% of patients already had a blood clot before they even started chemotherapy and that’s a really important finding. It suggests that cancer patients with a score of 3 or higher should really be screened for blood clots even before they start on treatment. A second thing we found was that the rate of VT was very high in the observation arm, it was 21%, and it came down to 12% in patients who received dalteparin.
What do you think this implies, then, for future therapy?
I think it strongly suggests that cancer patients at high risk can have that risk reduced by using a blood thinner. This study that we reported today is using a self-injection of low molecular weight heparin. An ongoing study of risk cut-off of 2 or higher is using rivaroxaban versus placebo in a global study, about 700 patients, and hopefully we’ll be able to report on that next time we meet.
So what should clinicians take home from your research findings?
There is a validated risk assessment tool, it can be used to find patients at high risk for blood clots. They can be at high risk or maybe even have a clot before they start on chemotherapy so consider screening for those patients. And consider using prophylaxis in the high risk patients to prevent blood clots.
