03/30/08
The data to support splitting doses in GIST are not nearly as robust as in CML. In that disease, there definitely appears to be a relationship between keeping the intensity of the dose high and keeping the CML in remission. Drug levels obtained from the blood are now being looked as a way to be able to better tailor a dose of Gleevec for an individual patient with CML (similar to that done for blood thinners). Obviously one size may not fit all.
The same rationale is being looked at for GIST, although the effect of the drug on the cancer in this disease appears to be quite different than in CML (hence the shorter durations of disease control with Gleevec in GIST compared to that in CML). Therefore, in GIST, recommendations are still to keep the doses as prescribed without splitting, except in cases where a patient and physician are concerned that side effects negate the ability to continue without splitting. In these situations, splitting the doses definitely appears to help curb the side effects in the majority of patients, but possibly (yet to be determined) at the risk of having less efficacy against the cancer. In these very individual decisions between a patient and his/her physician, the uncertainty of splitting doses compared to being off the medication completely is worthy of a frank discussion.
Hope this helps GSI and your peer patients.
Thom ____________________________ Thomas J. George, Jr., MD, FACP Assistant Professor Associate Program Director, HemOnc Fellowship Director, GI Oncology Program - Malcom Randall VAMC Dept of Medicine - Hematology/Oncology Division University of Florida UF (352) 273-7759 VA (352) 376-1611 Thom.George@medicine.ufl.edu