To test both the drug's safety and the best potential dose, SNS-032 was given intravenously as a "loading" dose an initially higher dose that is then reduced to a maintenance level over five minutes. This was followed by a six-hour infusion given to all patients on a weekly basis for three consecutive weeks.
Although the primary purpose of the study was to test the maximum safe dose that could be given to patients, Dr. Siegel and colleagues also looked at whether the medication had an effect on disease processes. One patient with CLL had more than a 50 percent reduction in measurable disease, but no improvement in disease markers in the blood. Another CLL patient had stable disease for four courses of treatment. For multiple myeloma, two patients had stable disease with treatment and one had normalization of spleen size, which is an indication of a reduction in blood cancer activity.
Looking at blood test results for the patients, the researchers found anti-cancer activity. The drug appeared to inhibit cyclindependent kinases 7 and 9, two of the three enzymatic proteins targeted in this study. They also caused apoptosis, or cell death, in cancer cells.
"Our study found that this drug is well tolerated and had some clinical effect, but it is important to note that this was a small, very early stage study," says Dr. Siegel. "Based on these findings, there is justification for additional research, which will show whether this drug has a place in the arsenal of treatments for hematologic malignancies."
Preclinical studies of SNS-032 demonstrated that the drug inhibited th
|Contact: Amy Leahing|
John Theurer Cancer Center