COLUMBUS, Ohio An early phase multiple myeloma trial has unexpectedly revealed that the drug lenalidomide interacts with another protein in cells that affect its dose level in the body, say researchers at the Ohio State University Comprehensive Cancer Center Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC James) who conducted the study.
Lenalidomide is an anti-inflammatory drug, and more than 390 clinical trials have been initiated to study its activity in a number of cancers and other diseases.
The study found that lenalidomide interacts with P-glycoprotein (Pgp), a molecule that pumps potentially toxic chemicals out of cells and aids in removing these chemicals from the body. Abnormally high levels of Pgp in cancer cells can be an important cause of drug resistance for many cancer patients.
The findings, published online in the Journal of Clinical Oncology, could lead to safer dosing of lenalidomide in a variety of diseases.
"This is the first report showing that lenalidomide interacts with Pgp, and our clinical data suggests this may be an important consideration for proper dosing of the drug," says study leader and researcher Dr. Mitch Phelps, assistant professor in Ohio State's College of Pharmacy. "Some toxicities induced by lenalidomide can be severe and life-threatening."
The phase I clinical trial, which evaluates the safety of a new drug or drug combination, involved 21 patients with relapsed multiple myeloma, a fatal disease that affects more than 20,000 Americans each year and kills more than 10,600 of them.
The trial combined lenalidomide with temsirolimus, a drug that the researchers knew from the start interacted with Pgp. During the study, lenalidomide levels in patients' blood were often higher than expected, and some patients experienced side effects such as electrolyte imbalances and rashes that were greater than expected.
To the investigators' surprise, laboratory expe
|Contact: Darrell E. Ward|
Ohio State University Medical Center