Carfilzomib induces a response in 45 percent of patients and reduces neuropathy
The second-generation proteasome inhibitor carfilzomib is showing noteworthy response rates and low levels of adverse side effects among multiple myeloma patients in a phase II clinical trial, researchers reported today at the 51st Annual Meeting of the American Society of Hematology.
The updated data from the 17-site study focuses on patients with relapsed or resistant multiple myeloma who have received one to three prior therapies, but not the drug bortezomib, the original proteasome inhibitor.
"These findings are truly an advance for patients with multiple myeloma," said Michael Wang, M.D., associate professor, Department of Lymphoma/Myeloma at M. D. Anderson and lead author on the study. "This is an incurable, challenging disease with devastating consequences.
"While new agents are extending life expectancies, they often have adverse side effects, including severe neuropathy. Carfilzomib is showing good response rates, with an improved side effects profile," Wang said. Neuropathy is peripheral nerve pain or numbness that can become debilitating enough to halt treatment.
According to the American Cancer Society, more than 20,000 cases of multiple myeloma will be diagnosed this year in this country. More than 10,000 people will die of this disease, which is a type of blood cancer.
Better tolerated than other agents
In preclinical studies carfilzomib has been better tolerated than bortezomib, allowing consecutive day dosing and treatment over extended periods of time. Both drugs work by targeting the cell's proteasome, which destroys mutated or damaged proteins. Blocking this process causes cell death. Carfilzomib targets and binds to the proteasome differently than bortezomib.
Researchers previously observed higher response rates to carfilzomib among patients who had never been treated with bortezomib compared to those with relapsed disease following bortezomib therapy.