The drug, VELCADETM (bortezomib) for Injection (formerly called PS-341), has produced at least partial responses in 32 percent of the 78 patients in the study's first cohort, including some complete responses (in which no evidence of active disease could be detected). Nearly 70 percent of the study participants had their condition either stabilize or improve after beginning the therapy and some continued to show a positive response to the therapy nearly a year after beginning the study treatment.
The study, a Phase II clinical trial, involved 202 patients in two cohorts with relapsed or refractory myeloma who averaged six prior lines of treatment. The overall response rate was 35 percent with 59 percent of patients achieving a response or disease stabilization. Paul Richardson, MD, Kenneth Anderson, MD, of Dana-Farber, and co-authors will present the findings from patients in both cohorts.
"The results of this trial suggest that VELCADE may represent a uniquely promising approach to the treatment of patients with relapsed and refractory multiple myeloma," says Richardson.
VELCADE, developed by Millennium Pharmaceuticals, Inc. of Cambridge, Mass., is the first of a class of substances known as proteasome inhibitors to reach the clinical trial stage. In pre-clinical studies by researchers led by Teru Hideshima, MD, at Dana-Farber, VELCADE TM (bortezomib) for Injection – which acts on tiny cell chambers called proteosomes – prevented multiple myeloma cells from proliferating, even those which were resistant to all known therapies. Later experiments found that the drug killed myeloma cells in mice without seeming to harm normal tissue.
Dana-Farber Cancer Institute (www.danafarber.org) is a principal teaching affiliate of the Harvard Medical School and is among the leading cancer research and care centers in the United States. It is a founding member of the Dana-Farber/Harvard Cancer Center (DF/HCC), designated a comprehensive cancer center by the National Cancer Institute.