May 20, 2002
Early findings suggest new type of drug shows promise in treating Multiple Myeloma
Paul Richardson, MD
Preliminary data from a Dana-Farber Cancer Institute study suggests that PS-341, a "first-in-class" proteasome inhibitor, produced a response in some patients with treatment-resistant multiple myeloma. The results from the first 78 patients who received the drug show that in the majority of cases the cancer either stopped advancing or regressed. The findings were reported at the annual meeting of the American Society of Clinical Oncology (ASCO) in Orlando on May 20.
PS-341 garnered much attention at the American Society of Hematology meeting last December because of a favorable safety profile and impressive evidence of anti-myeloma activity in patients with very poor prognosis.
Data on the first 78 of the 202 patients enrolled in this large multi-center trial were included in the ASCO poster presentation. The researchers found that in 77 percent of the 78 patients, the cancer either shrank or stabilized after treatment with PS-341 alone. Furthermore, a number of complete responses were observed. Treatment was administered by intravenous push on an outpatient basis twice a week for 14 days with one week off for up to six months, and the toxicity encountered was manageable.
Proteasome inhibition represents a novel pathway for targeted anticancer therapy. PS-341 blocks the activity of a cell signaling pathway regulated by the proteasome, an enzyme structure which controls the way cancer cells can continue to grow despite stressors that would normally promote programmed cell death, or apoptosis. The drug is the first to be aimed at this pathway, parts of which are used by cancer cells to help them resist standard chemotherapy and radiation.
Kenneth Anderson, MD
The lead author on the poster is Paul G. Richardson, MD, and the senior author is Kenneth C. Anderson, MD, both of Dana-Farber. Millennium Pharmaceuticals of Cambridge, Mass., is the manufacturer of the drug, formerly known as LDP-341. It was developed jointly by Dana-Farber and Millennium for the treatment of myeloma, and is also being studied in other malignancies.
Dana-Farber Cancer Institute (www.dana-farber.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.
