Because NPI-0052 and bortezomib attack the same intracellular target in different ways, the Dana-Farber researchers contend that combining these two agents might be more effective than using either therapy alone ?and be better tolerated by patients as well.
In preclinical studies, NPI-0052 blocks a wider range of proteasome activities than bortezomib, say the researchers, and works at lower doses. NPI-0052 also appears to be less toxic to normal cells. Bortezomib is currently given by intravenous infusion. "NPI-0052 can be given orally, although the first clinical trials will be using the intravenous route," says Paul Richardson, M.D, who is also a co-author in this study and will be leading the Phase-I clinical trial in myeloma at Dana-Farber.
NPI-0052 was discovered by William Fenical, PhD, and his collaborators at The Scripps Institute of Oceanography during the fermentation of Salinispora, a new class of marine gram-positive bacteria identified in sediment samples from the ocean floor. The substance has shown strong anticancer properties in laboratory tests. Nereus Pharmaceuticals holds an exclusive license to the compound for drug development.
Experiments with NPI-0052 began at Dana-Farber in 2003, said Dharminder Chauhan, PhD, lead author of the paper along with Laurence Catley, PhD. When added to cells from patients whose disease was resistant to both standard drugs and bortezomib, the compound efficiently killed the cells. Analyses showed that NPI-0052 and bortezomib express different profiles for inhibiting the three major proteasome activities.
In mice implanted with human myeloma tumor cells, NPI-0052 was well tolerated, prolonged survival and significantly reduced the rate of cancer recurrences. Because NPI-0052 and bortezomib bloc
Source:Dana-Farber Cancer Institute