Wyeth—which sells the only marketed drug conjugate, Mylotarg, for treating myeloid leukemia—now has a second conjugate called CMC-554 in Phase II and Phase III clinical studies. It too uses the cytotoxic agent calicheamicin, which causes breaks in cancer cell DNA, but couples it to an antibody with affinity for the CD22 antigen on lymphoma cells. Genentech, having licensed technology from ImmunoGen, is developing trastuzumab-DM1, which uses the antibody in its breast cancer drug Herceptin. The conjugate adds the cytotoxic power of ImmunoGen's DM1, a maytansinoid compound that's 1,000 times more potent then traditional anticancer agents. It's the first clinical candidate in Genentech's antibody-drug conjugate program, and the company is expected to make a decision this year about whether it will pursue Phase III studies.
by Ann M. Thayer |
June 16, 2008