Tetrathiomolybdate (TM) is a unique anticopper
drug developed for the treatment of the neurologic presentation of
Wilson's disease, for which it is excellent. Since it was known
copper was required for angiogenesis, TM was tested on mouse
cancer models to see if it would inhibit
tumor growth based on an antiangiogenic effect. TM was extremely effective in these models, but all the
tumors in the models started small in size - micrometastatic in size. Later, TM was tested in numerous human
cancer trials, where it showed only modest effects. However, the mouse lesson of efficacy against micro disease was forgotten - all the trials were against bulky, advanced
cancer. Now, the mouse evidence is coming back to life. Three groups are curing, or having major efficacy of TM, against advanced human
cancers, heretofore virtually incurable, particularly if the
cancer has been reduced to no evidence of disease (NED) status by conventional
therapy. In that situation, where the remaining disease is micrometastatic, TM
therapy appears to be curative. We have designed and initiated a study of TM in canine
osteosarcoma at the micrometastatic phase to help put these findings on a firm scientific basis. TM also has major anti-inflammatory properties by inhibiting
copper dependent
cytokines involved in
inflammation. This anti-inflammatory effect may be involved in TM's anticancer effect because
cancers, as they advance, attract inflammatory cells that provide a plethora of additional proangiogenic agents.