The drug, Sphingomab, may even completely wipe out some tumors -- all while leaving healthy tissue alone, early laboratory and animal studies show.
If the findings can be repeated in humans, the experimental cancer drug may offer a new, highly targeted approach to fighting tumors with few side effects, says Gordon Mills, MD, PhD, chairman of molecular therapeutics at the University of Texas M.D. Anderson Cancer Center in Houston.
Sphingomab zeroes in on a molecule that stimulates cancer growth known as sphingosine-1-phosphate, or S1P.
High levels of S1P have been found in tumor cells and have been associated with aggressive cancers that build up resistance to traditional chemotherapy drugs, says Roger Sabbadini, PhD, chief scientific officer of Lpath Therapeutics Inc., the San Diego-based company that makes the drug.
Reporting at the annual meeting of the American Association for Cancer Research, Sabbadini says that in excess, S1P is one of the really bad guys, instigating cancer spread in two distinct ways.
"First, S1P has a direct effect on cancer cells, stimulating the cells to [grow and spread]," he tells WebMD. "But S1P also signals the growth of new blood vessels that feed a tumor."
Sphingomab works like a molecular sponge to soak up S1P so it can't do its dirty work.
In doing so, the drug fights cancer on multiple fronts, says Mills, who is helping to test Sphingomab.
"It puts the molecular brakes on the growth of [tumor-feeding] blood vessels, but it also blocks cell proliferation, cell survival, cell invasion, and the production of other factors that promote the growth of tumor cells and blood vessels."
Sphingomab is a monoclonal antibody. Antibodies are the body's natural defense against foreign substances, such as infection or cancer cells. Monoclonal antibodies are synthetic copycats that target a very specific portion of foreign substances. With such high precision, treatment is ideally more effective, with fewer side effects.