Scientists are required to use the FDA's Good Manufacturing Practices (GMPs), which makes the cost of preparing the vaccine prohibitive for Slovin. Through each of her early cancer vaccine trials, which typically enrolled only 15 to 30 patients, Memorial Sloan-Kettering's own bioorganic chemistry laboratory, a nonGMP facility, synthesized the precursor of the vaccine and then a small GMP facility conjugated it. But for a larger Phase III trial with more than 200 patients, the FDA requires scientists to test the same compound that would be marketed if approved. And only GMP-manufactured vaccines fit the requirement. "You have to have the money," Slovin says. "You have already invested heavily, by a variety of grants or individual funding agencies, let's say about a million dollars, and you've synthesized the vaccine--you have the patient population. [But] you realize that [the money] is insufficient, and you really can't afford to do it."
Many researchers ...
