The FDA has approved renewed testing of a deadly compound, IL-12, in cancer patients. IL-12 is a cytokine, a substance extracted from blood and then synthesized. It has been called a "potential wonder drug." But when it was injected into kidney cancer patients last year it caused severe side effects, included multiple organ failures, and two deaths. The "wonder" was how anyone could agree to give--or take--such a drug.
Patients were given doses that FDA assured them were tolerable. Yet almost every patient who took it was harmed. The manufacturer, Genetics Institute (GI), says they have now "figured out the problem" and are prepared to start injecting patients again, and FDA agrees.
"Researchers donąt fully understand this insidious effect," said Science magazine, "but the good news is that they now know how to avoid it" (11/10/95).
The renewed testing is a major victory for GI, a company that was founded by Memorial Sloan-Kettering former chairman of the board, Benno Schmidt, Sr.
But scientists now say that the problem was in how the drug was administered to the patients. Instead of first giving them a small dose, and then waiting till it had cleared from the system, instead in the clinical trial they were given multiple doses of IL-12 right off the bat.
"I donąt know of anything quite like that," said Jay Siegel, an FDA immunologist
who works with the companies. IL-12 seems to rearrange populations of
T cells in mysterious ways--but to be honest, no one really knows what
it is doing or how it does it. Nevertheless, FDA has now lifted a "clinical
hold" on the drug and GI will start clinical trials again. According to
a GI vice president, the whole incident will generate a lot of lab interest.
"The biological phenomenon is really interesting."
