From Our 2007 Archives
Taking Cancer Drug With Food May Cut CostsBy Alan Mozes
TUESDAY, July 17 (HealthDay News) -- Taking a pricey breast cancer drug called lapatinib (Tykerb) with food rather than on an empty stomach may improve its absorption by the body -- lowering the doses needed and greatly cutting costs for patients, a new study shows.
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In a commentary published in the Aug. 10 issue of the Journal of Clinical Oncology, Drs. Mark Ratain and Ezra Cohen, of the University of Chicago, suggest that taking the recently approved medication with food -- particularly high-fat food -- cuts the dosage needed by at least 60 percent.
Ratain -- a professor of medicine and associate director for clinical sciences in UC's Cancer Research Center -- joined Cohen (from the hematology/oncology section of UC's department of medicine) to highlight the findings of a study presented in March at the American Society for Clinical Pharmacology and Therapeutics.
The study, which neither Ratain or Cohen was involved in, revealed that 500 milligrams of Tykerb taken with food appears to be as effective as 1,250 milligrams of the drug taken on an empty stomach, the current prescription protocol.
"What we have here is this unique situation where patients are shelling out more than they need to take a drug in a suboptimal manner," said Ratain.
The current regimen of five 250 milligram tablets per day, taken on an empty stomach, costs about $2,900 per month. But simply taking the pills with food could save the patient about $1,740 per month in drug expenses, a real "value meal" for patients, according to the experts.
Both Ratain and Cohen cautioned that physicians and patients should not alter Tykerb treatment protocols until further research substantiates these findings.
The drug's maker, GlaxoSmithKline (GSK), offered a much stronger warning in a statement released Tuesday, in which they called Ratain's and Cohen's commentary "speculative," with the "potential to be misunderstood and misused by clinicians and patients."
"While dosing Tykerb with food has been found to increase absorption, food effects are highly variable and hard to predict," the company said. "Taking Tykerb with food could result in increased side effects and decreased efficacy. Additionally, concurrent medicines that patients may be taking, including capecitabine, must be considered. Each medicine has its own potential for drug and food interactions. Therefore, it is imperative that patients follow the current FDA approved Tykerb dosing and administration recommendations without food."
Tykerb was approved for use against breast cancer by the U.S. Food and Drug Administration in March of this year. The oral tablet was developed by the GSK for patients battling a specific type of advanced-stage breast cancer, in which HER2 -- a protein that promotes tumor growth -- is expressed.
According to the American Cancer Society, every year approximately 180,000 American women are diagnosed with breast cancer. Annually, upwards of 10,000 women are projected to die from the advanced stage, HER2-positive version of the disease.
The new treatment was approved for use in combination with another medication known as capecitabine (or Xeloda), for cases in which a range of other drugs, such as Herceptin, have ceased to be effective.
According to the FDA, Tykerb inhibits tumor growth by going inside cells containing the HER2 protein and blocking signals that promote tumor growth. In contrast, older drugs such as Herceptin have larger molecular structures that target the outside of the cell.
The FDA approval of Tykerb was based on the results of a study involving approximately 400 breast cancer patients with advanced-stage HER2 disease. That study revealed that women who took Tykerb in combination with capecitabine were significantly more likely to respond positively to treatment and to experience a delay in tumor growth. The ultimate impact Tykerb may have on long-term survival was still unknown at the time of approval.
As is standard procedure with all new drug approvals, the FDA worked with the drug's manufacturer to compose the instruction labeling accompanying Tykerb.
As currently worded, physicians and patients are clearly informed that the medication should be taken on an empty stomach, in light of the fact that all the study patients consuming Tykerb did take the drug without food.
However, another section of the labeling material notes that absorption of the drug is boosted when ingested with food.
Ratain said this kind of confusion happens when "getting things done quickly is considered more important than getting things done right."
"Here's the problem: Since the drug company didn't do their trials with food, they can not recommend that their drug be given with food," he said. "I think if the company knew before they started their trial that food would help absorption, there's no question they would have done the study with food. But they wanted to get the study started quickly, and they guessed wrong."
"So," concludes Ratain, "they had two choices: have the drug approved by the FDA as they had tested it in their trials, or delay the drug until they do new testing with food. And this sort of boxes them into a corner, because the market expectations for this drug is about a billion dollars a year in sales, and they want to get it out there."
"So, the bottom line is that, in the end, the label in one part says take it fasting, and in another place, it says the concentration and absorption in the blood is markedly increased if taken with food," Ratain noted. "The remedy is potentially to take a lower dose with food, which results in a significantly lower cost to the patient and/or their payers."
Ratain emphasized that Tykerb's interaction with food must now undergo further study before it can definitively be said that the current labeling instructions should be altered. However, he pointed out that he is not aware of any current plans on the part of GSK or a third party to conduct such a study.
Meanwhile, Ratain said that he and his colleague Cohen simply want to draw attention to a clear labeling discrepancy with major financial implications for breast cancer patients -- one that he believes might very well have slipped through the cracks in the complex world of oncology treatment.
Dr. David Flockhart is director of the division of clinical pharmacology at Indiana University School of Medicine in Indianapolis. He said he's inclined to agree that Ratain and Cohen have identified a hidden cost saving for patients.
"I think Ratain's probably right," said Flockhart. "Drugs are usually studied for concentration effects on fasting volunteers. This is routine, because it's very hard to predict how food may speed up or bind with a drug and alter absorption. So, the drug company did what they would normally do. But there happens to be a nice little accident here that could benefit patients."
"Of course, they're calling for more studies," he noted. "As is needed. Meanwhile, because tons of labels don't have perfect instructions in them, doctors will try to do what they always do: use the best information they have. And doctors may want to consider this new information," Flockhart said.
SOURCES: Mark J. Ratain, M.D., professor, medicine and associate director, clinical sciences, Cancer Research Center, department of medicine, University of Chicago; David Flockhart, M.D., Ph.D., director, division of clinical pharmacology, Indiana University School of Medicine, Indianapolis; July 17, 2007, statement, GlaxoSmithKline; Aug. 10, 2007, Journal of Clinical Oncology
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