Lower Doses of Zytiga with Food

There was a small clinical trial, by Mark Ratain, M.D., of the University of Chicago, that suggests that it is possible to take a lower dose of Zytiga (abiraterone) along with a low-fat breakfast and achieve a response similar to the one we would expect to see with a full dose on an empty stomach.  

However, the trial does not tell us, if over the long term, taking the lower dose with food will affect the survival advantage that the higher dose offers.   

Since there is growing concern about the increasing cost of all cancer drugs, including Zytiga, the trial’s findings raise the possibility that something as simple as taking food with Zytiga may help to address this economic issue.

In the trial, subjects took one-quarter of the customarily prescribed dose of Zytiga along with food.  They found that with food these subjects had a similar reduction in their prostate-specific antigen (PSA) levels as did the men who took the full dose on an empty stomach. 

According to William Figg, Sr., Pharm.D., of NCI's Center for Cancer Research, an investigator on the study, although it is effective in slowing the progression of metastatic cancer, abiraterone is one of the most expensive drugs on the market.  “We’re trying to find ways to offset the exorbitant cost of these cancer drugs, and this is one potential approach,” Dr. Figg said.

Many drugs that are given by mouth have a food effect: when a medication is taken with a meal instead of on an empty stomach, the body tends to absorb more of it. This effect is because the fat molecules found in food carry the drug more efficiently through the stomach and intestines, so less of the drug is needed when taken with food to obtain the same concentration in the bloodstream.

It is standard procedure to test drugs with a strong food effect in a way that intentionally diminishes the impact. Testing a drug on an empty stomach is done to reduce the potential variability in dose between participants that could arise due to what types of and how much food different people eat.

 The food effect of Zytiga has long been recognized, the large clinical trials that led to the drug’s approval required that participants take it on an empty stomach to mitigate the food concern. As a result, the drug’s label directs patients to take it without food.

In both the food and nonfood groups, men lived for an average of about nine months without their disease progressing.

More extensive studies are needed to measure whether the effects of abiraterone can be maintained in the long term when given at a reduced dose with food, as well as evaluating the result of the reduced dose might have on survival.

In an editorial that accompanied the trial results, Jill Kolesar, Pharm.D., of the University of Kentucky, and Glenn Liu, M.D., of the University of Wisconsin, cautioned doctors, patients, and insurance providers against making dosing decisions based on a small trial with limited follow-up.

March 28 in the Journal of Clinical Oncology