Abiraterone acetate and the “food effect”

For a while now there have been questions about whether taking abiraterone acetate with food as opposed to without food could be clinically beneficial for patients.

A new paper by Stover et al. has provided us with a little more information on this topic (but not a lot!).

Here in the USA, the manufacturer clearly states that

  • “No food should be eaten 2 hours before and 1 hour after taking [abiraterone];”
  • Abiraterone should be taken on an empty stomach; and
  • “Taking [abiraterone] with food may cause more of the medicine to be absorbed by the body than is needed and this may cause side effects.”

(We have added emphasis to the word “may” in this last sentence.)

In fact, what is known is that combining abiraterone acetate with food may (that word again) result in additional inhibition of enzymes involved in the androgen synthesis process association with progressive, castration-resistant prostate cancer (CRPC). This has two possible implications:

  • Some men may be able to use abiraterone acetate initially at lower doses if it is combined with food.
  • Some men who start to progress on a standard dose of abiraterone acetate may be able to take that standard dose with food and gain a clinical benefit (but at potential risk of an increase in side effects).

So let’s be very clear:

  • Neither of these things should be done by any patient without an initial discussion with his doctor.
  • Starting on the standard dose of abiraterone acetate and taking it with food is probably not a very good idea, because if you are one of those patients at significant risk for side effects to this drug, you are going to make that risk significantly worse!

Having said that, let’s look at what Stover et al. did and learned.

They carried out chart reviews on a total of 60 men with metastatic CRPC who were treated with abiraterone between April 1, 2011 and December 31. Of these 60 men, 19 switched from taking abiraterone without food to taking it with food at the time of their initial PSA progression on abiraterone during the study period.

Here is what the authors found:

  • Among the 19 men who switched administration from without food to with food,
    • 14/19 patients (74 percent) had previously had an initial response to abiraterone when taking it without food.
    • 3/19 patients (16 percent) had a PSA decrease within 3 months when taking abiraterone with food.
    • All three responders to the switch had been initial responders to abiraterone when taking it without food
    • Testosterone levels declined in 5/7 patients (71 percent) who switched to taking abiraterone with food.
  • Median time on abiraterone therapy for the 19 men who switched to taking abiraterone with food on initial progression was 100 days longer than among the 41 men who continued taking abiraterone without food.
  • There were no observable increases in toxicity of  abiraterone among the men taking with with food as compared to those taking it without.

Stover et al. reach a very basic conclusion:

Some men with mCRPC may benefit from taking AA with food.

And at the moment that may be the best that we can say.

Prospective trials are being conducted to investigate the food effects of abiraterone. One small trial with 25 patients has been completed (but not yet reported); another trial — with 72 patients — is ongoing. But what is certainly worth knowing is that if you are receiving treatment with abiraterone acetate for CRPC (without food at time of drug administration), and you have an in initial, meaningful PSA response to treatment, then when you show initial signs of PSA progression you may want to talk to your doctors about switching to taking the drug with food … but do talk to your doctor about this; don’t just do it on your own.

5 Responses

  1. “Some men who start to progress on a standard dose of abiraterone acetate may be able to take that standard dose with food and gain a clinical benefit (but at potential risk of an increase in side effects).”

    I have seen Chuck Ryan, one of the abiraterone PI’s, use this strategy!


  2. How would the average uro have any idea as to whether one should take it with food or not?

  3. Dear Stu:

    The vast majority of physicians are going to give abiraterone acetate exactly as instructed in the prescribing information — without food. Why? Because it is legally safer for them to do this, and the data suggesting that it can be given with food is limited. However, …

    Many experienced advocates and patients are likely to tell you that they would only take a drug like abiraterone acetate under the supervision of a urologic oncologist or a medical oncologist who was experienced in the management of castration-resistant prostate cancer. This rules out a large number of “average” urologists. And the experienced urologic oncologists and medical oncologists are probably well aware of the food effect and can work with individual patients to make appropriate judgment calls.

  4. Sitemaster beat me too it … so I will fulfill his prediction.

    Never mind the “average” urologist — no urologist should be prescribing abiraterone. Urologists are trained for surgery, not to prescribe hormone therapy — especially second-line hormone therapy!

    And patients need to be smart enough to move their care to a genitourinary medical oncologist long before they are ready for abiraterone!

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