This news release on a study of a drug’s potential to help inhibit tumor growth in certain types of metastatic prostate cancer never informed readers that the study was done in mice and not men.
Maybe the best way to summarize this release is by parsing what the headline does and does not say: “Breakthrough Study Stops Fat-Eating Prostate Cancer Cells” may be literally true but completely and utterly misleading, lacking both evidence or relevance to real humans who may be suffering from castration resistant prostate cancer (CRPC) whose poor prognosis is due to their cancer’s ability to resist anti-androgen hormone therapy.
The study itself examines the use of CPT1A inhibitors and anti-androgen therapy which could increase a cancer’s sensitivity to enzalutamide in mice. But we think readers are left without even the most basic evidence to support the release’s claim that the study is a “huge development for men with CRPC that previously did not have many options.”
This study may have some relevance to men with a certain type of cancer somewhere in the distant future when it has been tested in those specific patients and proven to be safe and effective. A study that shows, somewhat, a drug’s ability to increase the potential effectiveness of another drug, in rodents, might prove to be an advance in basic science, but this study’s relevance to humans is not at all clear or well defined.
The drug in question, enzalutamide, is advertised and sold as Xtandi. The cost of the drug could easily have been included in the news release. According to GoodRx, the out-of-pocket cost for 120 capsules of 40 mg Xtandi is roughly $11,000.
Ranolazine (marketed as Ranexa), the other drug discussed, is priced at about $350 for a 60 day supply of 500-mg tablets.
Even though the researchers found that adding “ranolazine to anti-androgen therapy made tumors more sensitivity (sic) to the anti-androgen drug enzalutamide,” according to the release, we have no idea of the magnitude of those benefits to people. The scope of the benefits in mice is not even described with any precision. It is a huge leap to translate these basic science findings to clinical care.
The drug’s potential harms to people are known and reported in the New England Journal of Medicine. They include “fatigue, constipation, and back and joint pain as well as hypertension.”
The release doesn’t tell us if the mice in the study experienced any side effects from the drug.
The release explains how the drug inhibits fat-eating prostate cells but offers no explanations on how this would apply to human men with prostate cancer. This is not a comment on the quality of the evidence, but on how the evidence applies to the treatment of castration resistant prostate cancer.
There is no overt disease mongering here except to say that those actual men with actual prostate cancers who read a story based on this news release may be mightily concerned, wondering if they have the “fat-eating” type of prostate cancer and thus may be even more worried than they normally are.
The funders aren’t named in the news release. There is no information suggesting that the researchers are connected to the companies that make the drugs in question or are otherwise invested in this particular treatment paradigm, but it would have been nice to be informed if this was or was not the case.
Are there other drugs that have the same pharmalogical effect as enzalutamide? We learn nothing about what else is out there that treats this particular type of cancer and how effective it might be.
Another approach to treating castrate-resistant prostate cancer is the drug abiraterone (marketed as Zytiga), an androgen synthesis inhibitor, used in combination with prednisone.
The key drug in question, enzalutamide, (trade name Xtandi) is already widely marketed as a treatment for prostate cancer. This fact was not included in the news release.
The news release says: “In fact, we are already able to block the action of the CPT1A enzyme. The drug ranolazine is a fat oxidation inhibitor that earned FDA approval in 2006 to treat angina. When Schlaepfer and colleagues experimented with fat burning inhibitors and anti-androgens in cancer cell lines, they found that the addition of ranolazine to anti-androgen therapy made tumors more sensitivity to the anti-androgen drug enzalutamide.”
We interpret this as saying in a round-about way that the drug is not claiming any novelty that it doesn’t have.
This news release is almost a poster child for unjustifiable language including use of the word, “breakthrough” in the title. Then there is the suggestion that “This is a huge development for men with CRPC that previously did not have many options.”
This might be a huge breakthrough for mice with a certain type of cancer but that hardly justifies the use of the term “breakthough” in applying the study’s finding to human men.