We have another high visibility finding today about the prevention of progression of advanced prostate cancer in mice … which may or may not lead to a finding about whether the same strategy would work in men.
A paper due to be published on line, very soon, in the journal Cancer Research has suggested that a drug known as maraviroc (an antiretroviral agent of the type used in treatment of HIV/AIDS) can delay disease progression in about 60 percent of mice with laboratory-induced, metastatic prostate cancer. This result was first publicized in a media release from the Press Association on December 1, and the abstract of the paper by Sicoli et al. is now available on line too.
What is the basis for this finding having any importance?
- Maraviroc is approved for the treatment of HIV/AIDS under the names Selzentry (in the USA) and Celsentri (in other countries).
- Maraviroc affects a protein molecule called CCR5 that is found on the surface of certain cells; HIV uses the CCR5 protein to invade white blood cells.
- Genetic data from men with prostate cancer have shown that CCR5 is more active in prostate cancer tissue than in normal tissue and had a greater impact in men with metastatic disease.
- Other data support the idea that CCR5 activity is associated with the progression of prostate cancer.
Since maraviroc is already approved for the treatment of HIV/AIDS, it should be relatively easy to start testing this drug in humans — but this has not been done yet. Whether it will have the same effects on progression of metastatic disease in man as it does in special, highly selected, laboratory-bred mice is a whole other question.
It is also worth noting that (at least here in the USA) maraviroc carries a “black box warning” because of its association with risk for a specific set of serious problems affecting the liver:
Hepatotoxicity has been reported with use of [maraviroc]. Severe rash or evidence of a systemic allergic reaction (e.g., fever, eosinophilia, or elevated IgE) prior to the development of hepatotoxicity may occur. Patients with signs or symptoms of hepatitis or allergic reaction following use of [maraviroc] should be evaluated immediately.
At this time, and based on the available data, The “New” Prostate Cancer InfoLink advises that patients with prostate cancer should not take or use maraviroc unless (a) it is being prescribed to treat HIV/AIDS in a man who also has prostate cancer or (b) it is taken to treat prostate cancer in an IRB-approved clinical trial (and we will let readers know if and when such a trial or trials become available; at present there are none that we are aware of).
Filed under: Drugs in development | Tagged: laboratory, maraviroc, metastatic, mice |
THE "NEW" PROSTATE CANCER INFOLINK 
Hi! Do you know of any evidence (anecdotal or otherwise) which demonstrates that men with HIV who are being treated with maraviroc, have slower disease?
Philip:
I know of no relevant data at all.