Researchers are diligently trying to find new types of treatment for hormone-refractory prostate cancer (cancer that no longer responds to hormonal therapy). Only a few of these new treatments that are studied will ever be approved by the United States Food and Drug Administration (FDA) and ever make it to market. Others will fail in clinical trials or will be found to have side effects that are too toxic.

Ideally new medications that can cure prostate cancer are needed. Until that time, research is being conducted to discover medications that can increase survival times, delay the progression (spread) of the cancer, help to maintain or improve the quality of life of patients, and that have tolerable or no side effects. The most promising research being conducted is in the area of new, so-called “targeted” medications. Targeted medications work by attacking or blocking targets (small proteins or molecules in the body) that are specifically involved in the growth and spread of tumor or cancer cells. Medications of this type have already been developed to treat other common cancers, such as colon and breast cancer. 

In addition, it would be great if these targeted medications were given as convenient, oral capsules or tablets taken once a day instead of being given by injection in a doctor’s office or in a hospital setting. 
Several medications are currently being investigated as possible treatments for hormone-refractory prostate cancer. Just click on the names of the drugs below (or scroll down the page) to get more information.

Atrasentan (Xinlay™)	Bortezomib(Velcade®)	Calcitriol
Ertinolib(Tarceva™)	GVAX®	Gefitinib (Iressa®)
Imatinib(Gleevec®)	Ixabepilone	KOS-862
PROSTVAC®-VF	Provenge®	Satraplatin
Vitaxin™	ZD 4054

Other drugs will certainly enter clinical trials for advanced and hormone-refractory prostate cancer in the next year or so. 

Atrasentan (Xinlay™/Abbott) 

Atrasentan (previously known as ABT-627) is an investigational, once daily, oral targeted drug. Information gathered from two large clinical trials in nearly 1100 men with hormone-refractory prostate cancer is currently being reviewed by the FDA. If it is approved, it will be marketed under the brand name Xinlay™ (pronounced zin-lay). Atrasentan belongs to a new drug class known as “selective endothelin receptor-A antagonists” or SERA. It works by binding to the endothelin-A receptor which blocks the ability of endothelin-1 (naturally occurring small proteins) to bind with it. By blocking this receptor, it is anticipated that the cancer-causing reactions that take place are also blocked, thus preventing the growth and spread of the tumor; especially in bone. For more information about how SERAs work, you can visit the web site AboutSERA.com. Abbott is also investigating the potential of atrasentan in earlier stages of prostate cancer, as well as in other types of cancer.

Bortezimib (Velcade^®/Millennium)

Bortezimib is currently in early-stage (Phase II) clinical trials for the treatment of advanced forms of prostate cancer, including metastatic, hormone-refractory disease. It is already available for the treatment of a rare form of cancer called myeloma. It is the first of a new class of drugs called “proteasome inhibitors” and has effects that lead to programmed death of specific cells (“apoptosis”) as well as effects that are more like older forms of chemotherapy (“cytotoxic” effects). 

Calcitriol (Novacea)

Calcitriol (or DN-101 an investigational form of vitamin D) has shown interesting effects when combined with docetaxel (Taxotere^®) in the treatment of late-stage prostate cancer. This combination is currently in being studied in late-stage (Phase III) clinical trials. 

Erlotinib (Tarceva™/Genentech)

Erlotinib is in early clinical trials for the treatment of late-stage prostate cancer when used in combination with docetaxel (Taxotere^®). Like another similiar medication that is already available, gefitinib (Iressa^®), erlotinib belongs to the class of targeted drugs known as “epithelial growth factor receptor” (EGFR) inhibitors. 

GVAX^® (Cell Genesys)

GVAX is an investigational cancer “vaccine” (a form of cancer immunotherapy not to be confused with available vaccines that prevent certain ilnesses), currently in late-stage trials for the management of metastatic, hormone-refractory prostate cancer. Its effectiveness and safety is being compared to docetaxel (Taxotere^®) + prednisone—a combination therapy that recently received approval from the FDA for the treatment of metastatic, hormone-refractory prostate cancer.

Gefitinib (Iressa^®/AstraZeneca)

Gefitinib is available in several countries as a treatment for a type of lung cancer ((“non–small-cell lung cancer”) after other treatments have failed. It belongs to the class of drugs known as “epithelial growth factor receptor” (EGFR) inhibitors. It has also been used by oncologists in the treatment of many other types of late-stage cancer. Although clinical trials of gefitinib have been carried out in late stages of prostate cancer, there is currently no good evidence that it has significant clinical benefits in the treatment of hormone-refractory disease.

Imatinib (Gleevec^®/Novartis)

Imatinib is being investigated in early clinical trials for the treatment of hormone-refractory prostate cancer when used in combination with docetaxel (Taxotere^®). It is one of the first “targeted cancer therapies” to be developed. It is a member of the “protein tyrosine kinase inhibitor” (PTKI) drug class, and is currently approved to treat some forms of leukemia and rare gastrointestinal cancers. 

Ixabepilone (Bristol-Myers Squibb)

Ixabepilone is a new form of chemotherapy that is in early clinical trials for the treatment of several forms of cancer, including metastatic, hormone-refractory prostate cancer. Ixabepilone is classified as an “epothilone analog.” Ixabepilone works similar to paclitaxel (Taxol^®) and docetaxel (Taxotere^®) but may be effective in cancers that are resistant to treatment with one or other (or both) of these “taxane” chemotherapies.

KOS-862 (Roche)

Like ixabepilone, KOS-862 is an epothilone analog. It is also in early clinical trials for treatment of advanced prostate cancer.

PROSTVAC^®-VF (Therion Biologics)

PROSTVAC-VF, an investigational cancer “vaccine”, is in early stage clinical trials for the treatment of men with metastatic, hormone-refractory prostate cancer. As with other cancer vaccines, PROSTVAC-VF is intended to stimulate the immune system to attack and eliminate prostate cancer cells.

Provenge^® (sipuleucel-T)

PROVENGE (sipuleucel-T) is an investigational product that may represent the first in a new class of active cellular immunotherapies (ACIs) that are uniquely designed to stimulate a patient's own immune system. ACIs hold promise because they may provide patients with a meaningful survival benefit with low toxicity. PROVENGE targets the prostate cancer antigen, prostatic acid phosphatase (PAP), which is found in approximately 95% of prostate cancers. PROVENGE is in late-stage clinical development for the treatment of patients with early-stage and advanced prostate cancer. In clinical studies, patients typically received three infusions over a one-month period as a complete course of therapy. 

Satraplatin (GPC Biotech)

Satraplatin is a new chemotherapeutic agent that is in late stage (Phase III) clinical trials for treatment of men with metastatic hormone-refractory prostate cancer who have already failed one prior type of chemotherapy. Satraplatin is a platinum-based form of chemotherapy (similar to some older chemotherapeutic agents), but it may have some benefits in prostate cancer not evident with earlier chemotherapies. 

Vitaxin™ (Medimmune)

Vitaxin is in early-stage (Phase II) clinical trials for the treatment of metastatic, hormone-refractory prostate cancer. It is an investigational monoclonal antibody (an agent that can bind to specific types of cells to mark them for destruction by our immune system) with anti-angiogenic properties that may be able to slow the growth and development of prostate cancer metastases by cutting off their supply of oxygen-bearing blood and selectively initiating programmed cell death (“apoptosis”).

ZD 4054 (AstraZeneca)

ZD 4054, is currently in early (Phase II) clinical trials for the management of metastatic, hormone-refractory prostate cancer. Like atrasentan, is an oral, targeted, investigational endothelin-A receptor antagonist.