Testosterone Inactivating Pharmaceuticals
Hormonal therapy is a mainstay for Azure, Indigo, and Royal. The testosterone inactivating pharmaceuticals (TIP) fall into three broad categories:
Lupron-like medications work by blocking luteinizing hormone (LH) which comes from the pituitary gland. When LH levels in the blood drop, the testicles stop producing testosterone. There are two types of injectable drugs that block LH. The agonists, which are called Lupron, Eligard, Trelstar, and Zoladex. There is only one injectable drug that works as an antagonist. It is called Firmagon. There is one oral medication called Orgovyx that also works as an LH antagonist.
Anti-androgen pills “block” testosterone activity without eliminating it from the bloodstream. Anti-androgens are less potent but have fewer side effects and are occasionally substituted for Lupron-like drugs in frail or elderly men. The trade names of the FDA-approved anti-androgens are Casodex, Fluamide, and Nilutamide. Their generic names are bicalutamide, eulexin, and nilandron.
Second generation TIP such as Zytiga, Nubeqa, Erleada and Xtandi are FDA-approved medications for men who have become resistant to the “Lupron-like” medications. These medications also improve survival in men with High-Azure. 2nd Gen TIP medications work in the cancer cell internally by blocking the synthesis or the activity of testosterone. The side effects are similar to that of the Lupron-like drugs, with some exceptions
Both the anticancer efficacy and the treatment-related side effects of TIP are increased when treatment continues for longer duration. Therefore, the duration of TIP is adjusted in accordance with each individual’s specific situation.
The following list presents some roles that TIP plays in prostate cancer management:
Men with High-Teal who are undergoing radiation often begin TIP before starting radiation and continue for a total of four to six months of therapy.
Men with Low-Azure have historically been given 18 months of hormone therapy.
Men with Basic-Azure and High-Azure who are undergoing radiation are typically treated with TIP for 18-24 months.
Men with relapsed disease (Indigo) often receive intermittent TIP. This means that an initial course is continued for six to 12 months and then stopped. During the off-period, PSA levels are monitored every three months. A second cycle of TIP is initiated when the PSA rises to a prespecified level, usually between 3 to 6.
Men with Royal who become resistant to Lupron are usually administered 2nd Gen TIP. More recently, doctors are starting 2nd Gen TIP at the first sign of metastases.
TIP has a potential role for shrinking an enlarged prostate gland prior to radiation.
TIP is an alternative to surgery or radiation for treating men with Teal
TIP can be used in conjunction with surgery in men with Azure. This is controversial because older studies evaluating TIP for Teal after surgery showed no improvement in cure rates. However, those studies used only three months of TIP. Subsequent studies in Azure and Indigo using TIP for a longer duration show improved survival.
ABOUT THE AUTHOR
Mark Scholz, MD is the Executive Director of the Prostate Cancer Research Institute. He is also the Medical Director of Prostate Oncology Specialists Inc. He received his medical degree from Creighton University in Omaha, NE. Dr. Scholz completed his Internal Medicine internship and Medical Oncology fellowship at University of Southern California Medical Center. He is co-author of Invasion of the Prostate Snatchers. He has authored over 20 scientific publications related to the treatment of prostate cancer.