Relugolix for Prostate Cancer Treatment

Relugolix is an androgen deprivation therapy used for treating advanced prostate cancer, which was approved in 2020 by the United States Food and Drug Administration (FDA). In androgen deprivation therapy, the goal is to slow prostate cancer growth by reducing male sex hormone production.

Relugolix is a gonadotropin-releasing hormone (GnRH) antagonist, which binds to the GnRH receptors of your cells. It then quickly inhibits the release of gonadotropins from your brain’s pituitary gland, which helps to lower testosterone levels, fulfilling the goal of hormone therapy in prostate cancer.

While only recently approved, relugolix is likely to be the preferred option for androgen deprivation therapy, as it is much faster at reducing testosterone levels than the previous standard treatments, which include leuprolide, a GnRH agonist. In comparison, these GnRH agonists follow the opposite mechanism of relugolix, and deliver a continuous flow of drugs to activate the GnRH receptors, aiming to overstimulate and eventually desensitize them.

This would then suppress production of gonadotropins, reducing testosterone production as well. Unfortunately, this initial overstimulation results in a temporary testosterone surge, which would cause your symptoms to flare up for a short period before the drug can provide therapeutic relief.

Now however, relugolix provides the answer to this issue, by allowing you to bypass the testosterone surge completely, while still lowering testosterone levels quickly and effectively.

Relugolix is currently the only oral option available for this new drug type, which may be may be much more convenient for you. The other alternative GnRH antagonist is degarelix, which is usually administered by injections.

Furthermore, relugolix allows for testosterone levels to be easily reversed once the treatment is stopped. This makes it a good option for you if you are suited for and are keen on intermittent androgen deprivation therapy, which some may use to improve their quality of life.

Relugolix also has a much lower risk of cardiovascular events when compared to the alternative leuprolide. This is of particular significance, as death from cardiovascular issues is highly associated with prostate cancer. Relugolix may then be considered a good option for you if you have existing heart issues. However, your heart function may still need to be monitored periodically by electrocardiograms, in order to watch out for issues with your heart’s electrical function. If you experience issues with dizziness, fainting, or a racing heart, you should inform your doctor immediately.

Due to the risk of fetal toxicity, if your partner is of reproductive potential, effective contraception should be used when needed, up to two weeks after your last dose. If you intend to conceive after, you should note that there is a risk of infertility for you. Unfortunately, this risk is generally commonly associated with prostate cancer treatments as most target the reduction of the sex hormones or the removal of the prostate in order to limit cancer spread.

Below are some common side effects reported after taking relugolix. You may not experience all of these side effects, but there is a risk that you may encounter a few of these at the same time.

The side effects commonly reported in over 1 in 10 people include:

• Hot flashes
• Fatigue
• Muscle and joint pain
• Constipation or diarrhea
• Higher blood sugar levels
• Higher triglyceride levels
• Lower hemoglobin levels
• Higher levels of liver damage biomarkers

While relugolix does come with some side effects that should be monitored, they are generally considered tolerable and manageable. It is a hopeful new option for those with advanced prostate cancer found to be both safer, and easier to take compared to other injectable hormone therapies.