The Food and Drug Administration has very recently approved a new pharmaceutical, Xofigo, for the treatment of late stage prostate cancer. The drug is a new hope for the treatment of a kind of cancer that affects more than 50% of men over 55 and over 90% of men over 75 years of age. It is intended for men whose cancer has spread after receiving common surgeries relevant to prostate cancer.
The drug was actually approved three months ahead of schedule, an anomaly in the general course of drug approval by the FDA. Approval often takes years of trials and many delays. It was put on the priority list of drugs under FDA review, it being apparently largely side effect-free. There are also no other alternative treatments that currently exist.
Prostate Cancer Common Killer
Prostate cancer is one of the most common forms of cancer, with nearly 30,000 males estimated to die from complications due to the disease this year alone. It forms in men in the hormone-producing gland in the reproductive system and, if not removed, often spreads to other organs and bones. Testosterone stimulates the prostate tumor’s growth and the cancer, once it spreads to bones and other organs especially in late stages or in fatal cases or cases that were diagnosis too late, is quite often fatal.
The spread of prostate cancer to the bones is an inevitable development of metastatic and castration resistant prostate cancers particularly. The cancer spread is very hard to predict, however, and doctors use various methods to track the growth of prostate tumors to see if drugs like Xofigo, or surgeries like the often inevitable prostatectomy, will be necessary.
A large majority of prostate cancers are testosterone-dependent, which is why they appear on the the very gland in the prostate where the hormone is produced. Hormone-dependent cancers of this kind tend to be refractory and usually spread to other organs within two to three years of initializing radiation treatment. The vast majority of men with prostate cancer will die due to metastatic spread of the cancer from the prostate while few or none succumb to symptoms due to a disabled prostate alone.
How Xofigo Works
Xofigo is a radiopharmaceutical that binds to the minerals within the bone material itself, delivering radiation directly to the tumor or tumors therein. It uses alpha radiation from radium-223 to kill cancer cells. Radium-223 resembles calcium in its chemical composition, which allows the radium-223 in Xofigo to be absorbed by the bone and therefore to do its work within the tissue itself, which makes the drug very different and very effective. Other radiation treatments attempt to blast tumors from outside the actual cancerous tissue.
The half life of radium is just a few days, a relatively short period which makes for a fairly particular treatment regimen, especially since not all of the radium, or even the majority of it, is successfully absorbed by the bone tissue. However, any radium that is not absorbed is processed by the gut and excreted harmlessly from the body.
Trials and Side Effects
The drug’s effectiveness was evaluated in a clinical trial of 922 men with symptomatic castration-resistant prostate cancer that spread to bones but not to other organs. Patients were randomly assigned to receive Xofigo and others were given a placebo. The drug was given intravenously over four to six months in the trial.
Initially, however, the drug was discovered by showing promising results in a trial treatment for breast cancer in 2012. It showed significantly reduced levels of certain kinds of peptides, which indicate an increased rate of bone turnover. When tested on men with prostate cancer the results were vastly improved, with the most common side effects being nausea, diarrhea, vomiting and swelling of the leg or foot. There were some abnormalities, like a reduction in the number of red blood cells and platelets in the blood that could indicate a risk for anemia, but side effects were generally quite minimal.
In the end, and especially when compared to other drugs, Xofigo was a great success with very few life-threatening or debilitating side effects. The drug increased the life expectancy of prostate patients by as much as 20% on average, a big win for these cancer patients whose options, outside of a prostatectomy, are often few.
The drug will be available this year at cancer hospitals and other major hospitals throughout the United States. For patients with late stage castration-resistant prostate cancer the pharmaceutical offers a new hope for life expectancy and quality of life.