|Photo By HQuality via Shutterstock|
Johnson & Johnson and Pfizer have new drugs that promise to slow down the spread of prostate cancer for high-risk men. In two separate studies, J&J’s apalutamide and Pfizer’s Xtandi delayed by more than 70 percent the worsening of the most common tumor.
Taking the medication could be an alternative for males whose cancer is progressing, but it is still considered early-stage because it is localized to their prostate, Bloomberg reported. For most of the men in that situation, the watchful waiting is agonizing because the level of a protein is tied to the progression rises in their blood.
If there is no clear evidence that cancer has spread to other body parts, they cannot be treated with drugs that are approved for later stages of cancer.
40 months before metastasizing
For its Spartan study, J&J tracked 1,207 men with tumors that no longer responded to hormone therapy. Their castration-resistant prostate cancer led to a rapid hike in levels of a specific antigen in their blood. The men were treated with apalutamide for 40 months. It took 3.3 years before cancer metastasized, while those in the placebo group took only 16 months.
The J&J prostate drug will fill in a big unmet need, Eric Small, a professor of medicine at the University of California in San Francisco, said. The leader of the Spartan study pointed out that there is currently no approved standard of care for castration-resistant prostate cancer.
The Spartan study was held at 332 institutions worldwide. The men enrolled in the research were males whose prostate-specific antigen scores were rising rapidly while on androgen deprivation therapy and were at a significantly higher risk of developing metastases or dying.
The rate that the median PSA doubled for the men in the J&J study upon entry was about 4.5 months for the members of the apalutamide and the placebo groups, Uro Today reported. The researchers said that apalutamide was well tolerated by the patients, but 10.7 percent discontinued the medication because of adverse events.
The next step for the authors is to identify the patients who benefited the most from apalutamide. They will then analyze the molecular and circulating markers from blood samples. The researchers also plan to look in greater depth at the outcomes reported by the patients to evaluate the trial success or failure from the perspective of a patient.
Standard of care for advanced prostate cancer
Pfizer and Astellas Pharma said that Xtandi is already the standard of care for advanced prostate cancer that does not respond to hormone therapy and has spread. More than 75,000 patients in the US have been treated with Xtandi.
The 1,400 patients with early-stage prostate cancer who were given Xtandi survived for an average of 36 months before the cancer spread. Those given a placebo survived an average of 14.7 months. The Xtandi study was presented at the yearly Genitourinary Cancers Symposium in San Francisco.
In the US, there are about 65,000 men who live with non-metastatic prostate cancer that does not respond to hormone therapy. About 20,000 men are diagnosed with the condition each year.
However, Xtandi will cost them more than $10,000 a month for a 30-day supply. Analysts estimated sales of Xtandi will earn for Pfizer $1 billion in 2020.
Mace Rothenberg, the chief development officer for oncology of Pfizer, said that Xtandi will be a catalyst for change. The prostate cancer drug is going to provide a much stronger foundation, rationale, and level of evidence for treating men with non-metastatic prostate cancer that does not respond to hormone therapy, she said.
Delaying visibility of the cancer
Dr. Maha Hussain, the lead investigator of the Xtandi study, said the findings from the trial are quite impressive in terms of delaying the visibility of cancer. The current treatments for these types of patients are not life-prolonging or significantly impactful. There is a high unmet need for delaying the development of metastases and progression to advanced cancer, she said, Reuters reported.
Hussain, who is from the Robert H. Lurie Comprehensive Cancer Center of Northwestern University, said that the data is very likely practice- changing.
Albert Boula, the chief operating officer of Pfizer, pointed out that the treatment opportunities are almost double than the current indication. He added that the financial interest is larger because of the longer duration of the treatment.
Pfizer said that the adverse side effects of Xtandi were similar to those reported in past trials of more advanced cancer patients. The side effects caused about 9 percent of the Xtandi patients to discontinue the treatment. The major adverse cardiovascular events, such as heart attacks, were reported in 5 percent of Xtandi users.
J&J and Pfizer have requested approval for the two drugs from the US FDA and the European Medical Association.
[메디컬리포트=Vittorio Hernandez 기자]