New Hope for Men with Prostate Cancer in Biochemical Relapse
Biochemical relapse is a challenging time for men with prostate cancer. We know it’s a time when the cancer is becoming active again, because the PSA blood test begins to rise after a patient has had prostate directed treatment (such as surgery, radiation, focal therapy or some combination), but it is not yet visible in an organ such as bone, lung or liver. During biochemical relapse men do not have symptoms from the cancer, however the risk is that at some point the cancer will start to grow in an organ in the body. That is called a metastasis. Once a man has a metastasis then he is at risk of developing symptoms from the cancer.
Treatment for biochemical relapse varies and in some cases patients are cured, while others are not. The decision of when to start treatments to suppress testosterone, also known as androgen deprivation therapy, in these men is not always straight forward. However, once a man is on androgen deprivation therapy there will come a time when the cancer will start to grow despite this treatment. This is called castration resistance. Up until recently there were no FDA approved treatments for men with castration resistance if their cancer had not yet spread to other parts of the body (non-metastatic), however that has changed.
A New Treatment Option
Now FDA approved, apalutamide (ErleadaTM) is a medication taken by mouth once daily, that can delay the time to a metastasis developing and decrease the risk of metastasis or death in men with non-metastatic, castration-resistant prostate cancer. It blocks the androgen receptor on a cancer cell.
This medication was evaluated in the SPARTAN study, which was presented at a major cancer conference in February 2018, Genitourinary ASCO1 and published in the New England Journal of Medicine2. In the study apalutamide (ErleadaTM) was compared with placebo (a pill with no expected effect) in men already being treated with androgen deprivation therapy whose cancer had progressed and developed castration resistance. Men had to be considered at high risk from their cancer based on the rate of rise of the PSA test, and they could not have any cancer detectable on radiographs other than very small lymph nodes in the pelvis.
The primary end point of the clinical study was metastasis-free survival, which was defined as time to development of a distant metastasis (new bone, soft tissue or enlarged lymph node outside of the pelvis), or death due to any cause, whichever came first.
Men who were treated with apalutamide (ErleadaTM) had a much longer metastasis-free survival (40.5 months) than those who had placebo (16.2 months). The risk of metastasis or death was 70 percent lower in those men treated with apalutamide (ErleadaTM).
Overall the drug was well tolerated with the most common side effects being: fatigue, high blood pressure, rash, diarrhea, nausea, weight loss, joint aches, fall, hot flush, poor appetite, fracture and swelling of the limbs.
Based on this, the FDA approved apalutamide (ErleadaTM) for the treatment of men with non-metastatic castration-resistant prostate cancer, giving men another treatment option to consider.
References:
1. Small E, Saad F, Chowdhury S, et al. SPARTAN, a phase 3 double-blind, randomized study of apalutamide (APA) versus placebo (PBO) in patients (pts) with nonmetastatic castration-resistant prostate cancer (nmCRPC). J Clin Oncol 36, 2018 (suppl 6S; abstr 161)
2. Smith MR, Saad F, Chowdhury S, Oudard S, Hadaschik BA, Graff JN, Olmos D, Mainwaring PN, Lee JY, Uemura H, Lopez-Gitlitz A, Trudel GC, et a. for the SPARTAN Investigators. NEJM Feb 8, 2018 DOI: 10.1056/NEJMoa1715546