Raoul S. Concepcion, MD
Amid an expansion of therapeutic options for men with advanced prostate cancer, evidence is building that introducing recently developed agents and regimens earlier in the treatment timeline can benefit patients in several disease settings.
That was the central take-home message from an OncLive Peer Exchange® panel of experts who participated in a roundtable entitled “Treatment of Advanced Prostate Cancer: Expert Evaluations on Recent Articles and Studies.” The panel included specialists in urology and medical oncology.
“Recent and emerging data are providing signals as to the benefits of early treatment in patients who have high-grade prostate cancer,” noted Raoul S. Concepcion, MD, who served as moderator for the discussion. The panelists explored the results of several studies that addressed questions related to the treatment of patients with or without frank metastatic disease. In addition, the panel looked at mechanisms of resistance to therapy and the potential impact of early treatment.
Repeatedly, the discussion returned to the fact that there is an array of useful drugs available for these patients and, as Michael Fabrizio, MD, said, “all of these drugs need to be used earlier in the spectrum of the disease. The key is to treat these patients earlier, recognize advanced disease earlier.”
In light of the potential options, “defining your goals of treatment” for each patient is an essential step, noted Jorge A. Garcia, MD. Doing so will help clinicians determine “which is the best agent for that particular patient,” he said.
The panelists cautioned that it is probably important not to be overly focused on which patient has metastatic disease and which patient has disease that has not metastasized. All of these patients “have systemic disease and that’s really the crux of the issue,” Charles J. Ryan, MD, said. Garcia reinforced that comment, adding, “I think all of us recognize the fact that M0 patients do have metastatic disease,” although current technology “is not allowing us to detect that metastatic disease.”
Initiating Enzalutamide and Abiraterone
A recent study in The New England Journal of Medicine reported that patients with castration-resistant prostate cancer (CRPC) with androgen report (AR) splice variant 7 messenger RNA (AR-V7) detected in their circulating tumor cells had no clinical benefit whatsoever from either enzalutamide or abiraterone acetate, two therapies directed at the AR.1
Michael Fabrizio, MD
The study is important, Garcia said, in relation to biomarker development for prostate cancer. The study points to “one of the first examples of truly personalized medicine that could come to the forefront” in CRPC, explained Judd W. Moul, MD.
However, the relevant technology is not commercially available at the present time. So the findings of this study cannot be brought into the clinic at this time.
As to when to start enzalutamide or abiraterone, current indications are that, “the earlier intervention, the better,” for patients with chemotherapy-naïve CRPC, said Ryan. “If you’re waiting for a patient to suffer and have pain or complications, you’re waiting too long.” With some patients, those for whom PSA levels do not decline upon receiving AR-targeting therapy, the drugs might soon be stopped. “I really believe these agents that target AR must, with a big capital MUST, lower your PSA,” Garcia said. “I typically go 12 weeks. If I haven’t seen a PSA decline at all, they’re off the therapy and on to something else,” added Ryan. “And, actually, we now know that these might be the patients with the V7.”