THE "NEW" PROSTATE CANCER INFOLINK

We promised to give a summary of other interesting prostate cancer-related data presented at the Genitourinary Cancer Symposium out in San Francisco. Here is an an initial commentary on some of the presentations that seemed (to us) to be of particular interest:

• Gray et al. offered new data suggesting that while the early side effects from use of proton beam radiation therapy (PBRT) may be milder than those from intensity-modulated radiation therapy (IMRT), the longer-term side effects of the two forms of treatment are, in fact, similar. They call for a randomized, controlled trial of the two forms of therapy. However, Zelefsky et al. presented data showing that image-guided radiation therapy (IGRT) has a significantly lower risk for side effects than IMRT without image guidance, so maybe what we really need is a trial of PBRT vs. IGRT.

• Slovin et al. gave an update on early clinical trials on the use of ipilimumab in the management of metastatic, castration-resistant prostate cancer  -(mCRPC) — but what we are really waiting for are the results of the ongoing, major, Phase III trials of this drug in mCRPC.

• Initial data from the STAMPEDE trial (presented by James et al.) has shown that adding celecoxib (Celebrex^®) to initial hormone therapy for men with metastatic or high-risk non-metastatic prostate cancer has no apparent impact on survival, and accrual to this arm of the STAMPEDE trial has been terminated, although other elements of the STAMPEDE trial are continuing.

• Another small (single-institution), randomized, placebo-controlled clinical trial has suggested that the empiric use of antibiotic therapy prior to deciding whether a biopsy is necessary in men with an elevated PSA in otherwise asymptomatic patients is of no clinical benefit (see Large et al.). Whether a larger trial would have any value in confirming this result seems dubious.

• Rathkopf et al. reported data from the  Phase I stage of a Phase I/II trial of the investigational agent ARN-509 in men with mCRPC. ARN-509 appears to be safe and well tolerated on the basis of these very early results, and it showed potentially promising activity in treatment of late stage prostate cancer. The Phase II portion of the study is scheduled to enroll up to 90 patients with treatment-naïve, non-metastatic prostate cancer and mCRPC.

• There have been concerns that widespread community use of cabazitaxel (Jevtana^®) might be associated with a significant occurrence of serious side effects previously reported in the Phase III TROPIC study that led to the approval of cabazitaxel. A report by Bahl et al. on early access use of cabazitaxel in the UK has indicated that severe toxicities associated with the use of cabazitaxel have, in fact, been rare. However, it should be noted that in the UK this early access to cabazitaxel was really only available at major cancer centers with academic associations, so it may not be representative of what is happening in a US or other community setting.

• Fuller et al. offered data with 4 years of follow-up on their series of 59 patients treated with SBRT (CyberKnife radiation therapy). These results appear to be similar to those previously reported by two other groups, which is comforting. Quite why Fuller and his colleagues feel the need to describe their use of SBRT as “virtual HBR” is not at all clear, however.

• Hoppe et al. have reported a significant decline in potency rates at 2 years of follow-up among younger men (60 years of age and less) who were treated with PBRT for localized prostate cancer at the University of Florida Proton Therapy Institute. They state that this decline in potency rates is similar to those reported after radical prostatectomy. Yet again, this suggests that some of the historic claims for the quality of outcomes after PBRT may have been overblown.

• Liu et al. provided updated data from the Phase I clinical trial of the combination product AEZS-108 in the treatment of CRPC. It appears that AEZS-108 is well tolerated and has indicated significant antitumor activity in men with CRPC. Phase II trials of this investigational product are now being developed; it seems likely that the dose of this agent to be used in Phase II trials will be 210 mg/m².

• Goonewardene et al. described the development and early implementation of a community-based, prostate cancer survivorship initiative at their institution in the UK. Elements of this initiative include: a specially developed, web-based database that is monitored by specialist nursing staff; an annual survivorship conference, where patients have full access to heathcare professionals; and community-based services, including a specialized center where patients can meet with professionals ranging from dieticians to psychologists.

Filed under: Drugs in development, Living with Prostate Cancer, Management, Treatment