According to another study presented at the European Multidisciplinary Cancer Congress (EMCC) in Stockholm this weekend, the bone-strengthening bisphosphonate ibandronate (Boniva®) seems to work just as well as radiotherapy for the management of pain associated with prostate cancer that has metastasized to the bones.
Reuters quotes Prof. Peter Hoskin — a clinical oncologist at University College, London — as saying that, “We found that using [ibandronate] was as good as single dose radiotherapy in controlling pain.” Prof. Hoskin presented the data on Sunday at the EMCC.
In this randomized, Phase III clinical trial, a total of 470 patients initially received either a single dose of radiation or a single intravenous infusion of ibandronate. All patients had to have significant pain associated with prostate cancer that had metastatized to their bones. The patients were asked to provide information about the primary site of their pain at time of first treatment and then again at 4, 8, 12, 26, and 52 weeks post-treatment. Patients who had failed to respond to their initial treatment after 4 weeks were crossed over to the alternate therapy and were given the second therapy before the end of week 8 of the study.
The following data are provided in the Reuters report:
- More patients in the ibandronate group than in the radiotherapy group appeared to need, and were given, the alternate treatment after 4 weeks.
- At 6 and 12 months of follow-up, there was no long-term difference in pain relief between the two groups.
- Average (median) survival of patients in the four groups was
- 11.8 months for those given radiotherapy alone
- 11.4 months for those given ibandronate alone
- 12.7 months for those given radiotherapy followed by ibandronate
- 16.8 months for those given ibandronate followed by radiotherapy
There are no data about side effects of the two therapies in the Reuters report, but treatment with sbisphosphonate has been associated with several different side effects, most particularly a condition known as osteonecrosis of the jaw (ONJ).
The survival data reported above have not yet been analyzed for statistical significance. It would be inappropriate — as yet — to try to draw any conclusions about the relative benefits of combination therapy in a specific order as compared to single modality therapy.
Ibandronate is a bisphosphonate similar to zoledronic acid (Zometa®), which is widely used to prevent fractures and other skeletal-related events (SREs) in men with prostate cancer and other forms of cancer that metastasize to bone. However, ibandronate is given as a once-yearly injection as opposed to the more frequent injections of zoledronic acid. It should be noted that a once-yearly injection of zoledronic acid is available under the brand name Reclast®. The “New” Prostate Cancer InfoLink is not aware of data from any large clinical trial(s) of Reclast in the management of SREs or pain for men with prostate cancer.