STOCKHOLM |(Reuters) - Roche's bone strengthening drug Boniva is as good for pain relief as single dose radiotherapy in patients whose prostate cancer has spread to their bones, according to data from a late-stage trial released on Sunday.
Trial investigators said the level side effects of Boniva -- known generically as ibandronate (IB) -- were also comparable with radiotherapy, suggesting it could offer an alternative option for advanced cancer patients suffering pain.
Bone metastases, or secondary tumors in the bone, are common in many advanced cancers and "are a serious problem for men with prostate cancer," said Peter Hoskin a professor clinical oncology at University College, London, who presented the data at the European Multidisciplinary Cancer Congress (EMCC) in Stockholm on Sunday.
"We found that using IB was as good as single dose radiotherapy in controlling pain," he said.
Boniva is one of a class of osteoporosis drugs known as bisphosphonates, which work by sticking to calcium and binding to it. Others in the same class include Novartis's Zometa and Merck's Fosamax.
They prevent bone loss by inhibiting the activity of cells that break down bone, called osteoclasts.
For the late stage, or Phase III, trial, researchers gave 470 patients with painful secondary tumors in the bone either a single dose of radiation or an intravenous infusion of Boniva.
Patients reported their main site of pain when they began the trial, and then again at four, eight, 12, 26 and 52 weeks after treatment.
Those who had not responded to the first treatment at four weeks crossed over to the alternative therapy and received their second treatment no later than week eight.
Pain levels were measured at four and 12 weeks by analysing how many painkillers patients were needing to take, and by scoring their reported pain levels using two standard methods called the WHO pain ladder and the Mercadante method.
"Although there were more patients in the IB group with worse Mercadante scores at four weeks who needed re-treatment, at six and 12 months, there was no long-term difference in pain relief between the two groups," Hoskin said
The median survival of the four groups was 11.8 months for those on radiotherapy only, 11.4 months for those on the Roche drug only, 12.7 months for those on radiotherapy then Boniva, and 16.8 months for those on Boniva and then radiotherapy.
But Hoskin said it was too early to draw any conclusions from these data about the drug's relative impact on survival in this group of patients.
"We hope to analyze these survival differences further in the hope that it can give us... pointers as to how and whether we should use a combination of treatments," he said. "Currently we are unsure about the optimal timing and scheduling of treatment for these patients."
For now Hoskin said Boniva, which is also sold under the brand name Bonviva, would be addition to the arsenal of other possible treatments for cancer pain and could potentially be useful in other types of the diseases such as breast cancer, where secondary bone tumors are also common.
(Editing by John Stonestreet)