Bayer and Norwegian partner Algeta are celebrating after a late-stage trial of their prostate cancer drug Alpharadin was stopped early due to impressive overall survival data.

Bayer says the Phase III trial evaluating Alpharadin, the first in a new class of 'alpha-pharmaceuticals' which is based on radium-223, in patients with castration-resistant prostate cancer and symptomatic bone metastases met its primary endpoint by significantly improving overall survival - 14.0 months versus 11.2 months for placebo. The complete results from the study, which also revealed that the safety and tolerability of Alpharadin were consistent with previous Phase I and II findings, will be presented at an upcoming scientific meeting.

Based on a recommendation from the independent data monitoring committee, the study will be stopped and patients on the placebo arm will be offered treatment with Alpharadin. Noting that around 90% of men with advanced prostate cancer have bone metastases, "the main cause of disability and death in this disease,” Chris Parker of the Institute of Cancer Research and Royal Marsden Hospital (and principal investigator for the trial), noted that the disease has a poor prognosis and treatment options are limited.

He added that based on the "observed survival benefit and its safety profile, Alpharadin may become an important treatment”. The drug was expected to be submitted to regulators next year but Bayer said it is evaluating the filing strategy for the treatment based on the IDMC's recommendation.

Investors in Algeta, a Norwegian biotech, are particularly pleased with the news and its shares shot up this morning. At about 9.35 am (UK time), they were worth 54 Norwegian kroner, up 37%.