Bayer's blockbuster Alpharadin may roil fast-changing prostate cancer field

The experimental prostate cancer drug Alpharadin took center stage at the big EMCC meeting in Stockholm, with researchers reporting that they had suspended a registration trial after castration-resistant patients taking the alpha radiation drug lived significantly longer with less pain and fewer side effects. The independent monitoring board called for the early unblinding of the study so that everyone in the study could benefit from the therapy and analysts were quick to dub the treatment a potential game changer in the fast-changing prostate cancer market.

Investigators for Algeta and Bayer say that the treatment extended overall survival by 44 percent, with patients living a median average of 14 months compared to 11.2 months in the placebo arm. The treatment also delayed painful bone metastases. Alpha particles can demolish cancer cells far more effectively than standard radiation therapies. Because they have a very narrow target range, down to a few millionth of a meter, it's possible to pinpoint tumors without devastating healthy tissue - significantly easing side effects. "This appears to be an important study using a highly targeted form of radiation to treat prostate cancer that has spread to the bones," says Professor Gillies McKenna, Cancer Research UK's radiotherapy expert.

Just weeks ago the FDA announced that the agency would put Alpharadin on the regulatory fast track, slashing six months off of the review time as analysts widely expestpoct a swift approval. The drug is expected to hit peak sales of $1.7 billion on all indications. Bayer signed up for a global development deal on Alpharadin back in 2009. Algeta hung on to an option for up to 50/50 co-promotion and profit-sharing in the USA.

TheStreet's Adam Feuerstein, who has been closely following Exelixis's experimental prostate cancer therapy cabozantinib, astutely notes that the new data on Alpharadin could spell trouble for the rival program. Exelixis wants to mount a pivotal study on endpoints related to pain and bone scan resolution. Regulators, Feuerstein observes, may now insist that the investigators also focus on overall survival--a classic goal in registration studies for cancer drugs--now that Alpharadin has set the bar higher. The new data could also complicate things for Amgen, which is planning to seek an FDA OK to use Xgeva to delay the spread of prostate cancer to the bone without supporting data on added survival times.

- see the Bayer release
- read the BBC story
- here's the story from TheStreet