Drug companies scored a string of recent successes against advanced prostate cancer, ending a long drought during which there seemed to be few weapons to combat the disease.
In the latest evidence of progress, researchers reported Tuesday that an experimental drug from the San Francisco-based Medivation extended survival by nearly five months in a 1,199-patient study.
A second drug, a radiation-emitter being developed by Bayer and Algeta of Norway targeting prostate cancer that has spread to the bone, improved survival by nearly three months in a 922-patient study.
Results of both trials were released ahead of their presentation at the American Society of Clinical Oncology's Genitourinary Cancers Symposium being held this week in San Francisco.
If the drugs win approval soon from the US Food and Drug Administration (FDA), it would mean that after decades of frustration, the pharmaceutical industry will have turned out five new treatments for advanced prostate cancer within just three years.
Those already approved within the past two years include Dendreon's Provenge, Jevtana from Sanofi and Zytiga from Johnson & Johnson.
The pharmaceutical industry is increasingly looking for ways to speed development of new drugs -- including the realization that closer ties to academic researchers can aid in discovery. Medivation's compound, called MDV3100, is notable for how it was developed -- largely in the research laboratory of Charles Sawyers, a scientist at Memorial Sloan-Kettering Cancer Center with a track record in drug discovery.
Medivation expects to file its application with the FDA this year. Assuming all goes well, the drug could be on a track to win approval about five years after it was first tested in people. "By any standard, that would be considered very, very quick," according to David Hung, Medivation's CEO.
Also helping progress is a growing understanding of the biology of prostate cancer, a disease fueled largely by the male hormone testosterone.
The new treatments are not cures, and individually, their impact on survival is modest -- in clinical trials each added a median of roughly three to five months to patients' lives. Their high cost is likely to complicate adoption for many patients. Provenge, for instance, costs $93,000 for a course of three treatments, while Zytiga's price is about $5,000 for a monthly supply of pills.
But some researchers believe that the options will lead to new strategies where the drugs are used either sequentially or in combination to significantly extend survival. The new treatments are expected to cause the worldwide market for prostate cancer therapies to surge to $4 billion by 2015, according to Morningstar, up from about $1 billion currently.