Prostate cancer drug passes hurdle
A "triple whammy" drug that tackles advanced prostate cancer in three different ways has passed its first hurdle.
Scientists reported promising early trial results on galeterone, which is designed to treat cancer that no longer responds to hormone therapy.
The drug reduced levels of Prostate Specific Antigen (PSA), a prostate cancer blood marker, by 30% or more in around half of patients.
Eleven patients had PSA reductions of 50% or more, and in some there was significant shrinkage in tumour size. A total of 49 patients took part in the Phase I study, which primarily looked at safety and dosing levels.
All had "refractory" or "castration resistant" cancer that has ceased to respond to hormone therapy aimed at preventing tumours being fuelled by testosterone.
Currently there is little doctors can do to help prostate cancer patients who progress to this stage.
Galeterone works in three ways, by blocking "receptor" proteins that respond to testosterone, reducing the number of receptors in tumours, and targeting an enzyme linked to hormone pathways called CYP17.
Trial leader Dr Mary-Ellen Taplin, from Harvard Medical School in the US, said: "Because currently available therapeutic options to treat castration-resistant prostate cancer are limited, often poorly-tolerated and may fail because of resistance, patients are in urgent need of new safe and effective treatments. These Phase I galeterone data, demonstrating minimal toxicities, improved PSA response and a reduction in tumour size, are exciting for those of us in the medical community treating this life-threatening cancer."
The findings were presented at the annual meeting of the American Association for Cancer Research (AACR) in Chicago.
A larger Phase II trial focusing on the drug's effectiveness is planned later this year.