Allos Therapeutics Inc., a Westminster-based biopharmaceutical company, announced Tuesday it would discontinue a brain-cancer drug it had spent years developing.
The drug, Efaproxyn, did not significantly outperform a control group in survival rates for women with brain cancer originating from breast cancer. Efaproxyn was used in conjunction with radiation and averaged a survival rate of 8.5 months – about a month longer than the control group, said company spokeswoman Jennifer Neiman.
The drug performed similarly in earlier clinical trials, but the control groups in those studies had an average survival rate of only 4.5 months. The most recent Phase 3 study used a test group more than three times larger than the earlier study, Neiman said.
Phase 3 is the final step in testing before a drug is submitted for approval by the U.S. Food and Drug Administration.
Since oxygen-deprived cancer cells are more resistant to radiation, Efaproxyn aimed to improve the effectiveness of radiation by depriving red blood cells of oxygen, which was intended to increase oxygen in the cancerous region and make radiation more potent.
“(The drug) failed to act as a radio sensitizer in the manner in which it was intended,” Neiman said. “The hypothesis for testing the drug was not realized.”
Allos will now focus its efforts on two other cancer-fighting drugs, one focused on blood cancer and the other on solid tumors.
The more-developed of the two drugs, Pralatrexate, known as PDX, looks to kill a rare, deadly blood cancer known as peripheral T-cell lymphoma.
PDX works by inhibiting an enzyme needed for DNA construction. Not being able to replicate DNA contributes to the death of the cancerous cells, Neiman said.
Staff writer Zach Fox can be reached at 303-954-1755 or zfox@denverpost.com.
