June 25 (UPI) -- A new combination therapy has shown promise in effectively fighting prostate cancer, new research shows.
Two targeted treatments reduced PSA levels in patients with prostate cancer and had fewer side effects than traditional therapies, according to a study presented Tuesday at the Society of Nuclear Medicine and Molecular Imaging.
"The initial results of this phase I dose escalation study show that the combination targeted treatments were well tolerated together, with no increase in toxicity from 177Lu PSMA 617, and an apparent high efficacy in men who have already had extensive treatments," said Louise Emmett, associate professor at the University of New South Wales in Australia and study author, in a news release.
After enrolling 16 men with progressing metastatic castrate-resistant prostate cancer. The men took six doses of the targeted radionuclide therapy 177Lu PSMA 617 through six weeks.
Then the researchers decided to add another therapy to the treatment, tumor-specific radiation sensitizer idronoxil, or NOX66.
For 10 days, half of the men took an additional 400mg NOX66 each day, while the other eight men received additional doses of 800mg NOX66 each day.
For close to 70 percent of the patients, their PSA levels fell by over 50 percent. PSA levels went down by 62.5 percent for first half of men taking 400mg NOX66 and 75 percent for the half taking 800mg. Only 31 percent of the patients reported fatigue, pneumonitis and other side effects.
The American Cancer Society has estimated 174,650 cases of prostate cancer will be diagnosed in 2019, causing more than 31,000 deaths.
"We are now in a dose expansion phase II stage to further evaluate toxicity and efficacy. This raises the very important possibilities of combining tumor-targeted therapeutic agent to gain synergistic treatment effects without an increase in side effects," Emmett said.