New drug reduced PSA levels by more than half in patients with androgen-independent disease.
CHICAGO—Sagopilone, the first in a new class of microtubule stabilizer drugs, may be effective as part of first-line treatment for men with metastatic androgen-independent prostate cancer (AIPC), researchers say.
In a phase II trial, patients with metastatic AIPC received sagopilone 16 mg/m2 IV over three
hours every 21 days and prednisone 5 mg orally twice a day continuously. The treatment was repeated for up to six cycles.
Of the 37 patients who were evaluated, the majority showed positive results in the reduction of their PSA levels, according to investigators. During the three-month trial, 13 men (35%) had a greater than 50% reduction in their PSA levels. Twenty-three men (62%) showed a 30% reduction and one man, who had radiographically measurable disease, showed complete response according to RECIST criteria, the researchers reported. Many of the patients remain on treatment.
Sagopilone is a synthetic compound that inhibits the growth and the spread of malignant cells. It is similar to docetaxel, which has been the gold standard for treating meta-static APIC.
Docetaxel, however, is not a cure and not all patients benefit from it, said principal investigator Tomasz Beer, MD, associate professor of medicine and the director of the Prostate Cancer Research Program at the Oregon Health & Science University School of Medicine in Portland. He and Julie Graff, MD, a fellow in hematology and medical oncology at OHSU, presented the study findings here at the American Society of Clinical Oncology annual meeting.
“We are hoping this will be a better mousetrap than the current drugs,” Dr. Beer said. “It may need to go with another drug. It is an active drug and now we need to figure out how it can best help patients.”
So far, the side effects that have been reported are neuropathy and fatigue, which occurred in almost 25% and 8% of patients, respectively, the study found. In addition, some patients experienced diarrhea and dizziness.
This ongoing trial has finished enrolling patients, who now are being followed up to verify the level of drug activity and tolerability.
“This is a new drug with a significant amount of activity, and we hope to move it forward and hope it will create another option for men with an incurable form of prostate cancer,” Dr. Beer noted.
Sagopilone is an experimental drug made by Bayer Healthcare Pharmaceuticals, which is funding this research.