Abbott Laboratories' Atrasentan (ABT-627) Showed Delay in Progression of Hormone-Refractory Prostate Cancer in Phase II Study

15-May-2001

Data from a Phase II study presented today at the annual meeting of the American Society of Clinical Oncology (ASCO) showed that atrasentan (ABT-627), Abbott Laboratories' investigational endothelin-A receptor antagonist, significantly delayed the progression of hormone-refractory prostate cancer.

Results from the randomized, double-blind, placebo-controlled study in 244 men with metastatic prostate cancer showed that patients receiving an oral dose of 2.5 mg or 10 mg of atrasentan once daily experienced a longer median time to clinical progression of the disease, 184 and 196 days, respectively, compared to 129 days for patients receiving placebo (p<0.05). Clinical progression was defined as a worsening of the disease to a point that required intervention, pain requiring opiate therapy, or the appearance of new bone lesions that would indicate that the cancer had spread further.

"This research is promising because there are limited treatment options for prostate cancer that no longer responds to hormone therapy," said Michael Carducci, M.D., assistant professor of oncology and urology at Johns Hopkins University Medical Institution, and lead investigator in the trial.

According to results from the study, patients receiving the 10 mg dose of atrasentan, compared to those receiving placebo, demonstrated a significant median delay (155 days vs. 71 days) in the rise in the levels of prostate-specific antigen (PSA) in the blood (p<0.05). A rising level of PSA in the blood is used as a marker that may indicate the development or spread of prostate cancer. Measures of other markers that may indicate the spread of prostate cancer, including enzymes such as acid phosphatase, LDH and alkaline phosphatase, were also lower with use of atrasentan.

The most common adverse events, with the 10 mg dose of atrasentan vs. placebo, were peripheral edema (35 percent vs. 14 percent), rhinitis (29 percent vs. 13 percent) and headache (20 percent vs. 10 percent). These adverse events were mild to moderate in severity and were associated with few discontinuations.

"These data point to the potential for atrasentan in the treatment of hormone-refractory prostate cancer," said Joel Nelson, M.D., professor and chairman of urology, University of Pittsburgh Medical Center, senior investigator in the trial and lead researcher in preclinical studies. "The effect of atrasentan on key biochemical markers shown in this study provides a basis to understand its affects on prostate cancer and how it delays the clinical progression of the disease.”

"We are committed to the development of innovative cancer compounds and are excited to be sharing data that show promise for advanced prostate cancer," said Perry Nisen, M.D., divisional vice president, Global Oncology Development at Abbott Laboratories. "Endothelin receptor antagonists have traditionally been studied for cardiovascular conditions and Abbott's research is the first to evaluate this class of drug in oncology. These Phase II results show that this compound someday may provide an option for end-stage prostate cancer."

Atrasentan is currently beginning Phase III clinical trials in patients with hormone-refractory prostate cancer.

https://www.chemeurope.com/en/news/3158/abbott-laboratories-atrasentan-abt-627-showed-delay-in-progression-of-hormone-refractory-prostate-cancer-in-phase-ii-study.html