Phase II Ovarian Cancer Drug Extends Progression-Free Survival
AstraZeneca has announced that their Phase II experimental drug, Olaparib, significantly extends progression-free survival for patients of a certain type of ovarian cancer. The company will present their findings at the American Society of Clinical Oncology (ASCO) 2011 annual meeting.
For the trial, 265 participants with platinum-sensitive relapsed serous ovarian cancer (SOC), all who had completed at least two courses of platinum-based chemotherapy and were in partial or complete response after the last regimen. SOC is a common and aggressive form of ovarian cancer.
Olaparib Extended Survival and Time of Disease Progression; Adverse Events Mild to Moderate
The women in the experimental group were given 400 milligrams, twice daily, of olaparib (AZD2281 / KU-0059436), a Poly ADP ribose polymerase (PARP) inhibitor. PARP is an enzyme that is crucial for cancer cell repair and inhibiting the enzyme causes the cancer cells to become damaged and die. It is also being studied for the treatment of certain types of breast cancer.
The researchers noted that women given olaparib had extended progression free survival (PFS) by nearly four months more than a placebo – 8.4 months compared to 4.8 months. A secondary endpoint of time to progression or TTP was also encouraging. Olaparib TTP was 8.3 months compared to 3.7 for the placebo group.
Dr. Jane Robertson, Medical Science Director for AstraZeneca said, "These results are encouraging as they suggest that olaparib may have a positive effect on PFS in women with serous ovarian cancer, and may be a valuable therapeutic option for this aggressive form of cancer."
"A well-tolerated antitumor agent that could be used for months or perhaps years as maintenance therapy after standard chemotherapy could be a big step forward and ultimately extend survival," Dr. Jonathan Ledermann, the study's primary investigator, said in a statement.
The most common adverse events reported by women taking olaparib were nausea, fatigue, vomiting, and anemia. These were classed as CTCAE grades 1 or 2 (mild to moderate).
A second Phase II ovarian cancer study is expected to report in late 2011.
An estimated 22,000 females in the United States were diagnosed with ovarian cancer last year and more than 13,500 were estimated to have died. Approximately 60 to 80% of all ovarian cancer cases are diagnosed as the serous cancer subtype, which is the most aggressive form of the disease. More than 75% of serous ovarian cancer cases are detected at stage III or later.
Ledermann JA, et al "Phase II randomized placebo-controlled study of olaparib (AZD2281) in patients with platinum-sensitive relapsed serous ovarian cancer (PSR OSC)" ASCO2011; Abstract 5003.