FDA Questions Olaparib Trial Data
AstraZeneca Plc's proposed ovarian cancer drug, olaparib, “has put up some pretty lofty expectations,” according to Damien Conover, an analyst at Morningstar. The U.S. Food and Drug Administration (FDA), however, claims positive data collected for olaparib is questionable.
The experimental drug, which will take the name Lynparza if approved, showed an 83 percent reduction in the risk of disease progression and is claimed to have strong potential as a maintenance therapy option for those with relapsed ovarian cancer tumors that have responded completely or partially to platinum-based chemotherapy.
Olaparib is designed to block the activity of Poly (ADP-ribose) polymerase (PARP), which is an enzyme that aids cell repair.
Ovarian cancer is the fifth leading cause of cancer death in women. There is an estimated 22,000 new cases of ovarian cancer diagnosed in the United States in 2014. Additionally, there have been about 14,270 deaths as a result of ovarian cancer in the US in 2014.
Olaparib is aimed at women with certain hereditary BRCA gene mutations that cause 10-15% of ovarian cancer cases, or about 2,000 cases a year in the United States. However, the US Food and Drug Administration is questioning the validity and reproducibility of AstraZeneca’s olaparib studies.
Olaparib Clinical Trial Produces Questionable Results
In the olaparib clinical trial, patients had a seven-month median improvement in progression-free survival, meaning the patients generally lived seven months without the disease getting worse. Patients with the aforementioned mutations are more likely to respond to chemotherapy, so they will undergo multiple rounds.
Between rounds, patients take several periods to recover from the side effects of the treatment. Olaparib is claimed to extend the patient’s recovery time in between treatments; however, the FDA review states that the study results are questionable because AstraZeneca collected some of the data retrospectively using archived blood samples.
It seems AstraZeneca used a control arm that performed abnormally poorly. The review adds that there was no difference on overall survival between the two treatment arms, which calls into question “the reliability of the estimation of treatment effect.”
AstraZeneca shares recently fell 1.8 percent to 43.89 pounds on the London Stock Exchange, yet AstraZeneca believes the sales of olaparib could reach $2 billion a year.
Olaparib’s most common side effects in the study were:
- Abdominal pain