AstraZeneca (LON: AZN) announced that its oncology drug olaparib (Lynparza) led to clinically meaningful improvements in a Phase 3 study. The study focused on patients with germline BRCA-mutated high-risk human epidermal growth factor receptor 2 (HER2)-negative early breast cancer.
Some 5% of breast cancer patients have BRCA1 and BRCA2 mutations.
Clinical trial investigators have repeatedly demonstrated that olaparib is effective against BRCA-related cancer.
NEJM recently published a summary of the study, known as OlympiA, whose primary endpoint was disease-free survival. The study had 1,836 participants.
After a median follow-up period of 2.5 years, the 3-year invasive survival-free survival rate for olaparib recipients was 85.9% compared with 77.1% in the placebo group.
For patients who had received local treatment and standard neoadjuvant or adjuvant chemotherapy, olaparib led to a 42% reduction in invasive breast cancer recurrences, second cancers or death.
The drug also lowered the risk of distant disease recurrence or death by 43%.
Olaparib is currently FDA-indicated for several cancers including BRCA-mutated, HER2-negative metastatic breast cancer. In particular, the indication covers patients who have already been treated with neoadjuvant or adjuvant chemotherapy including those treated in a metastatic setting.
The recent clinical trial data could potentially support the use of olaparib as “a follow-on to all the standard initial breast cancer treatments to reduce the rate of life-threatening recurrence and cancer spread for many patients identified through genetic testing to have mutations in [BRCA1 and BRCA2] genes,” said OlympiA steering committee chair Andrew Tutt in a statement.
Adverse events from the drug were in line with other olaparib clinical trials. Nausea was the most common adverse event, affecting 57% of participants. Next in line were fatigue (40%), anaemia (24%) and vomiting (22%). Roughly 10% of patients who received olaparib discontinued treatment as a result of adverse events compared to 4% of placebo recipients.
Olaparib also fared well in the separate SOLO-1 trial. According to the five-year follow-up results from that study, olaparib prolonged progression-free survival in patients with newly diagnosed advanced ovarian cancer with a BRCA1 and 2 mutations.