Health Canada has approved the expansion of the ovarian cancer drug Lynparza (olaparib) as maintenance therapy for adult patients with platinum-sensitive relapsed (PSR), high-grade epithelial ovarian, fallopian tube or primary peritoneal cancer who are in response (complete response or partial response) to platinum-based chemotherapy.

Previously, patients with these forms of cancers were only approved to take Lynparza if they had the breast cancer gene mutation – BRCA– which accounts for 20-30% of ovarian cancer patients. The new indication means all patients with PSR ovarian cancer can take Lynparza.

In a news release, Amit Oza, M.D., Head, Division of Medical Oncology and Hematology at Princess Margaret Cancer Centre in Toronto said, “This new indication will have a huge impact on women living with high-grade ovarian cancer – a population that has seen limited treatment advances over the past few decades.” Dr. Oza added, “While it is still important for women to know their BRCA status, more women with this disease, regardless of a BRCA mutation, will now have access to the significant clinical benefits of maintenance treatment that can control their disease for a longer period of time.”

The approval was based on 2 randomized clinical trials, the SOLO-2 trial, involving BRCA-mutated patients (n=295) and Study 19, involving both BRCA-mutated and BRCA wild type patients (n=265).

In the SOLO-2 trial, Lynparza led to a 70% reduced risk of disease progression or death and the median progression-free survival (mPFS) was 19.1 months compared to 5.5 months for the placebo group.

In Study 19, Lynparza led to a 65% reduced risk of disease progression or death and the mPFS was 8.4 months compared to 4.8 months for the placebo group. In a subgroup analysis involving only BRCA wild type patients in Study 19, the results were not as impressive. In that group, Lynparza reduced risk of disease progression or death by 46% and the mPFS was 7.4 months compared to 5.5 months with the placebo group.

The new approval comes with a caveat. According to AstraZeneca, marketing authorization for Lyparza to treat patients with BRCA wild type status, was granted pending the results of trials to verify its ‘clinical benefit’ in those patients.

Previously, Health Canada approved Lynparza as a maintenance treatment for PRC ovarian cancer patients with the BRCA mutation. For that indication, the drug also received a good review from the pan-Canadian Oncology Drug Review (pCODR) Expert Review Committee given the very impressive improvement in mPFS observed in that group of patients.

It will be very interesting to see what pCODR thinks of this new indication. Given the improvement in mPFS seen in BRCA wild type patients is only 2 months compared to the 14 month improvement observed in patients with the BRCA mutation, I would not be surprised to see the pCODR expert review committee being less receptive to supporting this expanded indication. Let’s hope the new data being collected by AstraZeneca is more impressive that the data from Study 19.

For more information about ovarian cancer, visit Ovarian Cancer Canada.