FDA Approves PARP inhibitor Zejula for treatment of recurrent ovarian cancer.

courtesy:www.multivu.com

The U.S.Food and Drug Administration today approved Zejula (niraparib) for the maintenance treatment of epithelial ovarian, fallopian tube or primary peritoneal cancer in adult patients who have already responded well to platinum-based chemotherapy.

Richard Pazdur, M.D., acting director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research and director of the FDA’s Oncology Center of Excellence said “Maintenance therapy is an important part of a cancer treatment regimen for patients who have responded positively to a primary treatment. Zejula offers patients a new treatment option that may help delay the future growth of these cancers, regardless of whether they have a specific genetic mutation.”

According to an estimate by the National Cancer Institute more than 22,000 women will be diagnosed with these cancers in 2017 and more than 14,000 will die of these diseases.

Zejula is the first poly ADP-ribose polymerase (PARP) inhibitor to receive FDA approval to use without testing for BRCA mutation. It acts by preventing DNA repair by blocking an enzyme in the repair pathway.

The drug is niraparib and will be sold under the brand name Zejula by the manufacturer Tesaro (Waltham, Mass.).

FDA approved Zejula following results of a Phase III ENGOT-OV16/NOVA randomized trial of 553 patients who have already responded well to platinum-based chemotherapy. In addition, the patients were also tested for BRCA mutation although it does not require BRCA mutation or other biomarker testing. 

The study looked at the time for which the patients remained free from tumor recurrence irrespective of their BRCA status. Patients with BRCA mutation on Zejula did not have any recurrence for 21 months vs. 5.5 months for the same patient population taking a placebo. Patients who do not have BRCA mutation (n=350) on Zejula had 9.3 months of disease free survival compared to 3.9 months for patients on placebo.

Thus, the drug is more effective in patients who have the BRCA mutation but it can be given to patients who does not have the germline defect.

Partial trial results were published online December 1,2016 in the New England Journal of Medicine(NEJM).

Zejula have the usual side effects of chemotherapy drugs. Low blood counts, low platelets along with insomnia and high blood pressure are the most distressing side effects leading to discontinuation of drug in 15% of patients. It is contraindicated in pregnant and lactating mothers.

Zejula also received the ‘orphan drug status ‘by FDA because of its use in treatment of primary peritoneal cancer, a rare malignancy that is generally considered as ovarian-like. The orphan drug status is granted when a drug is used to treat rare disease.

The other two PARP inhibitors approved by FDA are olaparib (Lynparza, AstraZeneca) and rucaparib(brand name, Rubraca; Clovis Oncology, Boulder, Colo.) both are only used in patients with BRCA mutation and require testing for BRCA mutation.