GSK’s PARP Inhibitor, Zejula Gets Foot in the Door in EU to rival Rubraca and Lynparza

By Judy Ya-Hsuan Lin

GlaxoSmithKline (GSK), the science-led global healthcare company, shared the thrilling breakthrough on European Medicines Agency’s (EMA) validation of its Type II Variation (T2V) for Zejula (niraparib) as a maintenance treatment in the first-line setting for women with advanced ovarian cancer who responded to platinum-based chemotherapy regardless of biomarker status. Niraparib extends the time of relapse which is surprisingly high (85%) in patients who undergo Platinum-based chemotherapy alone.

In Europe, more than 65,000 are diagnosed with ovarian cancer annually, making it the sixth deadliest cancer among women. When diagnosed, most have advanced stage III or IV cancer and a five-year survival rate of approximately 30%. After dedicating years to maximizing patient survival through transformational medicines, GSK is actualizing its mission with the development of niraparib for ovarian cancer treatment.

Drug Information of Niraparib

Niraparib is an oral, once-daily PARP inhibitor which belongs to a group of pharmacological inhibitors of the poly ADP ribose polymerase (PARP) enzyme. Originally acquired from Tesaro Oncology, GSK launched a clinical development program on niraparib to further assess the drug’s activity on multiple tumor types and possible combinations with other therapeutics. At its current stage, niraparib is indicated as monotherapy for the maintenance treatment of adult patients with platinum sensitive, relapsed high grade serious epithelial ovarian, fallopian tube, or primary peritoneal cancer who are in response (complete or partial) to platinum-based chemotherapy. The drug received FDA approval for this indication last October and rivals Clovis Oncology’s Rubraca and AstraZeneca’s Lynparza, the other PARP inhibitors that have received EU approvals last year.

Clinical Study for Niraparib: PRIMA

The data from the PRIMA clinical study were presented at the 2019 European Society for Medical Oncology Congress and was published in the New England Journal of Medicine. PRIMA is a randomized, double-blind, Phase III study designed to assess the efficacy of niraparib in treating women with stage III or IV ovarian cancer. The clinical trials evaluated niraparib as maintenance therapy by measuring progression-free survival. The study only involved women who responded to first-line treatment with platinum-based chemotherapy, including those with a high risk of disease progression, previously under-represented in first-line ovarian cancer studies. As compared to placebo, twice the number of patients showed higher responsiveness to niraparib, meaning the drug offers a longer period of maintenance for chemotherapy before the next relapse.

Warnings & Adverse Effects

Patients treated with niraparib should keep track of their blood and circulatory health and personal medical condition, including galactose intolerance. Other side-effects are classified into the different levels of frequency for healthcare providers as a more holistic assessment.

Blood count tests should be done weekly for the first month of treatment and then monthly thereafter. If a patient develops serious persistent hematologic toxicity including pancytopenia (a reduction in the number of red blood cells, white blood cells, and platelets) that does not resolve within 28 days following interruption, niraparib should be discontinued. To avoid decreases in thrombocyte count, anticoagulants and medicinal products known to reduce platelets should be used with caution. If MDS (leukemia) and/or acute myeloid leukemia (AML) are confirmed, niraparib should be discontinued. Besides, Hypertension, including hypertensive crisis, has also been reported; thus, adequate control before starting niraparib treatment with antihypertensive therapy is necessary. Adverse symptoms of using niraparib include urinary tract infection, anemia, decreased appetite, headache, insomnia, nausea, vomiting, and diarrhea among others.

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References

1. https://www.gsk.com/en-gb/media/press-releases/european-medicines-agency-accepts-submission-of-gsk-s-marketing-authorisation-application-for-zejula-niraparib-in-first-line-maintenance-treatment/
2. https://www.nejm.org/doi/full/10.1056/NEJMoa1910962

Author

Judy Ya-Hsuan Lin

Success is the ability to go from one failure to another with no loss of enthusiasm.