PARP inhibitors set to expand foothold in first-line ovarian cancer
A larger proportion of ovarian cancer patients are set to benefit from up-front treatment with a PARP inhibitor, but recent US regulatory approvals will add complexity to the therapeutic paradigm.
For a new Therapy Trends FirstImpact report, FirstWord surveyed 87 US oncologists who treat an average of 36 ovarian cancer patients in a typical month to gauge how FDA approval of AstraZeneca and Merck & Co.'s Lynparza (in combination with Roche's Avastin) and GlaxoSmithKline's Zejula will impact the treatment landscape. Further information about this study is available on request.
The FDA recently approved AstraZeneca and Merck & Co.’s Lynparza (olaparib) in combination with Roche’s Avastin (bevacizumab) for the treatment of homologous recombination deficiency (HRD)-positive advanced ovarian cancer in women who are in complete or partial response to first-line platinum-based chemotherapy.
Days earlier the US regulator approved GlaxoSmithKline’s Zejula (niraparib) in a similar indication but with a notably broader label, stipulating use as a first-line maintenance treatment in ovarian cancer patients regardless of biomarker status.
The bigger picture
These approvals significantly broaden the proportion of US ovarian cancer patients who can be treated with a PARP inhibitor and build upon the practice-changing approval of Lynparza as a first-line maintenance therapy for patients with BRCA1/2 mutations, which was granted by the FDA in December 2018.
AstraZeneca estimates that approximately 50% of ovarian cancers are HRD-positive including BRCA1/2 mutation and some 22% of ovarian cancers have a BRCA1/2 mutation.
Offsetting the status of Lynparza as an established first-line treatment option in patients identified as BRCA mutation positive, Zejula’s broad label supporting use regardless of biomarker status sets up an intriguing commercialisation battle in the months and years ahead, amplified by the inclusion of data in Zejula’s label showing it is more effective at extending progression free survival (PFS) in HRD-positive patients.
Targeted therapies play an increasingly important role in the treatment of cancer but biomarker testing remains underutilised (see Physician Views: Only 60% of cancer patients are tested for biomarkers, say oncologists).
However, against this backdrop an overwhelming majority of the oncologists we surveyed appear committed to tailoring their treatment of ovarian cancer patients with PARP inhibitor therapy by HRD and/or BRCA testing.
Feedback also illustrates that the existing role of Avastin as a popular but not universally used first-line treatment option will play an integral role in shaping adoption of AstraZeneca and Merck & Co.’s Lynparza in combination with the VEGF inhibitor.
More detailed survey results, alongside estimated utilisation rates of different treatment options in BRCA-positive, HRD-positive, HRD-negative and biomarker status unknown patients, can be found in the new FirstImpact report. Further information about this study is available on request.
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