Side effect management algorithms for niraparib/abiraterone acetate in prostate cancer

Niraparib, a PARP1/2 inhibitor, is newly approved in combination with abiraterone acetate (AA) plus prednisone or prednisolone (niraparib/AA+P) for the treatment of adult patients with BRCA-mutated, treatment-naïve metastatic castration resistant prostate cancer (mCRPC). Detailed guidance beyond the prescribing information may be helpful in managing the side effect profile and dosing practicalities of this combination therapy.

A panel of specialists convened to design management algorithms for four common niraparib/AA+P treatment-related adverse events (AEs) in mCRPC; anemia, thrombocytopenia, hypertension, and nausea. The algorithms build on Health Canada-approved prescribing information to highlight practical considerations related to monitoring, treatment adjustment, and specialist referral to support clinical practice.

The panel's recommendations were largely aligned with the niraparib/AA+P product monograph. Single agent AA+P followed by reintroduction niraparib/AA+P using the low dose formulation of niraparib/AA were common strategies for managing higher grade AE's. Recommendations for hypertension management were expanded to include a sequence of anti-hypertensive medication trials prior to a change in anti-cancer therapy, where feasible.

These algorithms are intended to provide practical assistance to Canadian clinicians managing the most common AEs encountered with the novel combination, niraparib/AA+P, for mCRPC.