Niraparib

How it works

It inhibits poly(ADP-ribose) polymerase enzymes and traps them on DNA, so that cells deficient in homologous recombination repair accumulate lethal DNA damage.

Prescribing in practice

• It commonly causes dose-related myelosuppression, including thrombocytopenia, anaemia and neutropenia, which can be severe and necessitates regular blood-count monitoring.
• Hypertension, including hypertensive crisis, can occur and blood pressure should be controlled and monitored.
• There is a recognised risk of myelodysplastic syndrome/acute myeloid leukaemia with PARP inhibitors; use according to the SPC and biomarker eligibility.

Monitoring

Monitor full blood count regularly, especially in early treatment, alongside blood pressure throughout therapy.

Counselling the patient

• Attend for regular blood tests, particularly in the first months of treatment.
• Report unusual bruising or bleeding, breathlessness, severe tiredness or signs of infection.
• This medicine can harm an unborn baby; use effective contraception as advised.

Evidence & guidelines

PARP inhibition is supported by phase 3 trial evidence in homologous recombination repair-deficient cancers, with use guided by approved biomarker-defined indications.