Olaparib

How it works

It inhibits and traps poly(ADP-ribose) polymerase on DNA, causing synthetic lethality in tumour cells deficient in homologous recombination repair.

Prescribing in practice

• It can cause myelosuppression, including anaemia, neutropenia and thrombocytopenia, requiring regular full blood count monitoring and dose adjustment.
• Pneumonitis and a rare risk of myelodysplastic syndrome/acute myeloid leukaemia are recognised and warrant investigation of persistent respiratory or haematological abnormalities.
• Use requires confirmation of an eligible BRCA/HRR mutation and adherence to dose adjustments for renal impairment and interacting drugs per the SPC.

Monitoring

Monitor full blood count at baseline and regularly during treatment, with prompt evaluation of new respiratory symptoms or persistent cytopenias.

Counselling the patient

• Attend for regular blood tests during treatment.
• Report unusual bruising or bleeding, breathlessness, persistent cough or marked tiredness.
• Use effective contraception, as this medicine can harm an unborn baby.

Evidence & guidelines

The PROfound trial supported olaparib in homologous recombination repair-mutated metastatic castration-resistant prostate cancer, and it is recommended by NICE for defined groups.