Rucaparib

Rucaparib is an oral anticancer medicine belonging to the poly (ADP-ribose) polymerase (PARP) inhibitor class. It is used in selected adults with specific molecular features in certain ovarian and prostate cancers. PARP enzymes help cells repair damaged DNA. By inhibiting these enzymes, rucaparib interferes with DNA repair and can promote cancer-cell death, particularly in tumours with impaired homologous recombination repair, such as those carrying harmful BRCA1 or BRCA2 gene alterations. This approach is an example of targeted cancer treatment.

Rucaparib is supplied as tablets and is generally taken twice daily. Its use depends on the cancer type, treatment history, molecular test results, previous response to therapy, and the applicable regulatory indication. In ovarian cancer, it is used as maintenance therapy for eligible patients whose recurrent disease has responded completely or partially to platinum-based chemotherapy. In prostate cancer, it is an option for selected patients with BRCA-mutated metastatic castration-resistant disease following androgen receptor-directed treatment.

Treatment requires specialist supervision, blood-count monitoring, assessment of adverse effects, and review of ongoing clinical benefit. Although oral administration avoids routine infusion visits, it does not remove the need for regular medical follow-up. Rucaparib can cause significant blood-related toxicities and other adverse effects, so treatment decisions should be individualised according to the current prescribing information and local approvals.

Rucaparib was developed as a targeted therapy designed to exploit defects in DNA repair in cancer cells. The United States Food and Drug Administration (FDA) granted its initial approval in 2016. In the European Union, the European Medicines Agency (EMA) recommended authorisation for Rubraca in 2018, initially under a conditional marketing authorisation; this became a standard marketing authorisation in November 2022. Clinical development included the ARIEL programme in ovarian cancer and the TRITON programme in prostate cancer. The ARIEL3 phase III trial evaluated maintenance treatment after response to platinum-based chemotherapy, while TRITON3 provided confirmatory evidence for use in BRCA-mutated metastatic castration-resistant prostate cancer. Regulatory indications have changed as additional efficacy and safety data became available. In 2022, European regulators recommended withdrawal of the later-line ovarian cancer treatment indication after a study raised concerns about overall survival. In the United States, the FDA granted regular approval for BRCA-mutated metastatic castration-resistant prostate cancer on 17 December 2025. Approved indications differ between jurisdictions; clinicians should check the current local product information before prescribing.

Rucaparib is used for specific cancers in patients whose disease and molecular test results meet the relevant prescribing criteria. Under current US FDA labelling, it is indicated for maintenance treatment of adults with deleterious germline and/or somatic BRCA mutations associated with recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer who have achieved a complete or partial response to platinum-based chemotherapy. It is also indicated for adults with deleterious BRCA-mutated metastatic castration-resistant prostate cancer who have previously received androgen receptor-directed therapy, with patient selection based on an FDA-approved companion diagnostic. In the European Union, the authorised indications focus on maintenance treatment of eligible advanced high-grade ovarian, fallopian tube, or primary peritoneal cancer following response to platinum-based chemotherapy, including first-line and platinum-sensitive relapsed settings. Rucaparib may be used as monotherapy within these approved indications. It should not be assumed to be appropriate for every patient with ovarian or prostate cancer, and its role in other tumour types or treatment settings depends on clinical evidence and local regulatory approval.

Rucaparib is administered orally as tablets. The recommended adult dose under current US prescribing information is 600 mg twice daily, with or without food. Treatment is generally continued until disease progression or unacceptable toxicity, subject to the applicable indication and local product information. Dose interruptions or stepwise reductions may be necessary for adverse reactions; the prescribing clinician should follow the recommended adjustment schedule and assess renal function, blood counts, liver tests, and other relevant clinical findings. For metastatic castration-resistant prostate cancer, ongoing androgen-deprivation treatment with a gonadotropin-releasing hormone analogue or a history of bilateral orchiectomy is required. Patients should take doses consistently and follow professional advice if a dose is missed or vomiting occurs after administration. Treatment duration is individualised, with regular review of response, tolerability, and continued suitability.

Common adverse effects of rucaparib include fatigue, nausea, vomiting, reduced appetite, diarrhoea, abdominal discomfort, changes in taste, and changes in blood test results. Blood-related effects can include anaemia, reduced neutrophil counts, and reduced platelet counts. Increases in liver enzymes may also occur and require clinical interpretation and monitoring. The severity and combination of symptoms vary between patients and may depend on previous treatments, general health, and the duration of therapy. Some adverse effects can be managed through supportive treatment, closer observation, temporary interruption, or dose reduction under medical supervision. Patients should report persistent digestive symptoms, unusual tiredness, bruising, bleeding, or symptoms suggestive of infection rather than adjusting or stopping treatment themselves.

An important risk associated with rucaparib is myelodysplastic syndrome (MDS) or acute myeloid leukaemia (AML), which can be life-threatening and has been reported in treated patients. Complete blood counts should be checked before treatment and regularly during therapy; persistent or severe blood abnormalities require investigation, treatment interruption, and specialist assessment. If MDS or AML is confirmed, rucaparib should be discontinued in accordance with prescribing guidance. Rucaparib can also cause embryo-fetal harm, so pregnancy prevention and counselling are necessary where relevant. Clinicians should assess significant or persistent adverse reactions, including severe cytopenias or suspected organ toxicity, and determine whether treatment interruption, dose reduction, or permanent discontinuation is appropriate. Patients should promptly report fever, unusual bleeding, breathlessness, marked weakness, or other symptoms that may indicate serious toxicity.

Before starting rucaparib, clinicians should confirm the indication and required BRCA mutation status using the testing approach specified by the applicable product information. Baseline assessment generally includes a complete blood count, liver and renal function tests, review of previous cancer treatments, and evaluation of relevant medical conditions. Blood counts and biochemical parameters should be monitored throughout treatment, with additional investigations if abnormalities develop. Rucaparib may affect the activity of certain drug-metabolising enzymes and transport pathways, so the patient's prescription medicines, over-the-counter products, and supplements should be reviewed for potential interactions. Particular attention may be required for medicines with narrow therapeutic ranges or those whose exposure could be altered by enzyme inhibition. Pregnancy should be avoided during treatment, and breastfeeding precautions should follow the local product information. Vaccination decisions, including the timing of live vaccines, should be reviewed with the treating team according to the patient's immune status and concurrent treatment.

Confirm that the patient meets the molecular and clinical criteria for the intended indication before dispensing rucaparib, and document the relevant test result and prior treatment history. Explain the twice-daily oral schedule, the importance of adherence, and the need to contact the oncology team before making changes to treatment. Obtain baseline complete blood counts and liver and renal function tests, then monitor blood counts at least monthly as directed by prescribing information, with additional testing according to clinical findings. Review concomitant medicines for interactions and assess persistent cytopenias promptly, particularly when treatment-related changes do not resolve after interruption. Counsel patients about symptoms requiring urgent review, including fever, unusual bleeding, breathlessness, and severe or persistent fatigue. Reinforce pregnancy-prevention and breastfeeding advice where relevant. Coordinate follow-up with the oncology team to evaluate treatment response, tolerability, dose modifications, and the need for further investigation. Always consult the current local prescribing information because approved indications and regulatory requirements vary by jurisdiction.