CDK4/6 inhibitor

Ribociclib (Specialist drug)

Brand names: Kisqali

Ribociclib is an oral CDK4/6 inhibitor used as a specialist treatment, with endocrine therapy, for hormone-receptor-positive, HER2-negative advanced breast cancer.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

It selectively inhibits cyclin-dependent kinases 4 and 6, preventing retinoblastoma protein phosphorylation and arresting cell-cycle progression from G1 to S phase.

Prescribing in practice

It can prolong the QT interval, so baseline and periodic ECG and electrolyte correction are required and it is given with caution alongside other QT-prolonging drugs.
Neutropenia is common and dose-limiting, and hepatobiliary toxicity may occur.
It is a CYP3A4 substrate with multiple interactions, so concomitant strong inhibitors and inducers should be reviewed per current prescribing references.

Monitoring

Monitor full blood count, liver function tests, ECG (QTc) and serum electrolytes before and during treatment.

Counselling the patient

Report fainting or palpitations and any signs of infection such as fever.
Avoid grapefruit and tell the team about all other medicines.
Keep all blood test and ECG appointments.

Evidence & guidelines

Use is supported by NICE guidance and the MONALEESA series of phase III trials.

Reference: NICE TA496/TA593; SmPC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

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