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CDK4/6 inhibitor Pregnancy: §4.6: pregnancy status should be verified prior to starting treatment. Women of childbearing potential receiving Kisqali should use effective contraception (e.g. double-barrier contraception) during therapy and for at least 21 days after stopping treatment. 'There are no adequate and well-controlled studies in pregnant women. Based on findings in animals, ribociclib can cause foetal harm when administered to a pregnant woman. Kisqali is not recommended during pregnancy and in women of childbearing potential not using contraception.' Breast-feeding: it is not known if ribociclib is present in human milk; ribociclib and its metabolites readily passed into the milk of lactating rats; patients receiving Kisqali should not breast-feed for at least 21 days after the last dose. Fertility: no clinical data; based on animal studies, ribociclib may impair fertility in males of reproductive potential.

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.

Adult dose

Dose: SPECIALIST INITIATION ONLY — treatment with Kisqali should be initiated by a physician experienced in the use of anticancer therapies. ADVANCED OR METASTATIC HR-POSITIVE, HER2-NEGATIVE BREAST CANCER (this page's primary indication): 600 mg (three 200 mg film-coated tablets) of ribociclib once daily for 21 consecutive days followed by 7 days off treatment, resulting in a complete cycle of 28 days; treatment should be continued as long as the patient is deriving clinical benefit from therapy or until unacceptable toxicity occurs. EARLY BREAST CANCER (the SPC's other licensed setting, given here for completeness — it is a LOWER dose): 400 mg (two 200 mg film-coated tablets) once daily for 21 consecutive days followed by 7 days off treatment, a 28-day cycle, taken until completion of 3 years of treatment or until disease recurrence or unacceptable toxicity. Ribociclib is not given alone: when used with an aromatase inhibitor, the AI is taken orally once daily continuously throughout the 28-day cycle; when used with fulvestrant, fulvestrant is given intramuscularly on days 1, 15 and 29 and once monthly thereafter. Treatment of pre- and perimenopausal women with the approved Kisqali combinations should also include an LHRH agonist in accordance with local clinical practice; in pre- or perimenopausal women, or in men, the aromatase inhibitor should be combined with an LHRH agonist.
Route: Oral. Kisqali should be taken once daily with or without food. Patients should be encouraged to take their dose at approximately the same time each day, preferably in the morning. The tablets should be swallowed whole and should not be chewed, crushed or split prior to swallowing. No tablet should be ingested if it is broken, cracked or otherwise not intact. If the patient vomits after taking the dose or misses a dose, an additional dose should not be taken that day — the next prescribed dose should be taken at the usual time.
Frequency: Once daily for 21 consecutive days, then 7 days off treatment (a complete cycle of 28 days).
Max: 600 mg once daily (three 200 mg tablets) in advanced or metastatic breast cancer — this is the starting dose and the highest dose level in the SPC's Table 1 for this indication; every other dose level in that table is a reduction (first dose reduction 400 mg/day, second dose reduction 200 mg/day). If further dose reduction below 200 mg/day is required, treatment should be permanently discontinued.
The UK SPC for Kisqali 200 mg film-coated tablets (eMC product 8110) has since been recovered, and it is the right product for this page: the page names brand Kisqali, category CDK4/6 inhibitor, route PO, frequency 'OD x 21 days q28' and the clinical pearl 'HR+ HER2- advanced/metastatic breast cancer with endocrine therapy'. PATIENT SELECTION: selection based on tumour expression of HR and HER2 should be assessed by a CE-marked in vitro diagnostic medical device with the corresponding intended purpose; if a CE-marked IVD is not available, an alternative validated test should be used. DOSE REDUCTION LEVELS (Table 1) — advanced or metastatic breast cancer: starting dose 600 mg/day (3 tablets), first dose reduction 400 mg/day (2 tablets), second dose reduction 200 mg/day (1 tablet); early breast cancer: starting dose 400 mg/day (2 tablets), dose reduction 200 mg/day (1 tablet). Below 200 mg/day, discontinue permanently. STRONG CYP3A4 INHIBITORS: concomitant use should be avoided. If unavoidable, a patient taking 600 mg daily is reduced to 400 mg; a patient taking 400 mg daily is further reduced to 200 mg; a patient already on 200 mg daily has Kisqali interrupted. If the strong inhibitor is discontinued, the Kisqali dose should be changed back to the dose used before it was started, after at least 5 half-lives of the inhibitor. QT: ECG should be assessed before initiating treatment in all patients, and treatment should be initiated only in patients with QTcF values less than 450 msec; ECG should be repeated at approximately day 14 of the first cycle, then as clinically indicated. Kisqali is not recommended for use in combination with tamoxifen (based on study E2301/MONALEESA-7). RENAL IMPAIRMENT: no dose adjustment in mild or moderate impairment; a starting dose of 200 mg is recommended in severe renal impairment (Kisqali has not been studied in breast cancer patients with severe renal impairment). HEPATIC IMPAIRMENT: no adjustment in early breast cancer; in advanced or metastatic breast cancer, no adjustment for mild impairment (Child-Pugh A), while moderate (Child-Pugh B) and severe (Child-Pugh C) impairment warrant a starting dose of 400 mg once daily. ELDERLY: no dose adjustment is required in patients over 65 years of age. PAEDIATRIC: 'The safety and efficacy of Kisqali in children and adolescents aged below 18 years have not been established... but no recommendation on a posology can be made' — no paediatric dose is published here. NOT STUDIED: the efficacy and safety of ribociclib have not been studied in patients with critical visceral disease. Some sections of the product information we used were incomplete — check the full SPC.

Dose adjustments

Renal

No dose adjustment is necessary in mild or moderate renal impairment. A starting dose of 200 mg is recommended in patients with severe renal impairment; Kisqali has not been studied in breast cancer patients with severe renal impairment (§4.2).

Hepatic

Early breast cancer: no dose adjustment is necessary in patients with hepatic impairment. Advanced or metastatic breast cancer: no adjustment for mild impairment (Child-Pugh A); patients with moderate (Child-Pugh B) and severe (Child-Pugh C) impairment can have increased (less than 2-fold) exposure to ribociclib and a starting dose of 400 mg Kisqali once daily is recommended (§4.2).

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Hypersensitivity to the active substance or to peanut, soya or any of the excipients listed in section 6.1 (§4.3 — note the peanut and soya component, which is specific to this formulation)
  • PRECAUTION, NOT A FORMAL CONTRAINDICATION (§4.4): use of Kisqali should be avoided in patients who already have or who are at significant risk of developing QTc prolongation — including patients with long QT syndrome, with uncontrolled or significant cardiac disease (recent myocardial infarction, congestive heart failure, unstable angina, bradyarrhythmias), or with electrolyte abnormalities
  • PRECAUTION, NOT A FORMAL CONTRAINDICATION (§4.4): use with medicinal products known to prolong the QTc interval and/or with strong CYP3A4 inhibitors should be avoided, as this may lead to clinically meaningful prolongation of the QTcF interval
  • PRECAUTION, NOT A FORMAL CONTRAINDICATION (§4.4): Kisqali is not recommended for use in combination with tamoxifen, based on the findings from study E2301 (MONALEESA-7)

Side effects

  • Advanced or metastatic breast cancer — adverse drug reactions reported at a frequency of 20% or more where Kisqali plus any combination exceeded placebo plus any combination: neutropenia, infections, nausea, fatigue, diarrhoea, leukopenia, vomiting, headache, constipation, alopecia, cough, rash, back pain, anaemia and abnormal liver function tests (§4.8)
  • Advanced or metastatic breast cancer — most common Grade 3/4 reactions (frequency 2% or more): neutropenia, leukopenia, abnormal liver function tests, lymphopenia, infections, back pain, anaemia, fatigue, hypophosphataemia and vomiting (§4.8)
  • Early breast cancer — reactions at a frequency of 20% or more where Kisqali plus an aromatase inhibitor exceeded the AI alone: neutropenia, infections, nausea, headache, fatigue, leukopenia and abnormal liver function tests; most common Grade 3/4: neutropenia, abnormal liver function tests and leukopenia (§4.8)
  • Neutropenia — may require dose interruption, reduction or discontinuation according to Table 2 of the SPC; Grade 3 febrile neutropenia is defined as Grade 3 neutropenia with a single fever above 38.3 degrees C, or 38 degrees C and above for more than one hour and/or concurrent infection (§4.2, §4.4)
  • Hepatobiliary toxicity — AST and/or ALT elevations; if ALT and/or AST rise above 3 x ULN together with total bilirubin above 2 x ULN in the absence of cholestasis, Kisqali is discontinued irrespective of baseline grade (§4.2, §4.4)
  • QT interval prolongation — in study E2301 (MONALEESA-7) a QTcF increase of more than 60 msec from baseline was seen in 14/87 (16.1%) patients receiving Kisqali plus tamoxifen and 18/245 (7.3%) receiving Kisqali plus a non-steroidal aromatase inhibitor; in study O12301C (NATALEE, early breast cancer) in 19 (0.8%) patients receiving Kisqali plus an AI (§4.4)
  • Interstitial lung disease / pneumonitis — Grade 3 or 4 requires discontinuation (§4.2 Table 5)
  • Dose reduction due to adverse events occurred in 39.5% of patients in the advanced/metastatic phase III studies and 22.8% in the early breast cancer phase III study; permanent discontinuation in 8.7% and 19.7% respectively (§4.8)
  • SCOPE NOTE: §4.8 is truncated at the source-fetch limit — the SPC's full tabulated adverse-reaction list was not retrieved, so this is a partial list

Monitoring

  • Complete blood counts before initiating treatment, then every 2 weeks for the first 2 cycles, at the beginning of each of the subsequent 4 cycles, then as clinically indicated (§4.2)
  • Liver function tests before initiating treatment, then every 2 weeks for the first 2 cycles, at the beginning of each of the subsequent 4 cycles, then as clinically indicated; if Grade 2 or greater abnormalities are noted, more frequent monitoring is recommended (§4.2)
  • ECG before initiating treatment in all patients — initiate only if QTcF is less than 450 msec; repeat at approximately day 14 of the first cycle, then as clinically indicated. In case of QTcF prolongation during treatment, more frequent ECG monitoring is recommended (§4.2, §4.4)
  • Serum electrolytes (potassium, calcium, phosphorus and magnesium) — in early breast cancer, before initiating treatment, at the beginning of the first 6 cycles and then as clinically indicated; any abnormality should be corrected before and during treatment (§4.4)
  • Monitor for pulmonary symptoms of ILD/pneumonitis and manage by the SPC's Table 5 grading (§4.2)
  • Pregnancy status should be verified prior to starting treatment (§4.6)
  • Refer to the SmPC for the co-administered aromatase inhibitor, fulvestrant or LHRH agonist for their own dose modification and safety monitoring (§4.2)

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. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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