Regimen is considered appropriate as part of the standard care of patients; meaningfully improves outcomes (survival, quality of life), tolerability or costs compared to alternatives (recommended by the Disease Site Team and national consensus body e.g. pan-Canadian Oncology Drug Review, pCODR). Recommendation is based on an appropriately conducted phase III clinical trial relevant to the Canadian context OR (where phase III trials are not feasible) an appropriately sized phase II trial. Regimens where one or more drugs are not approved by Health Canada for any indication will be identified under Rationale and Use.
For treatment of refractory HR+/HER2- metastatic breast cancer
|(This drug is not currently publicly funded for this regimen and intent)|
Minimal – No routine prophylaxis; PRN recommended
Doses should be modified according to the protocol by which the patient is being treated.
Dosage with toxicity
|Dose Level||Abemaciclib Dose (mg BID)|
|Hematologic*||Grade 3||Hold until ≤ grade 2; resume at same dose.|
|Grade 4 or recurrent grade 3||Hold until ≤ grade 2; resume at 1 dose level ↓.|
If no resolution to ≤ grade 1 within 24 hours, hold until resolution; resume at same dose.
|Grade 2 that persists/recurs after resumption at the same dose (despite maximal supportive measures)||Hold until ≤ grade 1; resume at 1 dose level ↓.|
|≥ Grade 3 or requires hospitalization||Hold until ≤ grade 1; resume at 1 dose level ↓.|
|Interstitial lung disease (ILD)/ Pneumonitis||Persistent or recurrent grade 2 toxicity that does not resolve to baseline or grade 1 within 7 days (despite maximal supportive measures)||Hold until recovery to baseline or ≤ grade 1; resume at 1 dose level ↓.|
|Grade 3 or 4||Discontinue|
|Hepatotoxicity||Persistent or recurrent grade 2 or grade 3 (ALT, AST >5 to 20 times ULN) without increase in total bilirubin >2 times ULN||Hold until recovery to baseline or grade 1; resume at 1 dose level ↓.|
|AST and/or ALT >3 times ULN with total bilirubin >2 times ULN (in the absence of cholestasis)||Discontinue|
|Grade 4 (ALT, AST >20 times ULN)||Discontinue|
|All other non-hematologic toxicities||Persistent or recurrent grade 2 toxicity that does not resolve to baseline or grade 1 within 7 days (despite maximal supportive measures)||Hold until recovery to baseline or ≤ grade 1; resume at 1 dose level ↓.|
|≥ Grade 3||Hold until recovery to baseline or ≤ grade 1; resume at 1 dose level ↓.|
*If blood cell growth factors are required, hold abemaciclib for at least 48 hours after the last growth factor dose and until toxicity resolves to ≤ grade 2; resume at the next lower dose (unless already reduced due to the toxicity that required the growth factor). Growth factor use is as per current local guidelines.
**At the first sign of loose stools, begin management with antidiarrheal agents (i.e. loperamide) and increase oral fluid intake.
|Hepatic Impairment||Abemaciclib Dose|
|Mild or moderate impairment (Child-Pugh class A or B)||No dosage adjustment necessary.|
|Severe impairment (Child-Pugh class C)||Reduce the abemaciclib frequency to once daily.|
|Renal Impairment||Abemaciclib Dose|
|Mild or Moderate (CrCl ≥ 30 mL/min)||No dosage adjustment necessary.|
|Severe (CrCl < 30 mL/min); ESRD||Has not been studied.|
Dosage in the Elderly
No overall differences in safety or efficacy between patients ≥ 65 years of age and younger. No dosage adjustment is required. Patients ≥65 years of age reported more hematologic adverse events, hypokalemia (including grade 3), hypocalcemia, grade ≥3 infections, decreased appetite, and increased blood creatinine compared to younger patients in a subgroup analysis from clinical studies.
Dosage based on Ethnicity
Higher incidences of increased ALT and AST and neutropenia have been reported in East Asian patients compared to Caucasian patients in clinical trials. No dose adjustment based on race is required.
Refer to abemaciclib drug monograph(s) for additional details of adverse effects
Very common (≥ 50%)
Less common (10-24%)
Uncommon (< 10%),
but may be severe or life-threatening
Refer to abemaciclib drug monograph(s) for additional details
- CYP3A4 inhibitors (i.e. ketoconazole, clarithromycin, ritonavir, fruit or juice from grapefruit, Seville oranges or starfruit); Avoid co-administration with strong CYP3A4 inhibitors. Use caution when co-administered with moderate or weak CYP3A inhibitors. If co-administration with a CYP3A inhibitor is unavoidable, reduce abemaciclib dose to 50 mg twice daily* (based on a 150 mg or 200 mg twice daily starting dose) when combined with strong or moderate CYP3A4 inhibitors. If a CYP3A inhibitor is discontinued, increase the abemaciclib dose (after 3-5 half-lives of the inhibitor) to the dose that was used before starting the inhibitor.
*When combined with clarithromycin, diltiazem or verapamil, abemaciclib dose should be reduced to 100 mg twice daily.
CYP3A4 inducers (i.e. phenytoin, rifampin, dexamethasone, carbamazepine, phenobarbital, St. John’s Wort, etc); Avoid co-administration with strong CYP3A4 inducers. Use with caution when co-administered with moderate or weak CYP3A4 inducers.
OCT2, MATE1, MATE2 substrates (i.e. metformin); use with caution
Refer to abemaciclib drug monograph(s) for additional details
Abemaciclib tablets should be swallowed whole (do not chew, crush, or split tablets before swallowing). Tablets should not be ingested if they are not intact.
Abemaciclib doses may be taken with or without food and should be administered at approximately the same times every day.
Avoid fruit or juice from grapefruit, Seville oranges or starfruit.
Abemaciclib tablets contain lactose. Use with caution in patients with lactose intolerance.
If a dose is missed or vomited, the next dose should be taken at the scheduled time. The patient should not take 2 doses at the same time to make up for the missed dose.
Store at room temperature (15°C to 30°C).
- Patients who are hypersensitive to this drug or to any ingredient in the formulation or component of the container.
- There are no data regarding abemaciclib safety or efficacy in patients with prior exposure to other CDK 4/6 inhibitors.
Abemaciclib is not recommended for use in pregnancy. Adequate contraception should be used by both sexes during treatment, and for at least 3 weeks after the last dose.
Breastfeeding is not recommended during abemaciclib treatment and for at least 3 weeks after the last dose.
- In animal studies, no effects on female reproductive organs were observed. However, cytotoxic effects to the male reproductive tract in rats and dogs indicate that abemaciclib may impair fertility in males.
Recommended Clinical Monitoring
CBC; Baseline, every two weeks for the first 2 months, monthly for the next 2 months, and as clinically indicated.
Creatinine ; Baseline and as clinically indicated
Liver function tests; Baseline, every 2 weeks for the first 2 months, monthly for the next 2 months, and as clinically indicated.
Clinical toxicity assessment for signs and symptoms of venous thrombosis, infections, gastrointestinal, respiratory, dermatologic effects and fatigue; At each visit
Grade toxicity using the current NCI-CTCAE (Common Terminology Criteria for Adverse Events) version
Suggested Clinical Monitoring
- Electrolytes, including calcium; Baseline and as clinically indicated
Abemaciclib drug monograph, Cancer Care Ontario.
Dickler MN, Tolaney SM, Rugo HS, et al. MONARCH 1, a phase 2 study of abemaciclib, a CDK4 and CDK6 inhibitor, as a single agent, in patients with refractory HR+/HER2- metastatic breast cancer. Clin Cancer Res. 2017;23(17):5218-5485.
December 2019 Expanded into full regimen monograph
A Regimen Abstract is an abbreviated version of a Regimen Monograph and contains only top level information on usage, dosing, schedule, cycle length and special notes (if available). It is intended for healthcare providers and is to be used for informational purposes only. It is not intended to constitute or be a substitute for medical advice, and all uses of the Regimen Abstract are subject to clinical judgment. Such information is provided on an “as-is” basis, without any representation, warranty, or condition, whether express, or implied, statutory or otherwise, as to the information’s quality, accuracy, currency, completeness, or reliability, and Cancer Care Ontario disclaims all liability for the use of this information, and for any claims, actions, demands or suits that arise from such use.
Information in regimen abstracts is accurate to the extent of the ST-QBP regimen master listings, and has not undergone the full review process of a regimen monograph. Full regimen monographs will be published for each ST-QBP regimen as they are developed.
Refer to the New Drug Funding Program or Ontario Public Drug Programs websites for the most up-to-date public funding information.
The information set out in the drug monographs, regimen monographs, appendices and symptom management information (for health professionals) contained in the Drug Formulary (the "Formulary") is intended for healthcare providers and is to be used for informational purposes only. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects of a particular drug, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for a given condition. The information in the Formulary is not intended to constitute or be a substitute for medical advice and should not be relied upon in any such regard. All uses of the Formulary are subject to clinical judgment and actual prescribing patterns may not follow the information provided in the Formulary.
The format and content of the drug monographs, regimen monographs, appendices and symptom management information contained in the Formulary will change as they are reviewed and revised on a periodic basis. The date of last revision will be visible on each page of the monograph and regimen. Since standards of usage are constantly evolving, it is advised that the Formulary not be used as the sole source of information. It is strongly recommended that original references or product monograph be consulted prior to using a chemotherapy regimen for the first time.
Some Formulary documents, such as the medication information sheets, regimen information sheets and symptom management information (for patients), are intended for patients. Patients should always consult with their healthcare provider if they have questions regarding any information set out in the Formulary documents.
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