abemaciclib

Trade Name:

Verzenio®

Appearance:

tablet

in various strengths, shapes and colours

Monograph Name:

abemaciclib

Monograph Body:

Drug Monograph

A - Drug Name

abemaciclib

COMMON TRADE NAME(S): Verzenio®

B - Mechanism of Action and Pharmacokinetics

Abemaciclib inhibits cyclin-dependent kinases 4 and 6 (CDK4 and CDK6). It blocks retinoblastoma tumor suppressor protein phosphorylation and prevents progression through the cell cycle, resulting in arrest at the G1 phase, leading to suppression of tumour growth.

Absorption

Bioavailability

45% (following a single 200 mg oral dose)

Effects with food

Cmax increased by 26%; AUC increased by 9%, after a high-fat, high-calorie meal

Time to reach steady state

5 days (following repeated twice daily dosing)

Peak plasma levels

8 hours

Distribution

PPB

96-98%

Cross blood brain barrier?

Yes

Metabolism

Active metabolites

Yes

Inactive metabolites

Yes

Elimination

Feces

81%, mainly as metabolites

Urine

Half-life

24.8 hours

C - Indications and Status

Health Canada Approvals:

Breast cancer (HR positive, HER2 negative)

Refer to the product monograph for a full list of approved indications.

D - Adverse Effects

Emetogenic Potential:

Minimal – No routine prophylaxis; PRN recommended

The following table contains adverse effects from a phase III trial of early breast cancer patients (monarchE) where the incidences in patients receiving abemaciclib in combo with endocrine therapy were ≥2% more than endocrine therapy alone . Adverse effects from the advanced breast cancer clinical trial (Monarch 3) with abemaciclib in combination with anastrozole or letrozole are marked with “†”. Severe adverse events from other studies or post-marketing may also be included.

ORGAN SITE	SIDE EFFECT* (%)	ONSET**
Cardiovascular	Arterial thromboembolism (rare)	E
	Cardiotoxicity (rare)	E
	Hypotension (rare)	E
	Venous thromboembolism (2%)	E
Dermatological	Alopecia (10%) (≤ Grade 2)	E
	Dry skin (10%) †	E
	Hand-foot syndrome (rare)	E
	Nail disorder (5%)	D
	Rash, pruritus (10%)	E
Gastrointestinal	Anorexia, weight loss (12%)	E
	Constipation (10%)	E
	Diarrhea (83%) (8% severe)	E
	Dry mouth (5%) †	E
	Dyspepsia (8%)	E
	Mucositis (13%)	E
	Nausea, vomiting (29%) (Generally mild)	E
General	Edema - limbs (10%) †	E
	Fall (6%) †	E
	Fatigue (39%)	E
	Flu-like symptoms (12%) †	E
	Other - Lymphedema (10%)	E
Hematological	Myelosuppression (45%) (19% severe, including febrile neutropenia ≤1%)	E D
Hepatobiliary	↑ LFTs (10%) (severe 2%)	E D
Hypersensitivity	Hypersensitivity (rare)	E
Infection	Infection (48%) (severe 4%)	E
Metabolic / Endocrine	Abnormal electrolyte(s) (9%) † (↓ PO4, ↓ K, ↓ Ca)	E
Musculoskeletal	Musculoskeletal pain (21%)	E
Nervous System	Dizziness (10%)	E
	Dysgeusia (5%)	E
	Headache (18%)	E
Ophthalmic	Dry eye (5%)	E
	Watering eyes (5%) †	E
Renal	Creatinine increased (21%) †	E
	Nephrotoxicity (rare)	I E
Respiratory	Cough, dyspnea (15%) †	E
	Pneumonitis (5%)	E

* "Incidence" may refer to an absolute value or the higher value from a reported range.
"Rare" may refer to events with < 1% incidence, reported in post-marketing, phase 1 studies,
isolated data or anecdotal reports.

** I = immediate (onset in hours to days) E = early (days to weeks)
D = delayed (weeks to months) L = late (months to years)

The most common side effects for abemaciclib include diarrhea, infection, myelosuppression, fatigue, nausea/vomiting, creatinine increased, musculoskeletal pain, headache, cough/dyspnea and mucositis.

Diarrhea is the most common adverse reaction across clinical studies with a higher incidence during the initial month of treatment. Grade 3 diarrhea has occurred but Grade 4 has not been reported. Diarrhea had been associated with dehydration and infection. The median time to onset of the first diarrhea event was 6 to 8 days and the median duration of grade 2 and 3 diarrhea was 9 to 11 days and 6 to 8 days, respectively.

Myelosuppression was reported in patients receiving abemaciclib. Grade 3 or higher neutropenia has been observed with both monotherapy and combination therapy. The median time to first episode of neutropenia (≥ grade 3) was 29 to 37 days and the median duration of ≥ grade 3 neutropenia was 12 to 15 days. Febrile neutropenia has occurred rarely, and deaths due to neutropenic sepsis have been observed.

Venous thromboembolism (VTE), including deep vein thrombosis (DVT), pulmonary embolism, pelvic venous thrombosis, cerebral venous thrombosis, subclavian and axillary vein thrombosis, and inferior vena cava thrombosis have been reported in up to 6% of patients. Deaths due to VTE have occurred.

Hepatotoxicity and increases in ALT have been reported including Grade 3 or higher events. The median time to onset of ≥ grade 3 ALT elevation was 57 to 87 days and the median time to resolution (to < grade 3) was 13-14 days.

Severe, life threatening and fatal interstitial lung disease (ILD)/pneumonitis has been reported with abemaciclib. Across clinical trials, 3.2% of patients had ILD/pneumonitis of any grade with 0.4% of patients experiencing ≥ grade 3 ILD. The median time to onset was 8.2 months.

A higher rate of infections was reported in patients who received abemaciclib plus endocrine therapy compared to patients treated with placebo plus endocrine therapy. Infections were also reported in patients on single agent abemaciclib. Fatal cases were reported in clinical trials.

Abemaciclib may increase serum creatinine, without affecting glomerular function, by inhibiting renal tubular secretion transporters. It was observed within the first month of abemaciclib clinical trials. Serum creatinine levels remained elevated but stable during treatment, and were reversible at treatment discontinuation. Consider alternative markers that are not based on creatinine (e.g. BUN) for determining renal function.

E - Dosing

Refer to protocol by which patient is being treated.

Screen for hepatitis B virus in all cancer patients starting systemic treatment. Refer to the hepatitis B virus screening and management guideline.

Adults:

Monotherapy:

Oral: 200 mg BID

In combination with endocrine therapy*:

Oral: 150 mg BID

*Pre/perimenopausal women, and men treated with abemaciclib AND an aromatase inhibitor, tamoxifen, or fulvestrant should be treated with a gonadotropin releasing hormone (GnRH) agonist, according to local clinical practice.

Dosage with Toxicity:

Dose Level	Abemaciclib Dose (mg BID)
Dose Level	Combination with Endocrine Therapy	Single Agent
0	150	200
-1	100	150
-2	50	100
-3	Discontinue	50
-4	Not applicable	Discontinue

Toxicity	Grade	Action
Hematologic*	Grade 3	Hold until ≤ grade 2; resume at same dose.
Hematologic*	Grade 4 or recurrent grade 3	Hold until ≤ grade 2; resume at 1 dose level ↓.
Diarrhea**	Grade 2	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 ↓.
Interstitial lung disease (ILD)/ Pneumonitis	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
Venous thromboembolism	Grade 1 or 2	Early breast cancer: Hold; restart when patient is stable and if clinically appropriate Metastatic breast cancer: No dose modification required
	Grade 3 or 4	For early or metastatic breast cancer: Hold; restart when patient is stable and if clinically appropriate
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 ↓.
All other non-hematologic toxicities	Grade 3 or 4

*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.

Dosage with Hepatic Impairment:

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 abemaciclib frequency to once daily.

Dosage with Renal Impairment:

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 dosage adjustment is required. No overall differences in safety or efficacy between patients ≥ 65 years of age and younger. 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:

No dose adjustment based on race is required. Higher incidences of increased ALT and AST and neutropenia have been reported in East Asian patients compared to Caucasian patients in clinical trials.

Children:

Safety and efficacy have not been established.

F - Administration Guidelines

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; carefully consider use in patients with hereditary galactose intolerance, severe lactase deficiency or glucose-galactose malabsorption
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).

G - Special Precautions

Contraindications:

Patients who are hypersensitive to this drug or to any ingredient in the formulation or component of the container.

Other Warnings/Precautions:

There are no data regarding abemaciclib safety or efficacy in patients with prior exposure to other CDK 4/6 inhibitors.

Other Drug Properties:

Carcinogenicity:
No data

Pregnancy and Lactation:

Genotoxicity: Unlikely

Not observed in animal studies
Teratogenicity: Yes
Embryotoxicity: Yes

Observed in animal studies.

Abemaciclib is not recommended for use in pregnancy. Adequate contraception should be used by patients and their partners during treatment, and for at least 3 weeks after the last dose.
Breastfeeding:
Breastfeeding is not recommended during treatment and for at least 3 weeks after the last dose.
Fertility effects: Probable

Abemaciclib may impair fertility in males.

H - Interactions

Abemaciclib inhibits the renal transporters organic cation transporter 2 (OCT2), multidrug and extrusion toxin protein (MATE1), and MATE2.

In vitro, abemaciclib is a substrate of P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP).

AGENT	EFFECT	MECHANISM	MANAGEMENT
Strong or moderate CYP3A inhibitors (i.e. ketoconazole, clarithromycin, ritonavir, fruit or juice from grapefruit, Seville oranges or starfruit)	↑ abemaciclib concentration and/or toxicity	↓ metabolism of abemaciclib	Avoid co-administration with strong CYP3A inhibitors. Use caution when co-administered with moderate CYP3A inhibitors. If co-administration with a CYP3A inhibitor is unavoidable, reduce abemaciclib dose to 50 mg twice daily when combined with strong or moderate CYP3A inhibitors. When combined with ketoconazole, abemaciclib dose should be reduced to 50 mg once daily. When combined with clarithromycin, diltiazem or verapamil, abemaciclib dose should be reduced to 100 mg twice daily. If the CYP3A inhibitor is discontinued, increase the abemaciclib dose (after 3-5 half-lives of the inhibitor) to the dose used before starting the inhibitor.
Weak CYP3A inhibitors (e.g. ranitidine)	↑ abemaciclib concentration and/or toxicity	↓ metabolism of abemaciclib	Use with caution. If co-administration with a weak CYP3A inhibitor is unavoidable, reduce abemaciclib dose to 100 mg twice daily. If the CYP3A inhibitor is discontinued, increase the abemaciclib dose (after 3-5 half-lives of the inhibitor) to the dose used before starting the inhibitor.
CYP3A inducers (i.e. phenytoin, rifampin, dexamethasone, carbamazepine, phenobarbital, St. John’s Wort, etc)	↓ abemaciclib concentration and/or efficacy	↑ metabolism of abemaciclib	Avoid co-administration with strong CYP3A inducers. Consider alternative agents with less CYP3A induction. Use with caution when co-administered with moderate or weak CYP3A inducers.
OCT2, MATE1, MATE2 substrates (i.e. metformin)	↑ substrate concentration and/or toxicity	↓ substrate renal clearance and secretion	Caution

I - Recommended Clinical Monitoring

Treating physicians may decide to monitor more or less frequently for individual patients but should always consider recommendations from the product monograph.

Refer to the hepatitis B virus screening and management guideline for monitoring during and after treatment.

Recommended Clinical Monitoring

Monitor Type	Monitor Frequency
CBC	Baseline, every two weeks for the first 2 months, monthly for the next 2 months, 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.
Renal function tests*	Baseline 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

*Abemaciclib may increase serum creatinine, without affecting glomerular function, by inhibiting renal tubular secretion transporters. Consider alternative markers that are not based on creatinine (e.g. BUN) for determining renal function.

Suggested Clinical Monitoring

Monitor Type	Monitor Frequency
Electrolytes (including calcium)	Baseline and as clinically indicated

J - Supplementary Public Funding

Exceptional Access Program (EAP Website)

abemaciclib - For the adjuvant treatment, in combination with endocrine therapy, of adult patients with HR-positive, HER2-negative, node-positive early breast cancer at high risk of disease recurrence, according to criteria

K - References

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):5218-24.

Goetz MP, Toi M, Campone M, et al. MONARCH 3: Abemaciclib as initial therapy for advanced breast cancer. J Clin Oncol. 2017 Nov 10;35(32):3638-46.

Johnston SRD, Harbeck N, Hegg R. Abemaciclib Combined With Endocrine Therapy for the Adjuvant Treatment of HR+, HER2-, Node-Positive, High-Risk, Early Breast Cancer (monarchE). J Clin Oncol. 2020 Dec 1;38(34):3987-98.

Sledge GW, Toi M, Neven P, et al. MONARCH 2: Abemaciclib in combination with fulvestrant in women with HR+/HER2- advanced breast cancer who had progressed while receiving endocrine therapy. J Clin Oncol. 2017;35:2875-84.

Verzenio (abemaciclib) product monograph. Toronto, Ontario: Eli Lilly Canada Inc., January 2022.

February 2025 Updated Supplementary Public Funding section

L - Disclaimer

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.
While care has been taken in the preparation of the information contained in the Formulary, 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.
CCO and the Formulary’s content providers shall have no liability, whether direct, indirect, consequential, contingent, special, or incidental, related to or arising from the information in the Formulary or its use thereof, whether based on breach of contract or tort (including negligence), and even if advised of the possibility thereof. Anyone using the information in the Formulary does so at his or her own risk, and by using such information, agrees to indemnify CCO and its content providers from any and all liability, loss, damages, costs and expenses (including legal fees and expenses) arising from such person’s use of the information in the Formulary.

Info Sheet Name:

abemaciclib (patient)

Info Sheet Introduction:

For treating certain types of breast cancer

Info Sheet Date: Wednesday, August 23, 2023 Info Sheet body:

Medication Information Sheet

abemaciclib (a bem a SYE klib)

This document provides general information about your medication. It does not replace the advice of your health care professional. Always discuss your therapy with your health care professional and refer to the package insert for more details.

Other Name: Verzenio®

Appearance:

tablet

in various strengths, shapes and colours

What is this medication for?

For treating certain types of breast cancer

What should I do before I have this medication?

Tell your health care team if you have or had significant medical condition(s), such as:

lung, liver or kidney problems
any blood clots or
any allergies

Abemaciclib tablets contain a small amount of lactose. If you cannot have lactose, talk to your healthcare team.

Remember to:

Tell your health care team about all of the other medications you are taking.
Keep taking other medications that have been prescribed for you, unless you have been told not to by your health care team.

You will have a blood test to check for hepatitis B before starting treatment. See the Hepatitis B and Cancer Medications pamphlet for more information.

How will this medication affect sex, pregnancy and breastfeeding?

Talk to your health care team about:

How this treatment may affect your sexual health.
How this treatment may affect your ability to have a baby, if this applies to you.

This treatment may harm an unborn baby. Tell your health care team if you or your partner are pregnant, become pregnant during treatment, or are breastfeeding.

If there is any chance of pregnancy happening, you and your partner together must use 2 effective forms of birth control at the same time until at least 3 weeks after your last treatment dose. Talk to your health care team about which birth control options are best for you.
Do not use hormonal birth control (such as birth control pills), unless your health care team told you that they are safe. Talk to your health care team about the safest birth control for you.
Do not breastfeed while on this treatment and for 3 weeks after your last dose.

How is this medication given?

This medication is usually taken twice a day by mouth. Talk to your health care team about how and when to take your medication
Swallow whole with a glass of water, with or without food.
Take the dose at about the same time(s) each day.
Do not split, crush or chew the tablets.
DO NOT eat or drink grapefruit, starfruit, Seville oranges or their juices (or products that contain these) while taking this drug. They may increase the amount of drug in your blood and increase side effects.
If you vomit (throw up) after taking a dose, do not repeat the dose. Take your next dose at your normal time.
If you miss a dose, skip it and take your next dose as you normally do. Do not take an extra dose to make up for the missed dose.

To Treat Diarrhea

Abemaciclib can cause diarrhea. Diarrhea is when you have loose bowel movements (watery poo) or you need to go poo (have bowel movements) more often than usual. Diarrhea may start a few days after your treatment.

You may be given a medication called loperamide (Imodium®) to help treat your diarrhea. Take this medication only if you need it. Keep your loperamide with you all the time. When diarrhea starts, take the loperamide right away and drink more fluids.

What else do I need to know while on this medication?

Will this medication interact with other medications or natural health products?
- This medication can interact with other medications, vitamins, foods and natural health products. Interactions can make the treatment not work as well or cause severe side effects.
- Tell your health care team about all of your:
  - prescription and over-the-counter (non-prescription) medications and all other drugs, such as cannabis/marijuana (medical or recreational)
  - natural health products such as vitamins, herbal teas, homeopathic medicines, and other supplements
- Check with your health care team before starting or stopping any of them.
If you take seizure medications (such as phenytoin), your health care team may monitor your blood levels closely and may change your dose.
What should I do if I feel unwell, have pain, a headache or a fever?
- Always check your temperature to see if you have a fever before taking any medications for fever or pain (such as acetaminophen (Tylenol®) or ibuprofen (Advil®)).
  - Fever can be a sign of infection that may need treatment right away.
  - If you take these medications before you check for fever, they may lower your temperature and you may not know you have an infection.
How to check for fever:

Keep a digital (electronic) thermometer at home and take your temperature if you feel hot or unwell (for example, chills, headache, mild pain).
- You have a fever if your temperature taken in your mouth (oral temperature) is:
  - 38.3°C (100.9°F) or higher at any time
    
    OR
  - 38.0°C (100.4°F) or higher for at least one hour.
If you do have a fever:
- Try to contact your health care team. If you are not able to talk to them for advice, you MUST get emergency medical help right away.
- Ask your health care team for the Fever pamphlet for more information.
If you do not have a fever but have mild symptoms such as headache or mild pain:
- Ask your health care team about the right medication for you. Acetaminophen (Tylenol®) is a safe choice for most people.
- Talk to your health care team before you start taking Ibuprofen (Advil®, Motrin®), naproxen (Aleve®) or ASA (Aspirin®), as they may increase your chance of bleeding or interact with your cancer treatment.
- Talk to your health care team if you already take low dose aspirin for a medical condition (such as a heart problem). It may still be safe to take.

What to DO while on this medication:

DO check with your health care team before getting any vaccinations, surgery, dental work or other medical procedures.

What NOT to DO while on this medication:

DO NOT eat or drink grapefruit, starfruit, Seville oranges or their juices (or products that contain these) while taking this drug. They may increase the amount of drug in your blood and increase side effects.
DO NOT smoke or drink alcohol while on treatment without talking to your health care team first. Smoking and drinking can make side effects worse and make your treatment not work as well.

How should I safely store this medication?

Do not throw out any unused medications at home. Bring them to your pharmacy to be thrown away safely.
Keep this medication in the original packaging at room temperature in a dry place, away from heat and light. Keep out of sight and reach of children and pets.
How to safely touch oral anti-cancer medications

If you are a patient:
- Wash your hands before and after touching your oral anti-cancer medication.
- Swallow each pill whole. Do not crush or chew your pills.
If you are a caregiver:
- Wear nitrile or latex gloves when touching tablets, capsules or liquids.
- Wash your hands before putting on your gloves and after taking them off, even if your skin did not touch the oral anti-cancer medication.
- Throw out your gloves after each use. Do not re-use gloves.
- Do not touch oral anti-cancer medications if you are pregnant or breastfeeding.
What to do if oral anti-cancer medication gets on your skin or in your eyes

If medication gets on your skin:
- Wash your skin with a lot of soap and water.
- If your skin gets red or irritated, talk to your health care team.
If medication gets in your eyes:
- Rinse your eyes with running water right away. Keep water flowing over your open eyes for at least 15 minutes.

What are the side effects of this medication?

The following table lists side effects that you may have when taking abemaciclib. The table is set up to list the most common side effects first and the least common last.
It is unlikely that you will have all of the side effects listed and you may have some that are not listed.

Read over the side effect table so that you know what to look for and when to get help. Refer to this table if you experience any side effects while on abemaciclib.

Very Common Side Effects (50 or more out of 100 people)
Diarrhea (may be severe) What to look for? Loose, watery, unformed stool (poo) that may happen days to weeks after you get your treatment. What to do? If you have diarrhea: Take anti-diarrhea medication if your health care team prescribed it or told you to take it. Do not eat foods or drinks with artificial sweetener (like chewing gum or ‘diet’ drinks), coffee and alcohol. Eat many small meals and snacks instead of 2 or 3 large meals. Drink at least 6 to 8 cups of liquids each day, unless your health care team has told you to drink more or less. Talk to your health care team if you can’t drink 6 to 8 cups of liquids each day when you have diarrhea. You may need to drink special liquids with salt and sugar, called Oral Rehydration Therapy. Talk to your health care team if your diarrhea does not improve after 24 hours of taking diarrhea medication or if you have diarrhea more than 7 times in one day. Ask your health care team for the Diarrhea pamphlet for more information.	Talk to your health care team if no improvement after 24 hours of taking diarrhea medication or if severe (more than 7 times in one day)

Very Common Side Effects (50 or more out of 100 people)

Side effects and what to do

When to contact health care team

Diarrhea

(may be severe)

What to look for?

Loose, watery, unformed stool (poo) that may happen days to weeks after you get your treatment.

What to do?

If you have diarrhea:

Take anti-diarrhea medication if your health care team prescribed it or told you to take it.
Do not eat foods or drinks with artificial sweetener (like chewing gum or ‘diet’ drinks), coffee and alcohol.
Eat many small meals and snacks instead of 2 or 3 large meals.
Drink at least 6 to 8 cups of liquids each day, unless your health care team has told you to drink more or less.
Talk to your health care team if you can’t drink 6 to 8 cups of liquids each day when you have diarrhea. You may need to drink special liquids with salt and sugar, called Oral Rehydration Therapy.
Talk to your health care team if your diarrhea does not improve after 24 hours of taking diarrhea medication or if you have diarrhea more than 7 times in one day.

Ask your health care team for the Diarrhea pamphlet for more information.

Talk to your health care team if no improvement after 24 hours of taking diarrhea medication or if severe (more than 7 times in one day)

Common Side Effects (25 to 49 out of 100 people)
Side effects and what to do	When to contact health care team
Low neutrophils (white blood cells) in the blood (neutropenia) (may be severe) When neutrophils are low, you are at risk of getting an infection more easily. Ask your health care team for the Neutropenia (Low white blood cell count) pamphlet for more information. What to look for? If you feel hot or unwell (for example if you have chills or a new cough), you must check your temperature to see if you have a fever. Do not take medications that treat a fever before you take your temperature (for example, Tylenol®, acetaminophen, Advil® or ibuprofen). Do not eat or drink anything hot or cold right before taking your temperature. You have a fever if your temperature taken in your mouth (oral temperature) is: 38.3°C (100.9°F) or higher at any time OR 38.0°C (100.4°F) or higher for at least one hour. What to do? If your health care team has told you that you have low neutrophils: Wash your hands often to prevent infection. Check with your health care team before getting any vaccines, surgeries, medical procedures or visiting your dentist. Keep a digital thermometer at home so you can easily check for a fever. If you have a fever: If you have a fever, try to contact your health care team. If you are unable to talk to the team for advice, you must get emergency medical help right away.	If you have a fever, try to contact your health care team. If you are unable to talk to the team for advice, you MUST get emergency medical help right away.
Low platelets in the blood When your platelets are low, you are at risk for bleeding and bruising. Ask your health care team for the Low Platelet Count pamphlet for more information. What to look for? Watch for signs of bleeding: bleeding from your gums unusual or heavy nosebleeds bruising easily or more than normal black coloured stools (poo) or blood in your stools (poo) coughing up red or brown coloured mucus dizziness, constant headache or changes in your vision heavy vaginal bleeding red or pink coloured urine (pee) What to do? If your health care team has told you that you have low platelets: Tell your pharmacist that your platelet count may be low before taking any prescriptions or over-the-counter medication. Check with your healthcare team before you go to the dentist. Take care of your mouth and use a soft toothbrush. Try to prevent cuts and bruises. Ask your health care team what activities are safe for you. Your treatment may have to be delayed if you have low platelets. Your health care team may recommend a blood transfusion. If you have signs of bleeding: If you have a small bleed, clean the area with soap and water or a saline (saltwater) rinse. Apply pressure for at least 10 minutes. If you have bleeding that does not stop or is severe (very heavy), you must get emergency medical help right away.	Talk to your health care team if you have any signs of bleeding. If you have bleeding that doesn’t stop or is severe (very heavy), you MUST get emergency help right away.
Fatigue What to look for? Feeling of tiredness or low energy that lasts a long time and does not go away with rest or sleep. What to do? Be active. Aim to get 30 minutes of moderate exercise (you are able to talk comfortably while exercising) on most days. Check with your health care team before starting any new exercise. Pace yourself, do not rush. Put off less important activities. Rest when you need to. Ask family or friends to help you with things like housework, shopping, and child or pet care. Eat well and drink at least 6 to 8 glasses of water or other liquids every day (unless your health care team has told you to drink more or less). Avoid driving or using machinery if you are feeling tired. Ask your health care team for the Fatigue pamphlet for more information.	Talk to your health care team if it does not improve or if it is severe
Nausea and vomiting (Generally mild) What to look for? Nausea is feeling like you need to throw up. You may also feel light-headed. You may feel nausea within hours to days after your treatment. What to do? To help prevent nausea: It is easier to prevent nausea than to treat it once it happens. Take your anti-nausea medication(s) as prescribed, even if you do not feel like throwing up. Drink clear liquids and have small meals. Get fresh air and rest. Do not eat spicy, fried foods or foods with a strong smell. Limit caffeine (like coffee, tea) and avoid alcohol. If you have nausea or vomiting: Take your rescue (as-needed) anti-nausea medication(s) as prescribed. Ask your health care team for the Nausea & Vomiting pamphlet for more information. Talk to your health care team if: nausea lasts more than 48 hours vomiting lasts more than 24 hours or if it is severe	Talk to your health care team if nausea lasts more than 48 hours or vomiting lasts more than 24 hours or if severe

Less Common Side Effects (10 to 24 out of 100 people)
Side effects and what to do	When to contact health care team
Abnormal kidney lab tests Your health care team may check your kidney function regularly with a blood test. What to look for? Signs of a kidney problem include: Swelling Passing very little or no pee New unusual weight gain Nausea (feeling like you need to throw up) and vomiting Loss of appetite Fatigue and weakness Muscle twitches and cramps Itchiness that won’t go away What to do? If you have these signs, talk to your health care team or go to your closest emergency department. To prevent bladder or kidney problems, drink lots of water or other liquids. Your doctor may ask you to drink at least 6 to 8 cups (2 L) per day on treatment days, unless you have been told otherwise.	Talk to your health care team if it does not improve or if it is severe
Headache; Mild joint, muscle pain or cramps What to look for? Mild headache New pain in your muscles or joints, muscle cramps, or feeling achy. What to do? Take pain medication (acetaminophen or opioids such as codeine, morphine, hydromorphone, oxycodone) as prescribed. Read the above section: "What should I do if I feel unwell, have pain, a headache or a fever?" before taking acetaminophen (Tylenol®), ibuprofen (Advil®, Motrin®), naproxen (Aleve®) or Aspirin. These medications may hide an infection that needs treatment or they may increase your risk of bleeding. Rest often and try light exercise (such as walking) as it may help. Ask your health care team for the Pain pamphlet for more information.	Talk to your health care team if it does not improve or if it is severe
Cough and feeling short of breath (May be severe) What to look for? You may have a cough and feel short of breath. Symptoms that commonly occur with a cough are: Wheezing or a whistling breathing Runny nose Sore throat Heartburn Weight loss Fever and chills Rarely this may be severe with chest pain, trouble breathing or coughing up blood. What to do? Check your temperature to see if you have a fever. Read the above section "What should I do if I feel unwell, have pain, a headache or a fever?" If you have a fever, try to talk to your health care team. If you are not able to talk to them for advice, you MUST get emergency medical help right away. If you have a severe cough with chest pain, trouble breathing or you are coughing up blood, get medical help right away.	Talk to your health care team. If you are not able to talk to your health care team for advice, and you have a fever or severe symptoms, you MUST get emergency medical help right away.
Mouth sores What to look for? Round, painful, white or gray sores inside your mouth that can occur on the tongue, lips, gums, or inside your cheeks. In more severe cases they may make it hard to swallow, eat or brush your teeth. They may last for 3 days or longer. What to do? To help prevent mouth sores: Take care of your mouth by gently brushing and flossing regularly. Rinse your mouth often with a homemade mouthwash. To make a homemade mouthwash, mix 1 teaspoonful of baking soda and 1 teaspoonful of salt in 4 cups (1L) of water. Do not use store-bought mouthwashes, especially those with alcohol, because they may irritate your mouth. If you have mouth sores: Avoid hot, spicy, acidic, hard or crunchy foods. Your doctor may prescribe a special mouthwash to relieve mouth sores and prevent infection. Talk to your health care team as soon as you notice mouth or lip sores or if it hurts to eat, drink or swallow. Ask your health care team for the Oral Care (Mouth Care) pamphlet for more information.	Talk to your health care team as soon as you notice mouth or lip sores or if it hurts to eat, drink or swallow
Low appetite; Weight loss What to look for? Loss of interest in food or not feeling hungry. Weight loss. What to do? Try to eat your favourite foods. Eat small meals throughout the day. You may need to take meal supplements to help keep your weight up. Talk to your health care team if you have no appetite. Ask your health care team for the Loss of Appetite pamphlet for more information.	Talk to your health care team if it does not improve or if it is severe
Liver problems (May be severe) Your health care team may check your liver function with a blood test. The liver changes do not usually cause any symptoms. What to look for? Rarely, you may develop yellowish skin or eyes, unusually dark pee or pain on the right side of your belly. This may be severe. What to do? If you have any symptoms of liver problems, get emergency medical help right away.	Get emergency medical help right away
Rash; itchiness, dry, itchy skin What to look for? You may have cracked, rough, flaking or peeling areas of the skin. Your skin may look red and feel warm, like a sunburn. Your skin may itch, burn, sting or feel very tender when touched. What to do? To prevent and treat dry skin: Use fragrance-free skin moisturizer. Protect your skin from the sun and the cold. Use sunscreen with UVA and UVB protection and a SPF of at least 30. Avoid perfumed products and lotions that contain alcohol. Drink 6 to 8 cups of non-alcoholic, non-caffeinated liquids each day, unless your health care team has told you to drink more or less. Rash may be severe in some rare cases and cause your skin to blister or peel. If this happens, get emergency medical help right away.	Talk to your health care team if it does not improve or if it is severe
Hair thinning or loss (Generally mild) What to look for? Your hair may begin to become thin or fall out during or after treatment. In most cases, your hair will grow back after treatment, but the texture or colour may change. In very rare cases, hair loss may be permanent. What to do? Use a gentle soft brush. Do not use hair sprays, bleaches, dyes and perms.	Talk to your health care team if this bothers you
Mild swelling What to look for? You may have mild swelling or puffiness in your arms and/or legs. Rarely, this may be severe. What to do? To help prevent swelling: Eat a low-salt diet. If you have swelling: Wear loose-fitting clothing. For swollen legs or feet, keep your feet up when sitting.	Talk to your health care team if it does not improve or if it is severe
Constipation What to look for? Having bowel movements (going poo) less often than normal. Small hard stools (poo) that look like pellets. The need to push hard and strain to have any stool (poo) come out. Stomach ache or cramps. A bloated belly, feeling of fullness, or discomfort. Leaking of watery stools (poo). Lots of gas or burping. Nausea or vomiting. What to do? To help prevent constipation: Try to eat more fiber rich foods like fruits with skin, leafy greens and whole grains. Drink at least 6 to 8 cups of liquids each day unless your health care team has told you to drink more or less. Be Active. Exercise can help to keep you regular. If you take opioid pain medication, ask your health care team if eating more fibre is right for you. To help treat constipation: If you have not had a bowel movement in 2 to 3 days you may need to take a laxative (medication to help you poo) to help you have regular bowel movements. Ask your health care team what to do. Ask your health care team for the Constipation Pamphlet for more information.	Talk to your health care team if it does not improve or if it is severe
Dizziness What to look for? You may feel light-headed and like you might faint (pass out). What to do? Lay down right away so you do not fall. Slowly get up and start moving once you feel better. Do not drive a motor vehicle or use machinery if you feel dizzy.	Talk to your health care team if it does not improve or if it is severe

Other rare, but serious side effects are possible.
If you experience ANY of the following, speak to your cancer health care provider or get emergency medical help right away:

Irregular heartbeat, chest pain or fainting (passing out).
Pain, swelling and hardening of a vein in an arm or leg
Sudden or severe headache, trouble seeing, speaking, or using your arms and legs.
Signs of an allergic reaction: Itchiness, rash, swollen lips, face or tongue, chest and throat tightness.

Who do I contact if I have questions or need help?

My cancer health care provider is: ______________________________________________

During the day I should contact:________________________________________________

Evenings, weekends and holidays:______________________________________________

Other Notes:

____________________________________________________________________________

For more links on how to manage your symptoms go to www.cancercareontario.ca/symptoms.

The information set out in the medication information sheets, regimen information sheets, and symptom management information (for patients) contained in the Drug Formulary (the "Formulary") is intended to be used by health professionals and patients for informational purposes only. The information is not intended to cover all possible uses, directions, precautions, drug interactions or side effects of a certain drug, nor should it be used to indicate that use of a particular drug is safe, appropriate or effective for a given condition.

A patient should always consult a healthcare provider if he/she has any questions regarding the information set out in the Formulary. The information in the Formulary is not intended to act as or replace 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.

Info Sheet (English):

abemaciclib patient.pdf Info Sheet (French):

abmaciclib pour le patient.pdf Monograph:

abemaciclib.pdf Funding Program: Exceptional Access Program Funding Instance:

abemaciclib - For the adjuvant treatment, in combination with endocrine therapy, of adult patients with HR-positive, HER2-negative, node-positive early breast cancer at high risk of disease recurrence, according to criteria

Phonetic Spelling:

a bem a SYE klib

Cancer Type: Breast Type of Content: Drug Monograph Status: Null Info Sheet Status: Null Global Date: Thursday, February 27, 2025 Universal Date: 2025-02-27 00:00:00 AddThis: Title URL: abemaciclib Drug Display Status: Active Revision Summary:
Drug Monograph: Updated Supplementary Public Funding section