Verzenio (Abemaciclib): What to Expect, Side Effects, and More
If you were diagnosed with hormone receptor-positive, HER2-negative breast cancer, your doctor may prescribe Verzenio (chemical name abemaciclib) in combination with other hormonal therapies to prevent cancer from coming back or growing.
Verzenio is a type of targeted therapy called a CDK4/6 inhibitor, which interferes with the growth of cancer cells. Verzenio may be prescribed in the following situations:
You were diagnosed with advanced-stage or metastatic breast cancer and have gone through menopause. Your doctor may prescribe Verzenio in combination with an aromatase inhibitor. An aromatase inhibitor is a type of hormonal therapy that stops the body from making estrogen. Arimidex (chemical name: anastrozole), Aromasin (chemical name: exemestane), and Femara (chemical name: letrozole) are aromatase inhibitors.
You were diagnosed with advanced-stage or metastatic breast cancer that grew after receiving hormonal therapy treatment. Your doctor may prescribe Verzenio in combination with Faslodex (chemical name: fulvestrant). Faslodex blocks the ability of estrogen to fuel the growth of cancer.
You were diagnosed with advanced-stage or metastatic breast cancer that grew after receiving hormonal therapy and chemotherapy for metastatic cancer. Your doctor may prescribe Verzenio alone.
You were diagnosed with early-stage breast cancer and cancer cells were found in one or more of your lymph nodes during surgery. Your doctor may prescribe Verzenio in combination with either tamoxifen or an aromatase inhibitor. Verzenio is prescribed for two years when given for early-stage breast cancer.
See Verzenio prescribing information.
How Verzenio works
Cancer cells grow in an uncontrolled fashion. Like Ibrance (chemical name: palbociclib) and Kisqali (chemical name: ribociclib), Verzenio is a cyclin-dependent kinase (CDK) 4/6 inhibitor.
A kinase is a type of protein in the body that helps control cell division. CDK4/6 inhibitors work by interfering with the kinase and stopping cancer cells from dividing and growing.
What to expect during Verzenio treatment
Verzenio is a pill taken by mouth. The recommended starting doses of Verzenio are:
150 mg twice per day in combination with Faslodex, tamoxifen, or an aromatase inhibitor
200 mg twice per day used alone
There are certain medicines, supplements, and foods you should not take or eat if you are taking Verzenio.
You should not take a type of medicine called a strong CYP3A inhibitor because it increases the effects of Verzenio. This class of medicines includes antifungal medicines such as Nizoral (chemical name: ketoconazole).
You should not take a type of medicine called a strong CYP3A inducer because it decreases the effects of Verzenio. This class of medicines includes Rifamate (chemical name: rifampin), an antibiotic used to treat tuberculosis.
You should not eat grapefruit or drink grapefruit juice because they can increase the effects of Verzenio.
People who are pregnant or planning to get pregnant should not take Verzenio. Verzenio can harm the developing fetus. If there is any chance you can become pregnant, you must use effective birth control while you're taking Verzenio and for at least three weeks after your last dose.
Also, women who are breastfeeding or plan to breastfeed shouldn't take Verzenio. You and your doctor can decide if you should take Verzenio or breastfeed.
Pre-menopausal and peri-menopausal women who take Verzenio in combination with Faslodex also should take a medicine to suppress ovarian function.
Verzenio side effects
Like almost all breast cancer medicines, Verzenio can cause side effects, some of them severe.
The most common side effect of Verzenio is diarrhea, and for most people, it begins during the first week or so of treatment. If you’re prescribed Verzenio, your doctor will likely give you an anti-diarrheal medicine like Imodium (chemical name: loperamide) to take preventively.
Other common side effects of Verzenio are:
low red blood cell counts (anemia)
low platelet counts (thrombocytopenia)
Less commonly, Verzenio may cause serious side effects, including:
Liver problems: Tell your doctor right away if you have any of the following signs of liver problems:
yellowing of the skin or the whites of the eyes
dark or brown urine
feeling very tired
loss of appetite
pain on the upper right side of the abdomen
bleeding or bruising more easily than normal
Severe neutropenia (very low white blood cell count): Low white blood cell counts are a common side effect of Verzenio. Still, some women’s white blood cell counts may drop so low that they have to decrease the dose of Verzenio or stop treatment. Your doctor will check your white blood cell count before and during treatment with Verzenio.
Blood clots: Verzenio may cause serious or life-threatening blood clots in your arteries or lungs. Tell your doctor right away if you have shortness of breath, rapid heart rate, rapid breathing, or a sudden sharp chest pain.
Rare but severe lung inflammation: In some people, Verzenio may lead to severe pneumonia or interstitial lung disease. Interstitial lung disease describes a large group of conditions that cause scarring of the lungs. The scarring makes the lungs stiff, which makes it difficult to breathe. Tell your doctor right away if you have difficulty breathing or discomfort when you breathe or have shortness of breath when you’re resting or doing an activity that requires little exertion.
Because Verzenio is given with Faslodex, tamoxifen, or an aromatase inhibitor, you also may have side effects caused by those medicines.
Real patient reviews
Members of our community discuss their experiences with Verzenio in the community forum. Here are some of their comments. Remember, it's very important to talk to your doctor about any side effects you're having and ask about ways to manage them.
“The side effects were not fun — extreme fatigue, food aversion, and, of course, diarrhea — but the results are well worth it.” —seeq
“I am back on Verzenio after a few weeks break and a dosage change down to 100 mg twice a day. Other than a few bouts of diarrhea, I'm doing well at the one-week point.” —scaredme
“I’ve been on it for nine weeks now. It hasn’t been too bad. I did notice my leg hair isn’t coming back as fast. My biggest issue is fatigue. I get really tired at night.” —margecandoit
Read more in our Verzenio discussion forum.
Paying for Verzenio
The cost of Verzenio may vary. The price you’ll pay depends on the drug manufacturer, your health insurance provider and plan, where you live, and the pharmacy you use.
Note: Your insurance company may require you to get prior authorization before covering Verzenio.
Learn more about financial assistance and medicine cost-lowering tips.
— Last updated on January 31, 2025 at 6:15 PM
