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How long do you take Verzenio for?

Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on Nov 6, 2023.

Official answer


Key Points

  • You will typically continue your Verzenio treatment until you have unacceptable side effects or the disease progresses. Do not stop taking your medicine or change your dose unless your doctor tells you to. Take Verzenio exactly as prescribed.
  • If you are having side effects, speak with your doctor. Your doctor may decide that a dose interruption or a dose reduction is needed based on how you are tolerating Verzenio treatment.
  • Studies have shown that Verzenio may prolong your overall survival or length of time before the disease worsens. Therefore, if you choose treatment, it is important you continue your medication exactly as your doctor prescribes.

What is Verzenio?

Verzenio (abemaciclib) is an oral medicine used to treat a type of breast cancer known as HR+/HER2– (hormone receptor positive/human epidermal growth factor receptor 2–negative) in certain patients. HR+, HER2– breast cancer makes up approximately 70% of all breast cancers. Men and women of all ages can be diagnosed with breast cancer.

Verzenio is considered a targeted drug treatment, not a chemotherapy. It is known as a CDK 4 & 6 inhibitor and is given as an oral tablet taken twice a day. It works by blocking cyclin-dependent kinases 4 and 6 involved in promoting the growth of cancer cells.

Verzenio is given:

  • in combination with endocrine therapy (tamoxifen or an aromatase inhibitor) for the adjuvant treatment of adult women or men with HR+/HER2-, node-positive, early breast cancer at high risk of recurrence
  • if the cancer has spread to other parts of the body (metastasized), Verzenio can be used in 3 different groups: 1) In postmenopausal women, and men, it is given with an aromatase inhibitor as initial endocrine-based therapy. 2) It can be given in combination with fulvestrant in women or men whose cancer has gotten worse after hormone therapy. 3) in female or males whose cancer has gotten worse after both hormonal therapy and chemotherapy, and it is given alone.

How long did people take Verzenio in clinical studies?

Studies looking at the effectiveness of Verzenio looked at different endpoints, such as overall survival (OS) and profession-free survival (PFS).

  • Overall survival (OS) is how long someone lives with cancer overall, either after their diagnosis or after the time they start their medication. In terms of Verzenio, OS is the number of days, months, or years that this might add to life.
  • Progression-free survival (PFS) is the amount of time during and after treatment that the cancer does not worsen (progress). For example, with Verzenio, PFS is how long cancer growth is delayed from the time the treatment is started.

Verzenio in combination with an Aromatase Inhibitor (AI)

Verzenio was studied in combination with an AI (letrozole or anastrozole) as the first endocrine-based therapy in 493 postmenopausal women with newly diagnosed HR+/HER2– advanced or metastatic breast cancer (MBC). Overall, 328 patients were treated with Verzenio + AI and 165 were treated with an AI alone. Median duration of treatment was 15.1 months for the group taking Verzenio plus an AI.

  • In this study done by the manufacturers, Verzenio allowed patients to live longer without their cancer getting worse. Verzenio, when added to an AI, delayed disease progression for over 2 years (a median of 28.2 months) compared to 14.8 months when using an AI alone.
  • Over 50% of women saw their tumor shrink. Results showed that 55.4% of women on Verzenio plus an AI saw their tumors shrink compared to 40.2% of patients on an AI alone.
  • Clinical trials are still ongoing to determine if there is an overall survival benefit with Verzenio.

Verzenio plus fulvestrant

Verzenio was studied in a clinical trial of 669 women with HR+/HER2- MBC, whose disease had progressed after hormone treatment (such as with letrozole or anastrozole). In this study, 446 patients were treated with Verzenio plus fulvestrant, and 223 were treated with fulvestrant alone. The median duration of treatment with Verzenio plus fulvestrant was 12 months.

  • Verzenio plus fulvestrant helped women live significantly longer when compared to fulvestrant alone. In a clinical study, women taking Verzenio plus fulvestrant lived for a median of 46.7 months compared to 37.3 months on fulvestrant alone, regardless of menopausal status.
  • In the same study, Verzenio plus fulvestrant delayed disease progression for a median of 16.4 months compared to 9.3 months in the group that received fulvestrant alone.

Verzenio alone (monotherapy)

In this study, 132 patients with HR+/HER2– MBC were only treated with Verzenio. These patients, whose cancer had spread in the body, had progressed on or after prior hormone treatments, a taxane, and 1 or 2 chemotherapy regimens. The median duration of treatment with Verzenio was 4.5 months.

  • This study showed that Verzenio shrank tumors and delayed the spread of cancer when other treatments had stopped working. Overall, 19.7% of women (or 17.4% of women in an independent review) taking Verzenio alone saw their tumors shrink by 30% or more.
  • The median duration of response to treatment was 8.6 months (7.2 months by an independent review).

Verzenio in early breast cancer

The monarchE study looked at 2,003 eligible women and men with HR-positive, HER2-negative, node-positive early breast cancer at high risk of recurrence.

Patients were randomized to receive two years of Verzenio 150 mg twice daily plus physician's choice of hormone therapy, or hormone therapy alone. Patients in both treatment arms were instructed to continue to receive hormone therapy for up to 5 to 10 years as recommended by their doctor.

The primary endpoint of the study (still ongoing) is invasive disease-free survival (IDFS). IDFS is the length of time before breast cancer comes back, any new cancer develops, or death.

  • Verzenio given in combination with endocrine therapy showed a 37% decrease in the risk of breast cancer recurrence or death compared to standard endocrine therapy alone.
  • The number of IDFS events at the time of this analysis at 36 months was 104 with Verzenio plus hormone therapy compared to 158 with hormone therapy alone. A total of 95 (4.7%) of patients had died.
  • Overall survival data are not yet completed and additional follow up with patients is ongoing.

Related Questions

Common side effects with Verzenio treatment

Various types of side effects can occur frequently with Verzenio treatment. Discuss the risk of side effects with your doctor prior to treatment.

The most common side effects, occuring in more than 20% of patients, include:

  • Nausea
  • Abdominal (stomach area) pain
  • Diarrhea
  • Infections
  • Feeling tired
  • Low red or white blood cell counts (anemia, leukopenia)
  • Decreased appetite
  • Vomiting
  • Headache
  • Low platelet counts (thrombocytopenia)
  • Hair thinning or hair loss (alopecia)


In studies with Verzenio, diarrhea was a common side effect and can sometimes be severe. In most cases, diarrhea occurs during the first month, then decreases. However, the diarrhea can lead to dehydration or infection. Overall, roughly 81% to 90% of patients experienced diarrhea among the various clinical studies with Verzenio.

In most cases, the median time until patients had the first symptoms of diarrhea was about seven to eight days. Moderate to more significant diarrhea lasted between roughly 5 to 11 days, but was variable based on studies.

At the first sign of loose stools, tell your doctor. Diarrhea can be managed by your doctor with an anti-diarrhea medication such as loperamide (Imodium). Your doctor may also decide to reduce your dose. About 15% to 25% of patients may need a dose omission or lowering of a dose due to diarrhea, but this can vary between patients.

Be sure you have an over-the-counter anti-diarrhea medicine, such as loperamide (Imodium) available at home before you start taking Verzenio. Work out an action plan with your doctor about how to address diarrhea if it occurs.

Hair thinning or hair loss

On average, 12% to 27% of patients who received Verzenio experienced hair thinning or loss. Patients taking Verzenio plus an aromatase inhibitor (such as letrozole or anastrozole) experienced the greatest risk of hair thinning or loss at 27% of patients.

These are not all the possible side effects of Verzenio. Speak to your doctor about the possibility of serious and common side effects with Verzenio.

Verzenio and grapefruit Juice

Avoid grapefruit products while taking Verzenio. Grapefruit may increase the amount of Verzenio in your blood due to a drug-food interaction.

Other serious side effects

Other serious side effects that can occur with Verzenio treatment include: neutropenia (low neutrophils, a type of white blood cell), a severe type of lung disease (Interstitial Lung Disease (ILD)/Pneumonitis), liver toxicity, blood clots, and harm to an unborn baby.

Learn more about serious side effects with Verzenio here.

Bottom Line

  • Verzenio is a treatment you will usually continue to take until your breast cancer progresses or side effects become intolerable. Do not stop this treatment unless your doctor tells you to. If you are having severe side effects, call your doctor immediately.
  • In clinical studies, Verzenio treatment prolonged the overall survival or length of time before the disease worsened in patients with various levels of breast cancer progression.
  • For severe side effects, a dose reduction or interruption may be needed, and your doctor can advise you on the best course of treatment. Certain medications can be used temporarily that may help with some effects, too.

This is not all the information you need to know about Verzenio for safe and effective use. Review the full Verzenio product information here, and discuss this information with your doctor or other health care provider.


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