Is Verzenio better than Ibrance?

• Patients taking Verzenio are more likely to live for longer without their breast cancer getting worse according to a recent retrospective trial.
• Severe diarhhea is more likely in those taking Verzenio compared with Ibrance.
• Verzenio is taken twice daily, every day. Ibrance is taken every day for 21 days followed by a 7-day break.
• Verzenio can be used as monotherapy or in combination with other treatments. Ibrance is always taken in combination with either an aromatase inhibitor or fulvestrant.
• Both Verzenio and Ibrance can be used as combination treatment to treat breast cancer in men.

Verzenio may be more effective than Ibrance in certain HR-positive, HER2-negative breast cancer patients but it does not seem to be as well tolerated. Clinical trials have shown more people stop Verzenio treatment due to gastrointestinal side effects, such as diarrhea, when compared with Ibrance. Ibrance appears more likely than Verzenio to cause Grade 3 to 4 neutropenia.

• Improved progression-free survival (length of time a patient lives with breast cancer but it does not get worse) was reported in endocrine-resistant patients and those without visceral involvement taking Verzenio compared to those taking Ibrance according to a recent retrospective trial.

Both Verzenio and Ibrance are CDK 4/6 inhibitors, which are a type of targeted treatment that helps to reduce the growth and spread of cancer cells in the body. The active ingredient in Verzenio is abemaciclib and in Ibrance it is palbociclib.

Both Verzenio and Ibrance are used to treat advanced or metastatic breast cancer in adults with HR-positive, HER2-negative (HR+ HER2-) disease. They are given when cancer has progressed or spread to other parts of the body despite other treatments. Verzenio is also approved to treat adults with early breast cancer at high risk of recurrence in combination with endocrine treatment (tamoxifen or an aromatase inhibitor).

Both Verzenio and Ibrance can be used in combination with an aromatase inhibitor or, in those who have not reached menopause, with fulvestrant intramuscular injection.

Related questions

• How long does Ibrance extend life?
• Will insurance pay for the cost of Ibrance?
• What are 10 key Ibrance side effects to watch out for?

What is the difference in dosing between Verzenio and Ibrance?

Verzenio is taken twice daily, every day, whereas Ibrance is taken every day for 21 days followed by a 7-day break.

Verzenio can be used as monotherapy or in combination with other treatments. Ibrance is always taken in combination with either an aromatase inhibitor or fulvestrant.

Verzenio is more likely than Ibrance to cause diarrhea, which is a common reason people stop taking Verzenio, although many patients can manage this side effect with the anti-diarrhea medication loperamide.

How do Verzenio and Ibrance work?

Verzenio and Ibrance belong to the class of medicines known as CDK4/6 inhibitors. CDK4/6 inhibitors target particular enzymes, called CDK4 and CDK6. CDK stands for cyclin-dependent kinase, and it is an enzyme that is important for cell division. CDK4/6 inhibitors interrupt signals that stimulate the growth of cancerous cells.

Certain cancers, for example, hormone-receptor-positive breast cancer, are more likely to have disturbances in CDK4/6, and CDK 4/6 inhibitors may form part of the treatment protocol. Most often, CDK4/6 inhibitors are given at the same time as hormonal therapy (such as an aromatase inhibitor or fulvestrant), although Verzenio may be used alone to treat HR+ HER2- metastatic breast cancer in pre-treated patients.

Research suggests CDK4/6 inhibitors may increase the time people have before cancer spreads. More evidence is needed to determine their impact on overall survival.

Common side effects include fatigue and gastrointestinal disturbances, such as nausea, severe diarrhea, and vomiting. Bone marrow suppression resulting in neutropenia and leukopenia may also occur, although anemia and thrombocytopenia are less common. In general, the side effects associated with CDK4/6 inhibitor therapy are less severe than those experienced with chemotherapy.