• Although Verzenio starts inhibiting CDK4/6 enzymes quickly, it may take up two to four months before any change in outcomes, such as progression-free survival are noted. These changes have been shown to persist and deepen for the next 4 years at least.
• Verzenio reaches consistent blood levels within five days of taking it twice a day.
• Verzenio is a CDK4/6 inhibitor that works by interrupting signals that stimulate the growth of cancerous cells. Hormone-receptor-positive breast cancers are more likely to have disturbances in CDK4/6.
• Side effects, such as diarrhea usually occur within the first week or month of treatment.

Verzenio (abemaciclib) is a targeted treatment that helps to reduce the growth and spread of cancer cells in the body. It may be used to treat adults with HR+ HER2-, node-positive, early breast cancer at high risk of recurrence in combination with endocrine treatment (tamoxifen or an aromatase inhibitor). It may also be used to treat advanced or metastatic HR+ HER2- breast cancer.

Verzenio belongs to the class of medicines known as CDK 4/6 inhibitors which help to reduce the growth and spread of cancer cells in the body.

Verzenio is usually taken twice daily. When taken regularly, consistent blood levels are achieved within five days.

Gastrointestinal side effects, such as diarrhea, typically occur in the first month of treatment and can affect up to 81% of patients. The average time to onset of diarrhea was 6 to 8 days. Diarrhea can be severe and requires monitoring and proper management.

Clinical trials have shown Verzenio improves invasive disease-free survival for men or women with early breast cancer and high-risk clinical and pathological factors:

• Verzenio plus endocrine therapy (ET) decreases the risk of breast cancer recurrence by 35% compared to ET alone. 4-year data from the monarchE trial showed 85.5% of patients remained recurrence-free after 4 years compared to 78.6% of those assigned ET alone (an absolute difference of 6.9%).
• There was a statistically significant improvement in invasive disease free survival for a pre-specified subgroup of patients receiving Verzenio plus endocrine therapy (ET) compared to those who received ET alone (HR=0.643, 95% CI: 0.475, 0.872, p=0.0042)
• There was a 37% decrease in the risk of breast cancer recurrence or death compared to standard ET therapy alone (HR: 0.626 [95% CI: 0.49-0.80])
• An absolute benefit in invasive disease-free survival (IDFS) rate of 7.1% was reported at three years
• Preliminary results reported the number of IDFS events at the time of publication was 104 with Verzenio plus ET compared to 158 with ET alone.

For women taking Verzenio plus anastrozole or letrozole:

• Progression-free survival (the length of time without a worsening of their breast cancer) was longer with Verzenio: 28.2 months for women taking the Verzenio combination compared with 14.8 months for women taking the placebo combination
• 55.4% of women taking the Verzenio combination had either a complete response or a partial response compared to only 40.2% taking placebo
• A difference between progression-free survival rates with the Verzenio combination compared to the placebo combination was noted by two months with the most consistent differences reported from 4 months onwards

For women taking Verzenio in combination with fulvestrant:

• Fewer women experienced an “event” that impacted on their progression-free survival: 49.8% of women taking Verzenio experienced an event compared to 70.4% of those taking the placebo combination
• Overall survival was 46.7 months in women taking the Verzenio combination compared with 37.3 months in those taking the placebo combination
• 48.1% of women responded to the Verzenio combination compared with 21% of women taking the placebo combination.

For women taking Verzenio as monotherapy:

• 19.7% of women saw their tumors shrink by 30% or more
• The average duration of response was 8.6 months.

How does Verzenio work?

Verzenio belongs to the class of medicines known as CDK4/6 inhibitors. CDK4/6 inhibitors, such as Verzenio, 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 hormone receptor-positive, HER2-negative 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.