New Hope For Some Early-Stage Breast Cancer Patients: FDA Approves Targeted Therapy Drug Verzenio

Women with early-stage HR-positive and HER-2 negative breast cancer could have a new standard of care, SurvivorNet experts say, as CDK4/CDK6 inhibitor drug Verzenio is now approved to treat these kinds of cancer.

“In breast cancer, we have been giving many of the same drugs for so many years. This is definitely going to change the way we treat women with breast cancer in this category,” Dr. Neil Vasan, a medical oncologist at Columbia University Irving Medical Center, tells SurvivorNet. “It’s great for patients that this is an option. We all have patients that have so much disease that this will be a really wonderful thing.”

The drug is already approved to treat patients with hormone receptor positive (HR-positive) and HER-2 negative advanced or metastatic breast cancer. Now, Verzenio is approved to treat patients HR-positive and HER-2 negative early-stage breast cancer.

However, patients with early-stage disease must be high-risk and node-positive, and their tumors must have a Ki-67 protein score greater than or equal to 20% as determined by an FDA-approved test. (Ki-67 is a protein in cells that increases as they prepare to divide into new cells.)

“The question in the real world is whether all women who fit the criteria will be given this drug, or only the highest risk women,” Dr. Vasan says. “I will discuss it with everyone. The FDA approval gives us more confidence to offer this drug.”

Related: Verzenio is Significant — it Cuts the Risk of Cancer Coming Back in Some Women With Early Breast Cancer — a First For CDK4/6 Inhibitors

Dr. Elizabeth Comen explains the main aspects of early-stage breast cancer.

‘New Standard of Care’

Dr. Charles Shapiro, professor of medicine, hematology and medical oncology at the Icahn School of Medicine at Mount Sinai, tells SurvivorNet that Verzenio combined with endocrine therapy “represents a new standard of care for women with high-risk early-stage breast cancers.”

There are three points about this new FDA approval that stand out to Dr. Shapiro:

• 1. Most women with early-stage breast cancers are diagnosed with tumors that are less than 5 centimeters in size and are node-negative, he says. So, according to this approval for Verzenio (high-risk and node positive), only “a minority of women will be eligible” for the drug.
• 2. Verzenio is a CDK4/CDK6 inhibitor, and not all CDK4/6 inhibitors are the same. “In a similarly designed phase 3 randomized trial of palbociclib (brand name: Ibrance, which is referenced later on) plus endocrine therapy didn’t meet the primary endpoint.”
• 3. Grade 3 or higher side effects occurred in 50% of trial participants, in particular diarrhea. Dr. Shapiro says that awareness of diarrhea and how to manage it is critical for Verzenio’s use.

Managing Diarrhea When Taking Verzenio

As Dr. Shapiro says, awareness of diarrhea and how to manage it is critical for patients who are taking Verzenio as about half of the clinical trial participants experienced this side effect at a grade 3 level.

Dr. Vasan says that grade 3 diarrhea is going to the bathroom seven times more than the baseline. “We don’t want anyone to have this,” he adds.

However, if you’re taking Verzenio and you do experience diarrhea, here’s how you can manage it:

• Start by taking loperamide (brand name: Imodium). This is a diarrhea relief medicine; you can increase dosage aggressively, Dr. Vasan says.
• If Imodium doesn’t work, prescription medications exist. If you think this might be the right fit for you, talk to your doctor.

How Does Verzenio Work?

Verzenio is a CDK4/CDK6 inhibitor which helps slow down the growth of cancer in women with HR-positive, HER-2 negative metastatic breast cancer. And now women with early-stage disease.

Dr. Elizabeth Comen explains how CDK4/CDK6 inhibitors help fight metastatic breast cancer.

CDK4/CDK6 inhibitors are targeted therapies which attack proteins known as the cyclin-dependent kinases 4 and 6 (CDK4/CDK6). These proteins control how quickly cells divide and multiply, and for women with breast cancer, these proteins can cause cancer cells to grow uncontrollably. That’s where CDK4/CDK6 inhibitors come in — they slow down or stop the proteins from multiplying.

Women with HR-positive and HER-2 negative early-stage breast cancer have a 30% likelihood of their cancer returning, but in the phase 3 clinical trial published last year, the CDK4/CDK6 inhibitor significantly cut the risk of recurrence for these women when given alongside post-surgery endocrine therapy.

Verzenio marks the first CDK4/CDK6 inhibitor to have significant impact on improving invasive disease-free survival.

Verzenio is Beating its Competition

The stage 3 clinical trial findings for Verzenio from last year and its subsequent FDA approval are especially significant. This is because Verzenio is the first CDK4/CDK6 inhibitor to show significant decrease in recurrence, unlike competitors palbociclib (brand name: Ibrance) and ribociclib (brand name: Kisqali).

In a prior phase 3 trial, studies didn’t support that Ibrance (when combined with endocrine therapy) prolonged the amount of time before a recurrence in early-stage breast cancers.

However, the Verzenio and Ibrance clinical trials were different. In the Ibrance trial, they studied women who were at moderate- to high-risk of recurrence, as opposed to the Verzenio trial, which solely looked at high-risk women.

Contributing: Shelby Black