Oral Drugs Put a Focus on Adherence, Communication in Second-Line Breast Cancer

The advent of elacestrant (Orserdu) has drastically changed the second-line treatment landscape for patients with HR-positive, HER2-negative metastatic breast cancer who develop an ESR1 mutation after hormone therapy.

Since elacestrant—like other frontline therapies in this patient population—is an oral regimen, it puts a key focus on patient-provider communication to monitor for adherence and adverse events.

At a recent community case forum, Michelle Taylor, ANP, and other nurses and advanced practice providers discussed the evolving landscape of second-line treatment of HR-positive, HER2-negative metastatic breast cancer.

“We know we've had some recent changes in this field over the last couple years, which are quite exciting for our patients,” Taylor, who is a nurse practitioner at Dignity Health Cancer Institute at St. Joseph’s in Phoenix, AZ, said.

Considerations for Second-Line Therapy

Taylor mentioned that patients who have been on letrozole and an oral CDK4/6 inhibitor for years may not want to undergo chemotherapy or have to come into the infusion center to receive IV drugs.

“They've been able to treat this as like a chronic disease, and [sometimes] they don't really understand that this is a chronic disease, but it's an incurable chronic disease. So that means … eventually, in this setting, we will have to transition to an IV,” Taylor said.

The duration of prior therapies may also be considered when choosing a second-line therapy for this patient population. Of note, in a poll conducted at the forum, most attendees mentioned that patients at their practice are typically receiving a CDK4/6 inhibitor for approximately 1 year at their practice. Elacestrant tends to be more effective in patients who have been on an AI or fulvestrant plus CDK4/6 inhibitor for longer than 12 months, Taylor explained.

Elacestrant is an oral drug that is approved for ER-positive, HER2-negative ESR1-mutant advanced or metastatic breast cancer that has progressed after being treated with endocrine therapy. Considering the drug’s efficacy in this patient population—the phase 3 EMERALD trial (NCT03778931) demonstrated an improved progression-free survival (PFS) with elacestrant compared to standard of care—ESR1 testing is essential after a patient experiences progression.

“You have all those other older drugs you can reserve for later if you have something actionable now,” one attendee mentioned.

READ MORE: ESR1 Testing Is Crucial in Second-line HR+, HER2- Metastatic Breast Cancer

A Focus on Oral Adherence and Adverse Events

Similar to frontline CDK4/6 inhibitors, elacestrant is an oral drug, which puts a major focus on patient adherence. During the forum, Taylor asked attendees about the protocols they put in place to ensure that patients take their medications properly.

“Navigators and educators that go that have a chemo class for them … and then we go and reinforce,” one attendee said. “Every time we see them, we go over compliance, and then we have an oral compliance person that calls them as well.”

Providers should also discuss adverse events (AEs) with patients, as they can not only impact adherence but patient quality of life, too.

Since elacestrant can cause diarrhea, Taylor asked the panel of experts what they recommend for the AE. Answered included:

• Metamucil
• Immodium
• Banana flakes or prune juice

However, if patients are relying daily on those methods to treat diarrhea, it may indicate that they actually need a change in their elacestrant dosing.

“But if they’re using these every day, several times a day, then we need to do something with a dose adjustment,” Taylor said. “So I want to hear about those side effect reports and what they’re really dealing with.”

Others echoed Taylor’s sentiment that patient-provider communication is absolutely essential during the second-line treatment of HR-positive, HER2-negative metastatic breast cancer.

“With upfront management and frequent checks, patients tend to do just fine with those side effects,” an attendee said.