Use of New Cancer Drugs Needs a ‘Tincture of Time and Information’

While effective new cancer therapies have been approved in recent years, clinician education and patient advocacy is key to putting these drugs into practice, explained Jamie L. Carroll, APRN, CNP, MSN, of the Mayo Clinic.

In a recent Community Case Forum, Carroll and colleagues discussed the evolving second-line treatment landscape of patients with HR-positive, HER2-negative metastatic breast cancer. She mentioned that many community cancer centers treat with palbociclib (Ibrance) because that was the first CDK4/6 inhibitor to be approved for HR-positive, HER2-negative metastatic breast cancer that progressed on endocrine therapy_^.1

“Many of the community settings are using palbociclib because that was the first drug to market. In the academic center, we tend to use the other CDK4/6 inhibitors, but they came after [Palbociclib], so I think it's just going to be the tincture of time in getting that information to them and then having them start using and becoming familiar with new drugs and new therapies,” Carroll said in an interview with Oncology Nursing News after the event.

Among patients whose disease becomes recurrent to endocrine therapies, ESR1 mutations are common, occurring in 10-50% of metastatic endocrine therapy-resistant cancers.² For this population with ER-positive, HER2-negative breast cancer, the FDA approved elacestrant (Orserdu) — an oral selective estrogen receptor degrader (SERD).3

This approval put an importance on testing patients for ESR1 mutations after they experience disease progression on a CDK4/6 inhibitor.

“You don't need to test your patients every 3 months or every 6 months looking for an ESR1 mutation. You would test them when they progress on their CDK4/6 [inhibitor] to see, are they eligible for elacestrant,” Carroll explained during the forum. “It's also important that you don't use archived tissue.”

A poll at the forum asked nurses and advanced practice providers (APPs) in attendance what molecular testing method they would use for a patient with HR-positive, HER2-negative breast cancer who experienced disease progression on a CDK4/6 inhibitor. Answers were as follows:

• Tissue-based next-generation sequencing (NGS; fresh biopsy): 0%
• Peripheral blood (plasma) ctDNA: 64.3%
• Tissue-based NGS plus concurrent ctDNA: 0%
• Tissue-based NGS with ctDNA at progression: 35.7%

“For my clinic, we're looking for actionable mutations. So we're looking for biomarkers that we can do something with. We’re looking for an ESR1 mutation,” Carroll said.

Since nurses and APPs tend to spend more time with patients, they can be advocates to physicians for the best treatment option for each individual patients.

“It might be [a matter of saying] I just know my patient better. I know this little old lady that lives in Denison, Minnesota is not going to be able to get back for these labs. Or, you know, I know that transportation is an issue for her, or the financial toxicity piece, or she's not going to remember to take a pill three days on two days off,” Carroll said. “I feel like I know my patients really well.”

References

1. FDA. Palbociclib (Ibrance) Published February 22, 2016. Accessed October 30, 2024. https://www.fda.gov/drugs/resources-information-approved-drugs/palbociclib-ibrance-capsules

2. Zundelevich A, Dadiani M, Kahana-Edwin S, et al. ESR1 mutations are frequent in newly diagnosed metastatic and loco-regional recurrence of endocrine-treated breast cancer and carry worse prognosis. Breast Cancer Res. 2020 Feb 3;22:16. doi: 10.1186/s13058-020-1246-5

• FDA approves elacestrant for ER-positive, HER2-negative, ESR1-mutated advanced or metastatic breast cancer. FDA. November 1, 2024. Accessed January 27, 2023. bit.ly/3Hbxxln