Rise of Innovative Therapies for Breast Cancer Treatment

The Denver Regional Institute for Value-Based Medicine® event included Mei Wei, MD, an oncologist specializing in breast cancer at Huntsman Cancer Institute at the University of Utah who contributed to the session “New Treatment Opportunities in HR+/HER2- Breast Cancer."

Wei spoke with The American Journal of Managed Care® to discuss significant improvements in progression-free survival (PFS) and overall survival (OS) in both nonmetastatic and metastatic settings. She focused on 2 FDA-approved antibody drug conjugates (ADCs): trastuzumab deruxtecan (T-DXd; Enhertu; Daiichi Sankyo/AstraZeneca) and sacituzumab govitecan (SG), which have both demonstrated improved PFS and OS in metastatic breast cancer.

This transcript has been lightly edited.

Transcript

Can you discuss some of the emerging therapies for HR+/HER2– breast cancer, such as CDK4/6 inhibitors, poly ADP-ribose polymerase (PARP) inhibitors, and antibody-drug conjugates?

I'm so excited we have so many treatment options we can offer our patients right now. In the adjuvant setting, now we can offer CDK4/6 inhibitors in addition to traditional aromatase inhibitors and tamoxifen, and in addition to the ovarian function suppressions.

Previously, we could only use abemaciclib, and now we have a new ribociclib. If a patient is unable to tolerate abemaciclib, we can try ribociclib. The ribociclib population is more broad, so if the patients are not eligible for abemaciclib, we can offer the patients ribociclib. This is a CDK4/6 inhibitor in the nonmetastatic setting.

In the metastatic setting, CDK4/6 inhibitors plus aromatase inhibitors as the first line of therapy has significantly improved the PFS and the overall survival as well. We have 3 CDK4/6 inhibitors we can offer to our patients. This is good because if a patient could not tolerate 1 CDK4/6 inhibitors, we can try different ones. We have many options for our patients in the metastatic setting right now.

The ADCs are another exciting field. We have 2 FDA-approved ADCs right now. One is T-DXd, another one is a sacituzumab govitecan, and we're expecting the third ADC, Dato-DXd, that could potentially could be approved. We're waiting for that news. So those are very exciting drugs.

T-DXd and Enhertu have both have been used in ER-positive, HER2-negative [HER2–] metastatic breast cancer. They not only improve the PFS, but also improve the overall survival. It's really hard to see any drugs improve overall survival in the metastatic setting, and they both achieved that primary end point. Those are very exciting drugs.

The third one, Dato-DXd [datopotamab deruxtecan], if it is approved, I think will potentially be a good option for our patients. The Dato-DXd is based on the TROPION-Breast01, a phase 3 study comparing the physicians’ choice among patients with ER-positive, HER2-low or HER2-negative metastatic breast cancer who have had aromatase inhibitor plus a CDK4/6 inhibitor, and also have had 1 line of chemotherapy. Dato-DXd significantly improved PFS compared with the physicians’ choice.

We don't have the overall survival data yet. However, based on the toxicity profile and the PFS data, this drug seems very well tolerated. It is beneficial in terms of improved PFS, and the treatment schedule is pretty benign as well. Treatment is every 3 weeks compared with saci [SG] that is day 1, day 8, every 21 days over 1 cycle.

Another benefit of this medication is we are not too worried about the grade 5 ILD [interstitial lung disease] with Dato-DXd compared with T-DXd. Just my personal preference. I think the Dato-DXd compared with saci has a benefit of a more convenient treatment schedule compared with T-DXd, [that] has less concern of ILD with much better tolerance. It would probably become my "favorite child" if the FDA approves it.