Targeted Therapies, Genomic Profiling Revolutionize Breast Cancer Treatment

Mei Wei, MD, an oncologist specializing in breast cancer at Huntsman Cancer Institute at the University of Utah, highlighted the significant advancements in treating HR+/HER2– breast cancer. Wei spoke with The American Journal of Managed Care^® at the Denver Regional Institute for Value-Based Medicine^® event, where she participated in a session on new treatments for HR+/HER2– breast cancer.

She emphasized emerging research, such as the promising role of targeting specific mutations like PIK3CA and ESR1. Genomic profiling is increasingly being utilized to identify patients who may benefit from these targeted therapies, although its adoption in the first-line setting for metastatic breast cancer remains under discussion. Overall, the field of HR+/HER2– breast cancer is witnessing groundbreaking developments, with a focus on personalized medicine and targeted therapies to improve patient outcomes.

This transcript was lightly edited for clarity.

Transcript

What are the most promising areas of research currently exploring new therapeutic targets or approaches for HR+/HER2- breast cancer?

There's many exciting research [studies] going on. For the nonmetastatic setting, I think we are exploring more treatment options in addition to the traditional tamoxifen and aromatase inhibitors that try to improve the outcome and decrease the cancer recurrence risk.

For example, the recently FDA-approved ribociclib is 1 of the drugs. A couple years ago, adjuvant abemaciclib was also approved for this purpose as well. Both are used in the adjuvant setting.

In the metastatic setting, there's also many exciting developments as well. We have this PIK3CA mutation, and then many companies are trying to develop inhibitors to target that. Also, we have this ESR1 mutation, and we do have a medication that can target that at this moment.

There is also this concept of, "What if the patient has both PIK3CA mutation and ESR1 mutation? Should we use a combo-targeted mutation?" Those are some of the very exciting fields the research is currently focused on as well.

How is genomic profiling being used to tailor treatment plans for patients with HR+/HER2- breast cancer?

That's a very good question. I think historically we are running very behind compared with our peers. For example for lung cancer, they will check the EGFR at the time when the patient was diagnosed with metastatic disease.

However, because historically we don't have all of these actionable mutations, we don't have the drugs that can target those mutations, we are way behind compared with our peers. We don't check NGS [next-generation sequencing], but now because we have this medication that can target PIK3CA mutation, and also we have medication that specifically benefits a patient with ESR1 mutation, so we start to check the patient with more genomic testing with NGS and the circulating tumor DNA.

Now the thing is, because the PIK3CA inhibitor is approved for second line and also the elacestrant target ESR1 is also approved for the second line. Most of the time we still feel that's not much value to check the NGS when the patient was diagnosed with metastatic breast cancer because the result does not really change how we treat the patient in the first line. However, I don't think there is anything wrong if we check it at that time.

Now there is a study that was recently presented. It's the INAVO120 study that uses PIK3CA inhibitor [inavolisib] plus fulvestrant [Faslodex] plus Ibrance [palbociclib] for patients with endocrine therapy–resistant tumors with PIK3CA mutation to use this triplet combination as the first line.

I think that will trigger more breast medical oncologists to test the genomic testing at a time of patient developing metastatic breast cancer because if that triplet is approved, then we can offer this patient options if the patient has the PIK3CA mutation to use them as a first line.