HER2-Targeted Therapy in Early Breast Cancer

Transcript:Adam M. Brufsky, MD, PhD: Hello, and thank you for joining us today for this OncLive Peer Exchange® on the topic of “Precision Medicine in Breast Cancer.” In today’s discussion, I’ll be joined by an international panel of experts in the field of breast cancer research to discuss the very latest advances in systemic therapy. As part of the discussion, we will cover the data that have come out over the last few months, including information from the ESMO 2016 Congress. In addition, we will provide practical advice on how the data can be used to make decisions about treating your patients, in both the operable and inoperable settings.

I am Dr. Adam Brufsky, and I am a professor of medicine at the University of Pittsburgh and the associate director for Clinical Investigation at the University of Pittsburgh Cancer Institute. Participating today on our distinguished panel are Dr. Ahmad Awada, head of the Medical Oncology Clinic at the Jules Bordet Institute of Université Libre de Bruxelles (The Free University of Brussels), in Brussels, Belgium; Dr. Hope Rugo, professor of medicine and director of the Breast Oncology Clinical Trials Program at the UCSF Helen Diller Family Comprehensive Cancer Center in San Francisco, California; and Dr. Michael Untch, head of Clinic for Gynecology, Gynecologic Oncology, and Obstetrics and head of the Interdisciplinary Breast Cancer Center of the Helios Klinikum Berlin-Buch in Berlin, Germany. Thank you all for joining us. Now, let’s begin.

So, the first thing you really want to talk about, I think to start, is the therapy of HER2-positive breast cancer in 2016. And I think we all know this really was, and has been, one of the great successes in systemic therapy of breast cancer. Michael, can you start by talking a little bit about the neoadjuvant therapy of breast cancer with HER2-positive disease and how we got here?

Michael Untch, MD: We have seen a tremendous development in the treatment of patients with HER2-positive disease. And, as you all may remember, we started in the metastatic setting by using the first monoclonal antibody, which is trastuzumab, and then we moved onto earlier stages of cancer, which is adjuvant therapy. The idea then was to also use trastuzumab, an anti-HER2 therapy, together with chemotherapy in patients with locally advanced or even early breast cancer. But instead of starting with the surgery, the idea was to use it before the surgery, and that was a good idea because we have a lot of data on that. Today, we can tell that neoadjuvant therapy, with the addition of trastuzumab, is one of the standards of therapy in breast cancer patients. And, by the way, in our national guideline in Germany, this is one of the ways that is preferred in order to treat patients with HER2-positive disease.

So, we use it mostly in the neoadjuvant setting. Number 1: the patients see that the tumors are responding quite well; so, the tumors are shrinking. Number 2: we do less surgery after neoadjuvant therapy because tumors are smaller and lymph nodes that have been involved are then free at the time of surgery, so we do less axillary surgery. And number 3: we see pathologic complete response (pCR) rates that are in the region of 50% to 70%, which means that the tumor in the lymph nodes and in the breast are melting away. Patients are tumor-free at the end of adjuvant therapy with anti-HER2 treatment, and we know from meta-analysis of large new adjuvant trials that those patients are doing excellent during the follow-up. So, the achievement is higher pCR, higher survival of the patients. What we do today is we try to attempt new developed studies in which the pathologic complete response rate is higher.

Adam M. Brufsky, MD, PhD: I think that TH—that is, a taxane and trastuzumab—has been the standard from a lot of these trials like NOAH and a few other ones. And now we’ve tried to add things to it, again, with the idea of increasing pathologic complete response rate. So, because we have an international audience in front of us: before we start talking about the individual drugs, the United States FDA has allowed pathologic complete response rate to be an endpoint for approval in studies. Ahmad, does that same thing happen in Europe? Do the European authority guys allow that?

Ahmad Awada, MD, PhD: No, not yet to my knowledge. It’s not yet, let’s say, approved as an approach in the neoadjuvant setting. But from my point of view, I think this is really, as Michael mentioned, a very nice approach to give to our patient. And I would add something very important to Michael’s introduction: that the concept of dual inhibition of HER2, which was really studied in the neoadjuvant setting, really increased significantly the pathologic complete remission. And we know what the importance of pathologic complete remission for the outcome of our patient is. So, this is, in my opinion, one of the major advances in the field of HER2 disease in the neoadjuvant setting to increase this pathologic complete remission by doing dual HER2 inhibition.

Transcript Edited for Clarity