In this exclusive MedPage Today video, Hatem Soliman, MD, of the Moffitt Cancer Center in Tampa, Florida, shares insights on leading metastatic breast cancer research presented at the annual American Society of Clinical Oncology (ASCO) annual meeting.
Following is a transcript of his remarks:
We've got some interesting information revealed over the past couple of days for metastatic breast cancer in some of the sessions that were presented. One of the things that got a late-breaking abstract was the trial known as DESTINY-Breast06, which looked at the use of Enhertu, or trastuzumab deruxtecan, in earlier lines of treatment for women with metastatic, what we call HER2-low hormone receptor-positive breast cancer. And this is basically moving the treatment up pretty early in the algorithm to see if it's more beneficial to treat them with the drug.
The study was positive, it did show an improved progression-free survival compared to women that just got regular standard chemotherapy agents. I think it did open up this avenue potentially of using the drug earlier than what we were typically able to before, but also may allow other women to become eligible to treat. They're called ultralow, where they have very low levels of HER2 expression detectable in our current assays. They may benefit from some of these treatments as well. So that was one of, I think, the main updates that we got today.
There have been some other interesting abstracts presented, too. One was from Dr. Kalinsky looking at the , which was a trial that was asking the question about giving a CDK4/6 inhibitor, or a cyclin-dependent kinase 4/6 inhibitor, such as ribociclib [Kisqali], abemaciclib [Verzenio], those types of drugs. And mainly this study used abemaciclib after women had seen prior treatment with a drug like palbociclib [Ibrance].
And the trial also appeared to be positive to show an improvement in progression-free survival when women were switched from just getting anti-estrogen therapy alone after having progressed on first-line CDK 4/6 therapy to getting a combination of abemaciclib with anti-estrogen therapy -- they did better, had a longer progression-free survival. And so there may be a population of those patients that would benefit from continued use of a CDK 4/6 inhibitor, even if they progressed on the first one. And I think that opens up some avenues for us, as well.
And then also there was updates from the , which looked at what we would call a triplet combination for some particularly difficult to treat women with hormone receptor-positive breast cancer that has basically recurred mainly in a way that is very indicative of a resistant difficult kind of disease to treat that's very aggressive. And it harbors mutations that may cause the disease not to respond well to typical first-line treatment with anti-estrogen therapy and CDK 4/6.
And so they added this, what was called a PIK3CA inhibitor, [inavolisib], on top of two other drugs, basically the fulvestrant [Faslodex] and the palbociclib. And earlier data had shown that there was actually a very significant progression-free survival and overall survival benefit. At ASCO, they updated some of that information to show that women had good quality of life, reasonable toxicity with good management strategies, and that the benefit continued to hold up over time. So Dr. Juric was able to show some of this data to say that this could be an active triplet combination for these hard to treat women with metastatic disease.