Breast Cancer Highlights From ASCO 2023

In this video, Paolo Tarantino, MD, of the Dana-Farber Cancer Institute in Boston, provides an overview of key updates in breast cancer from the recent American Society of Clinical Oncology (ASCO) annual meeting, including the NATALEE and a retrospective analysis evaluating the sequencing of antibody-drug conjugates.

Following is a transcript of his remarks:

I think the highlight of the Congress was the NATALEE phase III trial. This was a trial of adjuvant ribociclib [Kisqali] for 3 years for patients with hormone receptor-positive, high-risk, early-stage breast cancer. And interestingly, we have already an adjuvant CDK[4/6 inhibitor] approved, that is abemaciclib [Verzenio] based on the monarchE data, but only for patients with node-positive disease. Whereas in NATALEE, there were also patients with high-risk, node-negative disease included, which is a very large population.

And it was important to see in this trial, the iDFS [invasive disease-free survival] curves diverge. And so there seemed to be a benefit at 2 and 3 years with the use of ribociclib versus placebo. And there was a 25% reduction in the risk of recurrence.

It is still an early time point, because more than 80% of the patients are still receiving ribociclib in this study. They still haven’t discontinued, haven’t completed the 3 years. And so I think we have to wait some more time in order to fully understand what will happen to these patients. But I think it’s very encouraging at this point to see this benefit that we did not see with palbociclib [Ibrance], for instance. And knowing that ribociclib improved overall survival in the metastatic setting, we hope that the benefit in the early setting can be maintained and that in the future we might have this treatment option for our patients if the benefit is confirmed.

There were other important trials, but I would like to highlight a small poster that was discussed yesterday during the poster discussion by Dr. [Rachel Occhiogrosso] Abelman.

This was an important clinical question because nowadays, we are utilizing antibody-drug conjugates [ADC] in clinical practice and sometimes we use sacituzumab govitecan [Trodelvy] after T-DXd [trastuzumab deruxtecan; Enhertu] or the opposite way around. And we really have no data with these agents used in sequence.

And this retrospective analysis of about 30 patients that received an ADC after another ADC that was presented yesterday showed that potentially there might be decreased activity of the second ADC used in sequence and suggested some potential features that we have to look at. So for instance, changing the target, changing the payload, and I think it’s very early. We need more data. We need larger real-world experiences. But I think it started to answer an important question for which we definitely need data in order to inform clinical practice.