In an interview with CancerNetwork®, Erica L. Mayer, MD, MPH, discussed whether switching to camizestrant (Etcamah) while maintaining the initial CDK4/6 inhibitor will become the default first-line strategy for patients with hormone receptor (HR)–positive, HER2-negative advanced breast cancer following the agent’s FDA approval, or whether practices will wait for full overall survival data before displacing traditional post-progression algorithms.1 Mayer is the director of Breast Cancer Clinical Research and an institute physician at Dana-Farber Cancer Institute, as well as an associate professor of medicine at Harvard Medical School.
The phase 3 SERENA-6 trial (NCT04964934) established camizestrant as an early molecular switch upon detection of an emergent ESR1 mutation in circulating tumor DNA (ctDNA) before clinical progression, and the FDA approved the agent on September 4, 2026, for patients with emerging ESR1 mutations detected during first-line aromatase inhibitor plus CDK4/6 inhibitor therapy.2 Mayer described the learning curve that accompanies every new strategy as it moves from a trial into practice, outlining the practical questions clinicians will need to resolve, ranging from patient selection and ctDNA testing frequency to how results are communicated to patients and acted upon.
Transcript:
We are very fortunate in the world of medical oncology that we have had multiple new drugs and new strategies approved over the past several years. For every new drug or strategy, we all have a learning curve as we begin to learn how to bring something that was studied in the context of a trial into our clinical practice and see how it works. Right now, the challenge for all of us in breast medical oncology is to start trying the SERENA-6 approach, seeing how this deploys in clinic, and learning what in the strategy is helpful, what is a bottleneck, what is a challenge, and how to overcome that.
For many of us, the questions that are going to come up when we deploy this in clinic will be: Who are the best patients to use this approach with? What are the clinical predictors that help us identify who should have a ctDNA strategy? How often should we be sending the ctDNA? What day do we send the ctDNA? How do we talk about these results with the patients? If we do have a positive result, how do we operationalize the next steps? There is going to be a lot that we need to work out in clinic. I don’t think we are going to immediately move this into practice for every single patient, but over time, as we gain more confidence and explore how this works in a real-world population, I do think this will become a popular strategy.
References
- FDA grants accelerated approval to a new breast cancer treatment. News release. FDA. September 4, 2026. Accessed September 9, 2026. https://tinyurl.com/ym8hw67u
- Bidard FC, Mayer EL, Park YH, et al. First-line (1L) camizestrant (CAMI) for emergent ESR1 mutations (ESR1m) in advanced breast cancer: final progression-free survival 2 from the phase III SERENA-6 trial. J Clin Oncol. 2026;44(suppl 17):LBA1007. doi:10.1200/JCO.2026.44.17_suppl.LBA1007
