SABCS 2025 | Real-world outcomes with 1L regimens in HER2+ metastatic breast cancer

After the results of the Cleopatra study, taxon chemotherapy in combination with trastuzumab-pertuzumab followed by maintenance trastuzumab-pertuzumab has become the standard of care for our patients with HER2-positive metastatic breast cancer. The goal of this study was to evaluate how many of our patients in the first line are receiving the Cleopatra regimen compared to other regimens. This was a flat iron-based data extraction, which included over 3,000 patients. Two-thirds of patients were in the community setting, which was 280 clinics and 800 centers. Demographics that were similar among patients included a very similar age, number of sites of metastatic disease, and the median treatment duration follow-up. The demographics that were different among our two patient populations were the patients that there was a high number of de novo metastatic patients in our Cleopatra regimen arm. There were fewer patients with HR positive disease, and there were fewer patients with brain metastasis. In terms of the results, the study demonstrated that real-world progression-free survival was longer for patients who received the Cleopatra regimen. That was a difference from 9 to 14 months. Time-to-next treatment was also longer for patients who received the Cleopatra regimen, and that was a difference from 6 to 16 months. The subsequent progression-free survival, which is the real-world PFS2, that was also longer in favor of the Cleopatra regimen. And that was the difference from 18 to 26 months. And real-world time to next treatment two, which was a subsequent time to next treatment, was also longer in favor of the Cleopatra regimen. And that was 17 to 30 months. So in conclusion, we learned that the study demonstrated that patients that are treated on the first-line Cleopatra regimen generally did better. We did identify a lot of factors that could have contributed to that. Perhaps those were higher-risk patients that needed an alternative regimen. We also saw that fewer patients were in the de novo metastatic group in the alternative regimen group. So that could be that there was a higher proportion of patients with recurrent cancers. Patients with ER positive were heavily represented in the alternative regimen group. And patients with brain mets were slightly more overrepresented in the alternative regimen group.

This transcript is AI-generated. While we strive for accuracy, please verify this copy with the video.