Advertisement


Sara A. Hurvitz, MD, on Updated Survival Results on T-DXd vs T-DM1 in Metastatic Breast Cancer

2022 San Antonio Breast Cancer Symposium

Advertisement

Sara A. Hurvitz, MD, of the University of California, Los Angeles, Jonsson Comprehensive Cancer Center, discusses phase III findings from the DESTINY-Breast03 study, which showed that second-line treatment with fam-trastuzumab deruxtecan-nxki (T-DXd) led to longer overall survival compared with ado-trastuzumab emtansine (T-DM1) in patients with HER2-positive metastatic breast cancer. Patients treated with T-DXd had a 36% lower risk of death than those treated with T-DM1 (Abstract GS2-02).



Transcript

Disclaimer: This video transcript has not been proofread or edited and may contain errors.
DESTINY-Breast 03 was a phase 3 randomized clinical trial looking at T-DXd versus T-DM1 in patients with HER2-positive metastatic breast cancer that had progressed after trastuzumab and a taxane. The primary endpoint was median progression-free survival by blinded independent central review. And a key secondary endpoint was overall survival. The data were originally presented in September 2021 when we showed a stunning significant improvement in median PFS associated with T-DXd, and that was really immediately practiced changing. But the overall survival data were not mature at that time. So at San Antonio we provided updated overall survival results. We had seen 169 overall survival events in July 2022, which triggered the analysis. We showed that the median overall survival had not been reached yet for either treatment arm. However, there was a statistically significant improvement in overall survival seen with T-DXd. The hazard ratio was 0.64. In addition, we presented updated median progression-free survival by independent review. And now the median PFS had been met with T-DXd and was 28.8 months, which was roughly four times longer than seen with T-DM1. In addition, we saw an objective response rate of almost 80% with T-DXd, which was higher than with T-DM1. 21% of patients having a complete response compared to 9.5% with T-DM1. So overall the results show real benefits with T-DXd firmly placing this as the standard of care in regions where it's available after trastuzumab and taxane. In terms of safety, the safety data looked fairly similar to what was previously reported. However, there were more all grade ILD events noted this time with longer treatment duration and longer follow-up. 15% or so of patients treated with T-DXd had ILD compared to about 10% at the time of initial reporting. But all of these additional events were grade one or two. There were no new grade three events and zero grade four or five events. So in summary, I think these data really solidly place T-DXd as the standard of care in the second line setting after trastuzumab and taxane. We have exciting studies ongoing looking at T-DXd in the frontline setting, in the adjuvant setting, so I'm looking forward to seeing more data emerge relating to this very effective regimen.

Related Videos

Breast Cancer

François-Clément Bidard, MD, PhD: Circulating Tumor Cells May Help Improve Outcomes in Metastatic Disease

François-Clément Bidard, MD, PhD, of the Institut Curie, discusses overall survival results from the STIC CTC trial. To guide the choice between chemotherapy and endocrine therapy for patients with metastatic, estrogen receptor–positive/HER2-negative breast cancer, researchers compared circulating tumor cell (CTC) count to physician’s choice of treatment. The data suggest that the CTC count resulted in better long-term outcomes (Abstract GS3-09).

Breast Cancer

Joannie M. Ivory, MD, MSPH, and Lisa A. Carey, MD, on PAM50 Subtype and 21-Gene Recurrence Scores in Younger and Black Women With Breast Cancer

Lisa A. Carey, MD, and Joannie M. Ivory, MD, MSPH, both of the University of North Carolina at Chapel Hill, discuss the higher frequency and treatment implications of nonluminal A or high-risk tumors in Black and younger women. In this study, PAM50 and 21-gene assays revealed different demographic patterns by race and age (Abstract PD1-08).

Breast Cancer

Mariana Chavez-MacGregor, MD, MSc, on Adjuvant Endocrine Therapy and Everolimus in HR-Positive, HER2-Negative Breast Cancer

Mariana Chavez-MacGregor, MD, MSc, of The University of Texas MD Anderson Cancer Center, discusses phase III results from the SWOG S1207 trial which was designed to evaluate the role of adjuvant everolimus in combination with adjuvant endocrine therapy among patients with high-risk, hormone­ receptor–positive, HER2-negative early-stage breast cancer. Adding everolimus did not improve invasive disease–free or overall survival and was associated with high rates of adverse events (Abstract GS1-07).

Breast Cancer

Yara Abdou, MD, on Race and Clinical Outcomes in the RxPONDER Breast Cancer Trial

Yara Abdou, MD, of the University of North Carolina, discusses results from the RxPONDER SWOG S1007 study, which showed that non-Hispanic Black women with hormone receptor–positive/HER2-negative breast cancer with one to three involved lymph nodes and a recurrence score of ≤ 25 have worse outcomes than non-Hispanic White women. In addition, Black patients were more likely to accept treatment assignment than their White counterparts and were just as likely to remain on estrogen therapy at 6 and 12 months, suggesting that outcome differences may be less likely attributable to lack of treatment compliance within the first year (Abstract GS1-01 ).

Breast Cancer
Immunotherapy

Sara A. Hurvitz, MD: New Findings on Neoadjuvant Trastuzumab Deruxtecan and Anastrozole in Early-Stage Breast Cancer

Sara A. Hurvitz, MD, of the University of California, Los Angeles, Jonsson Comprehensive Cancer Center, discusses phase II results from the TRIO-US B-12 TALENT study, which showed that patients with localized, hormone receptor–positive, HER2-low breast cancer who are treated with fam-trastuzumab deruxtecan-nxki (T-DXd) in the neoadjuvant setting had an overall response rate (ORR) of 68%. When combined with anastrozole, T-DXd led to a 58% ORR. This is the first trial to evaluate T-DXd in HER2-low breast cancer, a potentially curable disease (Abstract GS2-03).

Advertisement

Advertisement




Advertisement