Trastuzumab Deruxtecan Receives FDA Approval for Metastatic HER2+ Breast Cancer

Findings from the phase 3 DESTINY-Breast03 trial have led to the FDA approval of fam-trastuzumab deruxtecan-nxki for the treatment of patients with unresectable or metastatic HER2-positive breast cancer.

The FDA has approved the use of fam-trastuzumab deruxtecan-nxki (Enhertu) for the treatment of patients with unresectable or metastatic HER2-positive breast cancer who have previously received an anti-HER2 treatment in the metastatic, neoadjuvant, or adjuvant setting followed by disease recurrence during treatment or within 6 months of completing therapy, according to a press release from AstraZeneca.1

The approval went through the FDA's Real-Time Oncology Review program, which converted the agent's accelerated approval to a standard approval. This indication now broadens the use of trastuzumab deruxtean plus a taxane therapy in HER2-positive metastatic breast cancer patients in the US.

The approval was based on findings from the phase 3 DESTINY-Breast03 trial (NCT03529110), which highlighted a reduction in risk of disease progression or death by 72% compared with trastuzumab emtansine (T-DM1; Kadcyla; HR, 0.28; 95% CI, 0.22-0.37; P <.0001). Findings from the trial were published in The New England Journal of Medicine and indicated that the overall response rate was 79.7% (95% CI, 74.3%-84.4%) vs 34.2% (95% CI, 28.5%-40.3%) in both arms, respectively.2 Additionally, among those in the experimental cohort (n = 261), the 12-month progression-free survival rate was 75.8% (95% CI, 69.8%-80.7%) vs 34.1% (95% CI, 27.7%-40.5%) in the control group (n = 263).

The safety profile was consistent with previous findings, with no grade 4 or grade 5 treatment-related interstitial lung disease events being identified.

“This is an important day for the breast cancer community. With this approval, [trastuzumab] now provides a new treatment option for patients with HER2-positive metastatic breast cancer which can be used earlier in treatment to potentially delay progression of disease,” Catherine Ormerod, executive vice president of strategy and mission at Living Beyond Breast Cancer, said in the press release.

References

  1. Enhertu approved in the US for patients with HER2-positive metastatic breast cancer treated with a prior anti-HER2-based regimen. News release. AstraZeneca. May 5, 2022. Accessed May 5, 2022. https://bit.ly/3OZHpSs
  2. Cortés J, Kim SB, Chung WP, et al. Trastuzumab deruxtecan versus trastuzumab emtansine for breast cancer. N Engl J Med. 2022;386(12):1143-1154. doi:10.1056/NEJMoa2115022