Daiichi Sankyo announced that Enhertu (trastuzumab deruxtecan) in combination with pertuzumab has been approved in China for the first-line treatment of adult patients with unresectable or metastatic HER2-positive breast cancer.
The approval by China’s National Medical Products Administration (NMPA) is based on results from the phase 3 DESTINY-Breast09 trial. In the study, Daiichi Sankyo and AstraZeneca’s Enhertu in combination with pertuzumab reduced the risk of disease progression or death by 44% compared with taxane, trastuzumab and pertuzumab (THP), with a hazard ratio of 0.56 (95% CI, 0.44–0.71; p<0.00001).
Median progression-free survival (PFS), as assessed by blinded independent central review, was 40.7 months with Enhertu plus pertuzumab compared with 26.9 months with THP. Improvement in PFS was observed across prespecified subgroups, and efficacy results in the China subgroup were consistent with the global results.
The confirmed objective response rate was 85.1% with Enhertu plus pertuzumab versus 78.6% with THP. Median duration of response was 39.2 months with the Enhertu combination compared with 26.4 months with THP.
Jiang Zefei, MD, President-Elect of the Chinese Society of Clinical Oncology and Principal Investigator in China of DESTINY-Breast09, noted that HER2-positive metastatic breast cancer remains challenging despite advances in HER2-targeted therapies. Discussing the trial findings, he said:
“We are optimistic that this therapeutic approach will bring meaningful benefits to a broader population of patients in China.”
The safety profile of Enhertu plus pertuzumab in DESTINY-Breast09 was consistent with previous clinical trials, with no new safety concerns identified.
In a pooled safety analysis of 431 patients with unresectable or metastatic breast cancer treated with Enhertu 5.4 mg/kg plus pertuzumab across two clinical studies, grade 5 adverse reactions occurred in 0.9% of patients, including interstitial lung disease in 0.5%. Treatment discontinuation due to an adverse reaction occurred in 15.3% of patients.
Michio Hayashi, China President of Daiichi Sankyo, said the approval “marks a major milestone” for patients with HER2-positive metastatic breast cancer in China. He highlighted the move of Enhertu into the first-line setting and noted that the medicine has received four new indications in China in less than a year.
Mary Guan, General Manager, China Oncology Business at AstraZeneca, said:
“DESTINY-Breast09 sets a new benchmark for progression-free survival and offers more patients the opportunity for durable disease control earlier in the course of their disease.”
She also emphasized the opportunity for earlier durable disease control and AstraZeneca’s commitment to working with healthcare partners to expand access for eligible patients in China.
DESTINY-Breast09 is a global, multicenter, randomized, open-label phase 3 trial evaluating Enhertu alone or in combination with pertuzumab versus standard-of-care THP as first-line treatment for HER2-positive metastatic breast cancer.
The trial enrolled 1,157 patients across sites in Africa, Asia, Europe, North America and South America. The investigational arm evaluating Enhertu monotherapy versus THP remains blinded to patients and investigators and will continue to the final PFS analysis.
The approval is the fourth for Enhertu in China in less than a year, with Enhertu now approved for eight indications in China.
Read further on OncoDaily: DESTINY-Breast09 Shows Strong 24-Month PFS Benefit With Deep Responses
