In This Article:
Daiichi Sankyo and AstraZeneca's Enhertu (trastuzumab deruxtecan) with pertuzumab has shown progression-free survival (PFS) improvement in the Phase III DESTINY-Breast09 trial, when used as a first-line treatment for individuals with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer.
In the trial, the combination was compared to taxane, trastuzumab and pertuzumab (THP).
The international, multicentre, randomised, open-label Phase III trial is designed to assess the safety and efficacy of Enhertu, either as a single agent or with pertuzumab, against THP.
It enrolled 1,157 subjects across sites in Asia, Europe, Africa, South America and North America.
PFS is the trial’s primary endpoint, determined as per blinded independent central review evaluations in both the Enhertu’s single-agent and combo arms.
The planned interim analysis revealed that all pre-specified participant subgroups experienced the PFS benefit with the combination.
Although the key secondary endpoint of overall survival (OS) data is not yet mature, an early trend favours the combination over the THP treatment.
Other secondary endpoints include pharmacokinetics, objective response rate, investigator-evaluated progression-free survival (PFS), safety, and duration of response.
According to the companies, the second arm of the study, which evaluates Enhertu single agent against THP, remains blinded to investigators and subjects, and continues to the final PFS analysis.
Enhertu combo’s safety profile aligns with the known profiles of every individual therapy.
This HER2-directed antibody drug conjugate (ADC) is a key product in the oncology portfolios of both companies.
It is designed to leverage Daiichi’s DXd ADC Technology and has secured approval in more than 75 nations for the treatment of HER2-positive breast cancer.
Daiichi Sankyo research and development (R&D) global head Ken Takeshita said: “The results of DESTINY-Breast09 reinforce the importance of effectively targeting HER2 to achieve durable disease control early in the treatment of HER2-positive metastatic breast cancer.
“Building on the positive results seen with Enhertu in the second-line setting, these new findings suggest that starting treatment with Enhertu in combination with pertuzumab at the time of metastatic diagnosis delays disease progression, postponing the time until additional treatment may be needed.”
Last month, Enhertu showed improvement in overall survival in the DESTINY-Gastric04 Phase III trial for patients with gastric or gastroesophageal junction adenocarcinoma.