High-level results from the primary analysis of the ongoing DESTINY-PanTumor02 Phase II trial showed Enhertu (trastuzumab deruxtecan) demonstrated clinically meaningful progression-free survival (PFS) and overall survival (OS) in previously treated patients across multiple HER2-expressing advanced solid tumours, two secondary endpoints of the trial.
In the primary analysis, Enhertu continued to show durable responses based on investigator-assessed confirmed objective response rate (ORR), the primary endpoint of the trial, and duration of response (DoR), a secondary endpoint; reinforcing results from an interim analysis of the trial at the 2023 American Society of Clinical Oncology (ASCO) Annual Meeting.
Enhertu is a specifically engineered HER2-directed antibody drug conjugate (ADC) being jointly developed and commercialised by AstraZeneca and Daiichi Sankyo.
Cristian Massacesi, Chief Medical Officer and Oncology Chief Development Officer, AstraZeneca, said: “The progression-free survival and overall survival results for Enhertu alongside the continued robust and durable tumour responses seen with further follow up underscore the potential value of this important medicine for patients with HER2-expressing cancers who currently have no targeted treatment options. With a high unmet need in these cancers, we are working with health authorities to bring Enhertu to patients with HER2-expressing cancers that could potentially benefit from this medicine as quickly as possible.”
Mark Rutstein, Global Head, Oncology Development, Daiichi Sankyo, said: “These updated results from the DESTINY-PanTumor02 trial are important as we work to reshape the clinical landscape in HER2-expressing advanced cancers, where patients currently have limited treatment options and face a poor prognosis. The overall survival demonstrated by Enhertu in these patients is a significant step forward in the potential to advance current standards of care and offer new options for patients with HER2-expressing cancers.”
The DESTINY-PanTumor02 Phase II trial is evaluating the efficacy and safety of Enhertu in patients with previously treated locally advanced, unresectable, or metastatic HER2-expressing solid tumours not eligible for curative therapy, including biliary tract, bladder, cervical, endometrial, ovarian, pancreatic, and other cancers.
The safety profile observed in the primary analysis was consistent with prior data and with other trials of Enhertu with no new safety concerns identified. Interstitial lung disease (ILD) rates and severity were consistent with those observed in other trials of Enhertu, with a low rate of Grade 5 ILD events observed as determined by an independent adjudication committee.
These data will be presented at a forthcoming medical meeting and will support ongoing discussions with global health authorities.
Notes
HER2 expression in solid tumours
HER2 is a tyrosine kinase receptor growth-promoting protein expressed on the surface of various tissue cells throughout the body and is involved in normal cell growth.1,2 In some cancers, HER2 expression is amplified or the cells have activating mutations.1,3 HER2 protein overexpression may occur as a result of HER2 gene amplification and is often associated with aggressive disease and poor prognosis.4
While HER2-directed therapies have been used to treat breast, gastric, lung and colorectal cancers, more research is needed evaluating their potential role in treating other HER2-expressing tumour types.2,5,6
HER2 is an emerging biomarker in biliary tract, bladder, cervical, endometrial, ovarian and pancreatic cancers.3 Testing is not routinely performed in these additional tumour types and as a result, available literature is limited. HER2 overexpression (IHC3+) has been observed at rates from 1% to 28% in these solid tumours.7,8 There is an unmet need for effective therapies for certain HER2-expressing solid tumours, particularly for those who have progressed on or are refractory to standard of care therapies as there are currently no approved HER2-directed therapies for these cancers.2,9
DESTINY-PanTumor02
DESTINY-PanTumor02 is a global, multicentre, multi-cohort, open-label Phase II trial evaluating the efficacy and safety of Enhertu (5.4mg/kg) for the treatment of previously treated HER2-expressing tumours, including biliary tract cancer, bladder cancer, cervical cancer, endometrial cancer, ovarian cancer, pancreatic cancer and other tumours.
The primary efficacy endpoint of DESTINY-PanTumor02 is confirmed ORR as assessed by investigator. Secondary endpoints include DoR, disease control rate, PFS, OS, safety, tolerability and pharmacokinetics.
