Efficacy and safety results of DESTINY-Gastric02 trial of Enhertu are consistent with registrational DESTINY-Gastric01 study and will support ongoing discussions with global health authorities.- Daiichi Sankyo + AstraZeneca

Results were presented during a late-breaking mini-oral presentation at the European Society for Medical Oncology (ESMO) Congress 2021. Gastric cancer is associated with a poor prognosis, particularly in the advanced stages of the disease, with only 5% to 10% of metastatic patients surviving five years globally. Approximately one in five gastric cancers are HER2-positive.

In the primary analysis of DESTINY-Gastric02, the first trial of Enhertu specifically in Western patients with HER2-positive metastatic gastric cancer or GEJ adenocarcinoma, Enhertu (6.4 mg/kg) demonstrated a confirmed overall response rate (ORR) of 38% as assessed by independent central review (ICR). Three (3.8%) complete responses (CR) and 27 (34.2%) partial responses (PR) were observed in patients treated with Enhertu. These results were consistent with those from the registrational DESTINY-Gastric01 Phase II trial previously published in The New England Journal of Medicine.After a median follow-up of 5.7 months, the median duration of response (DoR) of Enhertu was 8.1 months (95% CI 4.1-NE). The median progression-free survival (PFS) was 5.5 months (95% CI 4.2-7.3). An exploratory endpoint of confirmed disease control rate (DCR) of 81% (95% CI; 70.6-89.0) was seen.

Eric Van Cutsem, MD, PhD, University Hospitals Leuven, said: “While the benefit of a HER2-targeted therapy in the first-line metastatic gastric cancer setting has been well-established, the disease will eventually progress. The positive results of DESTINY-Gastric02 show a strong response rate and reinforce the established efficacy and safety profile of Enhertu in patients who are in need of additional therapeutic options.”

The overall safety profile of Enhertu in DESTINY-Gastric02 was consistent with that seen in DESTINY-Gastric01. The most common Grade 3 or higher drug-related treatment-emergent adverse events seen in DESTINY-Gastric02 were anaemia (7.6%), neutropenia (7.6%), nausea (3.8%) and fatigue (3.8%). There were six cases (7.6%) of treatment-related interstitial lung disease (ILD) or pneumonitis reported, as determined by an independent adjudication committee. The majority (83%) were low Grade (Grade 1 or Grade 2), with one Grade 5 (ILD or pneumonitis-related death).