Initial US Approval
20191
Indications
For the treatment of adult patients with locally advanced or metastatic HER2-positive (IHC 3+ or IHC 2+/ISH-positive) gastric or gastroesophageal junction (GEJ) adenocarcinoma who have received a prior trastuzumab-based regimen.1
Recommended Dose/Route
The recommended dosage of T-DXd in HER2+ metastatic gastric cancer is 6.4 mg/kg given as an intravenous infusion once every 3 weeks (21-day cycle) until disease progression or unacceptable toxicity.1
Pivotal Studies
DESTINY-Gastric01 (NCT03329690)2,3
Key Inclusion Criteria: Patients with HER2-positive (IHC 3+ or IHC 2+/ISH-positive), locally advanced or metastatic gastric or GEJ adenocarcinoma who had progressed on at least 2 prior regimens including trastuzumab, a fluoropyrimidine- and a platinum-containing chemotherapy.1
Treatment
Patients were randomly assigned 2:1 to receive T-DXd, 6.4 mg/kg, intravenously every 3 weeks or physician’s choice of chemotherapy: irinotecan monotherapy, 150 mg/m2, intravenously every 2 weeks or paclitaxel monotherapy, 80 mg/m2, intravenously weekly.1
Safety
The most common any grade (≥20%) adverse events (AEs), including laboratory abnormalities, were decreased hemoglobin (75%), decreased white blood cell count (74%), decreased neutrophil count (72%), decreased lymphocyte count (70%), decreased platelet count (68%), nausea (63%), decreased appetite (60%), increased aspartate aminotransferase (58%), fatigue (55%), increased blood alkaline phosphatase (54%), increased alanine aminotransferase (47%), diarrhea (32%), decreased blood potassium (30%), vomiting (26%), constipation (24%), increased blood bilirubin (24%), pyrexia (24%), and alopecia (22%).1
Dosage Interruption due to AEs: 62%1
Dosage Reductions due to AEs: 32%1
Permanent Discontinuation due to AEs:15%1