AstraZeneca and Daiichi Sankyo’s Enhertu has been approved in the US for the treatment of adult patients with locally advanced or metastatic HER2-positive gastric or gastroesophageal junction (GEJ) adenocarcinoma who have received a prior trastuzumab-based regimen.
The approval by the Food and Drug Administration (FDA) was based on the positive results from the randomised DESTINY-Gastric01 Phase II trial conducted in Japan and South Korea. In the trial, Enhertu demonstrated a statistically significant and clinically meaningful improvement in overall survival (OS) and objective response rate (ORR) versus chemotherapy (irinotecan or paclitaxel) in patients with advanced gastric cancer or GEJ adenocarcinoma who had progressed on at least two or more prior regimens including trastuzumab plus a fluoropyrimidine- and platinum-based chemotherapy combination.
“The results from the DESTINY-Gastric01 trial highlight the potential to change clinical practice, showing a 41 per cent improvement in survival and a response rate more than three times higher with Enhertu compared to chemotherapy.”
“Today’s approval of Enhertu represents the first HER2-directed medicine approved in a decade for patients with HER2-positive metastatic gastric cancer. The results from the DESTINY-Gastric01 trial highlight the potential to change clinical practice, showing a 41 per cent improvement in survival and a response rate more than three times higher with Enhertu compared to chemotherapy. We are thrilled to bring this important medicine to more patients and physicians in the US,” says Dave Fredrickson, Executive Vice President, Oncology Business Unit, AstraZeneca.
Results from the DESTINY-Gastric01 trial were published in The New England Journal of Medicinein June 2020.
The most common adverse reactions, including laboratory abnormalities, of any grade (greater than or equal to 20%) for patients treated with Enhertu (n=125) in the DESTINY-Gastric01 trial were anaemia, leukopenia, neutropenia, lymphocytopenia, thrombocytopenia, nausea, decreased appetite, increased aspartate aminotransferase, fatigue, increased blood alkaline phosphatase, increased alanine aminotransferase, diarrhoea, hypokalaemia, vomiting, constipation, increased blood bilirubin, pyrexia and alopecia. Interstitial lung disease or pneumonitis occurred in 10% of patients.
The second indication approved for Enhertu in the US
This is the second indication approved for Enhertu in the US following the accelerated approval for adult patients with unresectable or metastatic HER2-positive breast cancer who have received two or more prior anti-HER2-based regimens in the metastatic setting based on the DESTINY-Breast01 trial.
Enhertu was previously granted Priority Review, Breakthrough Therapy Designation (BTD) in HER2-positive metastatic gastric cancer and Orphan Drug Designation for gastric cancer by the FDA. Two additional Phase II trials, DESTINY-Gastric02 and DESTINY-Gastric03, are underway, further evaluating treatment with Enhertu in patients with HER2-positive metastatic gastric cancer.
Following US approval, an amount of $115m is due from AstraZeneca to Daiichi Sankyo as a combined 2nd-line and 3rd-line milestone payment in HER2-positive gastric cancer. In AstraZeneca, the milestones paid will be capitalised as an addition to the upfront payment made in 2019 and subsequent capitalised milestones and amortised through the profit and loss.
“USD 115 million is due from AstraZeneca to Daiichi Sankyo as a combined 2nd-line and 3rd-line milestone payment in HER2-positive gastric cancer.”
Sales of Enhertu in the US are recognised by Daiichi Sankyo. AstraZeneca reports its share of gross profit margin from Enhertu sales in the US as collaboration revenue in the Company’s financial statements. For further details on the financial arrangements, please consult the collaboration agreement from March 2019.
Photo of Dave Fredrickson: AstraZeneca