In March, AstraZeneca signed a deal with Japanese drug maker Daiichi Sankyo that would pay up to $6.9 billion â€” $1.35 billion up front and $5.55 billion if sales and regulatory targets are hit â€” for a single experimental cancer drug. On Wednesday, data from that drug are being presented at the San Antonio Breast Cancer Symposium and published in the New England Journal of Medicine.
The new drug, trastuzumab deruxtecan, was tested in a clinical trial of 184 breast cancer patients whose tumors tested positive for a marker called HER2 and who had previously received cancer treatments including Rocheâ€™s Kadcyla. There was a response, meaning tumors shrank by at least 30%, in 112 patients, or 60.9% of those tested. Those responses lasted for a median of 14.8 months.