AstraZeneca and Daiichi Sankyo continue to flesh out Enhertu plans, claiming win in earlier breast cancer line
AstraZeneca and Daiichi Sankyo have big plans for their blockbuster-in-the-making Enhertu, and the pair touted another win Monday morning in the quest to conquer the breast cancer market.
Enhertu reached its primary endpoint in a study looking at HER2-positive metastatic breast cancer patients who had previously been treated with one prior line of HER2-based therapy, the companies announced, demonstrating superiority in progression-free survival over Roche’s Kadcyla and chemo. Full data aren’t available yet, but Daiichi Sankyo noted the trial has been recommended for unblinding by the IMDC after reaching this interim analysis.
The companies also said that while overall survival data showed a “strong trend” toward improvement over the control, the OS data haven’t matured enough to conclude anything.
“There is a continued need for new options and better outcomes for patients with HER2 positive metastatic breast cancer who often experience disease progression after initial treatment with available standards of care,” said AstraZeneca oncology chief Susan Galbraith in a statement.
Enhertu won a quick accelerated approval back in December 2019, with the drug receiving its FDA OK just nine months after AstraZeneca and Daiichi Sankyo agreed to collaborate on the program. Though the results from Monday’s study do not come from the confirmatory trial needed to seal full approval, the companies noted the trial is the first to pit Enhertu against an active control.
The accelerated approval came in a later-line indication: unresectable or metastatic HER2-positive breast cancer patients who have received two or more prior anti-HER2-based regimens in the metastatic setting. Monday’s study, however, suggests that for this earlier line of treatment, the companies are planning to shoot straight for a full approval. AstraZeneca and Daiichi Sankyo enrolled about 500 patients in the trial and recruited patients on five continents.
AstraZeneca and Daiichi Sankyo won their previous greenlight based on tumor response rate and duration of response. Their confirmatory study to convert to full approval in the third-line setting remains ongoing and is expected to read out data in the second half of next year.
Though Enhertu netted only $89 million in sales in 2021’s first half, the antibody-drug conjugate has been pushed as AstraZeneca’s next blockbuster drug. In addition to the second-and third-line breast cancer settings, Enhertu is approved for certain types of HER2-positive gastric cancer and is also being studied in non-small cell lung cancer.
But the AstraZeneca and Daiichi Sankyo partnership doesn’t stop there. The two are working on another ADC in datopotamab deruxtecan, agreeing to a deal worth up to $6 billion back in July 2020. For that program, the companies are chasing Gilead’s Trodelvy, which got FDA approval in April to treat metastatic TNBC patients in the second line or later as well as an accelerated nod in urothelial carcinoma the same month.