FDA approves AstraZeneca, Daiichi Sankyo's Enhertu for patients with HER2-positive breast cancer after at least two prior treatments

The FDA announced Friday that it granted accelerated approval to AstraZeneca and Daiichi Sankyo's Enhertu (fam-trastuzumab deruxtecan-nxki) to treat adults with unresectable or metastatic HER2-positive breast cancer who have received at least two prior anti-HER2-based regimens in the metastatic setting. The agency noted that clearance came three months ahead of its target goal date.

"There have been many advances in the development of drugs for HER2-positive breast cancer since the introduction of [Roche's] Herceptin (trastuzumab)," commented Richard Pazdur, acting director of the Office of Oncologic Diseases in the FDA's Center for Drug Evaluation and Research, adding that "the approval of Enhertu represents the newest treatment option for patients who have progressed on available HER2-directed therapies." 

The decision on Enhertu, also known as DS-8201, was supported by data from the single-arm Phase II DESTINY-Breast01 trial of 184 female patients with HER2-positive, unresectable and/or metastatic breast cancer who had received two or more prior anti-HER2 therapies in the metastatic setting. The agency noted that participants in the study were heavily pretreated, receiving between two and 17 therapies prior to Enhertu. Results showed an overall response rate of 60.3%, including a 4.3% complete response rate and a 56% partial response rate, while the median duration of response was 14.8 months. 

The label for Enhertu carries a boxed warning about the risk of interstitial lung disease and embryo-foetal toxicity. According to the FDA, interstitial lung disease and pneumonitis, including cases resulting in death, have been reported with the antibody-drug conjugate. The companies said Enhertu will be available in the US within the coming weeks. 

Antoine Yver, global head for oncology R&D at Daiichi Sankyo, noted that Enhertu "represents one of the fastest developed biologics in oncology," while José Baselga, executive vice president for oncology R&D at AstraZeneca, indicated that the companies intend to "further [explore] its potential in additional settings." In March, AstraZeneca agreed to pay Daiichi Sankyo $1.35 billion upfront as part of a deal potentially worth as much as $6.9 billion to jointly develop and commercialise Enhertu. Meanwhile, the drug is currently under review by regulators in Japan. 

For related analysis, see KOL Views Results: AstraZeneca, Daiichi Sankyo's newly approved Enhertu shows dramatic promise, says leading expert.

To read more Top Story articles, click here.