The European Commission granted conditional approval for trastuzumab deruxtecan as a monotherapy for the treatment of adult patients with unresectable or metastatic HER2-positive breast cancer who have received two or more prior anti-HER2-based regimens. 

The European approval was based on positive results from the DESTINY-Breast01 Phase 2 trial, where the treatment showed "clinically meaningful and durable antitumor activity," according to a press release from the manufacturer. 

The news follows the December 2020 recommendation for approval by the Committee for Medicinal Products for Human Use of the European Medicines Agency 

After a median follow-up of 20.5 months in the phase 2, trastuzumab deruxtecan showed a confirmed ORR of 61.4% including a 6.5% complete response, a 54.9% partial response rate, and an estimated median duration of response of 20.8 months for patients with HER2-positive metastatic breast cancer who had received at least two previous lines of therapy. 

Trastuzumab deruxtecan (5.4mg/kg) is approved in the US under accelerated approval and in Japan under the conditional early approval system, according to the release. 

Additionally, researchers continue to study the therapy in Phase 3 breast cancer trials and a confirmatory trial in third-line HER2-postiive metastatic breast cancer and as a second-line treatment. Another trial is testing patients with metastatic breast cancer and low expression of HER2 and as an adjuvant treatment of patients with high-risk HER2-positive early breast cancer.

"One in five women with breast cancer have HER2-positive disease and those with previously treated metastatic disease often progress quickly," Professor Fabrice André, Head of Research, Department of Medical Oncology, Gustave Roussy Cancer Campus, Villejuif, France, said in the release. "One of the biggest challenges in this setting has been identifying treatments that produce a durable response. The DESTINY-Breast01 trial showed a breadth, depth and durability of response not previously seen in this patient population."

"This expedited review underscores the practice-changing potential of [trastuzumab deruxtecan] for patients in the metastatic setting. [Trastuzumab deruxtecan] is the first-ever new medicine to be approved in breast cancer in Europe on the basis of Phase II single-arm data, and one of the fastest accelerated assessment procedures for an application in oncology," Gilles Gallant, Senior Vice President, Global Head, Oncology Development, Oncology R&D, Daiichi Sankyo, said. 


By MD /alert Staff