U.S. Food and Drug Administration Issues Complete Response Letter for Byondis’ [Vic-]Trastuzumab Duocarmazine
Complete response letter outlines FDA’s request for additional information 15 May 2023Byondis B.V., an independent, Dutch clinical-stage biopharmaceutical company creating targeted medicines, today announced that the U.S. Food and Drug Administration (FDA) has issued a complete response letter (CRL) for the Biological License Application (BLA) for [vic-]trastuzumab duocarmazine (SYD985). With this BLA, Byondis sought approval for its anti-HER2 antibody-drug conjugate (ADC) in HER2-positive unresectable locally advanced or metastatic breast cancer (MBC), a disease with a high unmet medical need.
According to the complete response letter, the FDA suspends the decision on the product’s approvability. The agency requested additional information that requires time and resources that extend beyond the current evaluation period.
While Byondis is disappointed with this outcome, the company remains optimistic about SYD985’s potential. “We continue to believe that SYD985 can present a meaningful treatment option for patients living with HER2-positive metastatic breast cancer,” said Byondis CEO Marco Timmers, Ph.D. “We appreciate the FDA’s guidance and support and will carefully evaluate the complete response letter and consider potential next steps.”
Timmers added, “We will continue with the SYD985 applications in EU and UK and await the outcome of the review process.”
[Vic-]Trastuzumab Duocarmazine Phase III TULIP® Study Results
The BLA and MAA are supported by data from the pivotal Phase III TULIP multi-center, open-label, randomized clinical trial comparing SYD985 to physician’s choice (PC) treatment in patients with pre-treated HER2-positive unresectable locally advanced or metastatic breast cancer (SYD985.002/NCT03262935). The study, the results of which were presented at the 2021 ESMO Congress, met its primary endpoint of progression-free survival (PFS), demonstrating a statistically significant improvement of 2.1 months over PC. TULIP also demonstrated supportive overall survival (OS) results.
