Beyondis reports positive results from Phase III trial of antibody-drug conjugate for breast cancer

Byondis has reported positive topline results from the Phase III TULIP study, a multi-centre, open-label, randomized clinical trial. The trial compared the efficacy and safety of the company’s antibody-drug conjugate (ADC) [vic-]trastuzumab duocarmazine (SYD985) to physician’s choice treatment in patients with pretreated HER2-positive unresectable locally advanced or metastatic breast cancer.

The Phase III TULIP study “SYD985 vs. Physician’s Choice in Participants With HER2-positive Locally Advanced or Metastatic Breast Cancer” met its primary endpoint of progression-free survival (PFS), demonstrating a statistically significant improvement over June 2021 25 | physician’s choice. PFS is defined as the time from the date of randomization to the date of first documented disease progression or death due to any cause, whichever occurred earlier. The study also demonstrated preliminary supportive overall survival results.

“There is considerable unmet medical need in patients with HER2-positive metastatic breast cancer and [vic-]trastuzumab duocarmazine represents a promising potential clinical advance,” said Byondis Chief Medical Officer Jan Schellens, M.D., Ph.D. “We are excited by the topline results of TULIP and indebted to all patients who participated in the clinical studies.”

Byondis CEO Marco Timmers, Ph.D., referred to the study’s culmination as a triumph over adversity. “A large trial involving breast cancer patients with advanced disease is difficult in the best of times, but it is especially challenging during a global pandemic. The completion of TULIP is a testament to the dedication of all involved, especially the patients, their families and participating clinical sites.”

Detailed results from TULIP will be published at scientific conferences in due course. Byondis will complete the biological license application and intends to submit it before the end of 2021.

With this positive study outcome, Byondis is planning to explore partnerships with pharma and biopharma companies in order to commercialize SYD985 and make it available to patients in need of new treatment options.

SYD985 incorporates Byondis’ distinctive, proprietary duocarmazine linker-drug technology ByonZine. Although in general, marketed ADCs have improved therapeutic indices compared to classical non-targeted chemotherapeutic agents, there is still need for improvement.

The ADC [vic-]trastuzumab duocarmazine is comprised of the monoclonal antibody trastuzumab and a cleavable linker-drug called valine-citrulline-seco-DUocarmycinhydroxyBenzamide-Azaindole (vc-seco-DUBA). The antibody part of [vic-]trastuzumab duocarmazine binds to HER2 on the surface of the cancer cell and the ADC is internalized by the cell. After proteolytic cleavage of the linker, the inactive cytotoxin is activated and DNA damage is induced, resulting in tumour cell death. SYD985 is considered a form of targeted chemotherapy.