Byondis Announces Positive Topline Results of Phase 3 TULIP Study Evaluating (ADC) [vic-]trastuzumab duocarmazine in Patients with HER2+ Breast Cancer

Byondis announced positive topline results from the Phase III TULIP study, which 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 study met the primary endpoint, confirming that ADC [Vic-]Trastuzumab Duocarmazine (SYD985) is superior to Physician’s Choice in delaying disease progression. 

The multi-center, open-label, randomized clinical trial enrolled 436 female patients aged 18 and over, at 83 sites across the United States, Canada, Europe and Singapore. To qualify, patients had either: (1) progression during or after at least two HER2-targeting treatment regimens for locally advanced or metastatic disease; or (2) progression during or after ado-trastuzumab emtansine treatment. Patients were randomly assigned (2:1) to receive SYD985 or physician’s choice treatment until disease progression or unacceptable toxicity. The trial met its primary endpoint of progression-free survival (PFS), demonstrating a statistically significant improvement over 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 (OS) results.

Detailed results from TULIP will be published at future scientific conferences. Byondis intends to complete a biological license application (BLA) and submit it before the end of 2021.

About ADC [Vic-]Trastuzumab Duocarmazine (SYD985)

ADC [Vic-]Trastuzumab Duocarmazine (SYD985) is an antibody drug conjugate and incorporates Byondis’ distinctive, proprietary duocarmazine linker-drug (LD) technology ByonZine. The ADC [vic-]trastuzumab duocarmazine is comprised of the monoclonal antibody trastuzumab and a cleavable linker-drug called valine-citrulline-seco-DUocarmycin-hydroxyBenzamide-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 tumor cell death. 

SYD985 was granted fast track designation by the U.S. Food & Drug Administration in January 2018 for last-line HER2-positive MBC.

About HER2 Breast cancer

In HER2-positive breast cancer, an overexpression of the human epidermal growth factor receptor 2 (HER2) protein causes out-of-control reproduction of breast cells. Research has shown that women with HER2-positive breast cancer have a more aggressive disease, greater likelihood of recurrence and poorer prognosis, compared to women with HER2-negative breast cancer. About 20 percent of all breast cancers are HER2-positive, with younger women being the most affected. Treatment of HER2-positive breast cancer generally consists of surgery, radiation, chemotherapy and targeted treatments.