Positive Topline Survival Data Observed in Phase 3 Trial of SYD985 for HER2-Positive Metastatic Breast Cancer
Data from the phase 3 TULIP trial showed that [vic-]trastuzumab duocarmazine yielded positive progression-free survival for patients with pretreated HER2-positive metastatic breast cancer.
Positive topline results were observed in the phase 3 TULIP study (NCT03262935), which investigated the safety and efficacy of [vic-]trastuzumab duocarmazine (SYD985) compared with physician’s choice of chemotherapy in patients with pretreated HER2-positive unresectable locally advanced or metastatic breast cancer, according to a press release from the company responsible for the antibody drug conjugate (ADC), Byondis B.V.1
The multi-center, open-label, randomized clinical trial met its primary end point of progression-free survival (PFS), with [vic-]trastuzumab duocarmazine having demonstrated a statistically significant improvement over physician’s choice of chemotherapy.
"There is considerable unmet medical need in patients with HER2-positive metastatic breast cancer and [vic-]trastuzumab duocarmazine represents a promising potential clinical advance," Jan Schellens, MD, PhD, chief medical officer at Byondis, said in a press release. "We are excited by the topline results of TULIP and indebted to all patients who participated in the clinical studies."
A total of 436 patients were enrolled in the TULIP study across 83 sites in the United States, Canada, Europe, and Singapore. In order to enroll, patients needed to be 18 years or older, progressed during or after at least 2 HER2-targeting treatment regimens for locally advanced or metastatic disease, or progressed during or after treatment with ado-trastuzumab emtansine (Kadcyla). The patients were randomized 2:1 for treatment with either [vic-]trastuzumab duocarmazine or physician’s choice of chemotherapy, wherein treatment continued until progression of unacceptable toxicity occurred.
Key secondary end points for the trial included overall survival (OS), objective response rate (ORR) assessed by blinded independent central review, investigator-assessed PFS, patient-reported outcomes regarding health-related quality of life, and safety.
The ADC, [vic-]trastuzumab duocarmazine, was previously granted a fast track designation in January 2018 by the FDA in the last-line for previously treated patients with HER2-positive metastatic breast cancer.2 The indication was based on the results of a 2 part, phase 1 trial examining the agent, with preliminary results revealing an ORR of 33% and a median PFS of 9.4 months in patients with heavily pretreated HER2-positive or HER2-low breast cancer.3
"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,” Marco Timmers, PhD, chief executive officer of Byondis, said in a press release. “The completion of TULIP is a testament to the dedication of all involved, especially the patients, their families, and participating clinical sites."
Looking ahead, detailed results from the TULIP trial will be presented at an upcoming scientific conference, with Byondis planning to complete and submit its biologics license application before the end of 2021.
[Vic-]trastuzumab duocarmazine, a targeted chemotherapy, contains the monoclonal antibody trastuzumab and valine-citrulline-seco-DUocarmycin-hydroxyBenzamide-Azaindole, a cleavable linker-drug. The antibody component of the agent binds to HER2 on the surface of the cancer cell and is subsequently internalized. Following proteolytic liker cleavage, the agents cytotoxin activates and induces DNA damage yielding cell death.
Reference
- Byondis announces positive topline results of pivotal phase III TULIP® study in patients with HER2-positive unresectable locally advanced or metastatic breast cancer. News release. Byondis B.V. June 8, 2021. Accessed June 29, 2021. https://bit.ly/364ysC0
- Synthon’s [vic-]trastuzumab duocarmazine (SYD985) granted FDA fast track designation for pre-treated HER2-positive metastatic breast cancer. News release. Synthon. January 25, 2018. Accessed June 30, 2021. https://bit.ly/368gf6s
- Saura C, Thistlethwaite F, Banerji U, et al. A phase I expansion cohorts study of SYD985 in heavily pretreated patients with HER2-positive or HER2-low metastatic breast cancer. J Clin Oncol. 2018;36(suppl 15):1014-1014. doi:10.1200/JCO.2018.36.15_suppl.1014
Treatment Combinations for HER2-Positive Breast Cancer
March 7th 2013As part of our coverage for the 30th Annual Miami Breast Cancer Conference, we bring you an interview with Dr. Mark Pegram, director of the breast cancer program at the Stanford Women’s Cancer Center and codirector of the molecular therapeutics program. Dr. Pegram will be discussing the potential for novel HER2 combination therapies at the conference.
