OncoMed Pharmaceuticals has initiated a multi-centre Phase Ib clinical trial of its first-in-class Wnt-pathway-targeting antibody vantictumab (OMP-18R5) in combination with paclitaxel to treat patients with first, second and third-line, locally advanced or metastatic HER2 negative breast cancer.
The study is the first of three Phase Ib clinical trials of vantictumab that the company expects to start in 2013 as part of its collaboration with Bayer Pharma.
Primary objectives of the trial are to assess safety of the combination regimen and show a recommended Phase II dose for vantictumab in combination with paclitaxel.
The trial's major secondary and exploratory objectives include assessment of the pharmacokinetics (PK) of vantictumab, as well as the pharmacodynamics (PD) and efficacy of this combination.
During the trial, tumour tissue from patients will be used to explore predictive biomarker hypotheses related to the efficacy of vantictumab.
Baylor Sammons Cancer Center medical director Carlos Becerra is the principal Investigator who treated the first patient enrolled in the trial.
Dr Donald Richards at the US Oncology Network, Tyler, Texas, and Dr Monica Mita at the Cedars-Sinai Medical Center in Los Angeles, California, are the other investigators and clinical sites to participate in the Phase Ib study.
Becerra said breast cancer patients with advanced HER2 negative disease are in need of novel agents that have a lasting impact on their cancer.
"Vantictumab has the potential to have an impact for breast cancer patients in combination with standard paclitaxel chemotherapy because of its novel mechanism of action targeting cancer stem cells," Becerra said.
OncoMed chief medical officer Jakob Dupont said: "The Wnt pathway has been an area of interest for breast cancer researchers for many years, and it is exciting to bring this novel Wnt targeting antibody, vantictumab, to the clinic to learn more about the safety and potential efficacy of the drug candidate in combination with paclitaxel in patients with advanced HER2 negative breast cancer."
The company said that clinical data secured from the current trial and two other Phase Ib trials could possibly lead to an opt-in decision by Bayer to take vantictumab into later stage randomised clinical trials.
Vantictumab, which inhibits the Wnt pathway, a key signaling pathway in cancer, has shown broad anti-CSC and anti-tumour activity in patient-derived xenograft tumour models.
It is based on HuCAL technology and is administered by intravenous infusion.
Image: Normal (left) versus cancerous (right) mammography image. Photo: courtesy of Morning2k.