US-based biotechnology firm MabVax Therapeutics has started dosing patients in a Phase I clinical trial of MVT-1075 to treat patients with CA19-9 positive malignancies such as pancreatic, colon and lung cancers.

Designed to combine radiation therapy and tumour specific targeting, MVT-1075 is a radioimmunotherapy (RIT) candidate comprising small doses of MVT-5873 antibody coupled with radioisotope for targeting and destroying pancreatic cancer cells. 

The open-label, multi-centre, dose-escalation Phase I trial will investigate the safety and efficacy of MVT-1075 in approximately 22 patients with recurring disease at Honour Health in Scottsdale, Arizona and Memorial Sloan Kettering Cancer Centre in New York City. 

The trial’s primary objective is the determination of maximum tolerated dose and safety profile, while the secondary endpoints include tumour response rate and duration, dosimetry and pharmacokinetics. 

"This is the third HuMab-5B1based clinical trial that the company has initiated in the last 16 months."

MabVax Therapeutics president and CEO David Hansen said: "This is the third HuMab-5B1based clinical trial that the company has initiated in the last 16 months.

“We believe that the development of this product candidate expands our pipeline to include a more potent therapy combining the clinically demonstrated tumour targeting characteristics of our fully human HuMab-5B1 antibody and commercially validated 177Lutetium, to deliver a dose of radiation to the targeted cancer cells.”

With interim data expected by the end of this year, the Phase I trial of MVT-1075 RIT is said to be supported by the preclinical data and results obtained from a Phase Ia trial.

While the product suppressed tumour growth in preclinical models with pancreatic cancer, the Phase Ia trial validated its safety and target specificity.