Biotechnology company Cytos Biotechnology AG has announced the start of clinical trials of CYT009-GhrQb, a therapeutic vaccine for the treatment of obesity.

"Obesity is on its way to become the leading cause of preventable death in western countries such as the United States," said Wolfgang Renner, CEO of Cytos Biotechnology. "Similarly to hypertension and smoking, obesity represents one of the most important risk factors for cardiovascular diseases which account for almost 30% of all global deaths.

"We are developing novel therapeutic vaccines that exactly address these major risk factors," he said. "Their mechanism of action is based on the modulation of complex disease mechanisms by antibodies directed to disease-related molecules."

CYT009-GhrQb is designed to instruct the patient's immune system to produce a specific anti-ghrelin antibody response, the company said. Ghrelin is a peptide, which has recently been identified as a regulator of eating behaviour. Peripheral administration of ghrelin in humans enhanced both appetite and food intake. In addition, the level of plasma ghrelin in obese individuals is increased after diet induced weight loss and seems to be implicated in the frequently observed rapid regain of weight after diet cessation.

These observations suggest that ghrelin may be a key regulator of food intake and body weight in humans, it said. Vaccination with CYT009-GhrQb is anticipated to induce antibodies that bind ghrelin in the circulation and thus inhibit or reduce uptake of ghrelin into the brain, where it exerts its activity. Preclinical experiments in mice have shown that vaccination with CYT009-GhrQb induced high levels of ghrelin-specific antibodies. Furthermore, in mice given a high-fat diet the weight gain was found to be up to 15% lower after vaccination. With CYT009-GhrQb Cytos Biotechnology aims to provide a novel and unique treatment approach for obesity that addresses a high unmet medical need, it said.