Novel peptide could help cure obesity

A new peptide-based drug is being developed that could help stop people over-eating.

A research team based at Imperial College London's Hammersmith Hospital campus, headed by Professor Steve Bloom, discovered that pancreatic peptide (PP) is secreted after eating a meal and tells the brain that hunger has been satiated.

The work is based on observations of people with benign PP-secreting tumours, who have elevated levels of the hormone and although very thin, show no other side effects. According to Bloom, the patients are unaware they even have a suppressed appetite. When the tumours are removed, the patients' appetite returns and they gain weight.

PP's appetite suppression effects only last up to 24 hours, however, so it currently needs to be administered daily. In human trials of overweight yet otherwise healthy volunteers, administration of PP lowered appetite in all patients to varying degrees, but an average reduction of around 15 to 25 per cent was measured.

Bloom and his team were awarded GBP 2.3 million (USD 4.5 million/ EUR 3.5 million) by the Wellcome Trust as one the three inaugural grants from its GBP 91 million (USD 180 million/ EUR 138.1 million) Seeding Drug Discovery programme.

Dr Ted Bianco, director of Technology Transfer at the Wellcome Trust, said: ìOur funding is designed to take the research forward to a point that makes it more attractive to venture capital firms, industry and public-private partnerships.î

Bloom's team will use the money to continue human trials of PP and also to try and develop a longer-lasting form of the hormone. The team is aiming for an injectable that can be administered weekly, but are examining other delivery methods, such as a nasal spray or a controlled-release chewing gum. Encapsulation of the peptide to prevent break down is also another way mooted to extend the life of the drug within the body.

A University of Alberta Hospital study published in the Lancet recently revealed that data on obesity drugs already in use was limited particularly over cardiovascular outcomes. Researchers analysed articles published over the last six years on three drugs: appetite suppressant sibutramine; orlistat, which restricts the absorption of fat, and rimonabont, a drug currently targeted at people with diabetes. The long-term impact of the drugs was not clearly known, with side effects including increased blood pressure and pulse rate for sibutramine and mood-related disorders for rimonabont reported.

As PP occurs naturally, a drug based on it could be used in people of all ages and also in cases of mild to moderate obesity.