Channel 4 – Investigation of Byetta and Victoza, a cause for concern?

Channel 4 – Investigation of Byetta and Victoza, a cause for concern?

An investigation into two drugs for the treatment of Type 2 diabetes was shown on Channel 4’s Despatches [June 10th 2013]. The drugs are Byetta [exenatide] and Victoza [liraglutide] and the investigation was carried by the British Medical Journal [BMJ] and Channel 4’s Despatches. They uncovered evidence that these drugs may contribute to the causes of pancreatic cancer.

Byetta and Victoza are injected and increasingly popular for the treatment of Type 2 diabetes. They contain a man-made version of the hormone glucagon-like peptide 1 [GLP-1], which is produced by the intestines and prompts the body to release insulin to control blood sugar levels. The drugs also suppress appetite which can help people to lose weight.

The investigation found that the manufacturers may be trying to hide potentially harmful side effects. They uncovered documents showing the drugs increase the risk of pancreatitis, which leads to 1,000 deaths in Britain a year. The investigation also found research which showed a number of patients taking the drugs had developed pancreatic cancer, which has the lowest survival rates of all cancers with only 5% of patients living five years beyond diagnosis.

The GLP-1 drugs were first approved for NHS use by NICE in 2009 and around 25,000 prescriptions are issued each year, although it is unclear exactly how many patients are taking them as some get monthly prescriptions while others receive longer or shorter supplies.


  • Dr Deborah Cohen, the BMJ’s investigations editor, said the individual pieces of evidence ‘may seem inconclusive’ on their own, but added: ‘When considered alongside other emerging and long standing evidence, a worrying picture emerges, posing serious questions about the safety of this class of drug.’
  • Dr Fiona Godlee, BMJ editor-in-chief, said the manufacturers had been ‘unwilling to share their data’ and that patients and doctors had ‘not been kept properly informed about the uncertainties surrounding these drugs’. 
  • The manufacturers said they were committed to patient safety and insisted they monitor their drugs with rigorous processes.

Other studies
There has been some evidence of these drugs causing pancreatic cancer for some time and separate research by the University of California has found that the drugs caused tumours which may lead to cancer in animals.
This risk of pancreatitis has been known since the drugs were first evaluated and there have been reported cases. Results from a study conducted by a group of independent academic researchers in the USA were recently published. The researchers suggest that there is an increased risk of pancreatitis and pre-cancerous cellular changes of the pancreas in patients with type 2 diabetes treated with these drugs.
The study involved the examination of a small number of pancreatic tissue samples obtained from organ donors with and without diabetes mellitus, who died due to causes other than diabetes. Some of the patients had received sitagliptin or exenatide in life, both of which belong to the same family of drugs.

The official comment
The European Medicines Agency is currently investigating the information provided by the researchers to determine the need for any change to the way these products are used. The MHRA is providing input to this assessment, which is ongoing; the EMA has not yet reached any conclusions on the investigation.
If you have concerns, discuss these with your doctor.

The Association of the British Pharmaceutical Industry [ABPI] comment issued June 13th 2013 is general and does not refer specifically to Byetta and Victoza

The medicines researched and developed by the pharmaceutical industry have transformed and saved the lives of people right across the world…To bring a medicine to market, clinical research and clinical trials must be conducted in order to demonstrate its safety and efficacy. The relevant data generated in this process is always submitted to the regulators – the European Medicines Agency (EMA) and the Medicines and Healthcare Products Regulatory Agency (MHRA). Only after the regulators are satisfied that a medicine has a favourable benefit to risk profile, can it be used to treat patients.

The ABPI is a strong advocate of transparency in clinical trial information and our Code of Practice goes above and beyond the legal requirement…The Code requires companies to publish all clinical trial results within one year of marketing authorisation and new clinical trials must be publically registered within 21 days of the first patient being enrolled. The latest research available, which is being prepared for publication in the coming weeks, shows that for recently approved medicines, the vast majority of the evaluable trials conducted in patients have been published within a year of completion or product launch.

To add to this and to reach our goal of 100 per cent disclosure of trial results, the ABPI will be introducing a transparency toolkit and a compliance monitoring service to help companies meet their obligations.