Miracle new weight loss injection hit by thyroid cancer fears
A miraculous weight loss injection is under investigation due to fears it could increase cancer risk.
MailOnline can reveal that health chiefs have demanded studies be initiated to monitor possible links to thyroid and pancreatic cancer.
Historical study data from this week showed that overweight people taking tirzepatide lost an average of 15.6 kg after 72 weeks. They all adopted a healthier lifestyle while using the once-a-week injection.
The company that makes the jab, nicknamed the “King Kong” of weight-loss drugs, wants it approved as a weight-loss-specific drug in both the US and the UK.
Mounjaro, a branded version of the powerful ingredient, has already cleared all regulatory hurdles for the treatment of type 2 diabetes.
According to the latest data, digestive problems were the most commonly reported side effects of tirzepatide, the active ingredient of Mounjaro. Among them was about one in five participants who experienced nausea and diarrhoea, and about one in ten who reported vomiting or diarrhea
The once-a-week injection works by mimicking certain natural appetite-suppressing hormones. It is the latest drug of its kind to hit the market after Wegovy.
But, like the others, also under the watchful eye of European health chiefs.
The European Medicines Agency (EMA) said research in rodents has suggested the artificial hormones packaged into tirzepatide may increase the risk of medullary thyroid cancer.
As such, it ruled that a monitoring study of patients taking the drug is needed to investigate the potential of an increased risk of cancer in humans.
“To evaluate the possible association, a surveillance study is planned to monitor the annual incidence of MTC and to identify any increase associated with tirzepatide,” it said.
A similar observational study is planned for pancreatic cancer, but the EMA said there is currently no evidence of a link.
While the EMA warned that there may be an increased risk of cancer, it noted that there is currently no ‘pharmacologically plausible mechanism’ by which the jabs can cause cancer in humans.
“The relevance of thyroid tumors in rodents to humans is not known,” they said in a July last year paper.
Health chiefs also stressed that if such a risk is identified, it will change the ‘benefit/risk’ of the medication.
Because a substantial link between tirzepatide and MTC has not yet been established, drug makers need not list it as a potential risk.
A spokesperson for Lilly said: “New drugs often undergo additional scrutiny to ensure we continue to research and develop the risk-benefit profile of the drug over time.”
“We are working with regulators around the world to ensure that safety information on our medicines is kept up to date based on new evidence.”
They added that while the relationship between the drugs such as tirzepatide and thyroid cancer was not clear, they conducted studies to investigate the possibility.
“The concern about the association between exposure to GLP-1 RAs and an increased risk of thyroid tumors is based on preclinical studies in rodents,” they said.
“Lilly has previously recognized the potential risk of medullary thyroid carcinoma MCT associated with exposure to GLP-1 RA and is working with regulatory agencies to conduct two trials of GLP-1 RAs and thyroid cancer, including MTC.”
The EMA last year recommended Mounjaro for use in the block for patients with type 2 diabetes, on similar grounds to US and UK regulators.
But tirzepatide is not alone in being targeted by EU health leaders’ monitoring.
Drugs, such as those containing semaglutide, the active ingredient in rival Wegovy and Ozempic injections, are also being scrutinized under similar concerns.
MTC is a rare form of thyroid cancer, accounting for between five and ten per cent of all thyroid cancers in the UK, according to Macmillan Cancer Support.
About three-quarters of patients will be alive five years after diagnosis.
Pancreatic cancer is one of the deadliest forms of the disease, with only 5 percent of people surviving 10 years after diagnosis.
Results from the massive trial of tirzepatide also suggest it is slightly more potent than its main rival Wegovy, produced by the Danish company Novo Nordisk, which studies suggest can help people lose between 12 and 15 percent of their body weight. Liraglutide and Orlistat are already available on the NHS
About 10,000 cases are found in the UK each year, with 9,500 deaths.
Both Wegovy and Mounjaro work in a similar way, using an artificial hormone to trick the body into thinking it is already full by suppressing appetite.
But Munjaro differs because it mimics the effects of two hormones, rather than just one.
Both jabs are expensive, with Wegovy costing £1,000 (about $1,500) a month, while similar estimates put tirzepatide at about £900 a month (about $1,000).
The latest trial results for tirzepatide showed that participants lost an average of 16 percent, about 34.4 lbs (15.6 kg), over 72 weeks, when they also adopted a healthier lifestyle.
Crucially, this was much more than the people who just adopted the healthier lifestyle and lost just 3.3 percent of their weight in 72 weeks.
Although tirzepatide is available in the US as a diabetes medication, full UK approval on the same grounds is still pending.
The Medicines and Healthcare products Regulatory Agency (MHRA) approved the drug in October, but it is currently being reviewed by the National Institute for Health and Care Excellence (NICE) to be made available to the NHS.
A decision from NICE is expected in August.
The hype surrounding tirzepatide has led some sellers to offer the drug to buyers in the UK under the label of ‘research use only’ for around £90 per dose.
Like any medication, tirzepatide has a number of potential side effects that vary in frequency and severity.
According to the latest Lilly study of tirzepatide, a study involving over 900 obese/overweight people with type 2 diabetes, digestive problems were the most commonly reported side effects.
Among them, about one in five participants experienced nausea and diarrhea, and about one in ten reported vomiting or constipation.
Lilly said the side effects were reported most often during the dose escalation period.
But current Mounjaro users have reported a range of other nasty side effects similar to those caused by a rival injection called Wegovy, including hair loss.
Regarding reports of hair loss in people taking the Mounjaro, a spokesperson for Lilly said, “Hair loss is a side effect that has been associated with significant weight loss in many previous clinical trials in the treatment of obesity.”
However, fear of side effects hasn’t stopped many from trying the weight loss jab, and some took to social media to show off their amazing 100lb (45.4kg) transformations.
As with other weight loss pills, people taking tirzepatide are given a starting dose of 2.5 mg once a week.
The picture above shows how the slimming drug tirzepatide works. It works to suppress hunger by mimicking hormones that signal the body to be full. It also shows the passage of food through the stomach by reducing the production of stomach acid and muscle contractions
One trial found that the diabetes drug tirzepatide, sold under the brand name Mounjaro, caused participants who were obese or overweight to lose an average of more than 34 pounds (15 kg).
This is then increased every four weeks until the target maximum dosage is reached.
Participants in the latest trial also had to adhere to an energy deficit of 500 kcal per day and 150 minutes of moderate exercise per week.
Lilly has said it expects a decision from US regulators on approving tirzepatide for some weight-loss patients by the end of 2023 and told MailOnline a filing with UK counterparts would be made this year.
Health chiefs have hoped more weight-loss shots come online, which could bring the price down, making them accessible to more people.
NHS figures show that 64 per cent of British adults are overweight, and more people are expected to gain weight in the future.
As well as increasing the UK’s waistline, obesity is costing healthcare, with the NHS spending an estimated £6.1 billion between 2014 and 2015 on the treatment of weight-related diseases such as diabetes, heart disease and some cancers.
In the US, about 42 percent of people are obese.