Hope for new heart attack treatment targeting dangerous immune response

A cancer drug could harness the power of the immune system to improve recovery after a heart attack and has the potential to become the first treatment of its kind available for patients, according to a clinical trial we have part-funded and published in the New England Journal of Medicine – Evidence.    

A heart attack triggers the body’s immune cells to rush to the damaged heart and surrounding blood vessels. However, instead of having a healing effect, this can cause further harm, increasing the risk of future heart attack, stroke, and heart failure. Right now, there are no treatments available to counter this damaging immune response.     

Now, a phase 2a clinical trial at Addenbrookes Hospital in Cambridge has shown that low doses of a drug called aldesleukin could improve recovery after a heart attack by stopping this harmful feedback loop. If proven effective in larger clinical trials, the researchers hope it could be used to treat patients within the next 5 years.   

 

High doses of aldesleukin stimulate the immune system to attack cancer cells. The researchers investigated whether using doses a thousand times lower than those used in cancer treatment could selectively target and boost anti-inflammatory cells in patients’ immune systems.   

 

In the study, 16 patients admitted to hospital with a heart attack were given one of two doses of aldesleukin or a placebo. The drug was injected under the skin in their abdomen once a day for five days, and they were then followed up again a week after they’d received the final dose of the drug.   

The patients that received aldesleukin had a significantly greater increase in the number of regulatory T cells, a type of white blood cell that calms inflammation, a week after their last dose of aldesleukin compared to those who received a placebo.   

 

Further analysis revealed that not only were the numbers of regulatory T cells increasing, but the cells themselves had features that suggested that they were also becoming more anti-inflammatory.    

 

Low doses of aldesleukin also decreased the levels of other types of immune cells that can have damaging effects on inflammation and recovery after a heart attack. The team thinks this is another way that the drug could promote healing.   

 

Encouraged by these results, the researchers are currently halfway through a larger clinical trial to investigate whether low doses of aldesleukin after a heart attack can reduce inflammation in patients’ blood vessels.    

Dr Tian Zhao, British Heart Foundation Clinical Lecturer in Cardiovascular Medicine at the University of Cambridge, said:    

 

“It’s only in the past decade that we’ve begun to understand the considerable role that the immune system plays in heart attack recovery.   

 

“In this study we’ve shown, for the first time, that low doses of aldesleukin given to heart attack patients can enhance the number of anti-inflammatory cells in the immune system. Previous research has suggested that this can reduce inflammation in blood vessels and improve heart healing.   

 

“Our ongoing study will give us the first signs of whether this is having clinical benefits for patients. We hope these results will bring us one step closer to the first treatment that can stop the damaging immune response that follows a heart attack.”   

 

Professor James Leiper, our Associate Medical Director, said:    

 

“In the UK one person is admitted to hospital with a heart attack every five minutes. Thankfully, more people than ever are surviving heart attacks, but some will be left with long-term health problems such as heart failure. We urgently need new treatments that can help people to make a better recovery after a heart attack and reduce their risk of future ill health.   

 

“Treatments that can unlock the anti-inflammatory power of the immune system have the potential to become a new treatment option for heart attack patients. This research is an important step towards making this type of treatment a reality.”   

 

This research was also funded by the Medical Research Council and the National Institute for Health Research (NIHR) Cambridge Biomedical Research Centre.

 

The breakthrough comes as we launch a campaign to raise funds to support more life saving discoveries.