Cancer drug shows promise as lupus treatment

Lupus

23 Aug 2016

A drug used for cancer patients has emerged as a potential treatment for lupus, with at least one randomised control trial already underway and some rheumatologists already believed to be testing it in clinical practice.

The study, published in Nature Medicine has revealed a natural immune system protein called interleukin-2 (IL-2) can help restore balance to the overactive immune system of lupus patients.

Significantly, the researchers found the amount needed for treating lupus was much less than the dose used in treating cancers, and the results observed were both safe and promising in terms of clinical results.

Monash Biomedicine Discovery Institute researcher, Dr Di Yu and Professor Zhanguo Li from Peking University People’s Hospital in China co-led the study. Dr Yu said he hoped the drug could be approved as a lupus treatment within a handful of years.

“This drug, which can help the immune system fight against cancer, was approved in the 1990s but is not commonly used now,” he said. “We’re now using this drug for a different purpose, based on our new knowledge of the immune system.”

Dr Yu told the limbic that he believed the study would have a significant impact on clinical practice and he knew of several rheumatologists who had already started to trial the treatment.

“There is an obvious unmet need for new therapies for SLE as many patients don’t respond to current therapies and flares are common,” he said.

“Low-dose IL-2 provides a new choice for those patients. It is very promising as the responding rate was high in this study.”

However, he noted that the levels of response varied among patients, meaning IL-2 was unlikely to suit all patients. There was no severe side effects seen in this study, although a small proportion of patients experienced injection-site reactions and influenza-like symptoms post-treatment.

“SLE is a very heterogenous disease and I don’t think there will be one for all therapy,” he said. “The next step for low-dose IL-2 therapy is to stratify patients to identify those with most benefit.”

He said when IL-2 was used for cancer it was given at a high dose, usually 600,000 or 720,000 IU per kg-dose every eight hours.

“This high-dose IL-2 that stimulates the immune system is quite different from the low-dose IL-2 that inhibits the immune response,” he said.

Dr Yu said low-dose IL-2 therapy that induces immune tolerance has also been trialed in GvHD, vasculitis and type I diabetes.

His fellow collaborators, Professor Zhanguo Li and Associate Professor Jing He in Peking University People’s Hospital in China are currently carrying out a randomised clinical trial of IL-2 for patients with SLE.

He said the fact that this was a repurposing of an old drug would speed up the approval process, although it was important to point out that more studies would be needed to further optimise this treatment in terms of dose scheme and also the patient selection.

Professor Eric Morand, fellow Monash University researcher on the study and founder of the Asia Pacific Lupus Collaboration, said that in this study, IL-2 was given to people whose lupus wasn’t responding well to standard treatments.

“The real promise of this treatment is that it calms the hyperactive immune system through multiple mechanisms, which is very important as this new therapy may be effective for many patients,” he said. ”As the drug has been on the market for some time for other diseases, it can be rapidly put into formal trials for lupus treatment right away.”

 

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