A treatment for Guillain-Barr茅 syndrome has worked well in a late-stage clinical trial and may be approved next year. This would make it the first targeted treatment for the sudden and debilitating autoimmune condition.
鈥淧atients got better sooner and more completely on every measure in our studies,鈥� says聽聽at Annexon Biosciences, the Californian company developing the treatment.
Guillain-Barr茅 syndrome is a rare condition that can affect anyone who has recently had an infection, like food poisoning or influenza. After fighting the bacterium or virus causing the infection, a person鈥檚 immune system starts mistakenly attacking their nerves, for reasons that are poorly understood.
Advertisement
This assault causes weakness or tingling in the arms and legs, which can progress to difficulty walking, speaking, swallowing and breathing, and sometimes paralysis or death. 鈥淚t鈥檚 one of the most striking diseases I鈥檝e seen in 30 years working in biotech,鈥� says Love. 鈥淚t is completely sudden, it is completely indiscriminate 鈥� it can affect young, old, male, female, rich or poor 鈥� and it is immediately life-threatening,鈥� he says.
The new treatment, called tanruprubart, is a monoclonal antibody that works by blocking a protein in the blood called C1q. This switches off a branch of the immune system called the classical complement pathway that聽.听
In a late-stage trial in Bangladesh and the Philippines, 241 people who had recently been diagnosed with the condition were given a single intravenous infusion of tanruprubart or a placebo infusion. On average, those treated with tanruprubart required 28 fewer days of mechanical ventilation to help them breathe and seven fewer days in intensive care, and were able to walk independently 31 days earlier. A higher proportion also reported feeling 鈥渧ery much improved鈥� after one week.
People with the syndrome often take a long time to recover, but the participants who received tanruprubart experienced greater quality of life and mobility after two months compared with those who had the placebo. The results were聽聽in Geneva, Switzerland, in June.
No serious side effects occurred in the trial, and even though tanruprubart switched off part of the immune system, it didn鈥檛 appear to make the participants more vulnerable to infection. 鈥淏ecause it鈥檚 only a single infusion and you鈥檙e not chronically blocking the immune system, the risk of getting an infection is diminished,鈥� says Love.
Based on these results, Annexon Biosciences recently submitted tanruprubart for approval from the European Medicines Agency. 鈥淚t鈥檚 under review and we hope to get approval in the first part of next year,鈥� says Love. The company will also submit it to the US Food and Drug Administration in the next few months, he says.
Guillain-Barr茅 syndrome is most prevalent in low-income countries due to there being higher rates of infections that can trigger it, but it also occurs in high-income nations, including about聽8000 cases in the US聽each year.
In rare cases, the condition can also be . This is because vaccines train the immune system to attack bacteria or viruses, which can sometimes lead to a mistaken immune attack on the nerves. However, infections are more likely to cause Guillain-Barr茅 syndrome than the vaccines designed to prevent them.
Although tanruprubart was effective at treating Guillain-Barr茅 syndrome in Bangladesh and the Philippines, it is unclear whether it will work as well in other countries, says at the Princess Alexandra Hospital in Brisbane, Australia. This is because the condition tends to be triggered by different infectious agents depending on the location. 鈥淚n developing countries, it鈥檚 often associated with gastrointestinal illnesses, like from [the bacterium] Campylobacter jejuni, whereas in developed countries it is much more associated with viral infections.鈥�
Currently, Guillain-Barr茅 syndrome is treated with plasma exchange or intravenous immunoglobulin, which help to calm the overactive immune system. However, because these treatments are non-targeted, they have聽limited efficacy. 鈥淭hey鈥檙e useful, but not fantastic,鈥� says Blum. 鈥淚t would be fantastic to have some new therapies for Guillain-Barr茅 syndrome because there鈥檚 been absolutely nothing new on the market for 25 or 30 years now.鈥�
