In a clinical trial, a new stem cell therapy helped stop the progression of multiple sclerosis (MS) in participants. What is there to hope for? We asked the question to Dr Wilfrid Casseron, neurologist.
Multiple sclerosis, or MS, is an autoimmune disease that affects the central nervous system and affects 120,000 people in Europe, including 700 children and 3,000 new cases per year. The dysfunction of the immune system which characterizes it leads to lesions which cause motor, sensory, cognitive, visual or even sphincter disturbances, which can progress towards different types of disability. To date, treatments exist (corticosteroids, immunomodulators, immunosuppressants) which aim to reduce flare-ups, accelerate recovery and live better on a daily basis, but no treatment can completely stop the progression of the disease or cure it.
But in the quest for such a treatment, a new study proposing an injection of stem cells could be a serious avenue.
An injection of stem cells directly into the brain of patients
The study we’re talking about, published on November 27, reports a trial of 15 patients with secondary multiple sclerosis (the progressive phase of the disease) aged 38 to 57, all with high levels of ‘disability.
The experiment involved injecting them with neural stem cells directly into the brain and observing over the next 12 months for any side effects and changes in their symptoms. For this, they were also forced to take immunosuppressive drugs for half of the follow-up period.
After a year, the trial revealed several things:
- The treatment was safe and well tolerated: there were no deaths or serious adverse effects, and when side effects did occur, they were either temporary or reversible;
- None of the patients experienced an increase in disability or worsening of symptoms during this observed period.
And an impact observed on brain metabolism
The team also monitored the possible effect of these injections on brain metabolism. According to previous animal research, changing the brain’s metabolism was able to reprogram the immune cells that attack the central nervous system in MS. They were thus able to observe two things.
The researchers then assessed a subgroup of patients for changes in brain tissue volume associated with disease progression. They found that the greater the dose of stem cells injected, the smaller the reduction in this brain volume over time. They think this could be because the stem cell transplant alleviated the inflammation.
The team also looked for signs that the stem cells had a neuroprotective effect, that is, they protected nerve cells from further damage. They measured changes in the fluid around the brain and in the blood over time and discovered some signs related to how the brain processes fatty acids. These signs were linked to the effectiveness of the treatment and the progression of the disease. The higher the dose of stem cells, the higher the fatty acid levels, which also persist over a 12-month period.
“I am cautious but very enthusiastic about our results, which constitute a step towards the development of a cell therapy for the treatment of multiple sclerosis,” said Stefano Pluchino, who co-led the study.
Several limiting factors to take into account, according to Dr Wilfrid Casseron
Consulted on the subject, Dr Wilfrid Casseron, neurologist, discusses for us the cellular track as a research avenue known today: “Stem cell treatments have been evaluated for several years in hematology, there have already been several publications on the transplantation of autologous stem cells (those of the patient themselves), not through blood. The results demonstrated were convincing in patients with a severe form of MS, resistant to immunosuppressive treatments. Another study demonstrated that blood transplantation had superiority over Fingolimod, but not compared to Natailzumab, Ocrelizumab which are disease-modifying treatments.
According to the doctor, the cellular route would therefore be interesting for patients who escape the usual therapeutic arsenal. Intracerebral transplantation therefore follows this same path, but nevertheless has several limiting factors, in addition to the very small number of participants:
“We must already know that these patients must receive chemotherapy to suppress their own immune system and can develop serious infections; we must carefully weigh the benefit/risk balance. In addition, there is the fact of injecting these stem cells into the brain: agreeing to receive a blood transplant is one thing, but accepting it for an intracerebral transplant is a little more complicated. This can only concern certain patients in particular, those who no longer have other therapeutic options.”
Despite these reservations, the cellular track nourishes a lot of hope among patients, “but today we have a certain therapeutic and medicinal arsenal which is not negligible in MS. In my opinion, this research concerns a very limited number of patients with very severe forms, so that the benefit/risk ratio is really interesting” concludes our expert.