Multiple sclerosis (MS) is an inflammatory disorder that causes damage in the brain and spinal cord, which can lead to a range of symptoms, including fatigue, depression, muscle spasms, and difficulty regulating the bladder and bowels. Several strategies using stem cells — self-renewing cells in the human body — are being explored as potential treatments for MS.
The majority of cells in the adult body are terminally differentiated, meaning they are fully mature and cannot grow into another cell type — a liver cell cannot turn into a brain or skin cell, for example. Stem cells are the undifferentiated cells in the body that are capable of self-renewing and have the potential to grow into all other types of cells. When these cells divide, they can originate a similar stem cell and a more differentiated cell, two daughter stem cells, or two more differentiated cells.
Stem cells play a key role in early development, and they are important for facilitating repair when the body’s tissues are damaged. For some types of tissue with rapid cell turnover, such as blood cells or the inner lining of the intestines, stem cells act as a source of self-renewal to continually regenerate cells that are lost.
These cells generally are divided into two main forms. Some are pluripotent, meaning they are able to grow into every single type of cell found within the human body. Pluripotent stem cells are mainly involved in early development and have been employed for cell studies in laboratories as they can be grown into other cell types.
Other stem cells are multipotent, meaning they can grow into some types of cells but not others — for example, hematopoietic stem cells can give rise to all blood cells, but not to other cell lineages, such as bone or nerve cells.
There are a number of different stem cells, each with specific biological properties. Stem cell types that have been used in MS research include:
No stem cell therapy has been approved by the U.S. Food and Drug Administration (FDA) specifically to treat people with MS. But some stem cell-based therapies are in clinical testing for MS, and hematopoietic stem cell transplants are already cleared for use in certain blood disorders. HSCs and MSCs have thus far been the most used and tested for MS.
HSCs reside in the bone marrow and give rise to all the cells in the blood, including most cells in the immune system. Because MS is caused by a faulty immune system, these cells are sometimes used to help manage MS via a one-time treatment called a hematopoietic stem cell transplant, in which these cells are infused into a patient.
While it is possible to do the transplant with cells collected from a donor, HSC transplants in MS are more commonly autologous, meaning they use stem cells collected from the patient. This procedure is called an autologous hematopoietic stem cell transplantation (aHSCT).
When used in the context of MS, the terms “stem cell therapy,” “stem cell transplant,” “bone marrow transplant,” or “blood stem cell transplant” usually refer specifically to aHSCT.
The basic goal of aHSCT is to reset a person’s immune system in an attempt to reduce the excess inflammation that drives MS. There is no one standardized protocol for aHSCT in MS, and various regimens may be used.
Typically, patients are first treated with medications to induce the production of more HSCs and stimulate their release (or mobilization) from the bone marrow into the bloodstream. This enables the collection of HSCs directly from the bloodstream, although some protocols skip the mobilization step and harvest cells directly with a bone marrow aspiration, which uses a special needle to collect a sample from the patient’s bone.
After the cells are harvested, the patient receives treatments like chemotherapy and/or radiation therapy that aim to completely wipe out the immune system — and specifically the abnormal immune cells causing neuronal damage. Finally, the HSCs are infused back into the patient to repopulate the immune system with healthy cells.
The procedure usually involves several weeks spent in a hospital. Before going home, patients have to wait for the HSCs to settle in the bone marrow and start producing healthy immune cells that can protect from infections. Because the immune system generally takes about one year to fully rebuild, there also are some recommended precautions to avoid infections after discharge.
While stem cell transplant is not specifically authorized by the FDA for MS, the National MS Society has supported aHSCT as a feasible treatment option for select patients with relapsing-remitting MS (RRMS).
These patients include individuals younger than 50 with disease duration less than 10 years who experienced continued disease activity — relapses and/or MRI activity — despite treatment with highly effective disease-modifying therapies (DMTs), or who are unable to take these medications.
Studies have generally been consistent in showing treatment with aHSCT can reduce relapse rates and slow disability progression in people with MS — especially younger patients with highly active disease. Many patients also reported an improvement in quality of life and a reduction in MS symptoms after the transplant.
A 2022 meta-analysis — where researchers pool data from many previously published studies — examined disease outcomes after aHSCT in 4,831 people with MS. The data came from 50 published studies, including eight clinical trials.
Five years after the procedure, 73% of patients were alive and without disability progression, 81% were relapse-free, and 68% had no evidence of disease activity. No disease activity means these patients had no relapses, no worsening disability, and no new damage detected on MRI scans.
Several factors affect the efficacy of aHSCT for MS, including:
Early transplant-related complications, like fever, diarrhea, and low blood cell counts, are common after the aHSCT procedure.
More rarely, serious complications may occur. For example, because aHSCT involves wiping out the immune system, patients undergoing the procedure may be more vulnerable to infections and certain cancers, necessitating appropriate precautionary care.
Also, aHSCT can lead to early menopause and fertility problems, especially when more intensive chemotherapy regimens are used.
As with any complex surgical procedure, there is a risk of treatment-related death in aHSCT, although modern care has dramatically lowered mortality rates. Older trials have reported transplant-related mortality as high as 20%, but this figure is at about 4% for studies conducted between 2002 and 2021. Moreover, that figure drops to nearly 0% in studies using low-intensity chemotherapy.
Researchers have noted that stem cell transplant is an emerging area of medical tourism, in which patients travel to other countries with the intent of accessing medical care that is not easily accessible in their home country. However, many clinics offering this treatment lack adequate expertise to minimize the complications of aHSCT.
It is recommended MS patients considering aHSCT consult with their medical care team to choose an adequate treatment center, and determine which medical professionals should be involved in their care during and after the procedure. A list of accredited aHSCT centers in the U.S. is available on the Foundation for Accreditation of Cellular Therapy (FACT) website.
Several ongoing studies are evaluating the safety and efficacy of aHSCT in people with MS, and comparing its outcomes against treatment with highly effective DMTs.
There also are ongoing observational studies (NCT02674217) tracking the long-term outcomes of MS for patients who undergo aHSCT. Some of these studies, including one in California (NCT05482542), are comparing the safety and efficacy of different aHSCT procedures.
Mesenchymal stem cells, or MSCs, have potent immune-modulating properties that tend to promote an anti-inflammatory effect. These cells have been explored as a potential basis for therapies in multiple sclerosis.
Preclinical research has suggested MSC therapies can reduce inflammation and slow disease progression in models of MS.
MSCs are usually collected from bone marrow or adipose (fat) tissue, but MSCs derived from the blood and human umbilical cords have also been used in some studies. Like HSCs, mesenchymal stem cells can be collected from a healthy donor, but the most common practice in MS involves the use of autologous (from-the-self) cells, which don’t require patient-donor matching.
In addition to the different sources of MSCs, other factors contribute to a significant variability among MSC-based therapies. For example, the collected cells can either be expanded in the laboratory to several millions before being infused, or they can be expanded and treated with certain chemical cues to acquire greater immunosuppressive and neuroprotective characteristics.
Further, administration can vary. MSCs may be given via infusion into the bloodstream or through injection into the spinal canal. The interval between administrations also may vary.
While numerous clinical trials have explored MSC-based therapies in people with MS, none have been definitive on efficacy. Almost all studies conducted thus far were small, early trials without a control group, and were mainly designed to assess the safety of different MSC treatment protocols.
Some early studies have reported these treatments reduced inflammation, eased disability, and/or improved quality of life, but other studies have not found consistent results. Therefore, the effectiveness of MSC-based treatments remains unclear.
Because research on MSC therapies in MS is still in early stages, the safety profile of these potential treatments is incompletely understood. However, these treatments do not compromise a person’s immune system like aHSCT does, and most studies to date have not reported any serious safety concerns related to MSC therapies.
Side effects such as fever, headache, urinary tract infection, and fatigue have been reported in some studies.
An MSC-based therapy called IMS001 is being developed as a potential treatment for MS by ImStem Biotechnology. The experimental treatment is derived from human embryonic stem cells and is being evaluated in people with MS in a preliminary Phase 1 clinical study (NCT04956744). The trial is recruiting 30 participants at sites in the U.S.
Another MSC-based therapy, UMSC01, is being developed by Ever Supreme Bio Technology as a potential therapy for MS and other conditions. The therapy uses umbilical cord MSCs isolated from healthy donors. A Phase 1/2 trial (NCT05532943) testing UMSC01 in about 40 patients with RRMS or secondary progressive MS is ongoing.
BrainStorm Cell Therapeutics also is developing an MSC-based therapy. With NurOwn, a patient’s own bone marrow MSCs are matured in the lab to produce large amounts of neurotrophic factors which promote nerve cell growth and survival. In a Phase 2 clinical trial (NCT03799718), 18 people with progressive types of MS received NurOwn via three spinal canal injections, two months apart. Results showed the treatment to be generally well-tolerated, and some participants experienced clinically meaningful improvements in disability measures after treatment.
Other clinical studies also are ongoing, including a Phase 1/2 trial (NCT04749667) in Norway testing MSCs in progressive forms of MS; a U.S.-based Phase 2 trial (NCT05116540) investigating MSCs from adipose tissue in RRMS patients; and an early Phase 1 trial (NCT05003388) of umbilical cord MSCs called AlloRx, with study sites in Antigua and Barbuda, Argentina, and Mexico.
Multiple Sclerosis News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
There is no cure for multiple sclerosis (MS), but studies suggest that some stem cell therapies can slow the progression of the disease. In particular, autologous hematopoietic stem cell transplant is seen as generally effective for reducing disease activity and slowing disability progression, notably in younger individuals with aggressive relapsing disease that is resistant to highly effective disease-modifying medications. The benefits of mesenchymal stem cells are less clear, though early clinical trials also suggest improvements in clinical outcomes.
Due to the risks associated with autologous hematopoietic stem cell transplant (aHSCT), more commonly known as stem cell therapy, the procedure should only be performed at a specialist center accredited by the Foundation for Accreditation of Cellular Therapy, known as FACT. People with multiple sclerosis interested in this treatment are advised to talk with their care team about whether they are good candidates for aHSCT, and to find centers that provide this type of care.
According to a large analysis of published studies, about two-thirds of people with multiple sclerosis (MS) who underwent an hematopoietic stem cell transplant did not have any disease activity within five years after the procedure. Trials of mesenchymal stem cells (MSC) conducted to date were mostly small and without a control group, so the efficacy of MSC-based treatments in MS remains unclear.
Hematopoietic stem cell transplants, or blood stem cell transplants, are generally more effective in individuals with relapsing-remitting multiple sclerosis than in those with progressive forms of the disease. Response to this treatment also tends to be better in patients who are younger than 50 and early on in the disease course. Ongoing trials are testing mesenchymal stem cell therapies across all multiple sclerosis types, but it’s not yet known if any disease type benefits the most from these therapies.
No form of stem cell therapy is specifically approved by the U.S. Food and Drug Administration to treat multiple sclerosis (MS). Nonetheless, the individual medications and procedures used in hematopoietic stem cell transplants have been approved by the regulatory agency, meaning that MS patients can access the treatment in the U.S. Stem cell transplant also is supported by the National MS Society to treat relapsing MS patients with highly active disease.
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