NIH. US: Three-year results from a clinical trial suggest that
depleting and then re-establishing the immune system can alleviate a
type of early-stage multiple sclerosis (MS). With further development and evaluation, this
approach could become an option for treating people with this
often-debilitating disease.
The most common form of MS is relapsing-remitting MS (RRMS), in
which periods of mild or no symptoms are interspersed with periods of
more severe symptoms, called relapses. RRMS can change into a
progressive form where symptoms worsen over time without any
symptom-free periods. RRMS can be treated with medications that
suppress the immune system and reduce inflammation. However, these drugs
can cause serious side effects.
One promising treatment for MS is HDIT/HCT (high-dose
immunosuppressive therapy with autologous hematopoietic cell
transplant). The goal of this treatment is to “reset” the immune system
so that it will cease attacking the central nervous system. First, a
patient’s hematopoietic stem cells (HSCs)—precursor cells that develop
into blood cells—are collected. High-dose chemotherapy and other drugs
are then used to deplete the patient’s immune system. Finally, the
patient is infused with his or her own HSCs, which develop into red and
white blood cells to re-establish the patient’s immune system.
Past clinical trials have suggested that HDIT/HCT may not work
in patients with later-stage, progressive MS who already show marked
neurodegeneration. However, the approach might be effective in patients
with early-stage RRMS. Researchers from across the country are
monitoring 24 volunteers with RRMS for 5 years following HDIT/HCT
treatment. The clinical trial is funded by NIH’s National Institute of
Allergy and Infectious Diseases (NIAID). Interim 3-year findings
appeared online on December 29, 2014, in JAMA Neurology.
Three years after HDIT/HCT treatment, nearly 80% of trial
participants had survived without an increase in disability, relapse of
MS symptoms, or new brain lesions. Patients didn’t receive any MS
drugs during those 3 years. Few serious early complications or
unexpected side effects occurred. Many participants experienced issues
that typically accompany high-dose immunosuppressive therapy, such as
infections and gastrointestinal problems.
“These promising results support the need for future studies to
further evaluate the benefits and risks of HDIT/HCT and directly
compare this treatment strategy to current MS therapies,” says NIAID
Director Dr. Anthony S. Fauci.
The researchers plan to follow participants for a total of 5
years. Final results from this and similar studies will help inform the
design of larger trials to further evaluate HDIT/HCT in people with
MS.