Understanding PPMS
The National MS Society is funding research to help identify differences between PPMS and other disease courses.
- Researchers at the University of Texas Southwestern Medical Center are comparing the specific immune responses mounted by different types of immune cells in people with relapsing-remitting MS (RRMS) and those with PPMS. Understanding how immune cells respond in PPMS may lead to the development of an effective therapy to treat it.
- At Brigham and Women’s Hospital in Boston, researchers are using novel imaging techniques to compare different parts of the brain in primary-progressive and other types of MS — which could eventually yield new strategies for predicting and monitoring MS progression.
- A new Collaborative MS Research Center at the Oregon Health Sciences Center is investigating possible causes for the degeneration of nerve fibers (axons) in the central nervous system.
Clinical trials of Disease-Modifying Drugs
People who have received a diagnosis of PPMS are often frustrated by the relatively small number of clinical trials in PPMS compared to the large number in RRMS. MS clinicians and researchers share this frustration and are actively looking for ways to increase the number of trials in PPMS.
Several obstacles have stood in the way:
- The immune-modulating drugs currently used to treat relapsing forms of MS do not seem to be as effective in PPMS.
- In PPMS, there is a lack of easily-identifiable outcomes to measure in clinical trials. In the trials for the approved disease-modifying therapies (the interferon beta medications, glatiramer acetate, natalizumab, and mitoxantrone) investigators looked at outcomes such as number of relapses and number of new lesions (also called plaques) seen on magnetic resonance imaging (MRI) to determine if people who received the treatment had lower numbers than those who received a placebo (non-active substance). In other words, the investigators looked at things they could easily count over the course of a two-three year trial. Because people with PPMS don’t experience relapses or the same kind of inflammation in the central nervous system, there are fewer events that can be counted.
- The disease progression that occurs in PPMS can be quite slow — which means that a trial would have to last many years to determine if a treatment slowed or halted that progression.
Researchers are working to identify other ways to measure the changes that occur in PPMS so that they can more easily test potential treatments.
Click here for a listing of ongoing trials in PPMS.
Nervous System Repair and Protection
Alongside these efforts to identify effective medications to slow the progression of PPMS, researchers are looking for ways to protect and repair brain tissue that is damaged or lost in MS. The Nervous System Repair and Protection Initiative, funded through the Society’s Promise: 2010 Campaign has brought together four teams of researchers in the U.S. and Europe to study possible mechanisms for preventing damage to brain tissue and restoring function in those individuals who have already experienced significant tissue loss.