PRX003 in MS

PRX003 is a monoclonal antibody under development by Prothena for the possible treatment of inflammatory diseases. It is currently being tested in patients with multiple sclerosis (MS).

Immune cells release cytokines that can trigger inflammation and are central to many inflammatory diseases. An MCAM (melanoma cell adhesion molecule) binds to a partner molecule the blood stream then then allows it to infiltrate adjacent tissues, leading to inflammation.

In healthy people, the blood-brain barrier prevents immune cells (lymphocytes) from entering the central nervous system. In people with MS, two types of lymphocytes, CD4 and CD8, find a way to cross the barrier. They then destroy the myelin sheath that protects neurons, resulting in brain lesions.

MCAM may play a crucial role in MS because it is necessary for the migration of both CD4 and CD8 lymphocytes across the blood-brain barrier. Blocking MCAM may delay the onset of MS and significantly slow its progression.

PRX003 binds to MCAM, blocks the route of inflammation, and prevents the migration of CD4 and CD8 lymphocytes into the brain tissue.

In March, Prothena completed a single ascending dose study of PRX003 in healthy participants (NCT02458677). All doses of PRX003 were reported as safe and tolerated following a single infusion up to 30 mg/kg dose. The results showed that PRX003 administration led to more than 95 percent MCAM neutralization.

Adverse effects reported were headache, balance disorder, seasonal allergies, and viral upper respiratory tract infection in 5 percent of participants.

A Phase 1b clinical study of PRX003 in people with psoriasis (NCT02630901) is ongoing.

Note: 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.

Permanent Ink: My Tattoo Serves as an Important Reminder

On July 10, I did something I never thought I’d do: I got a tattoo! I’ve always been fascinated by body art, and any time I see someone with ink I admire, I always ask a ton of questions about it. Sure, I ask how much time it took and how much pain was involved, […]

‘He’s Fallen in the Water!’

Any British comedy aficionados among you will know “He’s fallen in the water” is the most famous of all the innumerable catchphrases of “The Goon Show.” That show was the root of Monty Python and every bit of the new wave of comedy that swept through our country. And it still dominates today. That’s enough […]

From Diagnosis to Finding
the Right Treatment for Her:
Sara’s Relapsing MS Story

Sara is an actual patient. She was compensated for her time. Sara’s journey to managing relapsing multiple sclerosis (MS) started with her diagnosis back in 2005. She had just graduated from college and was beginning her career in healthcare administration. Driving home one day, Sara experienced blurry vision in her right eye. Following a series […]

It’s Not a Crime to Ask for Help When You Need It

“Do you need help?” The question came from a 30-something woman after I’d finished loading some cartons into the back of my SUV. I automatically replied, “No thanks, all done.” But lifting and loading isn’t an easy job for me. My upper body strength is good, but my legs are weak and offer no help […]

Hypertension Triples Disability Risk in Hispanic/Latino MS Patients

Hypertension — high blood pressure — triples the risk of severe walking disability in Hispanic and Latino people with multiple sclerosis (MS), a new observational study reports. The study, “Hypertension and hypertension severity in Hispanics/Latinx with MS,” was published in the Multiple Sclerosis Journal. Although the cause of MS is unknown, genetic and environmental factors […]

Skin Reactions ‘Frequent’ With Mavenclad, Real-world Study Finds

Skin reactions are common among relapsing-remitting multiple sclerosis (RRMS) patients being treated with oral Mavenclad (cladribine), affecting about one-third of the people evaluated in a real-world study in Germany. These findings suggest the need for careful clinical surveillance to rapidly diagnose and possibly treat skin problems stemming from Mavenclad’s use, its researchers noted. The study, “Skin reactions […]

Are You Prepared for a Fall?

I sit amid the flood of carpet stain remover. My left leg is elongated as my right leg is at a jackknife. The cool of the fluid penetrates my sweats. Shock dissipates into pain. I try to move, but pain sears down toward my tailbone. I sit in the dark of my tiny laundry room. […]

Multivitamins Reduce Fatigue, Improving Quality of Life

Multivitamin supplements reduce fatigue and improve quality of life in people with relapsing-remitting multiple sclerosis (RRMS), a new study reports. After 70 days of continuous use, patients taking multivitamin supplements containing vitamins A, B-complex, C, and D improved their blood antioxidant status and experienced up to a 34% reduction in fatigue. The study, “Reduction in […]

Combinations of Variants Contribute to Genetic MS Risk

Genetic susceptibility to multiple sclerosis (MS) depends on an individual’s particular combination of multiple risk variants, a study reveals. The study, “Genetic susceptibility to multiple sclerosis: interactions between conserved extended haplotypes of the MHC and other susceptibility regions,” was published in the journal BMC Medical Genomics. The risk of developing MS is thought to be […]

The Multiple Sclerosis Podcast


Survey Icon

Video