Vaccines in development for treatment of MS

There are currently three vaccines being tested in Phase 2 and 3 studies for the treatment of MS. The product in the most advanced stage of development is Tovaxin (Tcelna), manufactured by Opexa Therapeutics. Both BHT-3009 (manufactured by Bayhill Therapeutics) and Neurovax (manufactured by Immune Response BioPharma) are in Phase 2 testing.

 

Tovaxin (Tcelna)

Tovaxin is an autologous T-cell vaccine that is tailored to an individual’s immune response to myelin. It is designed to reduce the number and functional activity of specific subsets of myelin-reactive T-cells. Phase 2 and 2b (TERMS) studies of Tovaxin have been completed and the drug has been accepted for fast-track review by the FDA. A Phase 3 study is currently in the planning stages.

The randomized, placebo-controlled Phase 2b TERMS study (Tovaxin for Early Relapsing MS) was conducted in 150 people with relapsing-remitting MS (RRMS) or clinically isolated syndrome (CIS). Participants were randomly assigned to receive Tovaxin (n=100) or placebo (n=50). The primary efficacy endpoint (the key measure used to determine the effectiveness of the treatment) was cumulative number of gadolinium (Gd)-enhancing brain lesions on magnetic resonance imaging (MRI). There were no significant differences in MRI results or the frequency of relapses or progression of disability between Tovaxin and placebo in the study population as a whole. However, analysis of subgroups of participants suggest those with more active disease and those who had received prior disease-modifying treatment might derive greater benefit from Tovaxin.

 

BHT-3009

BHT-3009 is a DNA vaccine to myelin basic protein (MBP) developed by Bayhill Therapeutics. It builds immune tolerance to inhibit attack against MBP in the myelin sheath by various immune cells. A Phase 2 study of BHT-3009 has been completed.

In a Phase 1/2 randomized, double-blind, placebo-controlled study of BHT-3009, 30 people with MS (11 with RRMS and 19 with SPMS) were randomly assigned one of three doses of the vaccine or placebo. All three doses were well tolerated. BHT-3009 resulted in fewer gadolinium (Gd)-enhancing brain lesions as seen on MRI than placebo. However, the difference was not significant.

A randomized, placebo-controlled Phase 2 study of BHT-3009 was conducted in 289 people with RRMS. Participants, none of whom had taken prior disease-modifying treatment, received one of two doses of BHT-3009 or placebo for 44 weeks. The 0.5 mg dose of BHT-3009 resulted in a significant decrease in the volume (mean) of Gd-enhancing lesions on MRI compared with placebo at 44 weeks. No significant differences were seen between BHT-3009 and placebo in terms of risk for relapse, annual rate of relapse, or time to first relapse. However, when participants were tested 6 months after treatment was finished, those who received either dose of BHT-3009 continued to show signs reduced disease activity on MRI.

 

Neurovax

Neurovax is a T-cell receptor peptide vaccine that stimulates regulatory T-cells which inhibit the function of T-cells involved in the autoimmune process. It is under development by Immune Response BioPharma. Results from a Phase 2 study of Neurovax have been reported and a Phase 2b study is in the planning stages. Results from the completed open-label Phase 2 study, which included 23 people with RRMS or secondary-progressive MS who had not previously been treated, showed that the vaccination enhanced immunoregulation that might potentially control the inflammatory process in MS. A majority of participants had no change in disability over the course of the year-long study.

Written by: Jonathan Simmons | Last reviewed: May 2015.
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