Temelimab
Other names: GNbAC1
Summary
Temelimab is a new treatment under investigation for relapsing remitting and progressive multiple sclerosis (MS). It is taken as an injection.
Temelimab for relapsing remitting and progressive MS: Phase II
- Temelimab blocks the effect of a protein found in MS brain lesions which has been shown to cause inflammation and reduce remyelination.
- Clinical trial results suggest that temelimab may promote remyelination. It does not appear to have an effect on relapse rates or new active lesions seen on MRI scans.
- No significant side effects have been reported.
How does temelimab work?
Human endogenous retroviruses (HERV) are sometimes called fossil viruses because they are pieces of ancient viral infections which were incorporated into our DNA millions of years ago. One of these HERVs produces a protein (pHERV-W Env) which is found in active MS lesions and has been shown to activate microglia (immune cells which cause inflammation in the brain) and block the development of oligodendrocytes, cells which maintain the myelin coating of nerve cells.
Temelimab blocks the action of this protein; it is proposed that this will promote remyelination, thereby slowing down or stopping MS progression.
How is temelimab taken?
Temelimab is taken as an injection, once a month.
Temelimab research
What are the results so far?
The results of phase II studies have suggested that temelimab may have neuroprotective effects.
- CHANGE-MS (also known as GNC-003)
This study recruited 270 participants with relapsing remitting MS. Participants took one of three doses of temelimab or placebo for 24 weeks. After 24 weeks, those in the placebo group were randomized to receive one of the three temelimab doses for a second 24-week period. Individuals who had been receiving temelimab during the first 24-week period continued with their original doses for the second period.
Further details of this study.
Results of this study up to week 24 were presented at a scientific meeting in 2017. At 24 weeks, none of the doses of temelimab had a significant effect on the number of new active lesions on MRI. However, at 24 weeks, the highest dose of temelimab appeared to promote remyelination.
Results of the study at week 48 were presented at a scientific meeting in 2018. The data confirmed the results seen after 24 weeks, indicating that the higher dose of temelimab showed the potential to promote remyelination.
- ANGEL-MS (also known as GNC-004)
This study was an extension of CHANGE-MS. 220 participants from CHANGE-MS continued to take temelimab for a further 48 weeks.
Further details of this study.
Results of the study have also been presented at a scientific meeting. The data gave further support for an improvement in remyelination; reduced brain tissue loss (atrophy), improvement in MRI markers of remyelination (magnetization transfer ratio), lower proportion of participants with confirmed disease progression at 12 weeks, measured as EDSS or 20% worsening in the time to walk 25 feet.
What further research is planned?
Initial studies have not been able to show an effect on relapse rate or active MRI lesions, but have suggested potential for slowing down the progression of MS. The manufacturer has announced plans to evaluate temelimab in people whose MS is progressing in the absence of relapses. The one year study, which will be carried out at an MS clinic in Sweden, will evaluate temelimab’s safety and tolerability at increasing doses, as well as its effectiveness based on measures of MS progression. No further details have been announced so far.
Side effects
Temelimab has been well-tolerated in clinical trials. No significant side effects have been reported.


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