“One of the highlights of the AAN 2015 meeting so far was Biogen’s results of their anti-Lingo-1 trial presented yesterday. In short in the per protocol analysis, i.e. study subjects who completed the treatment as defined by the protocol, showed an average change in their electrical conduction speed in their affected optic nerve of 13.2 msecs compared to 22.4 msecs in the placebo-treated subjects. Treated nerves conducted electrical signals faster and hence are thought to have been remyelinated. What is interesting, and important, is that there was no difference in the so called retinal nerve fibre layer thickness between the eyes. In other words anti-LINGO-1 did not prevent nerve fibre loss. Dr Cadavid who presented the data made the comment at how surprised he was at how quickly the nerve fibres are lost in acute optic neuritis. He shouldn’t be surprised, we knew this fact from our animal model when we defined the so called inflammatory penumbra. We suspect this is probably in the order of 14-21 days in human optic neuritis. In the anti-Lingo-1 trial study drug could be given up to 4 weeks after the onset of optic neuritis; too late in our opinion and clearly too late to save optic nerve fibre loss, but early enough to improve the remyelination state of the surviving axons.”
“Until yesterday, I hadn’t appreciated how high the dose of anti-LINGO-1 was that was used in this trial; i.e. 100mg/kg iv every 4 weeks. In other words a 70kg MSer will get 7g of anti-LINGO-1 antibody monthly. This is a such a large dose that it may be working like high-dose intravenous immunoglobulin (IVIG), in other words it may be saturating the so called neonatal Fc receptor and reducing the half-life of other circulating antibodies. The dose may result in other problems not too dissimilar to what we see with high-dose IVIG; thromboses, renal dysfunction, headaches, aseptic meningitis, infusion reactions, etc.”
“Despite my guarded scepticism about remyelination strategies, congratulations to Biogen for taking this forward. This is truly innovative science and may make a difference to people with progressive MS. If I am not mistaken these are the first positive results of a trial of an agent specifically targeting remyelination.”
|Visual evoked potentials: the shorter the so called latency the faster the electrical conduction. In demyelinated nerves this is slow and when it is remyelinated it speeds up. The difference in so called latency between treated and untreated MSers indicates that anti-LINGO-1 improved remyelination.|
BACKGROUND: The demyelination and axonal injury during AON usually results in permanent structural and functional visual deficits. Although corticosteroid treatment can accelerate the rate of spontaneous recovery, no reparative treatment is available to reduce sequelae of AON. LINGO-1 is a CNS-specific membrane glycoprotein that suppresses oligodendrocyte differentiation and myelination. BIIB033 is a fully human monoclonal antibody which selectively antagonizes LINGO-1, is efficacious in preclinical models of remyelination, and was found to be safe and well tolerated in Phase 1 studies.
DESIGN/METHODS: RENEW (NCT01721161) is an ongoing, randomized, double-blind, placebo-controlled, parallel-group study in healthy subjects with a first episode of unilateral AON (treated with high dose IV methylprednisolone prior to randomization). Subjects (aged 18 to 55 years) were randomized 1:1 to receive 100 mg/kg BIIB033 IV or placebo once every 4 weeks (6 doses total). All key efficacy endpoints are assessed at 4 weekly intervals from randomization through week 24 and include: latency of optic nerve conduction measured by full-field visual evoked potential (primary endpoint); thickness of the retinal nerve fiber layer measured by spectral-domain optical coherence tomography (SD-OCT); thickness of the retinal ganglion cell layer/inner plexiform retinal layer measured by segmentation of SD-OCT, and change in low-contrast letter acuity from baseline measured by Sloan charts.
RESULTS: Eighty-two subjects were randomized to receive BIIB033 or placebo. Detailed descriptions of the efficacy assessments in RENEW will be presented.
CONCLUSIONS: Results from the RENEW study will provide evidence for the efficacy of BIIB033 in improving recovery from AON when dosing starts within 28 days of disease onset.
Study Supported by: Biogen Idec