GSK249320 is a humanised monoclonal antibody (mAb) that binds with high specificity to myelin-associated glycoprotein (MAG) and antagonises or neutralises MAG-mediated inhibition and has been shown to improve functional recovery after stroke in pre-clinical models, possibly by promoting neuroregeneration and plasticity. The present study is the first in patients with stroke. The main aim of this study is to select tolerated doses of GSK249320 that can be used in future trials to evaluate its efficacy in improving clinical function in patients recovering from stroke. This clinical trial is designed as a placebo-controlled, single-blind, multicenter study to investigate the safety, pharmacokinetics (PK) and pharmacodynamics (PD) of escalating repeat IV doses of GSK249320. Three sequential dose escalation cohorts (1, 5 and 15 mg/kg) are planned, with 8 patients on placebo and 8 on active in cohort 1 and 4 patients on placebo and 8 on active in cohorts 2 and 3. Each patient will receive 2 repeat IV doses 9 ± 1 days apart and assessments will extend to at least 16 weeks.