Each completed subject will attend 4 clinic visits. The maximum study duration is 13 weeks. The study includes a 1 week pretreatment period, during which the screening visit (visit 1 could be the last visit of previous double-blind study 112958 or any time within 3 months after completion of previous study) is to take place. Only one upper limb (meeting inclusion/exclusion criteria) will be evaluated and treated in the study. Subjects will receive a single intramuscular treatment with investigated drug at day 0 (visit 2). There will be two post-injection follow-up visits at week 6 and 12 (visits 3 to 4).