1. The use of the compounds of formula Ia! ! or its phosphate derivative of the formula! ! or their pharmaceutically acceptable salts in the preparation of a medicament for the treatment of amyotrophic lateral sclerosis (Lou Gehrig's disease), Guillain-Barré syndrome and uveitis. ! 2. The use according to claim 1, wherein said compound is represented by a compound of formula Ia! ! or a pharmaceutically acceptable salt thereof. ! 3. The use according to claim 1, wherein said drug is intended for the treatment of uveitis. ! 4. The use according to claim 1, wherein said drug is intended for the treatment of amyotrophic lateral sclerosis. ! 5. The use according to claim 1, wherein said drug is intended for the treatment of Guillain-Barré syndrome. ! 6. The use according to one of claims 1, 2 or 3, which consists in the joint administration to the subject, simultaneously or sequentially, of at least one second drug. ! 7. A method of treating amyotrophic lateral sclerosis, Guillain-Barré syndrome and uveitis, which consists in administering to a subject in need of such treatment an effective amount of a compound of formula Ia! ! or its phosphate derivative of the formula! ! or a pharmaceutically acceptable salt thereof. ! 8. The method of claim 7, wherein said treatment is directed to uveitis. ! 9. The method of claim 7, wherein said treatment is directed to amyotrophic lateral sclerosis. ! 10. The method of claim 7, wherein said treatment is directed to Guillain-Barré syndrome.1. Применение соединения формулы Ia ! ! или его фосфатного производного формулы ! ! или их фармацевтически приемлемых солей при приготовлении лекарственного средства для лечения бокового амиотрофического склероза (болезни Лу Герига), синдрома Гийена-Барре и увеита. ! 2. Применение по п.1, в котором указанное соединение представлено соединением формулы Ia ! ! или его фармацевтически приемлемой солью. ! 3. Применение по п.1, в котором указанное лекарственное средство предназначено дл
