Use of pridopidine for treating rett syndrome

1. A method for delaying the onset, preventing worsening, delaying worsening or improving at least one Rett symptom in the subject, wherein the Rett symptom is a partial or complete loss of acquired mobility skills; muscle weakness; abnormal eye movement; breathing irregularity; and/or cardiac abnormality; comprising administering to the subject an effective amount of pridopidine or pharmaceutically acceptable salt thereof so as to thereby delay the onset, prevent worsening, delay worsening or improve at least one Rett symptom.

2. The method of claim 1 , wherein the pridopidine is pridopidine hydrochloride, hydrobromide, nitrate, perchlorate, phosphate, sulphate, formate, acetate, aconate, ascorbate, benzenesulphonate, benzoate, cinnamate, citrate, embonate, enantate, fumarate, glutamate, glycolate, lactate, maleate, malonate, mandelate, methanesulphonate, the naphthalene-2-sulphonate, phthalate, salicylate, sorbate, stearate, succinate, tartrate or toluene-p-sulphonate salt.

3. The method of claim 1 , wherein the pridopidine is administered orally, nasally, inhaled, by subcutaneous injection, or through an intravenous, intraperitoneal, intramuscular, intranasal, buccal, vaginal, rectal, intraocular, intrathecal, topical or intradermal route.

4. The method of claim 3 , wherein the pridopidine is administered orally.

5. The method of claim 1 , wherein the pridopidine is administered in the form of an aerosol, an inhalable powder, an injectable, a liquid, a gel, a solid, a capsule or a tablet.

6. The method of claim 1 , wherein the pridopidine is administered periodically.

7. The method of claim 6 , wherein the pridopidine is administered less often than once daily.

8. The method of claim 6 , wherein the pridopidine is administered once daily or twice daily.

9. The method of claim 1 , wherein the amount of pridopidine administered is 10 mg/day-315 mg/day.

10. The method of claim 1 , wherein the amount of pridopidine administered is 45 mg/day-90 mg/day.

11. The method of claim 1 , wherein the amount of pridopidine administered is 45 mg/day-180 mg/day.

12. The method of claim 9 , wherein the amount of pridopidine administered is 20 mg/day, 22.5 mg/day, 45 mg/day, 67.5 mg/day, 90 mg/day, 100 mg/day, 112.5 mg/day, 125 mg/day, 135 mg/day, 150 mg/day, 180 mg/day, 200 mg/day, 225 mg/day, 250 mg/day, or 315 mg/day.

13. The method of claim 12 , wherein the amount of pridopidine administered is 45 mg/day or 90 mg/day or 180 mg/day.

14. The method of claim 1 , wherein the amount of pridopidine is administered in one dose or two doses per day.

15. The method of claim 14 , wherein the amount of pridopidine administered in a dose is 10 mg, 22.5 mg, 45 mg, 67.5 mg, 90 mg, 100 mg, 112.5 mg, 125 mg, 135 mg, 150 mg, 180 mg, 200 mg, 250 mg, or 315 mg.

16. The method of claim 15 , wherein the amount of pridopidine administered in a dose is 10 mg-45 mg.

17. The method of claim 16 , wherein the amount of pridopidine is administered in two doses per day at an amount of 10 mg-45 mg per dose.

18. The method of f claim 1 , wherein the pridopidine is first administered within 1 day, 1 week, 1 month, 3 months, 6 months, 9 months, 12 months, 18 months, 3 years, 5 years, 10 years, 15 years, 20 years, 25 years, or 30 years after birth of the subject.

19. The method of claim 6 , wherein the periodic administration of pridopidine continues for at least 3 days, at least 30 days, at least 42 days, at least 8 weeks, at least 12 weeks, at least 24 weeks, at least 6 months, at least 1 year, at least 2 years, at least 5 years, at least 10 years, at least 15 years, at least 20 years, at least 25 years, or 30 years or more.

20. The method of claim 1 , wherein the abnormal eye movement is prolonged staring, excessive blinking, crossed eyes, and/or closing one eye at a time.

21. The method of claim 1 , wherein the pridopidine improves the symptom by at least 20%, at least 30%, at least 50%, at least 80%, or 100%.

22. The method of claim 1 , wherein the pridopidine is effective to increase or maintain the brain-derived neurotrophic factor (BDNF) serum level in the subject and or to increase the brain-derived neurotrophic factor (BDNF) brain levels in the subject.

23. The method of claim 1 , wherein the subject is a human patient.

24. The method of claim 1 , wherein the subject has a mutation in at least one of the methyl CpG binding protein 2 (MeCP2) gene, the cyclin-dependent kinase-like 5 (CDKL5) gene or the Forkhead box protein G1 (FOXG1) gene.

25. A method of increasing BDNF serum level or brain-derived neurotrophic factor (BDNF) brain level in a subject afflicted with Rett comprising administering to the subject an effective amount of pridopidine so as to thereby increase BDNF serum level BDNF brain level in the subject.