Method of treating myasthenia gravis

1. A method of treating myasthenia gravis comprising administering subcutaneously to a human subject in need thereof a therapeutically effective amount of an agent that binds complement C5 protein, wherein the agent is:

(a) a protein comprising or consisting of the amino acid sequence of SEQ ID NO: 2;

(b) a protein comprising or consisting of amino acids 19 to 168 of SEQ ID NO: 2;

(c) a protein comprising or consisting of an amino acid sequence having at least 95% sequence identity to amino acids 19 to 168 of SEQ ID NO: 2; or

(d) a fragment of SEQ ID NO: 2, wherein said fragment comprises six cysteine residues that are spaced relative to each other at a distance of 32 amino acids apart, 62 amino acids apart, 28 amino acids apart, 1 amino acid apart, and 21 amino acids apart, respectively, as arranged from the amino terminus to the carboxyl terminus of SEQ ID NO: 2, wherein said fragment inhibits cleavage of C5 by classical and alternative C5 convertases.

2. The method according to claim 1 , wherein the agent binds complement C5 protein with an IC 50 of less than 0.2 mg/ml.

3. A The method according to claim 1 , wherein the agent is derived from a haematophagous arthropod.

4. The method according to claim 1 , wherein the therapeutically effective amount is a dose from 1 mg/kg to 15 mg/kg.

5. The method according to claim 1 , wherein the agent is administered as part of a treatment regimen also involving the administration of a further drug for the treatment of myasthenia gravis.

6. The method according to claim 5 , wherein the further drug is an anticholinesterase agent, neostigmine, or pyridostigmine, or an immunosuppressive drug, prednisone, cyclosporine, or azathioprine.

7. The method according to claim 5 , wherein the agent is administered simultaneously with the further drug.

8. The method according to claim 5 , wherein the agent is administered sequentially with the further drug.

9. The method according to claim 5 , wherein the agent is administered separately with the further drug.

10. The method according to claim 1 , wherein the myasthenia gravis is mild myasthenia gravis.

11. The method according to claim 1 , wherein the myasthenia gravis is severe myasthenia gravis.

12. The method according to claim 1 , wherein the therapeutically effective amount is a dose from 1 mg/kg to 10 mg/kg.

13. The method according to claim 1 , wherein the therapeutically effective amount is a dose from 2 mg/kg to 8 mg/kg.

14. The method according to claim 1 , wherein the agent is administered on a daily basis.