Pharmaceutical composition for treating migraine

1. A method of treating acute migraine in a patient in need thereof, said method comprising:

subcutaneously administering by a single-use, ready to use, disposable, auto-injector to the patient a composition comprising an aqueous solution of sumatriptan succinate in an amount of 4.2 mg, and sodium chloride in an amount of 4.2 mg contained in a 0.5 mL pre-filled syringe (PFS) fully assembled into the auto-injector;

wherein said composition has osmolality between 275 to 315 mOsm/kg;

wherein said composition has a pH of about 4.2 to 5.3;

wherein the patient is suffering from acute migraine and the composition is not administered for prophylactic treatment of migraine or treatment of cluster headache.

2. The method of claim 1 , wherein the subcutaneous administration of said composition to the patient results in a systemic exposure characterized by at least one of the following plasma profiles:

a. C max of about 35 ng/ml to about 57 ng/ml;

b. AUC 0-2 of about 30 ng·hr/ml to about 50 ng·hr/ml; and/or

c. AUC 0-inf of about 43 ng·hr/ml to about 70 ng·hr/ml.

3. The method of claim 1 , wherein the subcutaneous administration of said composition to the patient provides a reduction in injection site pain as compared to subcutaneous administration of a composition comprising an injectable solution of sumatriptan succinate in an amount of 4.2 mg sumatriptan succinate contained in 0.25 ml.

4. The method of claim 1 , wherein the subcutaneous administration of said composition to the patient provides a reduction in injection site pain as compared to subcutaneous administration of a composition comprising 5.6 mg sumatriptan succinate contained in 0.5 mL.

5. The method of claim 1 , wherein the subcutaneous administration of said composition to the patient provides a reduction in injection site pain as compared to subcutaneous administration of a composition comprising 8.4 mg sumatriptan succinate contained in 0.5 mL.