Study STS101-007 is a randomized, double-blind, parallel group, placebo-controlled, multicenter study to evaluate the efficacy, safety, and tolerability of single doses of STS101 (dihydroergotamine nasal powder) in the acute treatment of migraine.

Study STS101-007 is a multi-center, single-dose, randomized, double-blind, placebo-controlled, parallel group study in subjects with acute migraine (ages 18 to 65 years).

Key Inclusion Criteria:

• Males or females, 18-65 years of age at the time of Screening Visit
• Subject has at least 1-year history of migraines (with or without aura), according to the International Classification of Headache Disorder, 3rd Edition (ICHD3)

Key Exclusion Criteria:

• Pregnant or breast-feeding women
• Women of child-bearing potential not using or not willing to use highly effective contraception.
• Diagnosis of headache conditions other than migraine with or without aura, including diagnosis of basilar or hemiplegic migraines or cluster headache.
• History of coronary artery disease, coronary artery vasospasm (including Printz-metals' angina), clinically significant arrhythmia or, peripheral vascular disease, ischemic disease (e.g. Raynaud's syndrome, ischemic bowel syndrome, angina pectoris, myocardial infarction, or documented silent ischemia); percutaneous coronary intervention, or cardiac surgery.
• History of cerebrovascular disease, including but not limited to stroke, transient ischemic attack, cerebral hemorrhage, subarachnoid hemorrhage.
• Diagnosis of major depression with current symptoms, psychosis, alcohol abuse or dependence, drug abuse or dependence, major psychiatric conditions (e.g. schizophrenia, psychosis or Bipolar disorder), dementia. Other significant neurological or psychiatric disorders (including other pain syndromes or risk of suicide) that in the opinion of the investigator might interfere with study participation and assessments or subject safety.
• Any clinically significant symptoms or conditions, including but not limited to central nervous system (e.g., seizures), cardiac, pulmonary, metabolic, renal, hepatic or gastrointestinal conditions or history of such conditions that, in the opinion of the investigator might interfere with study assessments or safety of participant.