OBJECTIVE: To evaluate the efficacy and safety of galcanezumab, a humanized 
monoclonal antibody that selectively binds to calcitonin gene-related peptide, 
in the preventive treatment of chronic migraine.
METHODS: A phase 3, randomized, double-blind, placebo-controlled study of 
LY2951742 in patients with chronic migraine (Evaluation of Galcanezumab in the 
Prevention of Chronic Migraine [REGAIN]) was a phase 3 study with a 3-month 
double-blind, placebo-controlled treatment phase and a 9-month open-label 
extension. Eligible patients 18 to 65 years of age with chronic migraine were 
randomized 2:1:1 to monthly subcutaneous injections of placebo (n = 558), 
galcanezumab 120 mg (with a 240-mg loading dose, n = 278), or galcanezumab 240 
mg (n = 277). The primary endpoint was the overall mean change from baseline in 
the number of monthly migraine headache days (MHDs) during the 3-month 
double-blind treatment phase.
RESULTS: Mean number of monthly MHDs at baseline was 19.4 for the total sample. 
Both galcanezumab dose groups demonstrated greater overall mean reduction in the 
number of monthly MHDs compared to placebo (placebo -2.7, galcanezumab 120 mg 
-4.8, galcanezumab 240 mg -4.6) (p < 0.001 for each dose compared to placebo). 
There were no clinically meaningful differences between galcanezumab doses and 
placebo on any safety or tolerability outcome except for a higher incidence of 
treatment-emergent injection-site reaction (p < 0.01), injection-site erythema 
(p < 0.001), injection-site pruritus (p < 0.01), and sinusitis (p < 0.05) in the 
galcanezumab 240-mg group relative to placebo.
CONCLUSIONS: Both doses of galcanezumab were superior to placebo in reducing the 
number of monthly MHDs. Galcanezumab appears efficacious, safe, and well 
tolerated for the preventive treatment of chronic migraine.
CLINICALTRIALSGOV IDENTIFIER: NCT02614261.
CLASSIFICATION OF EVIDENCE: This interventional study provides Class I evidence 
that galcanezumab is superior to placebo in the reduction of the number of 
monthly MHDs.