Background Safety findings from a Phase 2b study of galcanezumab, a humanized 
monoclonal antibody against calcitonin gene-related peptide, for prevention of 
migraine (NCT02163993) are reported here. Methods Patients aged 18-65 years with 
episodic migraine were evaluated in this multicenter, double-blind, randomized 
study. After randomization, 410 patients were administered 5, 50, 120 or 300 mg 
of galcanezumab or placebo subcutaneously once every 4 weeks for 12 weeks, 
followed by a post-treatment off-drug period lasting 12 weeks. Results 
Treatment-emergent adverse events (TEAEs) were primarily rated as mild to 
moderate. Serious adverse events reported in galcanezumab dose groups were 
appendicitis, Crohn's disease, suicidal ideation, and congenital ankyloglossia 
in an infant of a paternal pregnancy; each of these were reported by one 
patient. Adverse events leading to discontinuation with galcanezumab treatment 
were abdominal pain, visual impairment, and upper limb fracture, each reported 
by one patient. Treatment-emergent injection-site reactions were reported 
significantly more frequently ( p = 0.013) with galcanezumab (13.9%) than with 
placebo (5.8%). Injection-site pain was the most common injection-site reaction 
(galcanezumab 11.4%; placebo 2.9%, p = 0.004). Upper respiratory tract infection 
(galcanezumab 10.0%; placebo 8.8%) and nasopharyngitis (galcanezumab 7.0%; 
placebo 2.2%) also occurred more frequently with galcanezumab treatment. 
Potential hypersensitivity events were reported at similar frequencies in 
galcanezumab (3.3%) and placebo (5.1%) groups. Incidence of treatment-emergent 
anti-drug antibodies in galcanezumab dose groups (4.6% of patients during 
treatment period) did not appear to have any meaningful effects on safety, the 
pharmacokinetics of galcanezumab, or its ability to bind to the target ligand. 
Conclusion The results from this 3-month Phase 2b study support the initiation 
of larger Phase 3 trials of longer duration.