An Overview of New Biologics for Migraine Prophylaxis

Philip Harvey, PharmD/MBA Candidate 2020; Pooja Shah, PharmD/MBA Candidate 2020; Scott Shipley, PharmD, BCPS


US Pharmacist. 2020;45(1):21-24. 

In This Article

Adverse-reaction and Safety Concerns

Injection-site Reactions

In clinical trials, the most common adverse events (in >10% of the study population) for all three CGRP antagonists were injection-site reactions and pain. Hypersensitivity reactions, including redness, swelling, pain, or irritation at the injection site, may occur. The patient should notify his or her physician immediately if he or she has serious injection-site irritation or signs of a severe allergic reaction.[6–8] In clinical trials, subjects experienced injection-site reactions while taking erenumab (occurring in 3% or more of treated subjects and more often than in those given placebo), fremanezumab (5% or more of subjects and more often than in those given placebo), and galcanezumab (incidence 2% or higher and at least 2% greater than in those given placebo).[1–3,8] Subjects taking galcanezumab 240 mg had significantly more injectionsite erythema than subjects given placebo.[14]

Neutralizing Antibodies

Patients taking CGRP antagonists may experience binding antibodies, and neutralizing antibodies may occur. In the erenumab trials, 35 of the 628 patients (5.6%) tested positive for anti–erenumab binding antibodies, and one of them (in the 70-mg erenumab group) tested positive for neutralizing antibodies (0.2%).[9,10] In the fremanezumab trials, antidrug antibodies developed in two patients who received fremanezumab quarterly.[12] In the galcanezumab trials, treatment-emergent antidrug antibodies occurred in 22 patients and 13 patients had neutralizing antibodies (0.6%, 2.3%, and 1.5% of the placebo, galcanezumab 120-mg, and galcanezumab 240-mg groups, respectively), with a significant difference between galcanezumab 120 mg and placebo (P <.05). Antidrug antibodies had no discernible effect on treatment efficacy or tolerability.[15]

Erenumab-specific Adverse Reactions

Constipation occurred in up to 3% of patients in the erenumab trials. Patients in these trials also experienced muscle cramps and spasms.[9,10]

Drug Interactions

Currently, there are no known significant drug interactions with erenumab, fremanezumab, or galcanezumab.[6–8]