Long-term open-label safety study of galcanezumab in patients with episodic or chronic cluster headache

Background CGAR, a Phase 3b open-label study, evaluated the long-term safety of galcanezumab in patients with cluster headache who completed one of two Phase 3 double-blind studies in chronic or episodic cluster headache. Methods Patients (N = 164) received galcanezumab 300 mg subcutaneously up to once a month. Primary endpoint was safety, as assessed by treatment-emergent adverse events, serious adverse events, and suicidality. Other endpoints included discontinuation rates, immunogenicity, efficacy as assessed by the Patient Global Impression of Improvement, and health values. Results At baseline, mean (standard deviation) age was 48.3 (9.8) years, 75.0% were men, and 85.4% were white. Treatment-emergent adverse events (n = 119 [72.6%]) were mostly mild-to-moderate, with nasopharyngitis the most commonly reported (22.0%). One of 18 serious adverse events was judged as treatment related (constipation). Two patients (1.2%) reported suicidal ideation. Five patients (3.1%) discontinued due to an adverse event. Eight patients were treatment-emergent anti-drug antibody positive, two of whom were not treatment-emergent anti-drug antibody positive in the parent studies. On the Patient Global Impression of Improvement, >= 81% reported their cluster headache status as very much, much, or a little better at Months 1, 6, and 12. Health value scores generally improved from baseline. Conclusions In this open-label study, galcanezumab was generally well tolerated and improved patient-reported cluster headache status.