Switching anti-CGRP(R) monoclonal antibodies in multi-assessed non-responder patients and implications for ineffectiveness criteria: A retrospective cohort study

Background: A pharmacological class effect was initially proposed for monoclonal antibodies against the calcitonin gene related peptide pathway. However, preliminary evidence shows that switching patients who were non-responding to one monoclonal antibody to another could provide some benefit. Herein, we assess treatment response to an anti-calcitonin gene related peptide/receptor monoclonal antibody in patients who have failed to respond to anti-calcitonin gene related peptide/ligand monoclonal antibodies calcitonin gene related peptide/ligand monoclonal antibodies and vice versa. In addition, we select non-responders to the first anti- monoclonal antibody by three or five more stringent variables. Methods: Retrospective cohort study including outpatients treated consecutively with two anti-calcitonin gene related peptide monoclonal antibodies. Ineffectiveness to the first monoclonal antibody was assessed using three (MIDAS score, monthly headache days, and analgesic monthly days) variables or five (monthly headache days, MIDAS score, analgesic monthly days, analgesic monthly number and HIT-6 score) variables in the same cohort of patients. The primary endpoints were the absolute change from baseline in monthly headache days, response rate, and persistence in medication overuse at three months of treatment with the second anti-CGRP mAb. Results: In patients selected by three variables, a sustained reduction in monthly headache days, analgesic monthly days, MIDAS and HIT-6 scores was observed at month-3 of treatment with the second monoclonal antibody. Ten (45.4%) patients achieved at least a ≥30% response rate. No difference was reported switching anti-CGRP mAb against ligand or receptor. In the patient subgroup selected by five variables, only HIT-6 was reduced from baseline at month-3. However, a trend toward a reduction in monthly headache days, analgesic monthly days, and MIDAS score was observed at month-3. Conclusions: Switching anti-calcitonin gene related peptide monoclonal antibodies in selected patients might be an option to achieve or improve clinical benefit. More studies are required to establish the effectiveness of switching these treatments.