Patients with chronic migraine who were started on Botox were significantly more likely to continue to be treated with Botox after one year than patients who were started on a CGRP monoclonal antibody (mAb). mAbs are given monthly by injection. This category includes erenumab (Aimovig), fremanezumab (Ajovy), and galcanezumab (Emgality).

The results of this large retrospective study that included 1,974 patients were presented at the last meeting of the American Headache Society held in June of this year. The lead authors were Dr. Todd Schwedt of the Mayo Clinic and Dr. Andrew Blumenfeld.

The study was sponsored by the manufacturer of Botox which makes it inherently biased. However, the difference between the two groups was striking. Of patients who were started on Botox, 66% continued the treatment at the end of the year. Less than a third of patients who were started on a mAb were still getting it at the end of the year.

The researchers looked at differences in outcomes in patients enrolled before and during COVID. The results were similar before and during the pandemic. This is surprising because, during the pandemic, many patients were reluctant to come to the office for Botox injections. Many preferred to self-inject mAbs at home. Despite this obstacle, Botox patients were twice as likely to continue treatment at the end of the year.

Besides efficacy, the major reason I recommend Botox ahead of mAbs and other drugs is its proven long-term safety. Botox was first approved by the FDA in 1989. Botox is my preferred treatment for chronic migraines even in pregnant women.

Both mAbs and Botox are fairly expensive. The same group of researchers presented a second study that evaluated all-cause and migraine-related costs in these two groups of patients. They found no difference in total healthcare costs and migraine-related costs, including emergency department expenses.