June 13, 2020
Profiling Physicians Prescribing Concurrent Anti-Calcitonin Gene-Related Peptide Monoclonal Antibody and OnabotulinumtoxinA for Migraine Prevention: Results from an Annual US Patient Chart Audit
Authors: Robert P. Cowan, MD, FAAN; Kristen Henn, MHSc; Jennifer Robinson; Virginia R. Schobel, MSc
The use of combination therapy for the preventive treatment of migraine is common. In 2018, the anti-calcitonin gene-related peptide (CGRP) monoclonal antibodies (mAbs) were introduced in the US, beginning with erenumab-aooe in May, fremanezumab-vfrm in September, and galcanezumab-gnlm in October. During the first year of access to CGRP mAbs, there were no clinical data nor payor restrictions on concurrent use of onabotulinumtoxinA (onabotA). With different mechanisms of action, it was postulated that concurrent use of an CGRP mAb and onabotA could result in a synergistic or additive benefit to migraine patients. The objective of this analysis is to profile physicians who are currently treating migraine patients with both a CGRP mAb and onabotA.
Fielded in June 2019, 221 US neurologists and migraine specialists completed an online survey and contributed chart review data for a cross-sectional audit of 1,016 patients treated with a CGRP mAb and/or onabotA for migraine prevention. Analyses were performed on the 941 charts provided by the physician who personally initiated the patient on their most recent preventive therapy.
33% of physicians contributed chart data for one or more patients concurrently prescribed CGRP mAb+onabotA (i.e., COMBO physicians; Figure 1). Of patient charts reviewed, 31% were for patients treated with concurrent CGRP mAb+onabotA; on average, 25% of charts contributed by COMBO physicians were for CGRP mAb+onabotA (Figure 2). When onabotA was prescribed with a CGRP mAb, patients were more likely to be treated with erenumab (16% of all charts contributed by COMBO physicians) than with galcanezumab (8%) or fremanezumab (7%; Figure 3). Physicians with no combination use (NCU) provided significantly more charts of patients treated with erenumab (35% vs. 19%; p<0.05) or galcanezumab (16% vs. 10%; p<0.05) compared to COMBO physicians; onabotA share did not differ significantly between subgroups (36% vs. 31%).
Based upon physician survey data, COMBO physicians were significantly more likely to be migraine specialists (56% vs. 39%; p<0.05) compared to NCU physicians (Figure 4). NCU physicians were more likely to be practicing in a community office/clinic (56% vs. 39%; p<0.05; Figure 5) and reported a higher proportion of their managed migraine patients being diagnosed with episodic migraine (EM; 52% vs. 45%; p<0.05) compared to COMBO physicians (Figure 6). While the preventive treatment rate for chronic migraine (CM) was similar between subgroups (87% vs. 82%), NCU physicians estimated a significantly higher preventive treatment rate for EM (64% vs. 53%; p<0.05) compared to COMBO physicians (Figure 7). COMBO physicians estimated significantly higher onabotA shares among preventive-treated EM (15% vs. 12%; p=0.013) and CM (33% vs. 24%; p=0.002) migraine patients (Figure 8) and were more likely to be self-reported onabotA prescribers (76% vs. 67% for EM; NS; 97% vs. 89% for CM; p<0.05; Table 1). Conversely, NCU physicians reported relying more on small molecule preventive therapies, specifically topiramate (31% vs. 24%; p=0.015) and antidepressants (23% vs. 18%; p=0.015) for CM. While the majority of CGRP mAb and onabotA use was after the failure of two or more prior preventive therapies, COMBO physicians reported greater first-line use of CGRP mAbs and onabotA compared to NCU physicians (Figure 9).
Physicians who concurrently prescribe a CGRP mAb with onabotA are more likely to be migraine specialists than general neurologists, most likely reflecting differences in managed patient populations, including a greater emphasis on CM management and onabotA prescribing among migraine specialists. Strong early adoption of first-to-market erenumab and shorter periods of access to the other CGRP mAb at the time of review led to onabotA being most likely to be prescribed in combination with erenumab. A prospective study of concomitant treatment with a CGRP mAb and onabotA would be instructive for clinical management.
Robert Cowan consults or serves on scientific advisory boards for all three CGRP mAb manufacturers providing product in the U.S.
Kristen Henn and Virginia R. Schobel are employees of Spherix Global Insights, an independent market intelligence firm and have received no industry funding to conduct and report on this study.
Jennifer Robinson is the founder of Spherix Global Insights, an independent market intelligence firm and has received no industry funding to conduct and report on this study.
Archived AHS Abstracts:
- Trending the First Two Years of Anti-Calcitonin Gene-Related Peptide Class Availability for Migraine Prevention: Results from an Independent Quarterly US Survey of Neurologists and Migraine Specialists
- Early Prescribing Patterns of the Anti-Calcitonin Gene-Related Peptide Monoclonal Antibodies Are Dominated by Adjunctive Use for Episodic and Chronic Migraine Prevention: Trending the First Year of US Adoption
- Impact of US Physicians’ Perceptions of the Distinct Pharmacological and Clinical Characteristics of the Novel Anti-Calcitonin Gene-Related Peptide Monoclonal Antibodies on Self-Reported Chronic Migraine Prevention Brand Share