California: Are Migraine Drugs Becoming a New Workers’ Comp Cost Driver?

Oakland, CA – Migraine Drugs represented less than 1% of all prescriptions dispensed to California injured workers in 2023 but they consumed 4.7% of workers’ compensation drug payments, a nearly 8-fold increase since 2018, which a California Workers’ Compensation Institute (CWCI) study links to the emergence of several high-cost brand drugs that are not listed in the Medical Treatment Utilization Schedule (MTUS) Formulary. 

Migraine, a genetic, neurological disorder characterized by severe throbbing headaches often accompanied by nausea, dizziness, and sensitivity to light and sound, is not a common work injury, though it is common in the general population, especially among women, as more than 1 out of 6 women suffer from migraine attacks, 3 times the proportion noted for men.  There is no diagnostic test for migraine, so diagnoses are based on a patient’s symptoms, personal and family history, and exposure to triggers that can include accidents or falls resulting in concussions or traumatic brain injuries, or events where work causation is more tenuous, including stress, exposure to light or odors, dehydration, diet, poor sleep, hormonal fluctuations, or overuse of medications.  Changes to a person’s lifestyle and routines can reduce or eliminate their exposure to certain triggers, but in recent years the use of Migraine Drugs has increased as new pain relieving and preventive drugs have been approved and hit the market.  Although the CWCI study notes that Migraine Drugs represented only 0.7% of California workers’ compensation prescriptions filled in 2023, that was up from 0.2% in 2018.  This, along with the ongoing evolution of the Migraine Drug market and the growing use of several high-cost brand-name drugs for which there are no generic equivalents, drove the Migraine Drugs’ share of the workers’ compensation drug spend up from 0.6% in 2018 to 4.7% last year. 

The study, based on data from CWCI’s Industry Research Information System (IRIS) database which contains details on more than 9.5 million California workers’ compensation prescriptions filled between 2010 and 2023, found that the top 2 Migraine drugs prescribed in 2023 were relatively inexpensive sumatriptan (i.e., Imitrex) and rizatriptan benzoate (Maxalt), which are used to relieve migraine symptoms.  However, from 2018 through 2023 these 2 drugs’ share of the workers’ compensation Migraine Drug prescriptions dropped from 75.6% to 52.3%, while their share of the Migraine Drug spend fell from 38.0% to 5.5%.  Over that same period, the study identified 6 cost-driver Migraine Drugs that were approved by the FDA and introduced into the system, but that are categorized as Not Listed drugs in the MTUS Formulary: 

• Aimovig Autoinjector (Erenumab-aooe) is a large molecule monoclonal antibody (made from immune system cells) used to prevent episodic and chronic migraines. Approved in May 2018, by 2020 Aimovig accounted for 23.4% of the California workers’ comp Migraine Drug spend and by 2021 it represented 8.8% of the Migraine Drug prescriptions.  With new drugs coming online, by 2023 it fell to 5.7% of the Migraine prescriptions, but with an average payment of $708 per prescription, Aimovig still consumed 6.7% of the Migraine Drug spend.  
• Ajovy (Fremanezumab-vfrm) is also a large molecule injectable monoclonal antibody that prevents migraines by blocking the CGRP protein molecule in the brain which is involved in pain transmission and which increases inflammation. Approved in September 2018, Ajovy comes in a monthly or quarterly dose.  By 2020 it represented 3.5% of California workers’ comp migraine prescriptions but at an average of $617 per prescription it represented 8.6% of the Migraine Drug dollars.  By 2023, Ajovy had grown to 4.6% of the Migraine prescriptions and the average payment grew to $817, but with the introduction of higher-cost alternatives, its share of the Migraine Drug spend fell to 6.7%. 
• Emgality (Galcanezumab-gnlm) is another large molecule injectable CGRP antagonist approved for migraine prevention in September 2018. In June 2019 it was also approved for treatment of episodic cluster headaches.  By 2020, Emgality represented 4.3% of the Migraine prescriptions and with reimbursements averaging $667 it consumed 11.5% of the Migraine Drug payments.  As non-injectable options came on the market, Emgality’s share of the prescriptions fell to 2.6% by 2023, but payments averaged $649 so it still represented 2.8% of the Migraine Drug spend. 

• Ubrelvy (Ubrogepant) is a second type of CGRP inhibitor – a CGRP receptor antagonist (gepant). Gepants are non-peptide small molecules that attach to blood vessels without constricting them and they block CGRP proteins from attaching to sensory nerve endings.  Gepants work quickly to alleviate migraine symptoms during an attack.  In December 2019 Ubrelvy became the first oral gepant approved for acute migraine pain and other symptoms, but it was not indicated as a preventive treatment.  By 2021 Ubrelvy accounted for 4.4% of workers’ comp Migraine prescriptions, but with an average payment of $1,426 it represented 17.2% of the Migraine Drug payments.  Ubrelvy’s share of Migraine prescriptions climbed to 7.0% last year, though the average paid has fluctuated along with the average number of tablets dispensed, so in 2023, the average payment was $1,507 while its share of the Migraine dollars was 17.4%.   
• Nurtec ODT (Rimegepant Sulfate), also a CGRP blocker, is a disintegrating tablet often dispensed in blister packs of 8 tablets. Approved in February 2020 for acute treatment of migraine, in May 2021 it was approved as a preventive treatment for adults experiencing 15 or more migraine days a month, which made it the only drug approved to treat migraines and prevent future attacks.  In 2021 Nurtec accounted for 3.7% of workers’ comp Migraine prescriptions and with payments averaging $1,277, it represented 12.8% of the Migraine Drug spend.  Nurtec’s share of the prescriptions jumped to 9.4% in 2022, then to 15.0% in 2023 while average payments rose steadily to $1,675 in 2023, driving its share of the Migraine dollars up to 41.6%, making it the fastest growing Migraine Drug in California workers’ comp, both in terms of utilization and payments.
• Qulipta (Atogepant) is one of the newer CGRP blockers used to treat injured workers. Approved for episodic migraines in September 2021 and for chronic migraines in April 2023, workers’ comp prescriptions for Qulipta first appeared in significant volume in 2023.  By the end of 2023 it accounted for 3.1% of the Migraine Drug prescriptions dispensed last year, and with an average reimbursement of $1,106 per prescription, it consumed 5.7 percent of the 2023 Migraine Drug spend.  The emergence of Qulipta in workers’ comp coincided with the declines in the three injectable monoclonal antibodies (Aimovig, Ajovy, and Emgality) which together fell from 16.2 percent of the Migraine Drug prescriptions in 2022 to 12.9% in 2023, while their share of the Migraine Drug spend fell from 24.4% to 16.2%, signaling an ongoing shift within this drug group.

With the addition of these new medications, Migraine Drugs, which a decade ago did not rank among the top 10 drug groups in California workers’ compensation, now rank sixth in terms of total payments, with aggregate expenditures approaching those of Opioids and surpassing those of Antidepressants and Musculoskeletal Drugs.  Their rapid growth in workers’ compensation raises concerns given the risks associated with these drugs, the long list of triggers that may or may not be work-related, the costs associated with long-term treatment of migraine, and the large percentage of American adults who suffer from the condition.  Such concerns make it incumbent upon physicians, claims administrators, PBMs, and utilization reviewers to confirm a migraine diagnosis (vs. a tension headache of other condition), the work-relatedness of the condition, and that use of a specific Migraine Drug is appropriate and supported by the MTUS or other evidence-based guidelines. 

CWCI has published more details and analyses on these drugs in a Spotlight Report, Trends in the Utilization and Reimbursement of Migraine Drugs in California Workers’ Compensation.  Institute members and subscribers can log on to www.cwci.org to access the report under the Research tab, others can purchase it from CWCI’s online Store.