Racial, Gender Inequities in CGRP, Gepant Prescriptions
SAN DIEGO, California — A review of prescription patterns reveals calcitonin gene-related peptide (CGRP) and gepant medications for migraine reveals significant gender and racial disparities that may affect access to care and health equity.
“The study serves as an early steppingstone in identifying opportunities for further research and intervention to expand access to migraine therapeutics,” lead investigator Kenneth Tan, MD, a neurology resident at Stanford Health Care, Palo Alto, California, told Medscape Medical News.
The findings were presented on June 15 at the American Headache Society (AHS) 2024 Annual Meeting.
The retrospective observational study used a Stanford database that includes de-identified data for patients attending the Stanford Headache Clinic. It included 1434 adults diagnosed with chronic migraine without aura who had received at least one prescription for either a CGRP from 2018 to 2022 (erenumab, fremanezumab, galanezumab, or eptinezumab) or gepant, a CGRP small molecule inhibitor, from 2020 to 2022 (ubrogepant, rimegepant, or atogepant).
The analysis did not include zavegepant, the first nasal spray for migraine, which was approved in 2023 outside the study period.
From the dataset, researchers extracted sex, age, race, ethnicity, and zip code, which they used as a surrogate for income. They divided zip codes into quartiles with the first quartile representing the lowest average annual earnings (up to $42,212), and the fourth the highest earnings ($77,250-$236,912).
Racial, Gender Differences
For CGRPs investigators found that men consistently received more prescriptions compared to females (P =.035). “This was an unexpected finding” because research shows that men tend to delay seeking treatment for migraine, said Tan.
A potential contributing factor is that CGRPs are contraindicated in pregnancy and women of childbearing age, he added.
The average age of patients who received a CGRP prescription varied over time from 41.5 and 42.5 years although this wasn’t statistically significant.
White patients consistently received significantly more prescriptions than did other racial groups although in about 2021, and there was a spike in Black patients receiving prescriptions. “There are many possible reasons for this spike, and we hope future studies can better understand this increase,” said Tan.
In terms of ethnicity, non-Hispanic, non-Latino patients consistently received more prescriptions compared wth Hispanic or Latino patients (P <.001).
As for income, the second-lowest quartile “consistently received the lowest number of CGRP prescriptions for every single year that our study was pursued,” said Tan. This may have something to do with insurance programs covering migraine medications for those in the lowest income category, he said.
“Patients in the second income quartile might have earnings that are high enough to not qualify for coverage, yet not high enough to afford more expensive medications without significant financial burden. We see a ‘donut’ phenomenon with a gap in coverage and access for those in the middle-income brackets.”
Gepant Inequities
With respect to gepants, men started out receiving more prescriptions than did women, but in 2021 and 2022 this changed, and women consistently received more prescriptions, thereafter, said Tan
Tan said the study was not designed to assess the reasons for such differences, but added future research will attempt to elucidate underlying causes so that disparities can be addressed.
The average age of patients who received prescriptions for gepants varied over time, but, as with CGRPs, this was not statistically significant.
Black or African American patients received the most gepant prescriptions in 2020. However, in 2021 and 2022, White patients had the highest number, although this wasn’t statistically significant. Non-Hispanic or non-Latino patients consistently received the largest number of gepant prescriptions overall.
Patients with lower incomes received the lowest number of gepant prescriptions.
Researchers were unable to assess Native American or Pacific Islander populations due to low numbers in the database. Other limitations were that the study used zip codes instead of exact income data, and study participants were seen at an academic medical center, which limits external generalizability of the findings.
The investigators are working on improving the database to better capture these variables.
Concerning Findings
Commenting on the findings for Medscape Medical News, Juliana VanderPluym, MD, a headache specialist at the Mayo Clinic in Phoenix, Arizona, noted that learning about disparities associated CGRPs because they’re a new class of drugs specifically designed for migraine.
“We should know who’s receiving the medications, so we also know who’s not receiving them,” she said. “We need to identify potentially unfair or inequitable issues so that we can address them.”
VanderPluym agreed the reason men received more CGRP prescriptions could be because these drugs may be unsafe in pregnancy, and women are urged to stop the drug 6 months before trying to conceive.
“Considering that many female patients with migraine are of childbearing age, there’s a possibility there’s a tendency to lean away from receiving the CGRP monoclonal antibodies,” she said.
However, the reason for the gender imbalance for gepants is not as clear.
“I would imagine that people would feel more comfortable with those medications because there’s a shorter washout period,” she said. “So, if women want to conceive or accidentally conceive, we don’t have that same concern that the medicine’s in their system for 6 months.”
The racial disparity highlighted in the study “is really concerning,” said VanderPluym. “Unlike the gender disparity where I can relate it to potential clinical factors, there shouldn’t be any clinical factors at play here. And we need to figure out ways we can address that.”
Patients in the lowest income brackets often qualify for patient support programs offered by drug companies for these drugs, which could partly explain why the inequity was found in the second-lowest income range and not the lowest, said VanderPluym.
The investigators and VanderPluym report no relevant financial disclosures.
