“There are several factors that are contributing to the slow uptake in these medications. Firstly, some newer medications are expensive and can require complicated insurance approvals as well as trips to doctors’ offices or infusion sites that are difficult to access for rural populations. Secondly, there are major challenges in transitioning pediatric SCD patients to receiving adequate care as adults,” lead study author Robert M. Cronin, MD, of the department of internal medicine at the Ohio State University, Columbus, said in an interview.
The retrospective study, published in Blood Advances, looked at private insurance claims of patients with SCD in the United States from 2016 to 2020. A total of 7,957 participants were included in the analysis (all were ≥ 18 years, median age 37, 61.2% female). Primary outcomes analyzed were the utilization of hydroxyurea, l-glutamine, and crizanlizumab (all shown in clinical trials to decrease acute vaso-occlusive pain), and voxelotor (approved for patients with SCD with lower hemoglobin levels).
Among study participants who had two or more pain episodes in a year, 31.5% were prescribed hydroxyurea, 3.2% l-glutamine, 2.3% crizanlizumab, and 2.9% voxelotor. Any combination therapy of drugs to decrease vaso-occlusive pain was used in about 3% of the study participants, and combinations of newer therapies were used in only 0.3%.
In contrast to these statistics, Dr. Cronin said, “All adults with sickle cell anemia should be at least offered treatment with hydroxyurea, and up to 63% of individuals with SCD have at least one vaso-occlusive pain episode in a year, making them eligible for crizanlizumab, l-glutamine, or both.”
As patients with SCD grew older, their odds of being prescribed hydroxyurea, l-glutamine, and crizanlizumab all decreased. Dr. Cronin speculated about the reasons for this decline. “It’s a huge problem to find adult providers who are knowledgeable about SCD. When pediatric patients become adults, they often can’t find anybody who knows about their disease,” he said.
Study results supported the hypothesis that rural location was a barrier to care. Not residing in a “super rural” geographic location was associated with nearly three times the likelihood of crizanlizumab prescription (odds ratio, 2.93; 95% confidence interval, 1.16-7.42).
“There is geographic variability as expected, with limitations in rural areas,” said Nirmish R. Shah, MD, director of the sickle cell transition program at Duke Health in Durham, N.C. Dr. Shah was not associated with the study.
Dr. Shah commented that he found the study’s findings unsurprising. He also noted that its results were based solely on data from private insurance databases and that some of the drugs included in the study were approved just before the COVID-19 pandemic began – another possible factor in their being underprescribed for patients with SCD.
Dr. Cronin warned that despite the study’s limitations, the actual situation for patients with SCD in the United States may be even worse than the data indicate, saying “A lot of people with SCD are actually on governmental insurance, and they may be even less likely to be getting access to these newer drugs, due to less robust coverage and more hurdles to jump through before getting treatment approved.”
Dr. Cronin disclosed no conflicts of interest. Dr. Shah reported ties with Emmaus, Novartis, GBT, Forma, Agios, Vertex, and Bluebird Bio.