Mepolizumab use was associated with fewer exacerbations, reduced oral corticosteroid use and lower costs among patients with asthma on Medicaid, according to a study published in The Journal of Allergy and Clinical Immunology: In Practice.

But because this population comprises individuals aged 65 years and older as well as younger individuals with long-term disabilities, these findings may not be generalizable to the full U.S. population, Sanjay Sethi, MD, professor and chief of pulmonary, critical care and sleep medicine at Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, and colleagues wrote.

Sanjay Sethi

“Most trial and real-world data on the impact of the use of drugs such as mepolizumab (Nucala, GSK) in patients with asthma is from young individuals,” Sethi, who is also vice president of health sciences at Jacobs School of Medicine and Biomedical Sciences, told Healio. “Asthma may differ in its manifestations and response to therapies in elderly individuals, which prompted this study.”

The researchers examined data from 1,278 patients (64.3% women; mean age, 67.9 years) with one or more prescription or administration claims for mepolizumab for asthma between Jan. 1 and Dec. 31, 2017, in the CMS fee-for-services Medicare datasets.

The baseline period spanned the 12 months before the index date, and the follow-up period spanned the following 12 months.

Compared with the baseline period, there was a 27% relative reduction in the proportion of patients who experienced an asthma exacerbation during the follow-up period, which met statistical significance (P < .0001), as well as a 36% relative reduction in the mean number of exacerbations leading to hospitalization per patient per year (P = .0164).

The number of patients with an exacerbation who needed hospitalization also fell from 99 (8%) to 60 (5%) from baseline to the follow-up, for a relative reduction of 40% (P = .0014).

The proportion of patients with one claim or more for all non-mepolizumab asthma treatments additionally fell. Comparing the follow-up to the baseline period, significantly fewer patients had one or more claim for:

• single-agent inhaled corticosteroids (62% vs. 66%; P = .03);
• short-acting beta 2 agonists (76% vs. 85%; P < .0001);
• short-acting muscarinic agonists (22% vs. 28%; P = .003);
• long-acting muscarinic agonists (33% vs. 41%; P < .0001); and
• leukotriene receptor antagonists (64% vs. 71%; P < .001).

The researchers also noted a significant 16% relative reduction in the proportion of patients with any oral corticosteroid (OCS) use from the baseline to the follow-up period (P < .0001) along with a 35% relative reduction in the mean number of OCS claims (P < .001).

Total costs fell from baseline to follow-up by $888 (P = .0002), as did pharmacy costs ($275; P < .0001), outpatient costs ($341; P = .0033) and other costs including skilled nursing facilities, home health agencies and hospice ($51; P = .0011). Inpatient costs fell by $219, but this did not reach statistical significance.

Further, the proportion and mean number of exacerbations and exacerbations leading to hospitalizations significantly fell from baseline to follow-up specifically for the 76% of the population who were aged 65 years or older, the researchers continued.

“The response rate in this elderly population to mepolizumab, measured in terms of reduction in exacerbations, hospitalizations and OCS use, were all of a magnitude larger than we had expected,” Sethi said. “Elderly patients with asthma have more fixed airway disease, comorbid COPD and other chronic conditions that could blunt the response to biologics.”

Based on these real-world findings, the researchers concluded that mepolizumab treatment was likely to result in fewer exacerbations, reductions in use of OCS, and reductions in health care costs related to exacerbations.

“These findings would suggest that in the appropriate patient with severe uncontrolled asthma, biologics such as mepolizumab should be considered irrespective of the patient’s age and comorbidities,” Sethi said.

However, Sethi cautioned that all such database real-world studies demonstrate association, not causation.

“A randomized placebo-controlled trial in an elderly severe uncontrolled asthma population that confirms and extends the findings of this study would be the next logical step,” he said.