FDA advisory impacts treatment practice patterns for atopic dermatitis in babies

October 1, 2007

A retrospective, longitudinal cohort study was undertaken to analyze the effects of the FDA advisory on off-label topical calcineurin inhibitor (TCI) treatment practice patterns for infants with atopic dermatitis (<2 years of age). The results show a reduction in overall utilization of AD-related medications and reduced utilization of TCIs coupled with early introduction of topical corticosteroid treatment after the advisory compared to the period preceding the advisory.

National report - Treatment practice patterns for managing atopic dermatitis (AD) in pediatric patients below 2 years of age have changed following issuance of the Food and Drug Administration (FDA) advisory on topical calcineurin inhibitors (TCIs), according to a retrospective, longitudinal cohort analysis undertaken by researchers at HealthCore, a health outcomes research and consulting company.

The investigation compared administrative claims data for pre-FDA advisory and post-FDA advisory cohorts of pediatric patients with AD who were up to 2 years of age. Patients in the pre-advisory cohort had an index date of AD diagnosis ranging from Feb. 1, 2003, to Feb. 1, 2005; the index date of AD diagnosis for the post-advisory cohort ranged from March 11, 2005, to July 31, 2005.

Results

"These changes have potential implications for outcomes, since early intervention with AD agents may have an important effect on AD progression and the development of atopic diseases. In addition, the question is raised whether the right trade-off is being made to achieve reduced exposure to TCIs. While the possibility of cancer-related safety concerns was the basis for the FDA advisory on the TCIs, topical corticosteroids have known local and systemic adverse effects. Ongoing monitoring of these pediatric patients will be important to identify potential adverse consequences of increased topical corticosteroid utilization," says Debra Wertz, Pharm.D., senior research analyst, Health Outcomes Research, HealthCore, Wilmington, Del.

The researchers at HealthCore were approached by personnel at Novartis, manufacturer of pimecrolimus cream 1 percent (Elidel), to help evaluate the impact of the FDA advisory on prescribing patterns. They chose to study "real world" AD treatment patterns for pediatric patients younger than 2 years of age.

"There has been little published data on off-label TCI use in infants in the real-world setting of daily clinical practice, and to our knowledge, no published information on the impact of the FDA advisory on TCI utilization in this population," Dr. Wertz says.

Comparing groups

The pre-advisory cohort included 23,959 patients and the post-advisory cohort included 5,007 patients. The two groups were similar with respect to mean age (15 months) and pre-index comorbidities. Both groups had approximately one year of follow-up available prior to the index date. In the 180-day period prior to the index date, patients in the pre-advisory group received slightly more medications than their post-advisory counterparts (mean 4.1 vs. 3.7). The duration of follow-up after AD diagnosis was longer in the pre-advisory cohort than in the post-advisory cohort (17 months vs. 6 months); however, patients were censored at 265 days (maximum possible in the post-advisory cohort) to ensure comparability of follow-up across the two cohorts in the multivariate analysis.

The analyses of medication use showed significantly fewer patients were started on any medication for AD after the advisory than before (57 percent vs. 64 percent). Considering only patients who started therapy, the proportion initiated on a TCI declined from 8.0 percent pre-advisory to 4.5 percent post-advisory. The rate of switching patients from a topical corticosteroid to a TCI also declined after the advisory, from 4.0 percent to 1.30 percent.

Multivariate analysis

A multivariate analysis adjusting for such factors as age, gender, baseline comorbidities, comorbidity burden and medication use was conducted to compare treatment patterns in the post-advisory and pre-advisory cohorts. These results showed the odds of initiating a TCI versus any other AD therapy was significantly reduced after the advisory by 57 percent. In addition, there was a 71 percent reduction in the odds of initiating a TCI compared with a topical corticosteroid, considering only patients started on a TCI or topical corticosteroid.

Compared with the pre-advisory cohort, the post-advisory cohort also had significantly greater odds of initiating topical corticosteroids earlier (110 vs. 210 days).

Disclosure: The study was funded by a research grant from Novartis. Dr. Wertz reports no financial interest in that company.