SAN ANTONIO — Compliance to omalizumab therapy among patients with asthma did not appear correlated to clinical response, according to study results presented at the 2015 American College of Allergy, Asthma and Immunology Annual Scientific Meeting.
“We expected [the] higher the compliance, [the] better the response would be to any therapy,” Harjinder Singh, MD, told Healio.com/Allergy. “But not in this case. The compliance and response has no direct relationship.”
Singh and colleagues conducted a retrospective chart review of patients with asthma who underwent omalizumab (Xolair, Genentech) therapy from 2004 to 2011. Researchers assessed compliance and adherence to the drug therapy, as well as clinical response.
The researchers calculated compliance and adherence by comparing the number of recommended injections (n = 10,128) to injections actually received (n = 7,890).
Researchers defined omalizumab response as at least a 50% reduction in asthma exacerbations, steroid bursts, ER visits and hospitalizations.
The analysis included 198 patients (male, n = 100). Nearly half (44%) were aged younger than 18 years, 27% were aged 41 to 60 years, 18% were aged 18 to 40 years, and 11% were aged older than 60 years.
The average age at first omalizumab injection was 31.6 years (range, 3-77), and mean duration of therapy was 2.49 years (range, 3 months to 8.3 years).
Researchers reported a 79% overall clinic compliance rate. From this group, 157 (79.3%) were classified as responders.
Results showed 135 patients (68%) were compliant — defined as receiving at least 75% of all doses — and 63 (32%) were noncompliant.
Researchers reported no statistically significant difference in response rates between study participants who were at least 90% compliant (72%), 75% to 89% compliant (87%), or noncompliant (81%).
“It’s against our grain to think that if you’re noncompliant then you’re not going to respond,” researcher Joseph D. Diaz, MD, an allergist at Allergy, Asthma & Immunology Associates of South Texas, told Healio.com/Allergy. “But we showed that you can be significantly less compliant then ideal and there’s no difference in the response rates.”
Diaz offered advice to clinicians about how they may interpret the study results.
“Maybe we don’t need to give as much omalizumab as we are,” he said. “A lot of physicians will stop therapy in patients that are noncompliant, [but] we’re recommending you don’t stop therapy because you [still] might get some response.” – by Ryan McDonald
Singh H, et al. Poster 66. Presented at: American College of Allergy, Asthma and Immunology Annual Scientific Meeting; Nov. 5-9; San Antonio.
Disclosure: The researchers report no relevant financial disclosures.