Omalizumab for Urticaria: Real World As Good or Better Than Clinical Trials
NOVEMBER 16, 2018
Christopher Lee, PhDA new meta-analysis of 67 published reports on the real-world effectiveness of omalizumab (Xolair/Genentech) demonstrate that its benefits and safety for the treatment of chronic idiopathic urticaria (CIU) in the real-world meet or exceed results gleaned from clinical trials.
This is not the first instance of real-world success for omalizumab. In September 2017, it was also shown to match clinical trial results in the real world as a treatment for asthma.
In the current meta-analysis, data on the change in Urticaria Activity Score (UAS) in response to omalizumab for CIU were available from 15 studies that involved 294 patients. Findings showed that real-world treatment with omalizumab therapy was associated with an average 25.6-point improvement in weekly Urticaria Activity Score (UAS7) (95% CI; P < .001), compared with the 14.9 to 22.1-point improvement in clinical trials. There was significant (Q15 = 357.89, P < .001) and substantive (I2 = 95.8%) heterogeneity in the improvement in UAS7 scores observed across studies, but omalizumab was equally effective in reducing UAS7 scores across study subgroups (between-group Q = 0.5, P = .79).
Investigators, led by Christopher S Lee, PhD, of the Boston College Connell School of Nursing, also pooled data on change in Dermatology Life Quality Index (DLQI) scores following omalizumab treatment of CIU, which were available from 6 studies involving 84 patients. Across studies, the therapy was associated with a 13.9-point reduction in DLQI scores (95% CI, P < .001). There was significant (Q5 = 96.3, P < .001) and substantive (I2 = 94.8%) heterogeneity in the improvement in DLQI scores observed across studies.
“Synthesizing results from 67 published reports, we have provided evidence that omalizumab therapy results in large and significant improvements in UAS7, UAS, DLQI, and CU-Q2oL scores,” the authors wrote. “We also have provided evidence that omalizumab therapy is associated with complete and partial response rates of approximately 72.2% and 17.8%, respectively, when examined simultaneously.”
Data on complete clinical response to real world therapy was available from 45 studies involving 158 patients. Across these studies, the average complete response rate was 76% (95% CI; P < .001). The average non-response rate was 7% (95% CI; P < .001). Further, data on partial response was available from 37 studies involving 908 patients, which showed that the average partial response rate was 15% (95% CI; P < .001).
Studies included in the meta-analysis most commonly defined complete response as symptom disappearance that could be followed by antihistamine discontinuation, and partial response as incomplete symptom improvement, or symptom improvement followed by worsening when discontinuing antihistamines.
“Likely most informative to practice and policy are our results that the average complete response rate was 72.2% with a partial response rate of 17.8% when modeled together as opposed to considering these outcomes independently. Specifically, these results reflect what might be observed in clinical practice when looking for both complete and partial responses,” the authors wrote.
In the meta-analysis of real-world studies, data on adverse events was available from 47 studies involving 1314 patients. Across these studies, the average adverse event rate of any level of severity was 4% (95% CI, P < .001). Contrarily, data from randomized clinical trials involving omalizumab and CIU range from 2.9% to 8% depending on the dosage. Hence, based on these real-world data, the authors noted that omalizumab has a safety profile that is similar to or better than what was gleaned from previous trials.
The authors urged that their results should be interpreted with caution, “because the monitoring and reporting of adverse events in real-world studies is not always comparable to how safety is evaluated in trials.” Moreover, the results may not be generalizable to all patient and clinician experiences with omalizumab in the treatment of CIU.