Indirect comparison of bronchial thermoplasty versus omalizumab for uncontrolled severe asthma

ABSTRACT

Objective: Bronchial thermoplasty (BT) as an add-on therapy for uncontrolled severe asthma is an alternative to biologic therapies like omalizumab (OM). We conducted an indirect treatment comparison (ITC) to appraise comparative effectiveness of BT and OM. Methods: A systematic literature review identified relevant randomized controlled trials. The ITC followed accepted methodology. Results: The ITC comprised a sham-controlled trial of BT (AIR2) and two placebo-controlled trials of OM (INNOVATE; EXTRA). Comparing the BT post-treatment period to ongoing treatment with OM, showed no significant differences in the rate ratios (RRs) for severe exacerbations (RR of BT versus OM = 0.91 [95% CI: 0.64, 1.30]; p = 0.62) or hospitalizations (RR = 0.57 [95% CI: 0.17, 1.86]; p = 0.53); emergency department visits were significantly reduced by 75% with BT (RR = 0.25 [95% CI: 0.07, 0.91]; p = 0.04); the proportions of patients with clinically meaningful response on the asthma quality-of-life questionnaire were comparable (RR = 1.06 [95% CI: 0.86, 1.34]; p = 0.59). The RR for exacerbations statistically favours OM over the total study period in AIR2 (RR = 1.50 [95% CI: 1.11, 2.02]; p = 0.009) likely reflecting a transient increase in events during the BT peri-treatment period. Conclusions: The ITC should be interpreted cautiously considering the differences between patient populations in the included trials. However, based on the analysis, BT compares well with a potentially more costly pharmacotherapy for asthma. Clinicians evaluating the relative merits of using these treatments should consider the totality of evidence and patient preferences to make an informed decision.

KEYWORDS:

• Comparative effectiveness
• GINA Step 5
• systematic literature review
• indirect treatment comparison
• informed decision

Declaration of interests

Authors contributions

DPT and SC contributed to the performance of the systematic review, data extraction, meta-analysis, and take responsibility for the integrity of the data and the accuracy of the data analysis. All authors contributed to the manuscript preparation, review, and response to peer-review comments.

Financial/non-financial disclosures

This study was funded by Boston Scientific, Marlborough, MA, USA. MJC and MRS are currently employed by Boston Scientific, which manufactures and markets Alair™, a device system for BT. DPT and SC are the employees of THEMA Consulting Pty Ltd, which was paid to conduct research described in this manuscript. NSS is a Consultant to Boston Scientific Corp. and was an employee of Boston Scientific when this study was being performed. RMN has received personal fees and non-financial support from Novartis, Chiesi and Boehringer Ingelheim, and personal fees from GSK, Boston Scientific, Astra Zeneca, Teva and Vectura.

Notation of prior abstract publication/presentation

This work was presented at the European Respiratory Society 2015 International Congress, Amsterdam, Netherlands.

The study is based on a systematic literature review and analysis of previously published data. As such, approval from an institutional review board was not required.