Plasma Galectin-3 and urine proteomics predict FEV 1 improvement in omalizumab-treated patients with severe allergic asthma: Results from the PROXIMA sub-study.

Background: Patients with severe allergic asthma (SAA) when treated with omalizumab may exhibit different extent of response. Identifying biomarkers that can predict the extent of treatment effectiveness in patients can be useful in personalizing omalizumab treatment. Methods: Patients from the longitudinal phase of the PROXIMA study were selected for this ancillary study. After 12 months of omalizumab treatment, patients were categorized according to their response to treatment as: "clinical responder" (Asthma Control Questionnaire [ACQ] total score <1 at Month 12 and/or with a reduction in number of exacerbation versus the previous year); "functional responder" (an increment of >= 0.1 L in forced expiratory volume in 1 s [FEV1] at Month 12 versus baseline); and "super responder" (among clinical responders group, who also showed a functional response). Plasma galectin-3 (GAL-3) levels were quantified using a micro titer plate-based enzyme linked immunosorbent assay kit. Results: The Majority of patients (86.36%) in sub-study population were identified as clinical responders. Of the total patients identified as clinical responders, 64.86% were identified as super responders. A statistically significant difference in the baseline plasma GAL-3 levels between responders and non-responders was observed only in the functional responders group (P = 0.0446). Patients with plasma GAL-3 level of >= 11 ng/mL had a greater probability of being a super responder (P = 0.0118) or a functional responder (P = 0.0032). Conclusion: Our findings support the use of plasma GAL-3 as a predictive marker to stratify responders and identify super responders and functional responders to omalizumab treatment in patients with severe allergic asthma using less invasive sample like plasma.