OMA has been for many years the only therapeutic choice for non-controlled severe allergic asthmatic patients, sensitized to perennial allergens. Nowadays, it is possible to switch OMA non-responder patients to other available biological treatments such as MEP, introduced in Italy since 2017 . In our study we enrolled 33 patients with severe eosinophilic allergic asthma, non-controlled by OMA, who switched to MEP. After 1 year of MEP therapy, we observed evident clinical benefits including significant decreases in asthma exacerbations, hospitalizations, OCS intake and working absenteeism. The most likely cause of unsatisfactory therapeutic response to OMA was probably related to the initial, obligatory choice of omalizumab due to unavailability of alternative biologics. In fact, at the beginning of this study and for more than the previous decade, OMA was the only available biologic therapy indicated for severe uncontrolled allergic asthmatics, and this drug was prescribed also in patients who did not represent the ideal targets . Instead of OMA, some of these patients could likely better benefit from MEP as first-line biologic treatment. However, such alternative therapeutic options should not be considered as comparisons between anti-IgE and anti-IL-5 pharmacologic approaches. Rather, in consideration of the increasing availability of biologic therapies, it is very important to gain scientific evidence supporting the rationale underlying the most effective drug choice for each specific patient.
The efficacy of MEP in patients not optimally controlled by OMA was previously evaluated in the OSMO trial , and also in an Italian observational study . Our results confirm the findings reported by both these studies. Moreover, we found significant decreases in exacerbation rate, hospitalization number, OCS-intake, and blood eosinophil count, which were very similar to those observed by Bagnasco, A few economic analyses regarding MEP have been published. A recent systematic literature review, aimed to investigate the cost-effectiveness of biological asthma treatments , identified just one paper evaluating the long-term clinical and economic impact of adding MEP to standard treatments with ICS and other controller medications on severe eosinophilic asthmatic US patients . Despite the significant improvement in quality of life, the estimated cost-effectiveness of MEP exceeded value thresholds. Similar results were detected by the authors of a more recent study , but they conducted a further sensitivity analysis comparing MEP with OMA; in this “active” comparison, MEP resulted dominant (more effective and less costly) with respect to OMA. The annual cost of MEP, viewed from the US payer perspective, was also estimated on the basis of data published in MENSA trial . The 12-month economic impact, not considering the cost of MEP, amounted to $ 1,277 per patient, and hospitalization cost was the main expense. The difference with our findings was probably due to the different cost structure between US and Italy. Moreover, in the US study, indirect costs have not been included. The potential economic benefit provided by MEP could be underestimated because of two study limitations emerging from our retrospective investigation. First, OCS use has important delayed clinical consequences [2,25], and morbidity costs in OCS-dependent patients have a relevant impact on NHS [26,27]. Thus, a 12-month follow-up could not allow to really evaluate the potential savings due to OCS-intake reduction. Second, the number of lost working days because of severe asthma was reported only for employed subjects, whereas for unemployed patients we considered only the length of hospital stay (if a hospitalization occurred during the study). Therefore, working day losses were not recorded in non-hospitalized unemployed patients, even if productivity impairments were unavoidable in case of frequent exacerbations. Since female prevalence was greater than that observed in real-life , gender distribution was highly unbalanced in our study, and it is well known that the employment rate is lower for women in comparison to men. Hence, it is very likely that a more balanced population could have allowed to verify greater savings with regard to the cost due to productivity loss.
To the best of our knowledge this is the first study investigating not only the clinical benefits, but also the economic impact of switching to MEP patients not optimally controlled by OMA. The economic analysis included both direct health care costs (drug consumption, hospitalizations, diagnostic exams, unscheduled visits) and indirect costs (absenteeism due to disease), that represented a significant portion of the total burden of asthma [29,30]. According to our findings, productivity loss accounted for about 22% of the annual cost due to uncontrolled asthma (excluding OMA cost); such percentage decreased to 9% after one year of treatment with MEP (excluding MEP cost).