Dostupni epidemiološki podaci sugeriraju da 3 – 10% bolesnika s astmom boluje od teške astme. U ovih bolesnika, usprkos adekvatnoj primjeni standardne inhalacijske terapije, provedbi mjera kontrole okolišnih čimbenika i primjerenoj suradljivosti, ne može se postići zadovoljavajuća kontrola bolesti. U znatnog broja bolesnika radi se o teškoj eozinofilnoj astmi u kojoj glavni etiopatogenetski mehanizam jest eozinofilni obrazac upalne reakcije u dišnim putovima, neovisan o alergenu. Za ove bolesnike odnedavno su dostupna dva biološka lijeka sa snažnim antieozinofilnim učinkom. To su monoklonska protutijela usmjerena protiv interleukina 5 (IL-5), reslizumab i mepolizumab. Ovi lijekovi znatno poboljšavaju plućnu funkciju, smanjuju broj akutnih pogoršanja astme, smanjuju potrebu za primjenom sustavnih kortikosteroida te poboljšavaju kvalitetu života sniženu astmom. Antieozinofilni lijekovi učinkoviti su u dobro definiranoj podskupini bolesnika s teškom astmom. Stoga je prije odluke o njihovoj primjeni potreban pažljiv probir bolesnika temeljen na fenotipskim karakteristikama astme.Available epidemiological data suggest that 3-10% of asthmatic patients suffer from severe asthma. Despite the adequate administration of standard inhalation therapy, the implementation of measures controlling environmental factors and appropriate compliance, it is not possible to achieve satisfactory control of the disease in these patients. A significant number of these patients have severe eosinophilic asthma in which the allergen-independent eosinophilic form of inflammatory reaction in the airway represents a major etiopathogenetic mechanism. Two biological drugs with a strong anti-eosinophilic effect have recently become available for these patients. These drugs, reslizumab and mepolizumab, are monoclonal antibodies directed against interleukin 5 (IL-5). They signifficantly improve pulmonary function, reduce the number of acute asthma aggravations, reduce the need to administer systemic corticosteroids, and improve the reduced quality of life in asthmatic patients. Anti-eosinophilic drugs are effective in a well-defined subgroup of patients with severe asthma. Therefore, prior to deciding on the administration of these drugs, careful patient screening based on phenotypic characteristics of asthma should be made