Can we trust the SOURCE ? Real world maintenance OCS reduction outcomes in complex severe asthmatics on Tezepelumab

<bold>Introduction:</bold> It is well established that the toxicity from daily maintenance oral corticosteroid (mOCS) use has an awful impact on severe asthmatics. Many RCTs have demonstrated riddance from daily mOCS with biologic use. The SOURCE RCT however, failed to show a significant mOCS dose reduction with Tezepelumab when compared to placebo. Whether these findings can be extrapolated to an unselected real-world severe asthma population remains to be explored. <bold>Methods:</bold> We retrospectively reviewed consecutive records of adult severe asthma patients who received Tezepelumab 210 mg s/c 4 weekly for 6 months. All patients were on mOCS with a large proportion unable to reduce mOCS whilst on prior asthma biologic therapies. <bold>Results:</bold> 39 patients received 6 doses of Tezepelumab. 27 (69%) demonstrated a favourable response to Tezepelumab by achieving ≥50% mOCS dose reduction. Of those, 18 (66%) achieved successful tapering off mOCS or managed to reduce prednisolone dosage down to 5mg, where further reduction was constrained due to the presence or need for adrenal insufficiency screening. Table 1 (below) exhibits the demographics and co-morbities of patients who were studied. <fig><object-id>erj;64/suppl_68/PA3563/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig> <bold>Conclusions:</bold> Despite the findings of the SOURCE RCT, our study shows that in a real-world severe asthma cohort, 6 doses of Tezepelumab enabled 69% of patients to achieve ≥50% mOCS dose reduction, with 46% being able to essentially taper off.