Long-term efficacy of A1-PI therapy in RAPID and its extension study

Background RAPID ([NCT00261833][1]) showed that augmentation therapy with alpha-1 proteinase inhibitor (A1-PI Z, Zemaira®, CSL Behring) slows lung density decline in A1-PI-deficient patients. Aim To assess clinical benefit over 48 months in subjects who completed RAPID and have data from ≥2 CT scans from the extension study to date ([NCT00670007][2]). Methods In a randomized, controlled design, RAPID subjects received A1-PI Z or placebo for 24 months, after which non-US subjects entered the 24-month extension study and all received A1-PI Z. Changes in adjusted lung density P15 at total lung capacity were assessed by CT. Results Rate of lung density decline was significantly reduced with A1-PI Z vs. placebo and was similar (1–1.5 g/L/y) among A1-PI Z subjects in the blinded and open-label phases. In the ongoing extension study, the delayed-start cohort (placebo–A1-PI Z) had a reduced rate of decline very similar to the early-start cohort. View this table: Changes in adjusted lung density P15 in RAPID and its ongoing extension study Conclusions A1-PI Z showed clinical benefit over 4 years and at different intervention points (early or delayed). Early treatment may reduce overall progression of emphysema in A1-PI-deficient patients. [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00261833&atom=%2Ferj%2F44%2FSuppl_58%2FP294.atom [2]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00670007&atom=%2Ferj%2F44%2FSuppl_58%2FP294.atom