7028Background: InO, an anti-CD22 antibody-calicheamicin conjugate, showed superior response vs standard care for R/R ALL in the phase III INO-VATE trial. Herein, effects of prior therapy on response and toxicities were assessed in patients (pts) receiving InO. Methods: Per protocol, intent-to-treat analyses of complete remission [CR]/CR with incomplete hematologic recovery [CRi] included the first 218 of 326 pts randomized (ITT218). The safety population included 139 pts who received ≥ 1 InO dose (max 1.8 mg/m2/cycle [0.8 mg/m2 on d1; 0.5 mg/m2 on d8 and 15 of a 21–28 d cycle for ≤ 6 cycles]). Minimal residual disease (MRD) negativity was assessed by central flow cytometry ( < 0.01%). Data as of October 2, 2014 are presented (trial ongoing). Results: 109 pts in the ITT218 received InO (CR/CRi rate, 81% [95% CI, 72–88]; MRD negativity rate in responders, 78% [95% CI, 68–87]; median remission duration [DoR], 4.6 [95% CI, 3.9–5.4] mo). 67% and 32% of pts received InO as salvage (S) 1 and S2 (missing, n = 1)...