Background: InO, an anti-CD22 antibody-calicheamicin conjugate, has demonstrated superior response vs standard care for R/R ALL in the phase 3 INO-VATE trial (complete remission [CR]/CR with incomplete hematologic recovery [CRi], 81% [95% CI; 72–88]; minimal residual disease [MRD] negativity in responders, 78% [68–87]; median remission duration [DoR], 4.6 [3.9–5.4] mo). Herein, the efficacy and safety of InO in patients (pts) aged ≥55 vs <55 y are assessed. Methods: Per protocol, the intent-to-treat analyses of CR/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/m²on d8 and 15 of a 21–28 d cycle for ≤6 cycles]). 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 (median age, 47 [range, 18–78] y; pts ≥55 y, 43 [39%]). Remission rates and DoR were similar whereas MRD-negativity rates in responders were numerically higher in older pts (Table). In the safety population, grade (Gr) ≥3 adverse events (AEs) were most frequently cytopenias (neutropenia, 46%; thrombocytopenia, 37%; febrile neutropenia, 24%); these Gr ≥3 AEs were more common in pts ≥55 (n=53) vs <55 y (n=86): thrombocytopenia (49% vs 29%), neutropenia (53% vs 42%), febrile neutropenia (28% vs 21%). Pts ≥55 vs <55 y had similar discontinuation rates due to AEs (both 17%). For pts ≥55 vs <55 y, any grade hepatobiliary AE rates were similar (both 26%): hyperbilirubinemia (both 15%), and veno-occlusive liver disease (VOD) including post-SCT VOD (both 11%; 2 fatal in pts <55 y [1 after second SCT]). Conclusions: InO was highly effective in older pts with R/R ALL for whom treatment options are currently limited; responses and safety profiles were generally similar to younger pts and the overall study population. Clinical trial information: NCT01564784

^aITT218; ^bBest response in 1–6 cycles; ^cn=51; ^dn=34