Prognostic implications of cytogenetics in adults with acute lymphoblastic leukemia treated with inotuzumab ozogamicin.

Karyotype is frequently used to predict response and outcome in leukemia. This post hoc exploratory analysis evaluated the relationship between baseline cytogenetics and outcome in patients with relapsed/refractory acute lymphoblastic leukemia (R/R ALL) treated with inotuzumab ozogamicin (InO), a humanized CD22 antibody conjugated to calicheamicin, in the phase 3, open-label, randomized INO-VATE trial. Data as of March 8, 2016, are presented in this analysis. Of the 326 patients randomized, 284 had screening karyotyping data (144 in the InO arm and 140 in the standard care [SC] arm). With InO, complete remission or complete remission with incomplete hematologic recovery (CR/CRi), minimal residual disease negativity rates, and overall survival (OS) were not significantly different between cytogenetic subgroups. CR/CRi rates favored InO over SC in the diploid with ≥20 metaphases, complex, and "other" cytogenetic subgroups. The OS hazard ratio favored InO over SC in the diploid with ≥20 metaphases, complex, and other cytogenetic subgroups. Generally, InO is effective and provides substantial clinical benefit in patients with R/R ALL who have specific baseline karyotypes.