Real-world effectiveness and safety of inotuzumab ozogamicin in adult patients with R/R B-ALL

Inotuzumab ozogamicin (InO) is a CD22-directed antibody–drug conjugate that demonstrated strong efficacy in clinical trials, leading to U.S. FDA approval in 2017 for adult patients with R/R B-ALL, and in 2024 for pediatric patients aged ≥1 year.¹ Whilst InO has changed the treatment paradigm and improved patient outcomes in ALL, real-world data are needed to confirm its effectiveness and update toxicity information in diverse patient populations in clinical settings. INO-CD22 (NCT03898128) is a retrospective, multicenter, real-world cohort study that enrolled 73 heavily pretreated adult patients who received InO across 24 centers in Italy.² The study aimed to evaluate the real-world effectiveness, survival, and safety profile of InO, with key endpoints of CR (including CRi), EFS, OS, and Grade ≥3 AE incidence. The results of INO-CD22 were published in Cancer by Papayannidis et al.²

Key learnings 

The ORR with InO was 74.0%, including 69.8% CR and 4.1% CRi rates, with a median time to response of 27 days and a median DoR of 4.4 months.

At a median follow-up of 37.2 months, median OS was 7.9 months, and median EFS was 4.5 months. The 3- and 5-year OS rates were 21.2% and 5.3%, respectively.

Following treatment with InO, 37% of patients were able to proceed to HSCT. Clinical trial evaluation may be warranted to evaluate the efficacy of InO as a bridge to HSCT. 

VOD-SOS occurred in 10.9% of patients, with most cases occurring post-HSCT. The most common hematologic AEs were thrombocytopenia and neutropenia, while infections were the most common nonhematologic AE.

These real-world data support the effectiveness of InO beyond clinical trials, including in patients with heavily pretreated disease and prior exposure to immunotherapies or HSCT.