UCART22 Advances to Phase 2 Following Encouraging Phase 1 Results in R/R B-Cell ALL: Nitin Jain, MD

In part 1 of his interview with The American Journal of Managed Care^® at the European Hematology Association 2026 Congress, Nitin Jain, MD, principal investigator of the phase 1 BALLI-01 trial (NCT04150497), explained that data demonstrated promising activity for UCART22, an allogeneic, off-the-shelf CD22-directed chimeric antigen receptor (CAR) T-cell therapy, in heavily pretreated relapsed/refractory B-cell acute lymphoblastic leukemia (ALL).

A switch to in-house manufacturing improved complete remission rates to about 36%, supporting a recommended phase 2 dose of 5×10⁶ cells/kg.

Building on this, Jain turned to the safety profile, noting that the study saw very limited grade 3 or higher cytokine release syndrome (CRS) and immune effector cell–associated neurotoxicity syndrome (ICANS), with no patients experiencing grade 4 or 5 events of either. Therefore, he described the therapy as "quite safe" with respect to CRS and ICANS.

That favorable profile came with a tradeoff of increased infectious complications, particularly cytomegalovirus (CMV) viremia and human herpesvirus 6 viremia. Jain attributed this in part to immunosuppression from the underlying disease itself but also to the use of alemtuzumab in the conditioning regimen, compounded by the refractory nature of the disease.

With 45 patients now enrolled across the completed phase 1 study, Jain said the encouraging findings supported the program's advancement into phase 2. He highlighted plans to implement infection-prevention strategies in the pivotal phase 2 study, including growth factor support, intravenous immunoglobulin, and potentially medications for CMV prophylaxis.

If the phase 2 trial is positive and UCART22 receives FDA approval, Jain emphasized that it could address a notable unmet need in relapsed/refractory B-cell ALL, particularly among patients who have failed prior CD19 CAR T-cell therapy or become CD19-negative after blinatumomab.

He also pointed to patients who cannot tolerate the wait for leukapheresis, whether because of low blood cell counts or rapidly progressing disease requiring urgent CAR T-cell administration, as a potentially eligible population.

"Maybe that's the group of patients who should consider it," Jain concluded.