Cellectis (ALCLS) EHA 2026 Congress presentation summary

Background and unmet need

• Third-line and beyond B-ALL is highly aggressive, with limited treatment options and frequent resistance mutations.

• CD22 remains a viable target in relapsed/refractory B-ALL, especially after CD19-directed therapies.

UCART22 product and mechanism

• UCART22 is an allogeneic CAR T-cell therapy targeting CD22, engineered to avoid GvHD and resist alemtuzumab-based lymphodepletion.

• TALEN® technology disrupts TCR and CD52, enhancing safety and persistence.

Study design and patient characteristics

• BALLI-01 Phase 1 trial enrolled 45 heavily pretreated patients (median 4 prior therapies), many with prior blinatumomab, inotuzumab, and CD19 CAR T exposure.

• Two manufacturing processes and multiple dose levels were tested, with lymphodepletion regimens including fludarabine, cyclophosphamide, and alemtuzumab.