Cellectis: 100% Response Rate for Lasmé-cel at EHA 2026, but with Only 7 Patients
Cellectis presented on Thursday the final Phase 1 results for lasmé-cel and preliminary data for éti-cel at the EHA 2026 congress. Both allogeneic CAR-T candidates showed strong response rates in heavily pre-treated populations, but the small size of the trials and the preliminary nature of the data raise critical questions before potential regulatory approvals.
100% Response Rate for Lasmé-cel, 88% for Éti-cel in Optimal Cohort
Lasmé-cel achieved a 100% overall response rate (ORR) (7 patients) in the target population of Phase 2 of the BALLI-01 trial, with a complete or near-complete remission rate (CR/CRi) of 57% (4 patients). The trial treated a total of 45 patients in third-line treatment or beyond, among which 15 received the recommended Phase 2 dose and 7 belonged to the Phase 2 target population.
The NATHALI-01 trial evaluating éti-cel recorded an ORR of 88% and a complete remission rate (CR) of 63% in the optimal dose cohort, among 14 patients with relapsed or refractory non-Hodgkin lymphoma. These rates came from a heavily pre-treated population: 93% of the patients in NATHALI-01 had previously received CD19-targeting CAR-T therapy.
Acceptable Tolerance Profile but Validation Required in Later Phases
Lasmé-cel demonstrated a controlled safety profile. The most common serious adverse effects were grade 3 or higher cytokine release syndrome (CRS) in 4% of patients, grade 3 or higher immune effector cell-associated neurotoxicity syndrome (ICANS) also in 4%, and grade 3 or higher macrophage activation syndrome (IEC-HS) in 2% of cases. All these cases were resolved.
However, these results come from very small cohorts. The BALLI-01 trial only treated 7 patients in the Phase 2 target population, while NATHALI-01 had 14. The data from éti-cel are explicitly described as preliminary by the press release. Nitin Jain, principal investigator of BALLI-01, emphasizes that these patients "have very few therapeutic options" and that "achieving deep remissions in these patients and subsequently enabling them to undergo transplantation is encouraging," but progression towards approval relies on confirming these data in later phases.
Pivotal Phase 2 Recruitment Open, First Interim Analysis Expected by End of 2026
The pivotal Phase 2 BALLI-01 trial is open for recruitment of eligible patients. A first interim analysis is expected in the fourth quarter of 2026. Meanwhile, NATHALI-01 continues to recruit, and the full clinical data from Phase 1 is also expected in the fourth quarter of 2026.
This schedule is part of a context where the success of the pivotal Phase 2 of BALLI-01 remains a critical step to validate Cellectis' clinical strategy.
