Cellectis SEC Filings

Cellectis S.A. filed a 6-K reporting new clinical data from the BALLI-01 Phase 1 study of lasme-cel (UCART22) in transplant-ineligible, relapsed/refractory B-ALL (3L+). The company states lasme-cel was generally well-tolerated with manageable cytokine release syndrome and neurotoxicity, and outlined a path to a pivotal Phase 2 study.

Activity signals were strongest with Cellectis-manufactured product (Process 2). In the P2 cohort, the overall response rate was 68% with 83% MRD-negativity among responders. Among 13 patients relapsed after prior CD22 therapy (inotuzumab), 31% achieved CR/CRi with MRD-negativity and all proceeded to HSCT. In a heavily pretreated subgroup that had three prior targeted therapies (n=22), 36% achieved MRD-negative CR/CRi. At the recommended Phase 2 dose (DL3; n=12), 7 had prior inotuzumab and 43% achieved MRD-negative CR/CRi, with all undergoing HSCT. The company plans to enroll the first patient in the pivotal Phase 2 in Q4 2025 and anticipates submitting a BLA in 2028.

Cellectis S.A. filed an amended Form 6-K/A to update its prior submission solely to provide the company’s unaudited interim financial statements in iXBRL format. The amendment covers the three- and six-month periods ended June 30, 2025 and is made in accordance with Rule 405 of Regulation S‑T and the Form 6‑K instructions.

The company states the amendment does not amend, revise, update, or restate other information in the original report. The materials are deemed incorporated by reference into Cellectis’s registration statements on Form F‑3 (Nos. 333‑284302, 333‑288491) and Form S‑8 (including Nos. 333‑204205, 333‑214884, 333‑222482, 333‑227717, 333‑258514, 333‑267760, 333‑273777, 333‑284301).