Cellectis Reports Third Quarter 2025 Financial Results and Provides Business Update

• Presented data underscore the potential of lasme-cel (UCART22) and eti-cel (UCART20x22) to improve outcomes in r/r B-ALL and r/r NHL:

Lasme-cel in r/r B-ALL (BALLI-01)

• ORR of 68% with lasme-cel Process 2 (n=22), 83% at RP2D (n=12) and 100% in the target Phase 2 population (n=9)
• Median OS of 14.8 months in patients who achieved MRD-negative CR/CRi
• First interim analysis for the BALLI-01 trial expected in Q4 2026

Eti-cel in r/r NHL (NATHALI-01)

• ORR of 86% and 57% CR rate (n=7)
• Development update to be presented at the ASH 2025 annual meeting
• Full Phase 1 dataset expected to be shared in 2026

 

• Servier arbitration: arbitral decision expected to be rendered on or before December 15, 2025
• Cash, cash equivalents and fixed-term deposits of $225 million as of September 30, 2025[1]provides runway into H2 2027

 

New York, NY – November 7, 2025 - Cellectis (the “Company”) (Euronext Growth: ALCLS - NASDAQ: CLLS), a clinical-stage biotechnology company using its pioneering gene editing platform to develop life-saving cell and gene therapies, today provided financial results for the third quarter 2025 ending September 30, 2025 and business updates.

“We are proud of the promising data from our core clinical product candidates. Our lasme-cel program for r/r B-ALL and eti-cel program for r/r NHL demonstrated their ability to induce deep and meaningful responses, underscoring their potential to improve outcomes in diseases with high unmet medical needs” said André Choulika, Ph.D., Chief Executive Officer at Cellectis. “We look forward to sharing an additional development update on eti-cel at the ASH 2025 Annual Meeting and to provide the first interim analysis for the pivotal Phase 2 BALLI-01 trial in Q4 2026. Together, these milestones strengthen our leadership in allogeneic CAR-T innovation and position Cellectis for a transformative year ahead."

Pipeline Highlights

UCART Clinical Programs

BALLI-01 study evaluating lasme-cel (UCART22)

• Clinical data from the Phase 1 BALLI-01 study with lasme-cel for the treatment of relapsed or refractory B-cell acute lymphoblastic leukemia (r/r B-ALL), were presented at the Cellectis’ R&D Day that took place on October 16, 2025. The presented data position lasme-cel as a potentially game-changing therapy for patients with r/r B-ALL.

In the Phase 1 of BALLI-01 study, 40 transplant ineligible third line or beyond (3L+) patients were dosed with lasme-cel: 18 patients (n=18) were dosed with product manufactured by an external CDMO (Process 1, or P1) and 22 patients (n=22) were dosed with Cellectis-manufactured product (Process 2, or P2).

Highlights include:

• • Efficacy: lasme-cel demonstrated an overall response rate (ORR) of 68% with Process 2 product (n=22), and an ORR of 83% at the recommended Phase 2 dose (RP2D; n=12) and 100% in the target Phase 2 population (n=9)
• • Safety: in Phase 1 (n=40), lasme-cel was generally well tolerated; there was one case of grade 2 immune effector cell–associated hemophagocytic syndrome (IEC-HS), which resolved.
• • Durability: among patients who achieved minimal residual disease (MRD)-negative complete remission or complete remission with incomplete hematologic recovery (CR/CRi), median overall survival was 14.8 months.
• • Depth of response in target Phase 2 population: the CR/CRi rate was 56%, with approximately 80% of these patients achieving MRD-negative status.
• • Transplant eligibility in target Phase 2 population: all patients (100%) became eligible for transplant, and 78% proceeded to transplantation.

 

• The survival curve for this study suggests a clear benefit: patients who proceeded to hematopoietic stem cell transplantation (HSCT) after lasme-cel therapy showed a trend to longer overall survival than those who did not undergo transplant.

The Phase 1 data showed that lasme-cel maintained its efficacy regardless of the number or type of prior lines of treatments, including CAR-T (60% of subjects), transplant (50% of patients), and blinatumomab (80% of subjects).

• Following successful End-of-Phase 1 meetings with the U.S Food and Drug Administration (FDA) and the European Medicines Agency (EMA), Cellectis provided a registration path for lasme-cel in r/r ALL. The first interim analysis for the Phase 2 of the BALLI-01 trial is expected in Q4 2026. Cellectis anticipates submitting a Biologics License Application (BLA) in 2028.

 

Commercial Opportunity for Lasme-cel

• As part of the R&D Day presentation, the Company discussed the potential commercial opportunity for lasme-cel in r/r B-ALL.

If approved for commercialization, Cellectis estimates that lasme-cel could achieve up to approximately $700 million in potential peak gross sales across the U.S., EU4 (France, Germany, Italy, Spain) and UK in 2035, corresponding to an estimation of about 1,100 patients treated annually. Furthermore, gross peak sales could increase to up to approximately $1.3 billion with potential label expansion to second line and first line MRD+ consolidation. These estimates highlight that lasme-cel has the potential to drive meaningful growth of the CAR-T market in B-ALL, leading to a robust peak sales potential with attractive margins stemming from the allogeneic approach.

 

American Society of Hematology (ASH) 2025 annual meeting poster presentation

• On November 3, 2025, Cellectis announced the acceptance of an abstract for lasme-cel for poster presentation at the American Society of Hematology (ASH) 2025 annual congress, that will take place on December 6-9, 2025.
• The poster highlights the correlation between alemtuzumab exposure and depth of response in the difficult-to-treat r/r ALL patients who have received lasme-cel. Additionally, the data identifies a threshold exposure level of alemtuzumab above which achieving a complete response/complete response with incomplete hematologic recovery (CR/CRi) is more likely without any increase in toxicities.

The poster presentation will occur on December 8, 2025, 6:00 PM - 8:00 PM ET, in Room OCCC - West Halls B3-B4.

NatHaLi-01 study evaluating eti-cel (UCART20x22)

• At the R&D Day, Cellectis unveiled preliminary data on eti-cel, its allogeneic CAR-T product candidate for relapsed or refractory non-Hodgkin lymphoma (r/r NHL), demonstrating an encouraging ORR of 86% and CR rate of 57% at the current dose level (n=7), with 4 out of 7 patients achieving a complete response. The preliminary high rate of complete responses underscores the potential of this innovative approach to transform outcomes for r/r NHL patients. Cellectis expects to present the full Phase 1 dataset for eti-cel, including low-dose IL-2 combination cohorts, in 2026.
• On November 3, 2025, Cellectis announced the acceptance of an abstract for poster presentation at ASH 2025.

The poster provides a development update on eti-cel for patients with r/r NHL and outlines the addition of low dose interleukin-2 (IL-2) to further deepen and extend anti-tumor activity of eti-cel in patients with r/r NHL, supported by compelling preclinical data.

The poster presentation will occur on December 7, 2025 at 6:00 PM – 8:00 PM ET, in Room OCCC – West Halls B3-B4.

Innovation

Circular single-stranded DNA (CssDNA) as a non-viral template for gene therapy

• In October 2025, Cellectis presented findings in a poster, highlighting the strong potential of circular single-stranded DNA (CssDNA) as a universal, efficient non-viral template for gene therapy, at the European Society of Gene and Cell Therapy (ESGCT) annual congress.

Over the past decade, non-viral DNA template delivery has been used with engineered nucleases to target single-stranded DNA sequences in hematopoietic stem and progenitor cells (HSPCs).

While developed for gene therapy purposes, so far this method has been restricted to gene corrections. To expand this scope, Cellectis developed an editing process using its gene editing technology and kilobase-long circular single-stranded DNA donor templates.

The data presented show that:

• CssDNA editing process achieved high gene insertion frequency in viable HSPCs.
• CssDNA-edited HSPCs show a higher propensity to engraft and maintain gene edits in a murine model than adeno-associated viruses (AAV)-edited HSPCs.

TALE base editors (TALEB) off-targets in the nuclear genome

• At ESGCT 2025, the Company presented in a poster a comprehensive study of TALE base editors (TALEB) off-targets in the nuclear genome.

TALE base editors (TALEB) are fusions of a transcription activator-like effector domain (TALE), split-DddA deaminase halves, and an uracil glycosylase inhibitor (UGI).

These recent additions to the genome editing toolbox can directly edit double strand DNA, converting a cytosine (C) to a thymine (T) through the formation of an uracil (U) intermediate without the need of DNA break. Base editing has great potential in therapeutic applications. However, being able to avoid potential off-target effects is key toward this goal.

To evaluate TALEB safety, Cellectis combined advanced bioinformatic predictions with multiple experimental approaches to investigate potential off-target effects in the nuclear genome of primary T cells.

The study found no evidence of biases towards off-site C-to-T editing at sites flanked by CTCF binding sites, a key DNA-binding protein that regulates genome organization and gene expression at genome wide level.

These results provide a strong framework for the safe development of TALEB in therapeutic cell engineering, supporting their potential for future nuclear and mitochondrial applications.

AstraZeneca – Joint Research and Collaboration Agreement

• In its presentation during the Cellectis’ R&D Day held in October, AstraZeneca highlighted the significance of its strategic investment and research collaboration with Cellectis to accelerate its cell therapy and genomic medicine ambitions. The collaboration leverages Cellectis’ gene editing expertise and manufacturing capabilities to develop up to 10 novel cell and gene therapy products for areas of high unmet medical need, including oncology, immunology and rare genetic disorders.

Servier arbitration

• With respect to the ongoing arbitration proceeding through the Centre de Médiation et d’Arbitrage de Paris, the arbitral decision is expected to be rendered on or before December 15, 2025.

Iovance

• In November 2025, Iovance reported that clinical results for IOV-4001, a PD-1 inactivated TIL cell therapy, in previously treated advanced melanoma patients are anticipated in the first quarter of 2026. Other potential indications for IOV-4001 are also in development.