Cellectis Reports Third Quarter 2026 Financial Results and Provides a Business Update

  

• .HEAL-101 achieved up to 70% in vivo APOC3 editing with liver-restricted activity and confirmed 76% triglyceride reduction in murine models (ESGCT 2026); Phase 1 IIT in China on track for initiation, with preliminary clinical data expected in H2 2027 

• .HEAL-201 achieved >90% reduction in plasma PCSK9 in a humanized liver mouse model; preliminary clinical data expected in H1 2028 

• Cash, cash equivalents and fixed-term deposits of $149 million as of September 30, 2026¹; realignment of the operating model targeting cash runway into H2 2028 

• Conference call scheduled for November 13 at 8 a.m. ET / 2 p.m. CET 

New York, November 12, 2026 – Cellectis (Euronext Growth: ALCLS – Nasdaq: CLLS), a genome engineering company developing genetic medicines for diseases that today demand a lifetime of treatment, today reported financial results for the third quarter 2026 ended September 30, 2026, and provided a business update.  

« Since September, our teams have been fully committed to our new in vivo gene editing chapter, and the expanded preclinical data we presented at ESGCT for .HEAL-101 reinforce our conviction » said André Choulika, Ph.D., Co-founder and Chief Executive Officer of Cellectis. « After a single administration, .HEAL-101 edited the human APOC3 gene at rates of up to 70% in a humanized liver model, with editing restricted to the liver, and consistently reduced triglycerides by 76% in a disease model. These results support the continued development of .HEAL-101, and the initiation of an investigator-initiated trial in China is on track with the goal of delivering first clinical data for .HEAL-101 in the second half of 2027. » 

In Vivo Gene Editing Pipeline 

.HEAL-101 - In vivo base editing of APOC3 for severe hypertriglyceridemia (sHTG) 

Expanded preclinical data presented in a poster at the European Society of Gene and Cell Therapy (ESGCT) 2026 Congress support the potential of .HEAL-101 to achieve efficient and specific APOC3 editing after a single administration: 

• In vitro: ~90% mean APOC3 editing in a human hepatic cell line, with no DNA double-strand breaks at the target site. 

• In vivo: in a normolipidemic humanized liver mouse model, a single intravenous dose of .HEAL-101 (LNP-mRNA) edited human APOC3 at a mean rate of ~65%, reaching up to 70%.  

• Disease model: in a hypertriglyceridemic human APOC3 transgenic mouse model, .HEAL-101 reduced APOC3 by 67% ± 12% and triglycerides by 75% ± 11% (mean ± standard deviation). 

• Liver-restricted activity: editing was detected in the liver, with no significant activity in the other tissues analyzed. 

The initiation of the Phase 1 investigator-initiated trial (IIT) in China is on track, with preliminary clinical data expected in the second half of 2027. 

.HEAL-201 - In vivo epigenetic editing of PCSK9 for severe hypercholesterolemia (sHC) 

Preclinical data support the potential of .HEAL-201 to durably silence PCSK9 without altering the DNA sequence: 

• In vitro: in a human hepatic cell line, PCSK9 TALE epigenetic modulator (TALEM) mRNA achieved high on-site epigenetic editing (mean >90%), resulting in a deep and stable reduction of PCSK9 transcript levels and PCSK9 secretion, with no off-site changes in gene or protein expression detected. 

• In vivo: intravenous injection of PCSK9 TALEM mRNA LNPs reduced mean plasma PCSK9 levels by more than 90% in a liver-humanized mouse model. 

Cellectis plans to initiate a Phase 1 IIT in China, with preliminary clinical data expected in the first half of 2028. 

Strategic Transformation Update 

Cellectis continues to execute the strategic transformation announced on September 14, 2026, to become an in vivo gene editing company. As part of this transformation, Cellectis’ discontinuation of the lasme-cel and eti-cel clinical programs is proceeding as planned: enrollment has stopped, site close-out activities are underway, and treated patients will continue to be monitored in accordance with protocol-specified follow-up requirements.  

The realignment of the Company’s operating model is ongoing. In connection with this initiative, the Company currently expects its global headcount to be reduced by up to 70% from its pre-transition level over the course of 2026 and 2027, subject to the completion of the applicable French works council consultation process and the compliance with applicable French and U.S. labor law requirements. 

Partnerships 

AstraZeneca – Joint Research and Collaboration Agreement 

Activities are continuing under the Joint Research and Collaboration Agreement with AstraZeneca, which 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 (through its sublicensee Allogene) – Anti-CD19 CAR-T 

In November 2026, Allogene announced that cema-cel is being evaluated in ALPHA3, the first pivotal, randomized trial in LBCL designed to assess whether minimal residual disease (MRD)-guided treatment following first-line therapy can delay or prevent clinical relapse, and that it continues to anticipate its next clinical update in mid-2027, with trial enrollment expected to be completed by year-end 2027. 

Cema-cel is a product candidate licensed to Servier under the License, Development and Commercialization Agreement signed by and between les Laboratoires Servier and Institut de Recherches Internationales Servier (“Servier”) and Cellectis (the “Servier Agreement”) and sublicensed by Servier to Allogene in certain territories. 

Iovance 

In November 2026, Iovance announced that a Phase 1/2 trial investigating IOV-4001, a PD-1 inactivated TIL (tumor infiltrating lymphocyte) therapy, is enrolling patients with previously treated metastatic melanoma and mNSCLC (non-squamous metastatic non-small-cell lung cancer). IOV-4001 is engineered to resist inhibitory signals and enhance the ability of TIL therapies to fight and kill cancer in the TME (tumor microenvironment).  

¹ As of September 30, 2026, cash, cash equivalents and fixed-term deposits include restricted cash of $2.3 million, classified as current and non-current financial assets, and fixed-term deposits of $118.3 million, classified as current financial assets.