Cellectis Announces Strategic Transformation To In Vivo Gene Editing Company
Cellectis is refocusing resources on two in vivo gene editing programs while exiting lasme-cel and eti-cel to extend its cash runway into H2 2028.
Rhea-AI Summary
Cellectis (CLLS) approved a strategic transformation on September 11, 2026 to focus on becoming an in vivo gene editing company targeting chronic metabolic diseases.
The company will prioritize two lead programs: .HEAL-101, a base-editing therapy targeting APOC3 for severe hypertriglyceridemia, and .HEAL-201, an epigenetic editing therapy targeting PCSK9 for severe hypercholesterolemia. Both are delivered via lipid nanoparticles and have shown high on-target activity and substantial APOC3 or PCSK9 reductions, as well as triglyceride lowering in humanized murine models. Phase 1 investigator-initiated trials in China are planned, with preliminary data expected in H2 2027 for .HEAL-101 and H1 2028 for .HEAL-201.
Cellectis will exit internal development of lasme-cel and eti-cel, seek partners for these assets, support existing cell therapy partnerships, and realign operations to extend its cash runway into H2 2028. Trading on Euronext Growth Paris will be temporarily halted on September 14, 2026, and management will host English and French webcasts the same day.
Positive
- .HEAL-101 preclinical data: ~55% APOC3 base editing and ~60% mean APOC3 reduction in a liver humanized murine model, with triglycerides reduced ~45% from baseline.
- .HEAL-101 hypertriglyceridemic model: ~70% mean APOC3 reduction and ~76% mean triglyceride decrease from pre-treatment baseline.
- .HEAL-201 preclinical data: >90% on-site epigenome editing in hepatic cell line and >90% mean PCSK9 reduction in a liver humanized murine model.
- Target populations: each of .HEAL-101 and .HEAL-201 addresses an estimated 1–2 million high-risk patients across the United States and Europe.
- Cash runway: operational realignment is designed to extend Cellectis’ cash runway into H2 2028.
- Pipeline focus: exit from lasme-cel and eti-cel frees resources to accelerate in vivo gene editing assets while maintaining partnered cell therapy programs.
Negative
- Lasme-cel and eti-cel: company will exit internal development of both product candidates, reducing direct exposure to their potential future revenues.
- Competitive landscape: advances in frontline regimens and emergence of bispecific antibodies and in vivo CAR-T have reduced the addressable B-ALL and NHL patient population for lasme-cel and eti-cel.
- Development challenges: for lasme-cel and eti-cel, slower enrollment and a potentially longer, more costly development pathway led to a delayed timeline to potential registration.
- Clinical timelines: first preliminary human data are expected only in H2 2027 (.HEAL-101) and H1 2028 (.HEAL-201), leaving several years before early clinical readouts.
News Explained
The organizational realignment remains subject to the relevant works-council consultation and applicable U.S. and French labor-law requirements, while the planned cash-runway extension into H2 2028 excludes any impact from potential future partnering of lasme-cel or eti-cel.
Key Figures
- HEAL-101 base editing
- >70%
- Mean on-site base editing activity in a hepatic cell line
- HEAL-101 triglyceride reduction
- ~45%; up to 68%
- Mean decrease in circulating triglycerides in a liver-humanized murine model
- HEAL-201 epigenome editing
- >90%
- Mean on-site activity in a hepatic cell line
- HEAL-201 PCSK9 reduction
- >90%
- Mean decrease in plasmatic PCSK9 in a liver-humanized murine model
- HEAL-101 Phase 1 data
- H2 2027
- Preliminary data planned from an investigator-initiated trial in China
- HEAL-201 Phase 1 data
- H1 2028
- Preliminary data planned from an investigator-initiated trial in China
- Cash runway
- H2 2028
- Targeted runway after operational realignment, excluding potential partnering impact
Historical Context
-
Reported lasme-cel and eti-cel clinical results and cash runway into Q4 2027
24h Move is the share-price change in the day after each event; other market factors may also have contributed.
Key Terms
base editing technical
epigenetic editing technical
lipid nanoparticles technical
alanine aminotransferase medical
AI-generated analysis. How Rhea-AI works. Not financial advice.
- Cellectis to advance two lead in vivo programs .HEAL-101 and .HEAL-201 in severe dyslipidemias with preliminary Phase 1 data planned in H2 2027 and H1 2028, respectively
- Transformation supported by continuing existing cell therapy partnerships while exiting lasme-cel and eti-cel development
- Realignment of the operating model targeting Cellectis cash runway extension into H2 2028
- Conference call and webcast on September 14: English at 8 a.m. ET, French at 9 a.m. ET
NEW YORK, Sept. 14, 2026 (GLOBE NEWSWIRE) -- Cellectis (the “Company”) (Euronext Growth: ALCLS – NASDAQ: CLLS), a pioneer in gene editing, announced that on September 11, 2026, the board of directors approved a strategic transformation to become an in vivo gene editing company focused on developing long-lasting treatments for chronic diseases.
A differentiated in vivo Gene Editing pipeline
The Company’s strategic transformation builds on the achievement of promising preclinical proof-of-concept for its lead candidate programs, .HEAL-101 and .HEAL-201. .HEAL-101 is an in vivo base editing product candidate targeting APOC3 for severe hypertriglyceridemia and .HEAL-201 is an in vivo epigenetic editing product candidate targeting PCSK9 for severe hypercholesterolemia.
.HEAL-101
- Severe hypertriglyceridemia (sHTG) remains a significant unmet medical need, with affected patients facing a high risk of acute pancreatitis, an increased burden of cardiovascular disease, and limited treatment options. .HEAL-101 is being developed for patients with high-risk sHTG, including those with triglyceride levels ≥880 mg/dL or ≥500 mg/dL with a history of acute pancreatitis, representing an estimated target population of approximately 1 to 2 million patients across the United States and Europe.
- .HEAL-101 targets the human APOC3 gene, a well-validated target for sHTG, via a TALE-base editor specific to the APOC3 gene (“APOC3 TALEB”) formulated in Lipid Nanoparticles (LNP).
- The APOC3 TALEB displayed high on-site base editing activity when transfected as mRNA in a hepatic cell line (mean base editing >
70% ) and base editing translated into a deep and significant reduction of APOC3 protein secretion (mean reduction >70% ). APOC3 TALEB displayed a highly specific base editing profile using an unbiased, genome wide off-site identification method. - Intravenous injection of .HEAL-101 in a liver humanized normolipidemic murine model successfully edited human APOC3 (mean on-site base editing ~
55% ) and decreased plasmatic APOC3 levels (mean decrease ~60% ; up to70% ), associated with a decrease of circulating triglycerides (mean decrease ~45% ; up to68% with respect to pre-treatment baseline). It did not significantly increase the level of liver ALT (alanine aminotransferase) compared to untreated control. - Intravenous injection of .HEAL-101 in a hypertriglyceridemic humanized APOC3 transgenic murine model significantly decreased plasmatic APOC3 levels (mean decrease ~
70% ) and triglyceride levels (means decrease ~76% ) compared to pre-treatment baseline, demonstrating the efficacy of .HEAL-101 in a relevant disease model. - The Company plans to initiate a Phase 1 investigator-initiated trial (IIT) in China and share the preliminary clinical data from this program in H2 2027.
.HEAL-201
- Severe hypercholesterolemia remains a major driver of atherosclerotic cardiovascular disease, with many high-risk patients continuing to experience elevated low-density lipoprotein cholesterol (LDL-C) levels despite currently available therapies. This burden is particularly significant among younger high-risk patients with severe genetic forms of hypercholesterolemia and those with premature cardiovascular disease, representing an estimated 1 to 2 million patients across the United States and Europe. .HEAL-201 is being developed to address the needs of these high-risk patient populations.
- .HEAL-201 targets the human PCSK9 gene, a well-validated target for severe hypercholesterolemia, via a TALE-epigenetic modulator specific to the promoter of PCSK9 (“PCSK9 TALEM”) formulated in LNP to treat severe hypercholesterolemia.
- The PCSK9 TALEM displayed a high on-site epigenome editing activity when transfected as mRNA in a hepatic cell line (mean base editing >
90% ). Epigenome editing translates into a stable, deep and significant reduction of PCSK9 transcript levels and PCSK9 secretion without evidence for off-site gene and protein modulation. - Intravenous injection of PCSK9 TALEM mRNA LNPs in a liver humanized murine model, successfully decreased plasmatic levels of PCSK9 (mean >
90% ). - The Company plans to initiate a Phase 1 IIT in China and share the preliminary clinical data from this program in H1 2028.
Cellectis’ differentiated gene editing platform
Cellectis’ core competencies encompass nuclease editing, base editing, epigenetic editing and transcriptional regulation. While most gene editing companies focus on a single editing modality, Cellectis’ broad gene editing toolbox built over a quarter century allows for a combination of therapeutic targets utilizing several gene editing modalities.
André Choulika, Ph.D., Co-Founder and Chief Executive Officer of Cellectis, commented: “Gene surgery has the potential to transform the treatment of high-risk metabolic diseases by delivering long-lasting benefits through a single IV injection. Our decision to focus Cellectis on in vivo Gene Editing reflects the progress we have made with .HEAL-101 and .HEAL-201 and our assessment of where our gene editing capabilities can be most effectively deployed. These programs use two distinct approaches from our platform, base editing of APOC3 and epigenetic editing of PCSK9, which are designed to provide highly specific genomic or epigenomic modulation with the goal of avoiding double-strand DNA breaks. They have generated encouraging preclinical proof-of-concept and our priority is now to advance both programs toward the clinic and generate first-in-human data.”
Lasme-cel and eti-cel
In 2026, despite our continued conviction in the promise of allogeneic CAR T-cell therapies and strong physician interest in lasme-cel and eti-cel, the commercial and clinical landscape for B-ALL and NHL changed materially. Continued and recently accelerated advances in frontline treatment regimens have lowered relapse rates, reducing the number of patients progressing to later lines of therapy. Concurrently, the rapid emergence of bispecific antibodies and in vivo CAR-T approaches has intensified competition in second and third-line treatment settings. Together, these dynamics have reduced the addressable patient population for lasme-cel and eti-cel, resulting in slower enrollment, a potentially longer and more costly development pathway, and therefore a delayed timeline to potential registration. We believe these trends are likely to continue and further constrain the commercial opportunity for both product candidates.
After a thorough assessment of the evolving therapeutic landscape and strategic review, the Company has determined that the most effective use of its financial and operational resources is to focus on and accelerate the advancement of its most promising in vivo gene editing assets. Cellectis will therefore exit the development of lasme-cel and eti-cel, while seeking strategic partnering opportunities to maximize their value.
Operational realignment to the new strategic direction
The Company will realign its organization1 and resources to focus on its in vivo Gene Editing pipeline and support its existing cell therapy partnerships with AstraZeneca, Allogene, Servier and Iovance. These combined actions are being designed to extend the Company's cash runway into H2 20282, providing financial flexibility to advance Cellectis’ in vivo Gene Editing pipeline through key development milestones.
Conference Call
The Cellectis management team will host a conference call and webcast on September 14, 2026:
- English-language at 8:00 a.m. ET.
Webcast link:
https://viavid.webcasts.com/starthere.jsp?ei=1775356&tp_key=7d1d05c480
Phone number: +1-800-717-1738 or +1-646-307-1865
- French-language at 9:00 a.m. ET.
Webcast link:
https://viavid.webcasts.com/starthere.jsp?ei=1775361&tp_key=2968b7b0ca
Phone number: +1-800-717-1738 or +1-646-307-1865
A replay will be available on the Company’s website, under the Investors section “Events & Webcasts” following the event.
In this context, the trading of Cellectis’ ordinary shares on the regulated market of Euronext Growth market of Euronext Paris will be temporarily halted, at the Company’s request, on Monday September 14, 2026 from the opening of the market at 9:00 a.m. CET until the opening of the Nasdaq Global Market at 3:30 p.m. CET.
About Cellectis
Cellectis is a genome engineering company developing genetic medicines for diseases that today demand a lifetime of treatment. Leveraging decades of expertise in programmable DNA-binding proteins, the Company has built a differentiated genome engineering platform spanning gene editing, base editing, epigenetic editing and transcriptional regulation. By delivering the genomic intervention each disease requires, Cellectis is advancing a new generation of genetic medicines designed to move beyond disease management and toward lasting therapeutic impact.
Cellectis’ headquarters are in Paris, France, with locations in New York, and Raleigh (NC). Cellectis is listed on the Nasdaq Global Market (ticker: CLLS) and on Euronext Growth (ticker: ALCLS). To find out more, visit www.cellectis.com and follow Cellectis on LinkedIn and X.
Cautionary Statement
This press release contains “forward-looking” statements within the meaning of applicable securities laws, including the Private Securities Litigation Reform Act of 1995. Forward-looking statements may be identified by words such as “believe,” “can,” “design”, “encouraging,” “expect”, “into”, “moving forward”, “plan”, “potential”, “promising,” “target”, “will”, or similar expressions and/or the negative of these. These forward-looking statements are based on our management’s current expectations and assumptions and on information currently available to management. Forward-looking statements in this press release include statements regarding the Company’s transition into an in vivo gene editing company, the ability of the Company to initiate a IIT in China, the planned timing for the release of first-in-human data for the Company’s lead programs, the potential for success of the Company’s in vivo gene editing programs, the ability to continue advancement of cell therapy activities through existing partnerships, the ability to partner lasme-cel and/or eti-cel, the anticipated impact, including potential cost savings, of the Company’s decision to cease the development of lasme-cel and eti-cel and to initiate a restructuring plan, the contemplated implementation of headcount reductions and other cost-savings initiatives and their planned timeframe, and the targeted extension of the Company’s cash runway. Actual results, performance or events may differ materially from those projected in any forward-looking statement. Many important factors may adversely affect such forward-looking statements and cause actual results to differ from those in any forward-looking statement, including, without limitation, uncertainties inherent in the initiation and completion of preclinical and clinical studies; the availability and timing of results from studies, once initiated; the acceptance by global regulatory agencies of data generated from IIT in China; the potential that pre-clinical animal model data may not translate into further preclinical development or clinical setting; promising preclinical data not yielding positive further preclinical data or clinical results; the performance of the IIT in China, changes in the competitive landscape for in vivo gene editing products; expectations for regulatory approvals to conduct clinical trials; availability of funding sufficient for the Company’s foreseeable and unforeseeable operating expenses and capital expenditure requirements; and impacts of the Company’s headcount reductions and other cost savings initiatives, which may include operational and strategic challenges. With respect to our cash runway, our operating plans, including product development plans, may change as a result of various factors, including factors currently unknown to us. Furthermore, many other important factors, including those described in our Annual Report on Form 20-F as amended and in our annual financial report (including the management report) for the year ended December 31, 2025 and subsequent filings Cellectis makes with the Securities Exchange Commission from time to time, which are available on the SEC’s website at www.sec.gov, as well as other known and unknown risks and uncertainties may adversely affect such forward-looking statements and cause our actual results, performance or achievements to be materially different from those expressed or implied by the forward-looking statements. Except as required by law, we assume no obligation to update these forward-looking statements publicly, or to update the reasons why actual results could differ materially from those anticipated in the forward-looking statements, even if new information becomes available in the future.
For further information on Cellectis, please contact:
Media contacts:
Pascalyne Wilson, Director, Communications, + 33 (0)7 76 99 14 33, media@cellectis.com
Patricia Sosa Navarro, Chief of Staff to the CEO, +33 (0)7 76 77 46 93
Investor Relations contact:
Arthur Stril, Chief Financial Officer & Chief Business Officer, investors@cellectis.com
_____________________________
1 Subject to the completion of the relevant works council consultation process and applicable US & French labor law requirements.
2 Excluding any impact from the potential future partnering of lasme-cel and/or eti-cel.
Attachment
FAQ
AI-generated questions and answers. How Rhea-AI works. Not financial advice.
What are the key technical features of the .HEAL-101 program?
.HEAL-101 is an in vivo base editing product candidate that targets the human APOC3 gene using a TALE-base editor (APOC3 TALEB) formulated in lipid nanoparticles. In a hepatic cell line, APOC3 TALEB showed mean on-site base editing above 70% and over 70% mean reduction in APOC3 protein secretion, with a highly specific off-site editing profile. In liver humanized normolipidemic murine models, intravenous .HEAL-101 achieved roughly 55% APOC3 editing, about 60% mean APOC3 reduction (up to 70%), and about 45% mean triglyceride reduction (up to 68%) without a significant ALT increase compared to untreated controls.
What patient population is Cellectis targeting with .HEAL-101?
.HEAL-101 is being developed for patients with high-risk severe hypertriglyceridemia, including those with triglyceride levels ≥880 mg/dL or ≥500 mg/dL with a history of acute pancreatitis. This group represents an estimated target population of approximately 1 to 2 million patients across the United States and Europe.
How is .HEAL-201 designed and what preclinical activity has been observed?
.HEAL-201 targets the human PCSK9 gene via a TALE-epigenetic modulator (PCSK9 TALEM) specific to the PCSK9 promoter, formulated in lipid nanoparticles. In a hepatic cell line, PCSK9 TALEM achieved mean on-site epigenome editing above 90%, leading to a stable, deep and significant reduction of PCSK9 transcript and protein secretion without evidence of off-site gene or protein modulation. Intravenous administration of PCSK9 TALEM mRNA LNPs in a liver humanized murine model produced a mean decrease in plasmatic PCSK9 levels greater than 90%.
Which patients is .HEAL-201 intended to treat?
.HEAL-201 is being developed for high-risk patients with severe hypercholesterolemia, including younger patients with severe genetic forms and those with premature cardiovascular disease whose LDL-C remains elevated despite current therapies. This group is estimated at 1 to 2 million patients across the United States and Europe.
What future clinical milestones has Cellectis outlined for its in vivo programs?
Cellectis plans to initiate Phase 1 investigator-initiated trials in China for both programs. Preliminary clinical data for .HEAL-101 are planned for H2 2027, and preliminary clinical data for .HEAL-201 are planned for H1 2028.
How will Cellectis handle lasme-cel and eti-cel after exiting their development?
Cellectis will exit the development of lasme-cel and eti-cel but plans to seek strategic partnering opportunities to maximize their value. At the same time, the company will continue to support its existing cell therapy partnerships with AstraZeneca, Allogene, Servier and Iovance.
What are the details of the September 14, 2026 conference calls and trading halt?
On September 14, 2026, Cellectis will host an English-language conference call at 8:00 a.m. ET and a French-language call at 9:00 a.m. ET. Webcasts are available via the provided Viavid links, and investors can dial +1-800-717-1738 or +1-646-307-1865. A replay will be posted under “Events & Webcasts” on the company’s website. At the company’s request, trading of its ordinary shares on the Euronext Growth market of Euronext Paris will be temporarily halted on September 14, 2026, from the 9:00 a.m. CET market opening until the Nasdaq Global Market opens at 3:30 p.m. CET.