ASH 2025: Cellectis Presents Development Plan to Further Enhance High Response Rate Observed for Eti-cel in r/r NHL
Rhea-AI Summary
Cellectis (NASDAQ:CLLS) presented updated Phase 1 NATHALI-01 data for eti-cel, an allogeneic dual CD20/CD22 CAR-T for relapsed/refractory non-Hodgkin lymphoma (r/r NHL).
At the current dose level, eti-cel showed an 88% overall response rate (ORR) and 63% complete response (CR) in n=8 patients. In vivo data suggested that low-dose interleukin-2 (IL-2) support may enhance CAR-T expansion and persistence without increasing toxicity. Cellectis will begin enrollment in an IL-2 support cohort in Q1 2026 and expects to present the full Phase 1 dataset in 2026. The poster will be posted on the company website.
Positive
- ORR 88% at current dose (n=8)
- CR 63% at current dose (n=8)
- IL-2 in vivo data shows enhanced CAR-T expansion
- IL-2 support cohort recruitment starts Q1 2026
Negative
- Very small clinical sample size: n=8
- Data described as preliminary; full dataset pending 2026
- IL-2 support evidence currently from in vivo models, not clinical
Key Figures
Market Reality Check
Peers on Argus
Biotech peers showed mixed moves with declines in ENGN (-2.42%) and FDMT (-5.31%) but gains in GLUE (+1.04%) and KRRO (+2.93%), pointing to stock-specific rather than sector-wide drivers for CLLS.
Historical Context
| Date | Event | Sentiment | Move | Catalyst |
|---|---|---|---|---|
| Dec 03 | Share capital update | Neutral | +3.6% | Routine disclosure of total shares and voting rights for November 2025. |
| Nov 19 | Gene-editing publication | Positive | +7.1% | Nature Communications paper on non-viral CssDNA gene insertion in HSPCs. |
| Nov 07 | Q3 2025 earnings | Positive | +11.3% | Q3 2025 results with strong lasme‑cel and eti‑cel data and cash runway. |
| Nov 07 | Share capital update | Neutral | +1.9% | Monthly share and voting rights report for October 2025. |
| Nov 03 | ASH 2025 preview | Positive | -5.2% | Announcement of ASH 2025 posters and preliminary eti‑cel/lasme‑cel data. |
Positive data-heavy updates and earnings have often coincided with upward moves, while at least one prior conference-focused eti-cel update saw a negative reaction, showing occasional divergence on conference news.
In the last months, Cellectis has highlighted progress across its gene-editing and CAR‑T pipeline. A Q3 2025 update reported strong lasme‑cel and eti‑cel response rates and cash of $225M, which coincided with a +11.29% move. A Nature Communications paper on CssDNA gene insertion preceded a +7.06% reaction. Routine share-capital reports saw modest gains. An earlier ASH 2025 eti‑cel development update on Nov 3 led to a -5.22% move. Today’s ASH 2025 data further refine eti‑cel’s profile with higher ORR/CR at the current dose.
Regulatory & Risk Context
Cellectis has an effective Form F-3 shelf filed on 2025-07-02, expiring on 2028-07-02, with 0 recorded usages to date. This structure provides flexibility for future registered securities offerings, though no specific amounts or takedowns are disclosed here.
Market Pulse Summary
This announcement provides updated Phase 1 data for eti‑cel in r/r NHL, showing an 88% overall response rate and 63% complete response rate in 8 patients at the current dose, and outlining a development plan that adds low‑dose IL‑2 support with enrollment starting in Q1 2026. Recent history includes positive stock reactions to data and earnings, but also a selloff after an earlier ASH preview. Investors may watch for the full Phase 1 dataset in 2026 and how it compares with prior CAR‑T updates.
Key Terms
orr medical
car-t medical
allogeneic medical
AI-generated analysis. Not financial advice.
- Eti-cel showed an
88% ORR and63% CR (n=8) at current dose level in r/r NHL after ≥2 prior lines of therapy - In vivo data suggest IL-2 may further enhance response rates and optimize eti-cel expansion and persistence
- IL-2 cohort enrollment to start in Q1 2026; full Phase 1 dataset expected in 2026
NEW YORK, Dec. 08, 2025 (GLOBE NEWSWIRE) -- 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, announced the presentation of encouraging updated data of patients treated in the Phase 1 NATHALI-01 clinical trial with eti-cel, at the 67th Annual Meeting of the American Society of Hematology (ASH) in Orlando, FL.
Eti-cel product candidate is the first allogeneic dual CAR-T targeting CD20 and CD22 simultaneously, being developed in Phase 1 of the NATHALI-01 clinical trial, for patients with relapsed/refractory non-Hodgkin lymphoma (r/r NHL), following at least two lines of therapy.
Cellectis presented preliminary results on eti-cel, which demonstrated an encouraging overall response rate (ORR) of
Additional in vivo data presented suggest that exogenous low dose Interleukin-2 (IL-2) support can significantly enhance the expansion and persistence of CAR-T cells to boost CAR-T efficacy without exacerbating toxicity.
“Cellectis believes that, with the addition of low dose IL-2 support, it is possible to further deepen the already high response rates seen with eti-cel in these patients who have relapsed following multiple prior lines of therapy including, in most cases, a CD19 CAR-T” said Adrian Kilcoyne, MD, MPH, MBA, Chief Medical Officer at Cellectis. “The trial will now investigate any potential impact of low dose IL-2 support in these difficult to treat patients. We look forward to sharing the full Phase 1 dataset expected in 2026.”
Next Steps
Overall, these preliminary data underscore the potential of this innovative approach to transform outcomes for r/r NHL patients. The Company will now investigate the potential impact of low dose IL-2 support and will start recruitment of patients in the IL-2 support cohort in Q1 2026. Cellectis expects to present the full Phase 1 dataset in 2026.
The poster presentation will be available on Cellectis’ website.
About Cellectis
Cellectis is a clinical-stage biotechnology company using its pioneering gene-editing platform to develop life-saving cell and gene therapies. The company utilizes an allogeneic approach for CAR T immunotherapies in oncology, pioneering the concept of off-the-shelf and ready-to-use gene-edited CAR T-cells to treat cancer patients, and a platform to develop gene therapies in other therapeutic indications. With its in-house manufacturing capabilities, Cellectis is one of the few end-to-end gene editing companies that controls the cell and gene therapy value chain from start to finish.
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 “can,” or “potential,” or the negative of these and similar expressions. These forward-looking statements, which are based on our management’s current expectations and assumptions on information currently available to management, include statements regarding the advancement, timing and progress of clinical trials (including with respect to patient enrollment and follow-up), the timing of our presentation of data and submission of regulatory filings, the sufficiency of cash to fund operations, the potential benefit of our product candidates and technologies, and the financial position of Cellectis. These forward-looking statements are made in light of information currently available to us and are subject to significant risks and uncertainties, including with respect to the numerous risks associated with biopharmaceutical product candidate development. 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, 2024 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
Attachment
FAQ
What were the reported response rates for eti-cel in r/r NHL (CLLS) at ASH 2025?
When will Cellectis (CLLS) start enrolling the IL-2 support cohort for eti-cel?
What is the significance of the IL-2 data for eti-cel (CLLS)?
When will Cellectis (CLLS) present the full Phase 1 eti-cel dataset?
Where can investors view the eti-cel ASH 2025 poster from Cellectis (CLLS)?
