# Cell Stem Cell: tBE-mediated Base Editing Therapy Achieves Durable Clinical Remission in Sickle Cell Disease and β-Thalassemia Across Different Genetic Backgrounds

- Link: https://www.thailand-business-news.com/pr-news/cell-stem-cell-tbe-mediated-base-editing-therapy-achieves-durable-clinical-remission-in-sickle-cell-disease-and-%ce%b2-thalassemia-across-different-genetic-backgrounds
- Published: 2026-09-08T07:00:00+07:00
- Author: PR Newswire

**_Following 100% transfusion independence in Chinese TDT patients, new study confirms
tBE is equally safe and effective for African SCD patients and TDT patients from
South/Southeast Asia._**

SHANGHAI, Sept. 8, 2026 /PRNewswire/ — On September 7, 2026, Shanghai, **_Cell Stem
Cell_** published online clinical research from [CorrectSequence Therapeutics](https://www.correctsequence.com/index.php?lang=en)(
[Correctseq](https://www.correctsequence.com/index.php?lang=en)) in collaboration
with multiple institutions in a paper titled "_**[Clinical base editing for β-hemoglobinopathies across different genetic backgrounds](https://doi.org/10.1016/j.stem.2026.08.009)**_",
demonstrating that **CS-101/CS-206**—base-editing therapy developed with the **transformer
Base Editor (tBE)**—achieved **consistent efficacy and safety** in **β-hemoglobinopathy**
patients of **diverse genetic origins**. This follows the team’s prior clinical 
report on five Chinese transfusion-dependent β-thalassemia (TDT) patients treated
with CS-101, all achieving transfusion independence ([Lai _et al._, **_Nature_**, 2026](https://www.nature.com/articles/s41586-026-10342-9)).
The new study extends treatment to four additional patients from **Nigeria, Laos,
Malaysia, and Pakistan**—one with sickle cell disease (SCD) and three with TDT. 
All achieved **rapid hematopoietic reconstitution, sustained high-level pan-cellular
HbF expression, complete transfusion independence or freedom from vaso-occlusive
crises (VOCs), with no detectable off-target edits, or product-related adverse events.**

[⌊Figure | As of August 2026, the SCD patient had sustained freedom from VOCs for
18 months after receiving Correctseq’s CS-206 treatment.⌉⌊Figure | As of August 
2026, the SCD patient had sustained freedom from VOCs for 18 months after receiving
Correctseq’s CS-206 treatment.⌉[
Figure | As of August 2026, the SCD patient had
sustained freedom from VOCs for 18 months after receiving Correctseq’s CS-206 treatment.

**Broad Applicability Across Various Ethnicities and Mutations**

β-hemoglobinopathies are among the most common monogenic disorders, with SCD affecting
over 300,000 and TDT over 40,000 newborns annually worldwide. Pathogenic mutations
vary significantly across populations. The team previously developed the ultra-high-
precision tBE ([Wang _et al_., **_Nat Cell Biol_**, 2021](https://www.nature.com/articles/s41556-021-00671-4))
to precisely edit the _HBG1/2_ promoter region in autologous HSPCs collected from
patients, reactivating γ-globin expression. The four patients’ genotypes in the 
current study encompassed β^(S)/β^(S) SCD and three TDT genotypes—β⁰/βᴱ, β⁰/β⁰ with
a large deletion, and β⁰/β⁰ with single-nucleotide insertion—validating the strategy’s
universal applicability.

**Clinical Data: Rapid Engraftment, Durable Response, Complete Transfusion Independence,
and No Off-target Mutations**

The SCD patient (21-year-old female from Nigeria), who experienced more than four
VOCs during the year prior to enrollment, achieved neutrophil and platelet engraftment
on days 13 and 21 post-infusion. Total hemoglobin level increased from 7.7 g/dL 
at baseline to 12.9 g/dL at month 3, remaining above 11 g/dL; HbF level increased
from 3.5% to 62.2%, while HbS level decreased from 76.1% to 31.6%, stabilizing at
a ~6:4 ratio. At 15.5 months follow-up, no VOCs occurred.

The three TDT patients (ages 3-29, from Laos, Malaysia, and Pakistan) achieved median
neutrophil engraftment at 13 days and platelet engraftment at 27 days. Mean total
hemoglobin concentration reached 11.6 ± 1.2 g/dL and mean HbF concentration increased
to 9.8 g/dL at month 3. At median follow-up of 17.5 months, all achieved sustained
transfusion independence. No off-target edits or product-related adverse events 
were detected.

**Comparison with Nuclease-Based Gene Editing Therapies: Faster Engraftment, Higher
Expression, Better Safety**

In SCD clinical trials, tBE achieved superior neutrophil engraftment (13 days) compared
to Cas9 (27 days) and Cas12a (23 days), and superior platelet engraftment (21 days)
versus Cas9 (35 days) and Cas12a (25 days). tBE sustained HbF >60% of total hemoglobin,
markedly outperforming Cas9 and Cas12a regimens (<50%).

Unlike nucleases that rely on DNA double-strand breaks (DSBs), tBE enables precise
base conversion without cutting DNA, avoiding p53 activation, apoptosis, large deletions,
and chromosomal rearrangements. Its dual gRNA and "lock-and-key" design further 
minimizes off-target risks. Through a cleavable "lock", tBE becomes active only 
at on-target sites to induce highly efficient editing. When binding at off-target
sites, tBE was "locked" to avoid triggering off-target mutations.

**Global Progress and Regulatory Pathway**

To date, CS-101 and CS-206 have treated more than 30 patients across China, Africa,
Southeast Asia, and South Asia, with 100% of patients achieving transfusion independence
or freedom from VOCs, accompanied by sustained, high-level hemoglobin expression.
CS-101, the world’s first ongoing base-editing therapy candidate to enter clinical
development, with the first patient dosed in October 2023, has completed Phase I
and is now being evaluated in pivotal trials. All patients treated in Phase I have
maintained transfusion independence for more than one year, with the longest duration
approaching almost three years. 

Professor Chen Jia, founder of Correctseq and Director of the Gene Editing Center
at ShanghaiTech University, stated: "This **_Cell Stem Cell_** paper validates tBE’s
broad applicability across diverse genetic backgrounds, completing the translational
journey from bench to global clinical application. Our team is also exploring RNA
editing, prime editing, and mitochondrial DNA editing for other therapeutic areas."

Dr. Mou Xiaodun, CEO of Correctseq, added: "The data demonstrate tBE as a global
Best-in-Class platform. We are also expanding into metabolic and cardiovascular 
diseases including hypertriglyceridemia/familial chylomicronemia syndrome (FCS),
ASCVD/hyperlipoproteinemia, homozygous familial hypercholesterolemia (HoFH), and
metabolic dysfunction-associated steatohepatitis (MASH). We are accelerating multiple
pipelines toward global IND submission to bring China-originated gene editing to
more patients worldwide."

**_Cell Stem Cell_** paper link: [https://doi.org/10.1016/j.stem.2026.08.009](https://doi.org/10.1016/j.stem.2026.08.009)

**About CorrectSequence Therapeutics**
[CorrectSequence Therapeutics](https://www.correctsequence.com/index.php?lang=en)(
[Correctseq](https://www.correctsequence.com/index.php?lang=en)), is a clinical-
stage biotech company employing its proprietary transformer Base Editor (tBE) to
pioneer next-generation gene editing therapies. The company has developed multiple
state-of-the-art base-editing systems that offer exceptional precision, minimize
off-target effects, and enhance_ ex vivo _and _in vivo_ editing efficiency. Its 
robust pipeline spans genetic disorders, metabolic diseases, and cardiovascular 
conditions, with several programs already advancing toward clinical development.

For more information, visit [**www.correctsequence.com**](http://www.correctsequence.com/).

**Acknowledgments:** The First Affiliated Hospital of Guangxi Medical University,
ShanghaiTech University, Children’s Hospital of Fudan University, Institutes of 
Biomedical Sciences, Fudan University, Shanghai Clinical Research and Trial Center.

Media Contact:

Business Cooperation: [BD@correctsequence.com](https://www.thailand-business-news.com/pr-news/BD@correctsequence.com)

Clinical Trial Recruitment: [CT@correctsequence.com](https://www.thailand-business-news.com/pr-news/CT@correctsequence.com)

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**Read the original article :** [Cell Stem Cell: tBE-mediated Base Editing Therapy Achieves Durable Clinical Remission in Sickle Cell Disease and β-Thalassemia Across Different Genetic Backgrounds ](http://www.prnasia.com/story/archive/5041651_CN41651_0?rand=184833)