CorrectSequence's Base-Editing Therapy CS-206 Shows 15-Month VOC-Free Success in Sickle Cell Disease Patient
核心洞察
CorrectSequence Therapeutics (搜索) reported that the first sickle cell disease (搜索) patient treated with CS-206 (搜索) in China has remained free of vaso-occlusive crises (搜索) for over 15 months following treatment.
The 21-year-old Nigerian patient achieved rapid hematopoietic recovery with neutrophil engraftment on Day 13 and sustained HbF-to-HbS ratio of 6:4 by Month 3 post-treatment.
CS-206 (搜索) utilizes transformer Base Editor technology to precisely edit HBG1/2 promoter (搜索) regions without DNA double-strand breaks, offering advantages over CRISPR-based therapies.
CorrectSequence Therapeutics (搜索) has announced promising 15-month follow-up data for its base-editing therapy CS-206 (搜索), marking a significant milestone in sickle cell disease (搜索) treatment. The first patient treated with CS-206 in China has remained free of vaso-occlusive crises (搜索) (VOCs) for more than 15 months following engraftment, achieving the primary efficacy endpoint while demonstrating favorable safety.
Patient Outcomes and Clinical Response
The 21-year-old Nigerian patient, who had experienced recurrent severe VOCs prior to treatment, received CS-206 (搜索) therapy in February 2025. Following treatment, she achieved rapid and efficient hematopoietic reconstitution, with neutrophil engraftment observed on Day 13 and platelet counts exceeding 50×10^9/L on Day 21 post-treatment.
Within one month after treatment, fetal hemoglobin (HbF) levels increased significantly and continuously, while sickle hemoglobin (HbS) levels declined substantially and persistently. Beginning at Month 3 after treatment, the HbF-to-HbS ratio stabilized at approximately 6:4 and has remained stable thereafter. Starting from 60 days after the last red-cell transfusion, the patient has remained free from VOCs and anemia (搜索) for 13 consecutive months. No product-related adverse events have been observed to date.
Technology Platform and Mechanism
CS-206 (搜索) is a proprietary base-editing therapy that utilizes the highly precise transformer Base Editor (tBE), an original gene-editing technology developed by CorrectSequence's scientific co-founders. The therapy precisely edits the HBG1/2 promoter (搜索) region in autologous hematopoietic stem cells collected from patients, mimicking naturally occurring beneficial mutations found in healthy individuals to reactivate γ-globin (搜索) expression and rapidly increase fetal hemoglobin levels.
Compared with CRISPR-based gene-editing therapies for sickle cell disease (搜索), CS-206 (搜索) offers the technological advantage of precise single-base correction without introducing DNA double-strand breaks, thereby avoiding risks such as large genomic deletions, chromosomal abnormalities, and off-target mutations. The therapy effectively suppresses red blood cell sickling and significantly reduces vaso-occlusive crises (搜索) and hemolysis.
Disease Burden and Market Context
Sickle cell disease (搜索) is a hereditary hemoglobin disorder caused by mutations in the β-globin gene (搜索). Patients may experience chronic anemia (搜索), recurrent pain crises, infections, and progressive organ damage, with severe cases becoming life-threatening. Approximately 3.5% of the global population carries the sickle cell mutation gene, and around 300,000 babies are born with the disease each year, with particularly high prevalence in Africa, the Mediterranean, the Middle East, and South Asia.
SCD and β-thalassemia (搜索) are both classified as hemoglobinopathies (搜索), among the world's most common monogenic inherited diseases. Approximately 7% of the global population carries abnormal hemoglobin genes, with an estimated 400,000 affected births annually worldwide.
Broader Pipeline Success
Based on the same tBE technology platform and therapeutic pathway, CS-101 developed by CorrectSequence for β-thalassemia (搜索) has successfully cured more than ten β-thalassemia patients from China, Laos, Malaysia, and Pakistan in clinical trials. As of the end of May 2026, all patients treated with CS-101 have remained transfusion-independent for more than 15 months, with the longest duration exceeding 30 months.
Clinical Development Progress
Global recruitment for the investigator-initiated trial (IIT) of CS-206 (搜索) for sickle cell disease (搜索) is currently ongoing. CorrectSequence is accelerating the clinical development and commercialization of both CS-101 and CS-206, with the goal of providing hemoglobinopathy patients worldwide with safer, more effective, and more affordable treatment options.