The purpose of this study is to evaluate the efficacy and safety of esophageal epithelial regenerative treatment by the transplantation of the product, CLS2702C, to the esophageal wound site after extensive ESD for superficial esophageal cancer.

This study is a multicenter, single-arm, open-label study of CLS2702C/D in patients who plan to undergo ESD for superficial esophageal cancer.

In this study, the efficacy and safety of CLS2702C (cell sheet) transplanted (applied) to the wound site after ESD using CLS2702D (transplantation device) will be evaluated.

Inclusion Criteria:

1. Patients who plan to undergo ESD for the treatment of superficial esophageal cancer

2. Patients aged ≥20 years at the time of consent

3. Patients with no clinical metastasis (cN0M0) by cervical to abdominal CT

4. Patients with an endoscopically diagnosed depth of wall invasion remaining in the epithelium (EP) or lamina propria mucosae (LPM)

5. Patients with ≥3/4 of circumference and a length of <8 cm

6. If the patient has multiple lesions, the circumference of all minor lesions other than the one lesion with the largest circumference (major lesion) must be <1/2, and the distance between the minor lesions and the major lesion must be 5 cm or more on the major axis.

7. Patients with squamous cell carcinoma (including high-grade intraepithelial neoplasia) as confirmed by biopsy

8. Patients whose lesion is confirmed to be localized in the thoracic esophagus (lesions in the cervical esophagus or abdominal esophagus will be excluded). The location of the lesion will be determined by endoscopy.

9. Patients who have not received pretreatment for esophageal cancer. Treatment by ESD for superficial esophageal cancer for which the depth of wall invasion has been assessed to remain in the epithelium (EP) or lamina propria mucosae (LPM) is not included in the definition of pretreatment. However, patients who have a scar due to previous ESD in the major or minor lesions will be excluded from the study.

10. Patients with an ECOG Performance Status (PS) of 0 or 1

11. Patients in whom a commonly used endoscope with a tip diameter of 8.9 mm can pass

12. Patients with a dysphagia score of 0

13. Patients whose laboratory values within 28 days before enrolment meet all of the following criteria:

    • White blood cell count: ≥4,000/µL
    • Platelet count: ≥100,000/µL
    • AST: ≤100 IU/L
    • ALT: ≤100 IU/L
    • Total bilirubin: ≤2.0 mg/dL
    • Serum creatinine: ≤2.0 mg/dL

14. Patients who have received sufficient explanation about the study and provided written voluntary consent

Exclusion Criteria:

1. Patients with cardiac disease (myocardial infarction, unstable angina, and heart failure), renal disease (nephrotic syndrome and kidney failure), or poorly controlled diabetes mellitus

2. Patients who have an active (within 1 year) malignancy other than esophageal cancer

3. Patients with active bacterial, fungal, or viral infection

4. Patients who are being treated with a corticosteroid

5. Patients with positive HBs antigen, positive HCV antibody, positive HIV antibody, positive HTLV antibody, or positive Treponema pallidum (tested at screening). For patients with positive HBc/HBs antibody, HBV-DNA test will be performed (if the result is negative, the patient will be allowed to enter the study).

6. Patients with a mental disorder that is difficult to control

7. Pregnant women, lactating women, and potentially pregnant women

   • Lactating women may be enrolled in the study if they discontinue lactation during the period from trans-plantation to confirmed wound healing.

   • Women of childbearing potential must agree to use the following birth control methods or completely ab-stain from sexual intercourse during the period from consent to participate in the study to the end of study participation.

     • Principal birth control methods: oral contraceptives, intrauterine contraceptive devices including intrauterine luteal hormone-releasing systems, tubal occlusion, and vasectomized partner
     • Supportive birth control methods: condoms and diaphragms

   • The use of principal birth control methods is essential. Supportive birth control methods should not be used alone and must be used together with the principal birth control methods. For oral contraceptives, changes in the birth control methods or other strategies should be considered because it is known that their effect is reduced if they are missed or concomitantly taken with certain types of drugs or dietary supplements.

8. Patients who have participated in another clinical study within 6 months, those who are participating in another clinical study, and those who plan to participate in another clinical study during participation in Study CLS2702-ESO-01

9. Patients from whom tissues cannot be collected due to a disease (e.g., stomatitis, erosion, mass, and blister) in the oral mucosa at the tissue collection site

10. Patients with a history of hypersensitivity to antibiotic preparations (ampicillin sodium, sulbactam sodium, streptomycin sulfate, gentamicin sulfate, or amphotericin B) or who have taken drugs that may affect the study (within 28 days before enrolment)

11. Patients who have undergone radiotherapy in the cervical to upper abdominal region, or surgery for head and neck cancer that may affect the assessment of ESD or stenotic symptoms

12. Patients whose swallowing function has been markedly reduced or completely lost due to a sequela of cerebral infarction or other reasons

13. Patients with porcine or latex allergy

14. Patients who, in the opinion of the treating physician, are not eligible for the study due to reasons other than those described above