Rotator cuff tear is one of the most common shoulder diseases and conservative treatment is commonly used for tears involving ≤50% of tendon thickness. Since conventional conservative treatments are not fundamental to repair tendon tissue, there is a growing need of new therapy to improve structural outcome. This study assesses the safety and efficacy of allogeneic fibroblasts on partial-thickness rotator cuff tear. The primary outcome is change in American Shoulder and Elbow Surgeons (ASES) score at 24 weeks after TPX-115 injection. Secondary outcomes include changes from baseline in Visual Analogue Score (VAS) pain score, functional evaluations including Range of Motion (ROM), Constant Score (CS), ASES score and Simple Shoulder Test (SST) at 4, 12 and 24 weeks after administration and structural evaluation using MRI at 24 weeks after injection.

Inclusion Criteria:

Participants must;

1. Be 19 years of age or older.
2. Have partial-thickness rotator cuff tear, ≤50% of tendon thickness or of Ellman grade I, II assessed by MRI.
3. Have unilateral shoulder pain lasting more than 3 months despite conservative treatment and VAS pain score ≥5 at screening.
4. Understand fully the study and voluntarily sign the informed consent for participation in the study.

Exclusion Criteria:

Participants with any of the following conditions will be excluded unless stated otherwise;

1. Have partial-thickness rotator cuff tear larger than 50% of tendon thickness or of Ellman grade III, or full-thickness rotator cuff tear confirmed by MRI.

2. Have prior medical history of shoulder surgery on the torn rotator cuff or the upper part of shoulder within 6 months prior to screening visit (shoulder trauma, fracture, upper cervical spine surgery, etc.).

3. Have had subacromial or intra-articular injections on the affected shoulder within 3 months prior to screening visit.

4. Have had received systemic steroid or immunosuppressive agents within 4 weeks prior to screening visit.

5. Have been diagnosed with the following diseases.

   • Inflammatory joint diseases
   • Other shoulder diseases which may cause shoulder pain or functional disorder
   • Autoimmune diseases
   • Active hepatitis B or C
   • HIV Ab positive
   • Malignant tumors within the last 5 years
   • Coagulopathy
   • Genetic disorders related to fibroblasts of collagen
   • Other serious diseases deemed to affect the results of the study

6. Have allergies to bovine proteins or gentamicin.

7. Be pregnant, breastfeeding, planning pregnancy or unwilling to use of contraceptive suggested in this study.

8. Have participated in other clinical trials and received investigational agents within 4 weeks of this study

9. Be deemed inadequate for the study by investigators.