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 Constant Score (CS) at 24 weeks after TPX-115 injection. Secondary outcomes include changes from baseline in CS, Visual Analogue Score (VAS) pain score, American Shoulder and Elbow Surgeons (ASES) score, Quick Disabilities of the Arm, Shoulder and Hand (Quick-DASH), Simple Shoulder Test (SST), and functional evaluations including Range of Motion (ROM) at 4, 12, 24 and 52 weeks after administration and structural evaluation using MRI at 24 and 52 weeks after injection.

Inclusion Criteria:

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

Exclusion Criteria:

1. Regardless of partial-thickness rotator cuff tear, have full-thickness rotator cuff tear confirmed by MRI.

2. Have been treated with the following

   • Have had painkiller within 1 week prior to screening visit.
   • Have had received systemic steroid or immunosuppressive agents within 4 weeks prior to screening visit.
   • Have had subacromial or intra-articular injections on the affected shoulder within 3 months prior to screening visit.
   • Have shoulder surgery on the rotator cuff tear or had received drug that included growth factor, within 6 months prior to screening visit.

3. 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

4. Have allergies to bovine proteins or gentamicin.

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

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

7. Be deemed inadequate for the study by investigators.