Efficacy and Safety Study of Intra-Articular Injections of Autologous Peripheral Blood Stem Cells Following Subchondral Drilling Surgery for the Treatment of Articular Cartilage Injury in the Knee

This is a 24-month, multicenter, randomized, open-label, standard treatment-controlled,
parallel-group, Phase 2 study for adults with large or complicated knee articular cartilage
lesions and are candidates for knee joint cartilage repair surgery. The safety and efficacy
of intra-articular injections of peripheral blood stem cells (PBSCs) together with hyaluronic
acid (HA) after subchondral drilling surgery will be evaluated to determine whether PBSC
therapy can improve functional outcome and reduce pain of the knee joint better than a
standard treatment (HA injections and physiotherapy regimen).

Inclusion Criteria:

- Aged between 18 to 55 years at screening (20 to 57 years for the open-label extension)

- Present for evaluation and treatment of knee pain, knee swelling, or knee mechanical
symptoms due to cartilage lesions

- Provide written informed consent

- International Cartilage Repair Society (ICRS) Grade 3 or 4 lesions diagnosis from MRI
scans of the target knee

- All subjects must also satisfy at least 1 of the following inclusion criteria:

- Isolated knee articular cartilage lesion (single lesion) estimated to be ≥3 cm2
as demonstrated on MRI scanning. Multiple knee articular cartilage lesions
(multiple lesions) with at least 1 lesion estimated to be ≥3 cm2 as demonstrated
on MRI scanning. Bipolar cartilage defects demonstrated on MRI scanning with at
least 1 articular surface lesion to be ≥3 cm2. One or more cartilage defects
involving the patello-femoral joint as demonstrated on MRI scanning with at least
1 lesion ≥3 cm2. One or more cartilage defects involving the tibio-femoral joint
as demonstrated on MRI scanning with at least 1 lesion to be ≥3 cm2. Previously
failed cartilage repair procedures (i.e., microfracture, osteochondral autograft
transplantation surgery (OATS), ACI)

Exclusion Criteria:

- Three or more previous surgical interventions on the knee in question.

- Preoperative flexion deformity greater than 10 degrees.

- Presence of ligamentous injury which would require reconstruction, varus or valgus
deformity requiring osteotomy, or cases that require complex surgery prior to
cartilage regeneration