MACI versus bone marrow stimulation for symptomatic ankle cartilage defects in people 17–65
A Prospective, Open-label, Randomized, Concurrent Active-controlled, Longitudinal, Multicenter, Phase 3 Clinical Study of the Safety and Efficacy of MACI in Patients With Symptomatic Chondral or Osteochondral Lesions of the Talus (MASCOT)
This treatment comparison tests whether MACI (your own cultured cartilage cells on a collagen membrane) works better than bone marrow stimulation for people aged 17 to 65 with symptomatic cartilage defects of the talus.
Quick facts
| Phase | Phase 3 |
|---|---|
| Study type | Interventional |
| Enrollment | 309 (estimated) |
| Ages | 17 Years to 65 Years |
| Sex | All |
| Sponsor | Vericel Corporation Industry-sponsored |
| Locations | 4 sites (Washington D.C., District of Columbia and 3 other locations) |
| Trial ID | NCT06915233 on ClinicalTrials.gov |
What this trial studies
This is a 2-year, prospective, multicenter, open-label Phase 3 randomized trial enrolling 309 participants aged 17–65 with symptomatic talar chondral or osteochondral lesions of at least 1.2 cm². After screening and an index ankle arthroscopy to confirm lesion size and eligibility, subjects undergo a cartilage biopsy and are randomized 2:1 to receive a one-time MACI implantation or arthroscopic bone marrow stimulation (BMS). MACI products are manufactured from the participant's biopsy at the Vericel facility and implanted on a porcine collagen membrane, while the BMS arm receives marrow stimulation during the same arthroscopy. Participants follow a standardized postoperative rehabilitation program and are followed for outcomes over two years.
Who should consider this trial
Good fit: Ideal candidates are people aged 17–65 with symptomatic ICRS grade 3–4 chondral or osteochondral lesions on the talus, at least one lesion ≥1.2 cm², FAOS pain and function scores ≤50, and who are suitable for surgical treatment and follow-up.
Not a fit: Patients unlikely to benefit include those with lesions smaller than 1.2 cm², lesions outside the talus, advanced degenerative joint disease, inability to undergo surgery or follow postoperative restrictions (including NSAID limitations), or those outside the 17–65 age range.
Why it matters
Potential benefit: If successful, MACI could provide more durable cartilage repair in the ankle, reducing pain and improving function compared with standard bone marrow stimulation.
How similar studies have performed: MACI and other autologous chondrocyte implantation techniques have shown positive results in the knee and smaller ankle series, but large randomized comparisons specifically in the ankle remain limited.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria:
1. Age 17 to 65 at the time of planned randomization visit (Visit 2).
2. One or more symptomatic chondral or osteochondral lesion/s as defined by FAOS Pain score ≤ 50 and FAOS Function (SRA) score ≤ 50.
3. International Cartilage Repair Society (ICRS) Score Grade 3 or 4 chondral or osteochondral lesion/s located on the talus with or without cysts, including shoulder lesions (lesions on the talar neck), and amenable to treatment with the surgical procedure specified at randomization.
4. At least 1 lesion ≥ 1.2 cm².
5. Written informed consent and assent (as applicable) per Institutional Review Board (IRB) requirements.
6. Subject will refrain from using Non-steroidal Anti-inflammatory Drugs (NSAIDS) for 12 weeks post-study treatment. (Post-surgical use of low-dose aspirin for clot prevention is acceptable).
7. Subject will restrict pain medication to over-the-counter analgesics (NSAIDs or acetaminophen/paracetamol) after 12 weeks post-study treatment.
8. Subject must have Hematocrit ≥30.0%; White Blood Cell count ≤14,000 cells/μL; Platelet Count ≥50,000 platelets/μL; Creatinine ≤2.0 mg/dL; and International Normalized Ratio (INR) ≤1.6.
Exclusion Criteria:
1. Lesions with an underlying bony defect depth of \> 5 mm.
2. Any surgery on the target joint within 24 weeks prior to Visit 1 (not including diagnostic ankle arthroscopy).
3. Previous investigational drug, biologic or device use within 12 weeks prior to Visit.
4. Avascular necrosis of the target ankle.
5. Symptomatic musculoskeletal conditions in the lower limbs that could impede measurement of efficacy for the target ankle joint.
6. Subjects with "kissing lesions" (bipolar lesions, involving both the tibia and talus), or with bilateral lesions in both ankles.
7. Subjects with lesions that require an osteotomy procedure to allow for MACI implantation as determined at the time of ankle arthroscopy (Visit 2).
8. Concomitant systemic inflammatory diseases or other conditions that affect the joints (e.g., rheumatoid arthritis, metabolic bone disease, psoriasis, symptomatic chondrocalcinosis).
9. History of advanced or severe osteoarthritis of the ankle as determined by prior surgical history confirming no joint space (i.e., "bone on bone") or radiographic evidence of Modified Kellgren-Lawrence Grade 4 arthritis (i.e., osteophytes on lateral and medial malleoli and at the tibiotalar joint margins, narrowing of the joint space width \> 50%, and tibiotalar sclerosis), Van Dijk Grade III (i.e., total or subtotal destruction of the joint space) or the equivalent.
10. Known history of septic arthritis in the target ankle joint within 1 year prior to Visit 1.
11. Current malignancy or treatment for malignancy within the past 5 years prior to Visit 1, excluding non-melanoma skin cancer.
12. Known history of hypersensitivity to gentamicin, other aminoglycosides, or products of porcine or bovine origin.
13. Females who are pregnant or lactating.
14. Patients who, in the opinion of the Investigator, have significant medical or psychosocial problems that warrant exclusion. Examples of significant problems included but are not limited to:
1. Any condition that has potential for negatively impacting intra- or postoperative course.
2. Conditions that limit compliance with rehabilitation program.
3. Any condition that has potential for significantly limiting patient's ability to assess postoperative ankle function.
4. Any condition, psychiatric or otherwise, that would preclude informed consent/assent, consistent follow-up, or compliance with any aspect of the trial.
5. Patient is currently abusing drugs or alcohol or, in the opinion of the Investigator, at high risk for poor compliance.
6. Any result from screening blood work (including complete blood count, Prothrombin Time (PT)/Partial Thromboplastin Time (PTT)/INR, liver function, and creatinine) that exceeds 1.5x the upper limit of normal or is below 0.5x the lower limit of normal.
Where this trial is running
Washington D.C., District of Columbia and 3 other locations
- MedStar Georgetown University Hospital — Washington D.C., District of Columbia, United States (Recruiting)
- NextStage Clinical Research Wichita - Kansas Joint and Spine specialists — Wichita, Kansas, United States (Recruiting)
- NextStage Clinical Research Houston - All American Orthopedic and Sports Medicine — Houston, Texas, United States (Recruiting)
- NextStage Clinical Research San Antonio - San Antonino Podiatry Associates — San Antonio, Texas, United States (Recruiting)
Study contacts
- Study coordinator: Vericel Clinical Affairs
- Email: clinicalhotline@vcel.com
- Phone: 978-347-2876
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.