Dose Comparison Study of Allogeneic Mesenchymal Stem Cells in Patients with Ischemic Cardiomyopathy (The TRIDENT Study)
Rationale: Cell dose and concentration play crucial roles in phenotypic responses to cell-based therapy for heart failure.
Objective: To compare the safety and efficacy of two doses of allogeneic bone marrow-derived human mesenchymal stem cells (hMSC) identically delivered in patients with ischemic cardiomyopathy (ICM).
Methods and Results: Thirty patients with ICM received in a blinded manner either 20 million (20M, n=15) or 100 million (100M, n=15) allogeneic hMSCs via transendocardial injection (10 0.5 cc injections/patient). Patients were followed for 12-months for safety and efficacy endpoints. There were no treatment-emergent serious adverse events (SAE) at 30 days or treatment related SAEs at 12 months. The Major Adverse Cardiac Event rate was 20.0% (95% CI, 6.9%, 50.0%) in 20M and 13.3% (95% CI, 3.5%, 43.6%) in 100M (p=0.58). Worsening heart failure re-hospitalization was 20.0% (95% CI, 6.9%, 50.0%) in 20M and 7.1% (95% CI, 1.0%, 40.9%) in 100M (p=0.27). Whereas scar size reduced to a similar degree in both groups: 20M by -6.4g (IQR, -13.5g, -3.4g, p=0.001) and 100M by -6.1g (IQR, -8.1g, -4.6g, p=0.0002), the ejection fraction (EF) improved only with 100M by 3.7 units (IQR, 1.1, 6.1, p=0.04). NYHA class improved at 12 months in 35.7% (95% CI, 12.7%, 64.9%) in 20M and 42.9% (95% CI, 17.7%, 71.1%) in 100M. Importantly, pro-BNP increased at 12 months in 20M by 0.32 log pg/mL (95% CI, 0.02, 0.62, p=0.039), but not in 100M (-0.07 log pg/mL; 95% CI, -0.36, 0.23, p=0.65; between group p=0.07).
Conclusions: Although both cell doses reduced scar size, only the 100M dose increased EF. This study highlights the crucial role of cell dose in the responses to cell therapy. Determining optimal dose and delivery is essential to advance the field, decipher mechanism(s) of action, and enhance planning of pivotal Phase III trials.
Clinical Trial Registration: NCTO2013674 [https://clinicaltrials.gov/ct2/show/NCT02013674]
- Received August 4, 2017.
- Revision received September 12, 2017.
- Accepted September 14, 2017.