The (Translational) Road Less Traveled

Time to end the war on cell therapy

“…This position is epitomized by an anonymous and oft‐cited editorial in Nature Biotechnology that claimed that cell therapy for cardiovascular disease is ‘futile’ . As pointed out already, this editorial is misleading because it contains statements that are demonstrably incorrect, e.g. that no clinical trial of cell therapy has met its primary endpoint.…”

Introduction to a Compendium on Regenerative Cardiology

“…Considering that the precise mechanism(s) of action of cell-based therapies remains unclear, and that many important aspects have not yet been defined (e.g., the optimal cell type, the optimal cell dose, the optimal route of delivery, the optimal number of treatments, etc. ), it is actually remarkable that the results obtained heretofore in patients with refractory angina [6, 7, 8] and heart failure [3, 9, 10, 11, 12] are encouraging, i.e., that a signal for efficacy has emerged at all. The development of cell therapy is a work in progress.…”

“…Numerous studies from many labs have documented the ability of various types of adult progenitor/stem cells to improve left ventricular function and remodeling in a variety of animal models of ischemic cardiomyopathy, including mice, rats, and pigs [4, 5]. In the clinical arena, much progress has been made in recent years: overwhelming evidence indicates that CD34 + cell therapy is effective in patients with refractory angina [6, 7, 8], and small- and medium-size clinical trials of cell therapy have produced encouraging results in the setting of chronic heart failure, which appears to be a promising target for the development of cell-based therapies [3, 9, 10, 11, 12]. Clinical data are less encouraging in the setting of acute myocardial infarction [3, 11, 12].…”

“…In the end, only rigorous, properly designed, and adequately powered clinical trials will answer the question as to whether cell therapy is effective in patients with heart disease. Although the mechanism of action is unclear, cell therapy is safe [3] and the results in refractory angina [6, 7, 8] and heart failure [3, 9, 10, 11, 12] are encouraging, as mentioned above. Therefore, while the mechanism of action is investigated at a basic level, it is important that clinical studies of cell therapy continue [3].…”

“…As is often the case for major, disruptive advances, the progress of cell therapy has encountered many obstacles. A major one has been the bias, hostility, and nihilism of certain segments of the academic community and lay press, which have declared cell therapy to be “futile” even before conclusive clinical data are obtained and despite encouraging results in the settings of refractory angina [6, 7, 8] and chronic heart failure [3, 9, 10, 11, 12] (including randomized clinical trials that have met their primary endpoints, such ixCELL-DCM [9] and the CD34+ cell trials [6]). Another problem has been the proliferation of unregulated “stem cell clinics” that offer expensive cell-based treatments to patients using misleading, at times fraudulent, claims not based on solid clinical trial evidence.…”