Stem cell trials for the heart, getting bigger
The FDA has given the go-ahead for a medium-scale trial to test bone-marrow cells to treat heart disease. Previously, the company had tested using patients’ own cells for heart therapy, but this time they hope to use cells derived from other patients. An April release from the company describes another, smaller trial using non-self or allogeneic cells. The just-announced trial will include study 15 control patients plus 45 patients who will receive different doses of cells, and patients’ outcomes will be followed for a year. If done correctly, such a design could answer important, growing questions in the use of these mesenchymal cells for heart disease. Also, it’s unclear whether it better to use a patient’s own supposedly weak cells or more robust cells from donors, which the recipients’ body may not accept, or how best to design trials to answer these questions. (See our articles Questioning the self cell and Stem cells for the heart, a new wave of clinical trials.
While several clinical studies have found that these kinds of stem-cell treatments seem safe, researchers are just now beginning to ask whether these treatments are effective.
Scientists have strong doubts about the cells’ ability to become new heart tissue, and to provide long-lasting benefit. (See our interview with Christine Mummery on regenerating the heart)
There is much debate on how best to proceed, with some scientists arguing that the most-effective and least risky route is more basic research. Other researchers argue for a more clinical approach; scientists can only learn so much from rodents, and patients have few other treatment options. (Read about this discussion at an NIH meeting on cardiovascular medicine.)