Despite the ethical, moral, and political dimensions that currently frame discussions about stem cell research, there are scientists, business professionals, and investors who are solely focused on the scientific promise that one day the most recalcitrant diseases will be addressed by replacing diseased cells with stem cells that can be coaxed into reviving health and functionality. Stem cell-based therapeutics that enter clinical trials within the next five years will likely enter clinical practice in the next 10 years. Here's a look at a few of the companies that will help make that happen.

Aastrom Biosciences This Ann Arbor, Michigan–based company specializes in the development of proprietary adult stem cell-based products intended for tissue regeneration and cell therapy. Aastrom Biosciences' efforts, several of which are currently in clinical trials, use a diversified set of tissue repair cells (TRCs). TRCs are produced in the company's patented cell production platform, the AastromReplicell System (ARS), which was developed to address the issue of cell yield so that the company could grow large quantities of highly robust human cells, including adult stem cells and progenitor cells, outside of the human body.

Search for a Perfect Union

Transplants Andrew L. Pecora, MD, chairman and director of the Cancer Center at Hackensack University Medical Center in New Jersey, has used ARS to successfully treat people with leukemia. One notable patient was an overweight diabetic who received umbilical cord blood-derived stem cells during a transplant procedure for leukemia. Pecora used ARS to increase the number of available cells threefold. The engraftment was successful and nine years later, the patient is alive and well. "Replicell makes the engraftment more robust," Pecora says. "It holds promise that by expanding certain subsets of cells there may be clinical benefit, but you have to prove these cells can do what you want them to do."

Bone grafts Aastrom's TRCs are a mixture of bone marrow-derived stem cells and progenitor cells. Chief among the company's portfolio is its orthopedic product for severe fractures, currently in Phase I/II clinical trials in the United States and Europe for bone graft applications.

Aastrom is partnered with the Musculoskeletal Transplant Foundation, the largest producer of allograft tissue products for orthopedic surgery. More than one million patients a year with severe non-healing fractures undergo bone grafting, a painful and often debilitating process that removes bone marrow from a patient's hip and autografts it to the fracture site. Using ARS, surgeons can extract a minimal amount of bone marrow containing key progenitor and stem cells, then replicate these cells. The next step is to combine TRCs with a glue-like matrix, pack the admixture into the fracture site, and let the cells go to work.

So far, the safety and efficacy data of more than 175 clinical patients has been positive, and TRCs have also been successful in a compassionate-use case. In a baby diagnosed with infantile hypophosphatasia, a genetic bone disease with a 50 percent mortality rate, TRCs generated healthy bone in the now seven-year-old girl. Aastrom anticipates completing some of its clinical trials by the end of 2006. A spokesperson for the company, Kris Maly, says, "Pending acceptable results, Aastrom's TRC product for fractures could move into the marketplace in calendar year two thousand six." The company also is developing TRC products for vascular regeneration applications.