be sold with the ease and scale of a traditional pharmaceutical. Cells are taken from a single donor, expanded, frozen and shipped for use in thousands of people.
"We wanted to create a product that everyone could receive and not have to match every donor to every recipient," said Robert Hariri, chief executive of Celgene's Cellular Therapeutics unit.
Aastrom, Baxter, NeoStem and Cytori Therapeutics Inc use cells taken from a patient's own body in what is known as an autologous transfer. This personalized approach eliminates the risk that the cells will be rejected.
"There are going to be dividing lines in the industry between autologous and allogeneic and there are some indications where one will be better than the other," said Jason Kolbert, head of business development at NeoStem.
"It may be that immediately following a heart attack you would want to use an allogeneic therapy to limit the damage in those first few hours, and then follow up after day five with an autologous product like ours."
Different types of stem cell are being used for different diseases. Cytori is developing a heart disease product derived from fat cells, for example, while Celgene is using placental cells for Crohn's disease and rheumatoid arthritis therapies.
Fetal cells are also being explored. Neuralstem Inc, for example, is developing treatments for neurological disorders from an aborted fetus and is in the early stages of testing a treatment for amyotrophic lateral sclerosis, known also as Lou Gehrig's disease.
"I think Neuralstem is one to watch," said Aspire's Martin.
As cell therapies move further through clinical trials, companies will need more money, and funding is scarce. Aastrom's shares have fallen 37 percent since reaching a year high of $3.47 in June as investors brace for another dilutive capital-raising effort.
Companies with credible partners will likely have an advantage. Athersys has a partnership with Pfizer; Cytori has a partnership with General Electric Co ; Pluristem has a partnership with United Therapeutics Corp. Celgene, which makes cancer drug Revlimid, has resources of its own.
Yet even if companies remain afloat long enough to bring a product through late-stage clinical trials, it is unclear what regulators like the Food and Drug Administration will require in order to approve them.
Some believe the regulatory hurdles for treatments derived from a patient's own cells will be lower than those where the cells come from donors, since there is less risk of cell rejection. However, no clear pathway has yet been established.
"We need a clear, consistent and rigorous regulatory framework," said Athersys's Van Bokkelen "The FDA is actually willing to provide lots of guidance and assistance to sponsors, if you just ask them." (Reporting by Toni Clarke in Boston and Deena Beasley in Los Angeles; Editing by Michele Gershberg, Edward Tobin and Tim Dobbyn)