CHICAGO - Wednesday, the final day of the 2006 conference of the Biotechnology Industry Organization (BIO; Washington) dawned warm and sunny, and inside the air-conditioned McCormick Place convention center, attendees strolled through the halls, took one last trek through the exhibit hall and sat through a few more panel discussions.
Inside a fourth-floor meeting room, panelists gathered for a discussion on the use of non-embryonic stem cells, derived from various sources, including bone marrow, umbilical cord blood and adipose tissue, and highlighted promising early data in the area of cardiovascular disease.
While most of the media attention has focused on the controversial use of embryonic stem cells, several companies and research institutions have been steadily advancing adult stem-cell therapies into the clinic, leading to "a new era in medical therapies," said Douglas Losordo, from the Tufts University School of Medicine (Boston), who works with the Caritas St. Elizabeth Medical Center (Houston), which has conducted human trials using autologous CD34+ cells in heart disease.
Researchers at St. Elizabeth's were among the first in the 1990s to discover the potential of blood- or bone marrow-derived stem cells to repair damaged tissues and promote angiogenesis. Since then, preclinical testing has demonstrated the ability of those stem cells to treat ischemia by stimulating revascularization.
Patients suffering heart disease "really don't have a lot of great options out there," said Amit Patel, director of the Center for Cardiac Cell Therapy, University of Pittsburgh Medical Center , adding that the most effective treatment is cardiac transplantation, a procedure that carries its own health risks.
The aim of adult stem cell therapies is to "use the patients' own cells to fix their hearts," Patel added.
Patel's group conducted pilot studies of bone marrow-derived stem cells, administered during coronary artery bypass graft (CABG) surgery, vs. CABG surgery alone, and results indicated significant improvement when the stem cells were added to the mix.
"It's by no means a cure," he said. "But we are alleviating a lot of the symptoms," shown clearly on both "a clinical and a metabolic level."
A number of companies are developing adult stem cell products, including Osiris Therapeutics (Baltimore), which also focuses on cardiovascular indications. Osiris recently completed enrollment in a 53-patient Phase I trial testing Provacel, its intravenously administered formulation of adult stem cells aimed at repairing damaged tissue following a heart attack. That product is being developed in collaboration with Boston Scientific (Natick, Massachusetts).
In addition to heart disease, the use of bone marrow-derived stem cells is being investigated in other indications. For instance, Aastrom Biosciences (San Diego), has several ongoing Phase I and Phase II trials of its Tissue Repair Cells (TRCs), which comprise a mixture of bone marrow-derived adult stem cells and progenitor cells produced ex vivo using the AastromReplicell system, in long-bone fractures, spine fusion and upper jaw bone reconstruction.
And in the neurodegenerative arena, BrainStorm Cell Therapeutics (New York) is investigating the potential of bone marrow-derived stem cells as a treatment for Parkinson's disease.
Viacell (Cambridge, Massachusetts), meanwhile, is investigating another source of non-embryonic stem cells: umbilical cord blood.
Viacell, which operates in part as a cryopreservation business for umbilical cords - and is working to add the preservations of oocytes to their services - is developing a cell therapy pipeline using stem cells isolated from umbilical cord blood.
The company's goal is to create "true, off-the-shelf, allogeneic stem cell products," said Mark Beer, Viacell president and CEO, that can be marketed as a "cartridge of cells you can click into a catheter" for intravenous administration.
Leading Viacell's clinical pipeline is CB001, a cord blood stem cell product for use in hematopoietic stem cell transplantation in cancer patients. That product, which is being co-developed with Amgen (Thousand Oaks, California), is in Phase I study, with results expected in the second half of this year.
A third potential source for adult stem cells is adipose tissue.
Keith March, professor of medicine, physiology and biomedical engineering at Indiana University School of Medicine , said those cells can be found and isolated from the stromal (non-adipocyte) fraction of adipose tissue. The tissue is "harvested" from patients during an outpatient liposuction procedure, he said.
So far, preclinical studies of adipose-derived stem cells, administered by intramuscular injection into nude mice, have suggested a potential to preserve tissue and promote angiogenesis, March said, adding that his researchers plan to move into the clinic soon in patients suffering critical limb ischemia.
March said one question still to be addressed is the method of delivering the adipose-derived stem cells to patients.
That issue was explored by stem cell firm Cytori Therapeutics (San Diego), which developed a device specifically to administer its own adipose-derived stem cell products to patients. The company recently gained approval for its Celution system, which is designed to isolate and concentrate a patient's own stem and regenerative cells in about an hour.
This system will be used when Cytori begins clinical studies of its adipose-derived stem cell products. The company expects to pursue therapies targeting cardiovascular disease, and has partnered with Olympus (Tokyo) in a joint venture (Medical Device Daily, Feb. 27, 2006). In the agreement Cytori has granted Olympus the right to negotiate a collaboration for the use of adipose stem and regenerative cells for a specific therapeutic area outside of cardiovascular applications. In exchange, Cytori receives $1.5 million from Olympus.