Aastrom Biosciences responds to article regarding contaminated stem cell lines

Aastrom Biosciences responded today to the publication in the Sunday online edition of Nature Medicine of findings by California researchers that indicate that certain lines of human embryonic stem cells have been contaminated through the use of mice feeder cells.

The Company has received numerous inquiries regarding these findings and their impact on Aastrom Biosciences.

Aastrom does not use embryonic stem cells, nor does it use mouse-derived feeder cells to support stem cell growth, the two major topics of yesterday's article. This is a critical fact that differentiates our Tissue Repair Cells (TRCs) from other stem cell approaches currently in development. Aastrom utilizes proprietary technology in the production of its TRCs, which are an adult, patient-derived bone marrow stem and progenitor cell mixture. The TRC process generates native stromal feeder cells that support stem cells and so, does not require adding mouse feeder cells to the culture. Also, because the TRC stem cell culture process is short-term (12 days), the cells are less conducive to the changes that can occur with the long-term or repeated passage type cultures that are used for embryonic stem cells.

Furthermore, in our clinical trials completed to date, Aastrom has shown that TRCs are safe and can generate normal tissue in human patients.

Tissue Repair Cells (TRCs) are Aastrom's proprietary mixture of adult bone marrow stem and progenitor cells produced using patented single-pass perfusion technology in the AastromReplicell(R) System. The clinical procedure begins with the collection of a small sample of bone marrow from the patient's hip in an outpatient setting. TRCs are then produced in the automated AastromReplicell System over a 12-day period. It has been demonstrated in the laboratory that TRCs are able to develop into different types of tissue lineages in response to inductive signals, including blood, bone, cartilage, adipose and vascular tubules. In previous clinical trials, TRCs have been shown to be safe and reliable in regenerating certain normal healthy bone marrow tissues.