StemCells, Inc.’s Neural Stem Cells Show Promise for Treating Age-Related Macular Degeneration

StemCells, Inc. (NASDAQ:STEM) announced today new preclinical data showing that its human neural stem cells protect cone photoreceptors (cones) in the eye from progressive degeneration and preserve visual function long term. Cones are light sensing cells that are highly concentrated within the macula of the human eye, and the ability to protect these cells suggests a promising approach to treating age-related macular degeneration (AMD), the leading cause of vision loss and blindness in people over the age of 55. These important findings were presented today in Chicago, Illinois at the Society for Neuroscience 2009 Annual Meeting, one of the leading forums for neuroscientists from around the world to present and discuss cutting-edge research in the field.

"We have long recognized that a number of eye disorders may be suitable candidates for stem cell-based therapies,” stated Stephen Huhn, MD, FACS, FAAP, vice president and head of the CNS program at StemCells, Inc. "The demonstrated ability of our human neural stem cells to preserve cones is very meaningful, because it is the progressive deterioration of these specific cells that ultimately results in vision loss in AMD. These data support our hypothesis that our neural stem cells may provide neuroprotection to existing cells, and it is our hope that we will be able to replicate these promising results in the clinic.”

This study, which was conducted in collaboration with researchers from the Casey Eye Institute at Oregon Health & Science University (OHSU), focused on assessing photoreceptor survival and vision preservation following transplantation of StemCells’ human neural stem cells. Results of the study demonstrate that, when transplanted into the eye of the Royal College of Surgeons (RCS) rat, a well-established animal model of retinal degeneration, the neural stem cells preserve visual function as measured by two separate visual tests, and exhibit robust, long-term protection of both rod and cone photoreceptors.

Raymond Lund, Ph.D., professor of Ophthalmology at the Casey Eye Institute, commented, "My lab has been involved in researching many cell therapy approaches for diseases of the eye, and the results we have seen with the human neural stem cell are particularly exciting. This study provides novel evidence that neural stem cells may provide significant therapeutic value for clinical cases of retinal degeneration, and we look forward to testing their potential in additional studies with StemCells, Inc.”

The eye contains millions of photoreceptor cells, known as rods and cones, which are responsible for picking up light and converting it into electrical impulses that are sent along the optic nerve for the brain to interpret what we see. Rods allow us to see under dark conditions, while cones allow us to see color and fine detail. Cones are highly concentrated within the macula, the part of the eye that is responsible for our central, "straight ahead” vision. Patients with AMD lose central vision when the cones within the macula degenerate. It is estimated that 25 – 30 million people worldwide suffer from AMD, including as many as 15 million Americans, and today there is no cure.

StemCells is pursuing additional preclinical studies of its neural stem cells in the hope of one day achieving a breakthrough in treating AMD. The encouraging results of this latest study follow previously reported data showing that StemCells’ neural stem cells engraft, survive long term, and can protect the retina from progressive degeneration in the RCS rat. StemCells is currently developing its human neural stem cells as a potential therapeutic product, HuCNS-SC^® cells, for multiple degenerative disorders of the central nervous system.

About HuCNS-SC^® Cells

StemCells’ lead product candidate, HuCNS-SC cells, is a highly purified composition of human neural stem cells that are expanded and stored as banks of cells. The Company’s preclinical research has shown that HuCNS-SC cells can be directly transplanted in the central nervous system. The transplanted cells are able to engraft, migrate, differentiate into neurons and glial cells, and possess the ability to survive for as long as one year with no sign of tumor formation or adverse effects. These findings show that HuCNS-SC cells, when transplanted, behave like normal stem cells, suggesting the possibility of a continual replenishment of normal human neural cells.

StemCells recently completed a Phase I clinical trial of its HuCNS-SC cells for the treatment of a Neuronal Ceroid Lipofuscinosis (NCL), a fatal brain disorder in children. Data from this trial demonstrated the safety and tolerability of these cells. StemCells has also announced that it will soon initiate at the University of California, San Francisco (UCSF) Children’s Hospital a Phase I trial of the HuCNS-SC cells in Pelizaeus-Merzbacher Disease (PMD), a fatal myelination disorder that primarily affects young children. The human safety data that StemCells is accumulating for its HuCNS-SC cells through these clinical trials is expected to facilitate the pathway for future clinical testing in other central nervous system disorders, including retinal degenerative diseases such as AMD and retinitis pigmentosa.

About StemCells, Inc.

StemCells, Inc. is focused on the development and commercialization of cell-based technologies. In its cellular medicine programs, StemCells is targeting diseases of the central nervous system and liver. StemCells’ lead product candidate, HuCNS-SC^® cells (purified human neural stem cells), is in clinical development for the treatment of two fatal neurodegenerative disorders that primarily affect young children. StemCells also markets specialty cell culture media products under the brand SC Proven^®, and is developing its cell-based technologies for use in drug screening and drug development. The Company has exclusive rights to approximately 55 issued or allowed U.S. patents and approximately 200 granted or allowed non-U.S. patents. Further information about StemCells is available on its web site at www.stemcellsinc.com.

About OHSU and Casey Eye Institute

Oregon Health & Science University is the state's only health and research university, and Oregon's only academic health center. OHSU is Portland's largest employer and the fourth largest in Oregon (excluding government). OHSU's size contributes to its ability to provide many services and community support activities not found anywhere else in the state. It serves patients from every corner of the state, and is a conduit for learning for more than 3,400 students and trainees. OHSU is the source of more than 200 community outreach programs that bring health and education services to every county in the state.

The Casey Eye Institute, named after the founders of United Parcel Service, opened on the OHSU Marquam Hill Campus in 1991. The Casey Eye Institute is an academic regional eye center dedicated to preventing blindness through research, and to bringing advanced technology to the Pacific Northwest through continuing education of physicians. Casey is the seventh and final regional eye research center in the nation sponsored by Research to Prevent Blindness, the world's leading voluntary organization in support of eye research.

Apart from statements of historical fact, the text of this press release constitutes forward-looking statements regarding, among other things, the potential of the Company’s neural stem cells to treat retinal disorders such as AMD, the Company’s plans to pursue additional studies of its neural stem cells for the treatment of retinal disorders, and the prospects for future commercialization of a product to treat retinal disorders. These forward-looking statements speak only as of the date of this news release. The Company does not undertake to update any of these forward-looking statements to reflect events or circumstances that occur after the date hereof. Such statements reflect management’s current views and are based on certain assumptions that may or may not ultimately prove valid. The Company’s actual results may vary materially from those contemplated in such forward-looking statements due to risks and uncertainties to which the Company is subject, including: uncertainties with respect to the fact that additional preclinical studies followed by clinical trials will be required to confirm the safety and demonstrate the efficacy of the Company’s HuCNS-SC cells for the treatment of retinal disorders or any other disease; risks whether the FDA or other applicable regulatory agencies will permit the Company to continue clinical testing of its HuCNS-SC cells in NCL, PMD or in future clinical trials for retinal disorders or other diseases or conditions despite the novel and unproven nature of the Company’s technologies; uncertainties about the design of future clinical trials and whether the Company will receive the necessary support of a clinical trial site and its institutional review board to pursue future clinical trials in NCL, PMD, retinal disorders or in proposed therapies for other diseases or conditions; uncertainties regarding the Company’s ability to obtain the increased capital resources needed to continue its current and planned research and development operations, uncertainty as to whether HuCNS-SC cells and any products that may be generated in the future in the Company’s cell-based programs will prove safe and clinically effective and not cause tumors or other adverse side effects; uncertainties regarding whether results in preclinical research in animals will be indicative of future clinical results in humans; uncertainties regarding the Company’s manufacturing capabilities given its increasing preclinical and clinical commitments; and other factors that are described under the heading "Risk Factors” in the Company’s Annual Report on Form 10-K for the year ended December 31, 2008 and in its subsequent reports on Form 10-Q and Form 8-K.