MENLO PARK, CA, USA I May 22, 2014 I Asterias Biotherapeutics (“Asterias”) presented today the results of its Phase 1 clinical trial assessing the safety of its product, AST-OPC1, in subjects with spinal cord injury. The results were presented by Dr. Jane Lebkowski, President of R&D of Asterias, at the American Society for Gene and Cell Therapy (ASGCT) Annual Meeting in Washington, DC. The study represented the first-in-man trial of a cell therapy derived from human embryonic stem cells (hESCs). The study was first initiated by Geron Corporation in 2010; in 2013 Asterias acquired all of Geron’s stem cell assets. The results provide support for the safety of the product and provide a path for advanced clinical studies of AST-OPC1. The full contents of Dr. Lebkowski’s presentation are available on Asterias’ website, www.asteriasbiotherapeutics.com.
AST-OPC1 is a population of cells derived from hESCs that contain oligodendrocyte progenitor cells (OPCs). OPCs and oligodendrocytes provide several important supportive functions for nerve cells in the central nervous system. In the phase 1 clinical trial, five patients with neurologically complete, thoracic spinal cord injury as classified by the American Spinal Association Impairment Scale, were administered a relatively low dose of two million AST-OPC1 cells at the spinal cord injury site 7-14 days post-injury. The subjects received low levels immunosuppression for the next 60 days. The patients have been followed to date for 2-3 years through numerous clinical visits, MRIs, and neurological assessments. The trial was conducted by Dr. David Apple at the Shepherd Center in Atlanta GA, Dr. Richard Fessler at Northwestern University in Chicago IL, and Drs. Gary Steinberg and Stephen McKenna at Stanford University/Santa Clara Valley Medical Center in Palo Alto, CA.
Delivery of AST-OPC1 was successful in all five subjects with no serious adverse events associated with the intraoperative administration of the cells. In addition, there were no serious adverse events associated with AST-OPC1 itself, or the immunosuppressive regimen. There was no evidence of expanding masses, expanding cysts, infections, cerebrospinal fluid leaks, increased inflammation, or neural tissue deterioration at the injury site of these subjects. Immune monitoring of subjects through one year post-transplantation showed no evidence of antibody-based or cellular immune responses to AST-OPC1, despite complete withdrawal of all immunosuppression at sixty days post-transplant. In four of the five subjects, serial MRI scans performed throughout the 2-3 year follow-up period indicate that reduced spinal cord cavitation may have occurred and that AST-OPC1 may have had some positive effects in reducing spinal cord tissue deterioration. This effect was seen in the animal model testing of AST-OPC1. There were no unexpected neurological degenerations or improvements in the five subjects in the trial as evaluated by the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) exam. Patients in the trial will be followed for a total of 15 years.
There have been three serious adverse events observed in the trial that were not associated with AST-OPC1, its delivery or the transient immunosuppression, but which are common in spinal cord injury patients. These included one each of pyelonephritis, urinary tract infection, and dyspnea due to autonomic dysreflexia. There were no deaths in the trial.
“We are grateful to our patients, clinical investigators and their institutions for their tremendous support throughout the execution of this first-in-human trial of a human embryonic stem cell based therapy,” stated Dr. Edward Wirth III, Chief Translational Officer of Asterias.
“The safety demonstrated in this trial positions Asterias to start a new phase 1/2a clinical trial in 2014, subject to clearance from the FDA,” stated Dr. Lebkowski.
“Spinal cord injury represents a tremendous unmet medical need that not only results in severe disability, but can also significantly shorten the projected lifespan of affected individuals,” stated Dr. Stephen McKenna, Director of the Rehabilitation Trauma Center, Santa Clara Valley Medical Center. “There are no approved therapies that can repair spinal cord injuries. We look forward to participating in the future clinical development of AST-OPC1.”
About Spinal Cord Injury and AST-OPC1
Over 12,000 individuals suffer a spinal cord injury (SCI) each year in the United States alone, and approximately 1.3 million Americans are estimated to be living with a spinal cord injury. Traumatic SCI most commonly impacts individuals in their 20s and 30s, resulting in a high-level of permanent disability in young and previously healthy individuals. Individuals with SCI not only have impaired limb function, but suffer from a wide range of additional disabilities which can each significantly impact quality of life, and can even be life threatening in some instances. According to the National Spinal Cord Injury Statistical Center, the life expectancy of an individual suffering a cervical spinal cord injury at age 20 is 20-25 years lower than that of a similarly aged individual with no SCI.
In addition to its dramatic impact on quality of life for patients and their families, SCI is responsible for tremendous costs to society. At one year post injury, only 11.8% of SCI patients are employed, and fewer than 35% are employed even at more than twenty years post-injury. Additionally, many patients require help with activities of daily living such as feeding and bathing. As a result, the lifetime cost of care for SCI patients are enormous; a recent paper estimated lifetime costs of care for a patient sustaining a cervical SCI at age 25 at $4.2 million. Overall, it has been estimated that SCIs cost the U.S. over $14.5 billion per year in direct medical costs and disability support, plus an additional $5.5 billion in lost productivity.
There are currently no approved therapies for the treatment of SCI, and the complex pathology of the injury is unlikely to be addressed by a traditional small molecule or protein therapeutic. AST-OPC1, an oligodendrocyte progenitor population derived from human embryonic stem cells, has been shown to have three potentially reparative functions which address the complex pathologies observed at the SCI injury site. These activities of AST-OPC1 include production of neurotrophic factors, stimulation of vascularization, and induction of remyelination of denuded axons, all of which are critical for survival, regrowth and conduction of nerve impulses through axons at the injury site. In preclinical animal testing, AST-OPC1 administration led to remyelination of axons, improved hindlimb and forelimb locomotor function, dramatic reductions in injury-related cavitation and significant preservation of myelinated axons traversing the injury site.
About Asterias Biotherapeutics
Asterias Biotherapeutics (“Asterias”) is a biotechnology company focused on the emerging field of regenerative medicine. Our core technologies center on stem cells capable of becoming all of the cell types in the human body, a property called pluripotency. We plan to develop therapies based on pluripotent stem cells to treat diseases or injuries in a variety of medical fields, with an initial focus on the therapeutic applications of oligodendrocyte progenitor cells (AST-OPC1) and antigen-presenting dendritic cells (AST-VAC1 and AST-VAC2) for the fields of neurology and oncology respectively. AST-OPC1 was tested for treatment of spinal cord injury in the world’s first Phase 1 clinical trial using human embryonic stem cell-derived cells. We plan to seek FDA clearance to reinitiate clinical testing of AST-OPC1 in spinal cord injury this year, and are also evaluating its function in nonclinical models of multiple sclerosis and stroke. AST-VAC1 and AST-VAC2 are dendritic cell-based vaccines designed to immunize cancer patients against telomerase, a protein abnormally expressed in over 95% of human cancer types. AST-VAC2 differs from AST-VAC1 in that the dendritic cells presenting telomerase to the immune system are produced from human embryonic stem cells instead of being derived from human blood.
In October of 2013, Asterias acquired the cell therapy assets of Geron Corporation. These assets included INDs for the clinical stage AST-OPC1 and AST-VAC1 programs, banks of cGMP-manufactured AST-OPC1 drug product, cGMP master and working cell banks of human embryonic stem cells, over 400 patents and patent applications filed worldwide including broad issued claims to fundamental platform technologies for the scalable growth of pluripotent stem cells and compositions of matter for several hESC-derived therapeutic cell types, research cell banks, customized reagents and equipment, and various assets relating to the AST-VAC2 program and preclinical programs in cardiology, orthopedics, and diabetes.
SOURCE: Asterias Biotherapeutics
