International Stem Cell Corporation Demonstrates Positive Animal Efficacy Results in Metabolic Liver Disease Program

CARLSBAD, CA--(Marketwire - February 12, 2013) - International Stem Cell Corporation (OTCQB: ISCO) (www.internationalstemcell.com) (“ISCO” or “the Company”) a California-based biotechnology company, today announced the conclusions from its study demonstrating the efficacy and safety of the hepatocyte-like cells (HLC) derived from human parthenogenetic stem cells (hpSC) in a well-established animal model of a congenital liver disorder associated with bilirubin metabolism. The data from this pre-clinical study indicates that implanting HLC in rodents produced both a significant initial decrease and the long-term stabilization of bilirubin levels in blood serum.

Criggler-Najjar syndrome type 1 (CN1) is a rare inherited metabolic disorder in which the sufferer’s liver lacks a specific enzyme -- UGT1A1, which is essential for the clearance of the toxin bilirubin. The syndrome results in unconjugated hyperbilirubinemia, a disorder characterized by severe neurological complications which, if left untreated, can lead to irreversible acute encephalopathy. Allogenic hepatocyte transplantation (HT) has been used as an alternative therapeutic option for patients with liver-based metabolic diseases including CN1. However, one of the major factors limiting the clinical advancement of human HT is a shortage of mature, functioning human hepatocytes as well as the limited repopulation capacity of grafted adult cells.

The use of HLCs to treat CN1 has several potential advantages over transplantation of primary hepatocytes. Firstly, HLC would circumvent the shortage of primary cells, as they can be produced and expanded in vitro. Secondly, there is evidence to suggest that grafting HLC may yield better long-term repopulation and persistent metabolic activity than using immature fetal hepatocytes. HLCs can also be given before the onset of bilirubin encephalopathy occurs, and can thus provide sufficient amounts of UGT1A1 to allow the liver to metabolize this toxin.

ISCO has previously reported how these HLC engraft in the liver of Gunn rats, a well-validated model of CN1 where the animals lack UGT1A1 and therefore accumulate toxic levels of unconjugated bilirubin. In addition to this result, no adverse safety signals were detected 16 weeks after the implantation of a therapeutic dose of HLC, and serum levels of bilirubin continued to decline, compared with the control group, up to the conclusion of the observation period at week 19. Moreover, the overall structure and morphology of the liver in all rodents in the treatment group appeared to be undamaged, with no apparent inflammation, tumorigenicity or cell rejection observed.

Dr. Ruslan Semechkin, Vice President - head of R&D for ISCO comments: “This study provides important evidence for the use of our HLC product as a viable source of transplantable cells for the treatment of CN1. Having completed this study, we can now discuss with the FDA the requirements for our Investigational New Drug (IND) application and phase 1 clinical trial.”

About International Stem Cell Corporation

International Stem Cell Corporation is focused on the therapeutic applications of human parthenogenetic stem cells (hpSCs) and the development and commercialization of cell-based research and cosmetic products. ISCO’s core technology, parthenogenesis, results in the creation of pluripotent human stem cells from unfertilized oocytes (eggs) hence avoiding ethical issues associated with the use or destruction of viable human embryos. ISCO scientists have created the first parthenogenetic, homozygous stem cell line that can be a source of therapeutic cells for hundreds of millions of individuals of differing genders, ages and racial background with minimal immune rejection after transplantation. hpSCs offer the potential to create the first true stem cell bank, UniStemCell™. ISCO also produces and markets specialized cells and growth media for therapeutic research worldwide through its subsidiary Lifeline Cell Technology (www.lifelinecelltech.com), and stem cell-based skin care products through its subsidiary Lifeline Skin Care (www.lifelineskincare.com). More information is available at www.internationalstemcell.com.

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