Zeitschrift für klinische Toxikologie
Offener Zugang
ISSN: 2161-0495
ISSN: 2161-0495
Tehila Sonnenfeld*, Einat Rauchbach*, Rotem Downey*, Daniel Blumenkrants, Arik Hasson, Graciela Kuperstein, Noam Kronfeld, Raanan Margalit, Kfir Molakandov, Vered Morad, Abraham Nyska, Shalom Guy Slutsky, Michel Revel, Michal Izrael*
Background: AstroRx® is an allogeneic cell therapy, composed of healthy and functional human astrocytes derived from pluripotent embryonic stem cells. An intrathecal injection of a fresh formulation of AstroRx® cells for the treatment of Amyotrophic Lateral Sclerosis (ALS) was evaluated in an early-phase I/IIa clinical trial. The results of this study indicated that the treatment is safe and showed a signal of a clinical benefit in attenuating ALS progression. Due to the logistical challenges associated with the manufacturing and distribution of a fresh cell product and to allow completion of safety and quality control testing before cell administration, a cryopreserved formulation of AstroRx® was developed. The cryopreseved AstroRx® product includes 3.5% DMSO as a cryoprotectant. Upon thawing at the clinical site, the cryopreserved product is diluted before its use to achieve a concentration of 0.23% DMSO.
Objective: To evaluate the toxicity of DMSO-containing cryopreserved AstroRx® as compared to the fresh AstroRx® following their intrathecal injection into mice.
Methods: In vitro compatibility assessment between cryopreserved and fresh AstroRx® formulations, including cell viability, cell number, cell identity, impurities, safety and potency, was performed. In addition, a neurotoxicity assessment of intrathecal injection of DMSO alone was tested in immunocompetent Institute of Cancer Research (ICR) mice using two concentrations of DMSO, 0.25% and 0.5%. The neurotoxicity of DMSO-containing cryopreserved AstroRx® product was evaluated in immunodeficient NSG mice.
Results: In vitro comparability results demonstrated similarity between fresh AstroRx® (n=13) and cryopreserved AsrtroRx® (n=11) cell batches in all tested parameters. Intrathecal injection of DMSO at a concentration of 0.25% or 0.5% showed no difference, as compared to the control group, in food consumption, body weight, clinical symptoms, as well as neurological locomotor and beam tests, for 7 days post injection. Similarly, a single intrathecal injection of AstroRx® cryopreserved with DMSO following thawing or fresh AstroRx® to NOD scid gamma mice (NSG) mice was not associated with neurological signs or major systemic adverse effects during the 4 week study period. The presence of both fresh and cryopreserved AstroRx® cells at 4 weeks post injection was confirmed by Alu in-situ hybridization.
Conclusion: According to the study findings, intrathecal injection of a DMSO-containing formulation of cryopreserved AstroRx® cells does not appear to have a toxic effect on mice.