CNTF and amyotrophic lateral sclerosis: Encapsulation is a promising approach to reduce the risks and complications associated with cellular therapies in the central nervous system: In a first phase I clinical trial in ALS to assess safety and tolerability of encapsulated genetically engineered baby hamster kidney (BHK) cells releasing human ciliary neurotrophic factor (CNTF), therapeutic levels of the secreted peptide could be detected for several weeks without limiting side effects [37].