Table 4.

Summary of studies on benzamide M344 for the treatment of spinal muscular atrophy.

Study	Country	Study type	Results	Disadvantage
Riessland et al. (2006)	Germany	In vitro (cell-based)	M344 increased FL-SMN2 mRNA levels by restoring the splicing pattern and transcriptional activation of SMN2; there was also an increase in the level of SR and SR-like splicing factors and in the number of nuclear gems. M344 increased the SMN protein levels by 3–7 folds at concentrations of 30–50 μM after 64 h of treatment.	Cytotoxic at > 50μM (MTT assay)
Hahnen et al. (2006)	Germany	In vitro (cell-based) Ex vivo	M344 increased the SMN protein levels in human SMA-affected fibroblasts by up to 168% at 10 μM. In rat OHSC the SMN transcript levels increased by 149% after a 48 h exposure to M344.	Cytotoxic for rat OHSC at > 20 μM (propidium iodide staining)
Hauke et al. (2009)	Germany	In vitro (cell-based)	M344 increased the total SMN2 transcript levels in human OHSC by up to 188% at 16 μM by bypassing gene silencing.	Not reported