Table 2.

Ex vivo gene therapy vectors under development for the treatment of LSDs.

LSD	Drug Name and Trial ID	Action Mechanism	Trial Phase
GD	AVR-RD-02 (NCT04145037)	CD34+ cells from patients treated with a Lentiviral vector to correct mutations in GBA	I/II
FD	AVR-RD-01 (NCT03454893)	CD34+ cells from patients treated with a Lentiviral vector to correct mutations in GLA	I/II
MLD	OTL-200 [53] (NCT04283227 III) (NCT03392987) (NCT01560182)	CD34+ cells from patients treated with a Lentiviral vector to correct mutations in ARSA	I/II
MPSI	IDUA LV (NCT03488394)	Lentivirus-based vector to correct defects in IDUA gene in CD34+ cells	I/II
MPS II	L2SN-transduced lymphocytes	Mononuclear cells from blood are extracted from patients and transduced with a retroviral vector which express iduronate-2-sulphatase. Cells are stimulated in order to enrich the lymphocyte T population which are re-implanted in the same patient	I/II