Table 1.

Potential complications of gene therapy

General	AAV-FIX specific*	Potential solutions	References
Gene silencing	—	—	—
Genotoxicity	—	—	—
Immunotoxicity	Neutralizing antibodies that block delivery	Current; exclude subjects with neutralizing antibodies	—
		Plasmapheresis?	23
		Pharmacologic reduction of antibodies?	24, 25
	T-cell response to capsid	Prednisolone	2
Phenotoxicity	—	—
Vertical transmission	Risk of germline transmission	Barrier birth control until semen is negative by PCR	14
Horizontal transmission	—	—	—

— indicates not applicable.

^*Based on observations in clinical trials.