Table 3.

Pharmacological and clinical characteristics of PegIFN-α-2a and PegIFN-α-2b.

Characteristic	PegIFN-α-2a	PegIFN-α-2b
PEG structure	Branched 40-kDa	Linear 12-kDa
Molecular weight	~60 kDa	~31 kDa
Half-life	~80 hours	~40 hours
Volume of distribution	Largely vascular	Wider tissue distribution
Dosing regimen	Fixed dose: 180 μg weekly	Weight-based: 1.5 μg/kg weekly
Primary clearance	Hepatic + renal	Hepatic + renal
Key references	(32, 35)	(32–35)

Data compiled from (32–35). Half-life values represent population estimates and may vary between individuals.

PEG, polyethylene glycol; kDa, kilodalton; μg, microgram; wk, week.