Table I.

Characteristics and methodological quality of the randomized controlled trials for sipuleucel-T compared to placebo for castration-resistant prostate cancer

Parameter		D9901 (Small et al. 2006) [21]	D9902A (Higano et al. 2009) [25]	IMPACT (Kantoff et al. 2010) [26]
Number of participants in study group	Sipuleucel-T	82	65	341
	Placebo	45	33	171
Median age of participants		Approx. 72 years (47-86)	Approx. 71 years (51-87)	Approx. 70 years (40-91)
Diagnosis and eligibility criteria		Men with asymptomatic metastatic hormone refractory prostate cancer (HRPC); expected survival of at least 3 months	Men with asymptomatic metastatic hormone refractory prostate cancer (HRPC); expected survival of at least 3 months	Men with metastatic castration-resistant prostate cancer; expected survival of at least 6 months; any Gleason score; patients with asymptomatic disease or minimally symptomatic
Median serum prostate specific antigen (PSA) level (range)		Approx. 47 ng/ml (3.5-3621.0 ng/ml)	Approx. 50 ng/ml (8.0-1342.0 ng/ml)	> 5 ng/ml; approx. 50.0 ng/ml
Serum testosterone level		< 50 ng/dl (< 17 nmol/l)	< 50 ng/dl (< 17 nmol/l)	< 50 ng/dl (< 17 nmol/l)
Design		Double-blind, randomized; possibility to allocate from placebo group after disease progression	Double-blind, randomized; possibility to allocate from placebo group after disease progression	Double-blind, randomized; possibility to allocate from placebo group after disease progression
Randomization		2: 1; block randomization stratified by: study center and bisphosphonate use	2: 1; block randomization stratified by: study center and bisphosphonate use	2: 1; stratified by: Gleason score, number of bone metastases, bisphosphonate use
Jadad score		3	3	3