Background: Phase III studies of B in unselected pts with APCA have demonstrated no improvement in outcome. Recent data suggest certain subsets of APCA patients may benefit from B. Lower b- alb results in a 15-20% increased rate of B clearance that may decrease exposure to B. The resulting clinical implications are not well understood. We evaluated the potential predictive and prognostic role of b-alb in pts with APCA receiving gemcitabine (G)-based tx with or without B. Methods: Relevant data were collected from 3 prospective phase II studies of G-based tx. Pts were grouped according to exposure to B (Gr 1) or no B (Gr 2) and by b-alb < 3.4 g/dL (< LLN) or > 3.4 g/dL (>LLN). Univariate and multivariate analyses of clinical outcome (OS, TTP) were conducted for each group and all pts. Results: 100 pts (46M, 54F) with median age 63 (range 28-82) were included. 94% had stage IV. Median b-alb was similar in both groups. Clinical outcomes by alb are outlined in the table. In Gr 1 but not Gr 2, b-alb > 3.4 g/dL was significantly associated with improved OS and TTP. For pts with b-alb >3.4 g/dL, maintenance of alb >3.4 g/dL throughout tx was significantly associated with improved survival in Gr 1 but not Gr 2. Multivariate analysis revealed significant association between alb > 3.4 and OS regardless of B status (p=0.004) although this was strongly influenced by the survival differential in Gr 1. Conclusions: APCA pts with b-alb > 3.4 g/dL appear to derive significant benefit from B and this benefit is most pronounced in pts who maintain alb > 3.4 g/dL throughout B tx. This finding was not observed in pts treated without B. b-alb > 3.4 g/dL including maintenance of alb > 3.4 g/dL during B tx may predict for improved efficacy of B in APCA. These findings require further investigation in larger prospective trials.

Clinical outcome according to alb.

	Group 1 (N=42)			Group 2 (N=58)
	b-alb > 3.4 g/dL (N=28)	b-alb < 3.4 g/dL (N=14)	p	b-alb > 3.4 g/dL (N=43)	b-alb < 3.4 g/dL (N=15)	p
mOS (m)	10.7	3.1	0.00175	7.3	5.4	0.22
mTTP (m)	7.7	2.7	0.009	3.9	2.8	0.76
	alb > 3.4 w/tx (N=9)	alb ↓to < 3.4 w/tx (N=19)	p	alb >3.4 w/tx (N=8)	alb ↓to < 3.4 w/tx (N=29)	p
mOS (m)	20.1	8.6	0.003	8.9	5.9	0.63