Exploring the optimum approach to the use of CT densitometry in a randomised placebo-controlled study of augmentation therapy in alpha 1-antitrypsin deficiency

Table 4 Changes in PD15 (g/L) in basal, middle and apical regions of the lung in patients treated with Prolastin versus placebo (mITT population)

Basal region	Prolastin (n = 36)	Placebo (n = 35)
Change from baseline to last CT scan (mean ± SD)	-2.336 ± 4.362	-3.760 ± 4.284
Change from baseline to last CT scan (LS mean [SE])	-2.118 (0.587) 0.0006^a	-3.840 (0.604) < 0.0001^a
Estimated treatment difference between LS mean changes from baseline (95% CI)	1.722 (0.082, 3.362)
p value for treatment difference^b	0.040
Middle region	Prolastin (n = 36)	Placebo (n = 35)
Change from baseline to last CT scan (mean ± SD)	-2.845 ± 5.796	-3.838 ± 4.696
Change from baseline to last CT scan (LS mean [SE])	-2.504 (0.655) 0.0003^a	-3.816 (0.673) < 0.0001^a
Estimated treatment difference between LS mean changes from baseline (95% CI)	1.312 (-0.511, 3.135)
p value for treatment difference^b	0.155
Apical region	Prolastin (n = 36)	Placebo (n = 35)
Change from baseline to last CT scan (mean ± SD)	-3.503 ± 7.433	-3.911 ± 5.939
Change from baseline to last CT scan (LS mean [SE])	-3.217 (0.990) 0.0018^a	-3.799 (1.001) 0.0004^a
Estimated treatment difference between LS mean changes from baseline (95% CI)	0.581 (-2.159, 3.322)
p value for treatment difference^b	0.673

PD15, 15th percentile lung density; CT, computed tomography; SD, standard deviation; LS mean, least squares mean; SE, standard error; 95% CI, 95% confidence interval. ^ap values are for the comparison of change from baseline to last CT scan versus no change from baseline within the individual treatment groups. ^bProlastin treatment minus placebo (LS mean change).

ISSN: 1465-993X