Observations on Marketed Alpha-1-Proteinase Inhibitor Products

Ewa Marszal, PhD

FDA/CBER

BPAC, November 2005

Presentation Contents

Differences between 1-PI products

Consistency of manufacturing

Differences between 1-PI products

Contaminating plasma proteins

Inactive 1-PI (e.g., polymer/latent form)

Modifications of the primary structure

Protein impurities(SDS-PAGE, reducing)

Prolastin Aralast Zemaira

albumin →1-PI →

Specific activity: ≥ 0.35 ≥ 0.55 ≥ 0.7mg functional 1-PI/mg total protein

-4 0 0 0 0 0

-2 0 0 0 0 0

0

2 0 0 0 0 0

4 0 0 0 0 0

6 0 0 0 0 0

8 0 0 0 0 0

1 E +0 6

1 E +0 6

0 5 1 0 1 5 2 0 2 5 3 0 3 5

Presence of high molecular weight species(SE-HPLC, absorbance@215 nm)

M%

95.4

89.8

88.1

Zemaira

Aralast

ProlastinM

1-PI + albumin)

Isoelectric focusing (IEF)

cathode (-)

anode (+)

pH gradient

higher pH

lower pH

zero net charge

Heterogeneity of 1-PI in plasma by IEF(charge heterogeneity)

3 polysaccharide chains (sialic acid)

N-terminal pentapeptide EDPNG

Polymorphism, e.g., E342K

EDPNG N N N

EDPNG N N NM6

M4

M2

Dominant 1-PI isoforms in plasma (charge heterogeneity)

EDPNG N N N

Heterogeneity of 1-PI products by IEF P

lasm

a

Ara

last

Zem

aira

Pro

last

in

Pla

sma

Ara

last

Zem

aira

Pro

last

in

desialylated

M6 → M4 → M2 →

Consistency of manufacturing by IEF

Analysis of patients’ plasma from Aralast pivotal clinical trial

Analysis of current and historical lots of 1-PI products

Conclusions

1-PI products contain: different levels of contaminating plasma proteins different amounts of inactive 1-PI species different levels of primary structure modifications

1-PI in each product differs somewhat from 1-PI in plasma (IEF, polymer)

Manufacturing of each 1-PI product appears to be consistent over time by IEF

Consistency of manufacturing

Bayer Baxter Behring

Desialylated

Non-desialylated