Tying Higher Order Structure with in-vitro

Transcription

1 Tying Higher Order Structure with in-vitro Activity Through a Forced Degradation Study Laura Duitch Haihong Fan Wasfi Al-Azzam HOS 2013 Feb Property of GlaxoSmithKline

2 Outline Introduction Study Design ph3 ph10 Thermal Results FTIR/Near UV ECD Spectra Quantitative Spectral Analysis SEC, cief, Biacore, Cell Based Potency Assay Conclusions

3 Introduction Particles Aggregates Normal Activity Fragments

4 Study Design Bulk Batch IgG Stres ss Condit tion BDS BDS BDS mg/ml mg/ml mg/ml Acidic; ph 3; Basic; ph10 Thermal 1M HCl 1M NaOH 50 C Day Day Day Day Day 0 Day Day Day Day Day Day Day Pu ulling Time points SEC, cief, Biacore, Cell Based Potency Assay, FTIR, & near-uv ECD

5 ph 3 ph C

6 Second Derivative FTIR Spectra at ph Progressive Shifts in spectral features Arbitray Units (AU) Reference Standard Day 0 Day 1 Day 3 Day Intra-Molecular β- Sheet 1637cm -1 Decreasing in intensity Shifting to lower wavenumbers Inter-Molecular β- Sheet 1621cm -1 Growing peak with time Wavenumber (cm -1 )

7 Tertiary Structure by Near UV CD spectra at ph3 50 Elipticity 0-50 No significant shifts in the near-uv ECD spectra Molecular RS Day 0 Day 1 Day 3 Day Wavelength (nm)

8 Analyzing FTIR Spectra Spectral Comparisons Spectral Correlation Coefficient (SCC) Most commonly used Area Overlap (AO) Create an overlap spectrum Modified Area Overlap (MAO) Square the intensity at each wavenumber Create an overlap spectrum Secondary Structure Quantification PROTA (Biotools) Factor analysis Uses crystal structure data and known FTIR spectra in a database Compiles the best fit of the unknown spectra Al-Azzam, W. JPharmSci. Comparability of protein therapeutics: Quantitative comparison of second-derivative amide I infrared spectra, Vol. 101, , 2012

9 Second Derivative FTIR Spectral Comparisons (ph 3) % Similar Reference Standard Day 0 Day 1 Day 3 Day 6 Area Overlap Modified AO SCC Comparison Three methods to assess spectral similarity Reference standard compared to itself to establish a baseline Each trial of each day was compared to all three trials of reference standard All three comparison methods agree with progressive structural changes as a function incubation time

10 Secondary Structure Quantification of FTIR Spectra by PROTA (ph 3) Reference Standard Day 0 Day 1 Day 3 Day 6 Progressive decrease in helix content and increase in sheet content % Co ontent % Helix Helix Sheet Bend Turn Coil Structure y= x r 2 = % Sheet

11 Correlating HOS with in-vitro Activity Structural changes detected by FTIR correlates well with gradual decreases in antigen binding and relative potency As % sheet increases and % helix decreases, % aggregate is % gg g increasing

12 Correlation Between Secondary Structure, Aggregates, and Binding by Biacore at ph % Aggreg gate % Antigen Binding y=( x)/( x) r 2 = y = -2.00x r 2 = % Beta Sheet % Aggregate As % beta sheet increases, the % aggregate also increases As aggregation grows there is a direct correlation with loss of binding activity

13 ph 3 ph C

14 Second Derivative FTIR and Near-UV ECD Spectra at ph Arbitrary Units (A AU) Reference Standard Day 0 Day 1 Day 3 Day Molar Elipticity Ref Std Day 0 Day 1 Day3 Day Wavenumber (cm -1 ) 1 Wavelength (nm) Second derivative amide I IR and near-uv ECD spectra at ph10 over 6 days show minor spectroscopic differences

15 Correlating HOS with in-vitro Activity (ph 10) % Day 0 Day 1 Day 3 Day 6 No significant changes in secondary structure A slight increase in aggregation with time An increase in the Acidic peak %Acidic peak An increase in binding at day 6 Possibly due to aggregation 0 AO % Aggregatee Antigen Binding Relative Potency % Acidic (cief) % Helix % Sheetet

16 Different Degradation Pathways CH2 CH3 CH3 CH3

17 ph 3 ph C

18 Second Derivative FTIR Spectra, Near-UV ECD and Correlations at 50 C trary Units (AU) Arbit Reference Standard Day 0 Day 1 Day 3 Day % Day 0 Day 1 Day 3 Day 6 Molar Elipticity Wavenumber (cm -1 ) Ref Std -150 Day 0 Day 1 Day 3 Day Wavelength (nm) 0 AO % Aggregate Antigen Binding Relative Potency % Acidic (cief) % Helix % Sheet Second derivative amide I IR and near-uv ECD spectra at 50C over 6 days show minor spectroscopic differences There are very slight trends in some of the techniques

19 Conclusions There is a time dependant loss in activity and shift in secondary structure when the IgG is exposed to low ph The FTIR could pick up these structural changes A slight increase in activity on day 6 as well as a time dependent increase in aggregation and acidic species was observed when the IgG was exposed to high ph There was no significant loss in activity or change in structure to the IgG when exposed to heat Correlating higher order structure attributes with in-vitro data provides insights into degradation pathways with different stresses These insights can provide useful data for formulation development as well as stability

20 Thank you Aston Liu Lee Olszewski BAS Joe Minetti Peter Suchecki Marisa Jones Terri Westervilt Hillary Montgomery Will Riches Yu Xue

21 Property of GlaxoSmithKline

22 Back Up Slides

23 Spectral Correlation Coefficient (SCC) Correlation coefficient, r, is calculated using the following equation r = N x i y i 2 2 yi x i y where x i and y i represent the spectral absorbance values of the reference and sample spectra at the ith frequency position r value of 0.0 indicates no similarity between spectra r value of 1.0 indicates that spectra are identical

24 Area Overlap (AO) The maximum signal between two spectra at the each wavenumber was recorded to create an overlap spectrum Wavenumber (cm -1 ) Reference standard Sample Area Overlap: 82% % AO = Area Area Reference overlap *100

25 Modified Area Overlap (MAO) MAO method was developed in order to enhance the sensitivity of the AO algorithm. Square the signal at each wavenumber. Modified Area Overlap (MAO) method amplifies the residual intensity near the baseline throughout the entire range. S = MAO ( S 2 2 nd. der. ) A sq S 2nd.der. : signal of the 2 nd derv. spectrum at a given wavenumber A sq : is the total area of (S 2nd Der ) 2 S MAO : the resulting signal Al-Azzam, W. JPharmSci. Comparability of protein therapeutics: Quantitative comparison of second-derivative amide I infrared spectra, Vol. 101, , 2012

26 PROTA Structure Analysis (Thermal) Reference Standard Day 0 Day 1 Day 3 Day 6 % Co ontent Helix Sheet Bend Turn Coil Structure

27 Spectral Comparisons (Thermal) % Similar Area Overlap Modified AO SCC Reference Standard Day 0 Day 1 Day 3 Day 6 Comparison

28 PROTA Structure Analysis (ph 10) Reference Standard Day 0 Day 1 Day 3 Day 6 ent % Cont Helix Sheet Bend Turn Coil Structure

29 Spectral Comparisons (ph 10) % Similar Reference Standard Day 0 Day 1 Day 3 Day 6 AO MAO SCC Comparison