# Presentation: 425483

## Use of Analytical and Characterization Technology for the Development of     Follow-On Protein Products

- Andrew J.S.  Jones, D. Phil.Staff Scientist,
- Formulation and Analytical DevelopmentGenentech, Inc.

## Requirements for the Development of Protein Products

- Production cell line:  Substrate safety demonstration and genetic consistency
- Process:  Characterization and validation
- Drug substance:  Extended characterization of lots used in clinical trials
- Control System and specifications

- Analytical/characterization technology is used to address and ensure consistency of safety and efficacy.

## Capability of Current Analytical Technology  Non-Resolving Methods

- Spectroscopy (CD, UV/Vis/fluorescence etc.) immunoassays, NMR, etc., rarely have sufficient dynamic range or precision to be informative for comparison purposes and are also inadequate substitutes for bioassays for demonstrating the presence of the correct 3D structure for activity.
- With regard to differences in structure,
-      “Absence of evidence is not evidence of absence.”

## Different processes yield different products :

- Jones AJS. Developments in biologicals. Karger (Basel) 2002:109;10718.

**Cause of Immunogenicity Remains Unknown**

## Capability of Current Analytical Technology:Resolving Methods 

- Resolving methods (chromatography, electrophoresis, MS etc.) provide very detailed information on structural and charge heterogeneity and are the main tools for characterization and for use in the Control System.
- They add to the accumulation of knowledge about the process AND product resulting in:
- Continuous improvement of characterization capability to enable the identification and control of critical product quality attributes
- The informed ability to select the most relevant and appropriate specific methods and conditions

- A follow-on manufacturer does not know WHAT is critical to measure.

## Complexity of Protein Products

**Complexity of Protein Products**

- Microheterogeneity is a natural property of glycoproteins. Analytical methods cannot usually prove “sameness” because of the complexity of the mixture.

- Capillary IEF of 3 glycoprotein lots

## GlycoproteinA’s Clearance Depends on Terminal GlcNAc(i.e., not the “usual” sialic acid content or IEF pattern)

## Factors to Consider When Assessing the Similarity of Different Protein Products

- Case-by-case approach!
**Clinical** experience	Identification of key parameters**Process** data	and selection of methods for**Analytical** data	use in the Control System and	comparability evaluations
- Clinical evaluation may be required to assess the consequences of a process change by an innovator........ ........even if only subtle changes are detected in the product.

## MAb 3:  Process Changes during Phase III

- Increase in percent Man5 oligosaccharide
- Mouse PK bioequivalence study was insufficient to resolve this matter
- Could only be resolved by a human PK bioequivalence study
- Bioequivalence was later demonstrated

## Improved Analytical Technologies May Reveal New Sources of Heterogeneity

- 1997MAb1 Light ChainGlycated Form Hidden in Baseline Noise
- (Early instrument)

- 1999MAb2 Light Chain
- Glycated Form is Clearly Distinguished
- (by new instrument)

- +162 Da (glycation)

- *

## Product X Cation Exchange ChromatographyChromatography columns improve over time

| Method | Number of Peaks | Modifications |
| --- | --- | --- |
| IND | 5 | 2 |
| Phase III | 8 | 5 |
| Post-approval | 10 | 7 |

## Use of Analytical Studies to Predict Safety and Efficacy

- Animal and human studies are required for evaluation of safety of both known and unknown components/variants.
- Clinical experience with the product of a controlled, consistent process and appropriate analytical characterization
- Beyond clinical trials, continued safety is ensured by the validated consistency of the:
- 		 Approved manufacturing process
- 	 	 Control System
-     The product

## Use of Analytical Studies to Predict Safety and Efficacy (cont’d)

- Potency assay
- 		 Typically shows only some aspects of 			biological activity
- 	  May not be directly related to MoA
- 		 Does not measure “efficacy” in man
- If there is no acceptable PD marker/surrogate, acceptable pharmacokinetics (“bioequivalence”) will not be sufficient to ensure comparable efficacy.
- Efficacy would need to be addressed.

## Conclusions

- Analytical technology cannot bring knowledge of a protein product and its heterogeneity to the same state as for a “small molecule.”
- 	“You don’t know what you don’t know.”
- What the innovator “doesn’t know” is not the same as what the follow-on manufacturer “doesn’t know”
-  However, the innovator has substantial clinical safety and efficacy data to address whether what remains unknown matters or not.