A streamlined approach to biosimilar development to reduce timelines using insights gained from work on hundreds of biosimilar programs.

1. Increasing the Likelihood
of Biosimilar Success with
Chemistry, Manufacturing
and Control
Siân Estdale BSc, MPhil, PhD
Head of Science and Innovation, Chemistry Solutions
To date, there have been 18 biosimilars approved by the FDA through the 351(k) pathway as of the
end of March 2019. Though this demonstrates the strength of the biosimilars market, there are also
hurdles that prevent a number of biosimilars from reaching their intended targets.
Challenges typically arise when a program has failed to progress either during or subsequent to
submission of the first in man stage. Though there are a variety of reasons, some may have been
abated with earlier understanding during the CMC characterization stage. During these activities,
learnings around the structure/function relationship of the molecule could significantly contribute
to a more effective, efficient and economical biosimilar development program.
The aim is to understand and minimize the residual uncertainty at the clinical stage. While all
biosimilars show differences, the key is to recognize the impact of these differences and address
them at the CMC stage.
DISCOVERY DRUG DEVELOPMENT
Research IND Enabling Ph I
BIOSIMILAR STRATEGY DOCUMENTATION
Literature
Review
CQA Target
Optimized
Method
Development
Methods
Demonstrated
Fit for Purpose
Tracking and
Trending Charts
Purchase
Innovator
Assay Validation
Regulatory
Guidelines1
and
Intelligence
Characterize
Multiple Lots
of Reference
Product
Physiochemical
and Biological
Similarity
Studies
QTPP
CQA
Develop Biosimilar
Construct Cell Line
Formulation Studies Forced Deg
Batch Release
Stability
CQAs Risk Assessed and Biosimilar Statistical Parameters Defined
Figure 1: CMC requirements from discovery to Phase I
CMC Analytics for Biosimilars: An Ideal Approach
Blockbuster status for biologics like Humira®
, Avastin®
, Eylea®
and Keytruda®
has meant that a crystal
ball is not required to determine high-value biosimilar targets. Staying ahead of the competition not
only requires an understanding of current market data and potential shifts that could indicate or affect
future targets, but also streamlining development.
Using insights gained from work on hundreds of biosimilar programs across geographic areas
regulatory requirements, an approach to streamline biosimilar development was developed to reduce
biosimilar development timelines. This approach is a risk-assessed, stepwise solution reflecting
regulatory guidelines and built upon a profound understanding of how structure can be correlated
to function. This includes safety based on experience of both state-of-the-art CMC characterizaton
and clinical outcomes of many hundreds of biologic products.

2. At the outset, a literature review is made of any publicly accessible information for a target
innovator. Molecule characteristics, development changes and functionalities mentioned
regarding stability in the public assessment report, the intended patient group, and most
importantly the mechanism of action (MOA) are documented and reviewed. A risk
assessment of all attributes is made based on the MOA, which is the CMC attribute most
closely linked to clinical outcome.
Mechanism of Action
The primary MOA is thoroughly reviewed and all molecular functionalities that are known to
impact or could potentially impact that MOA are listed. Consideration is also given to any relevant
knowledge that might impact the MOA based on potential degradation routes (e.g., aggregation,
deamidation and oxidation) and functionalities that may impact immunogenicity, pharmacokinetics
and effector function. The manufacturing cell line and glycosylation description are also reviewed as
attributes to the quality of the product.
Most biosimilar targets currently in development are monoclonal antibodies and can be classified based
on their MOA2
. Once classified, a risk assessment can be made. For example, a monoclonal antibody with
an MOA that does not involve cell surface binding would not be expected to engage the immune system via
the Fc domain. Therefore, the Fc functionality and associated molecular attributes are designated low risk.
Using this rationale, a consideration of the overall risk can be made for a biosimilar program depending
on whether the effector function contributes to the overall MOA.
CMC Characterization
Based upon a review of the literature and the MOA, a list of molecule attributes can be tabulated. From
this review, a preliminary assignment of criticality of these attributes (critical quality attributes or CQAs)
and associated risk can be made relating to their ability to impact the MOA. Optimal methodologies are
then selected that can best describe these CQAs.
The initial characterization is always performed by LC-MS to describe as much functionality as possible.
One hundred percent coverage of the peptide map is expected through orthogonal digestion. The
glycosylation is also completely characterized using an endoglycosidase array to unequivocally structurally
describe all N-glycans.
Bioassay is the most important assay that should reflect the MOA and is a surrogate for clinical efficacy.
This assay is also typically the most variable and takes the most time to develop and optimize. In addition,
potency always ranks as a high-risk attribute, so it is important to obtain an assay that is as precise as
possible.
For example, the Tumour Necrosis Factor-α assay using L-929 cells is a high-performing assay for
Covance, with a functional end point. However, reporter gene assays are now showing increased precision
and vendors are producing cell lines for biosimilar targets that make these assays desirable for biosimilar
potency assessment. In addition, regulators expect a functionally relevant assay and, therefore, a
correlation study must exist between the reporter gene and the functional assay prior to registration.
For secondary MOA of monoclonal antibody targets, an Fc screen is performed regardless of the risk in
order to evaluate this functionality by surface plasmon resonance.
Quantitation of Biosimilarity
Over the years, it has become clear that the developer must interpret the parameters of biosimilarity for
the targeted molecule. From a CMC perspective, this is why a risk assessment of molecular attributes is
important. A more tightly defined specification of biosimilarity would be expected for an attribute that
impacted the MOA and by extension, its clinical outcome.
These specifications are defined through a risk assessment as the first step. However, to make
meaningful objective calculations, the target molecule must be sourced from the market and
characterized. Access to lots from different manufacturing campaigns provides the clearest evidence

3. of the allowable changes in the molecular attributes from a manufacturing perspective.
With a risk assessment, statistical analysis can be applied to the results of the molecular
attribute thereby resulting in a target window.
With a target window for each parameter, the biosimilar manufacturer can adjust the clone
selection as well as the upstream and downstream processing to meet this acceptable range.
A Streamlined Program Targeting High-Value Innovators
Since 2008, Covance has conducted aspects of CMC support for 44 distinct biosimilar programs,
with several targets being repeated across sponsors. Through this work, a number of regulatory
and scientific themes have emerged, leading Covance to develop a strategy for biosimilars ahead
of client queries to fast-track biosimilar development programs.
Covance Analytical Master Files
The Analytical Master File is designed to enable sponsors to bring their biosimilar products to market
at least nine months sooner through earlier assessment of biosimilarity. Each Analytical Master File
contains documentation related to:
Literature search references
Description of the MOA
Scientific rationale for the selection of
molecular attributes and the associated risk
in terms of the description of biosimilarity
A prospective statistical analysis
suggesting correlated risk ranking of the
attribute and target range to demonstrate
biosimilarity
The commercially sourced target molecule
– Typically, this contains one or two lots
from the US or Europe, but can contain
more based on the market presentation
of the target
All developed methodologies, including:
– Protocol
– Report documenting the steps used in
developing the methods
– Molecule-specific optimization
– Preliminary robustness parameters
– Precision and accuracy as a minimum
– Method standard operating procedures
– Tracking and trending charts for each
method and target reference product
DISCOVERY DRUG DEVELOPMENT
Research IND Enabling Ph I
BIOSIMILAR STRATEGY DOCUMENTATION
Literature
Review
CQA Target
Optimized
Method
Development
Methods
Demonstrated
Fit for Purpose
Tracking and
Trending Charts
Purchase
Innovator
Assay Validation
Regulatory
Guidelines and
Intelligence
Characterize
Multiple Lots
of Reference
Product
Physiochemical
and Biological
Similarity
Studies
QTPP
CQA
Develop Biosimilar
Construct Cell Line
Formulation Studies
Batch Release
Stability
CQAs Risk Assessed and Biosimilar Statistical Parameters Defined
n Master File n CMC Activity
Figure 2: Information contained within Covance Analytical Master File

4. Learn more at www.covance.com
Covance Inc., headquartered in Princeton, NJ, USA, is the drug development business of Laboratory
Corporation of America Holdings (LabCorp). COVANCE is a registered trademark and the marketing
name for Covance Inc. and its subsidiaries around the world.
The Americas + 1.888.COVANCE (+1.888.268.2623) + 1.609.452.4440
Europe / Africa + 00.800.2682.2682 +44.1423.500888
Asia Pacific + 800.6568.3000 +65.6.5686588
© Copyright 2019 Covance Inc. WPCMC001-0619
1
European Medicines Agency: Guideline on Similar Biological Medicinal Products Containing Biotechnology-Derived Proteins as Active Substance: Quality Issues
(Revision 1) and May 2014: EMA/CHMP/BWP/247713/2012
Committee for Medicinal Products for Human Use (CHMP); FDA: May 2019 (Draft Guidelines): Development of Therapeutic Protein Biosimilars: Comparative
Analytical Assessment and Other Quality-Related Considerations Guidance for Industry, and Apr 2015: Scientific Considerations in Demonstrating Biosimilarity to
a Reference Product, Guidance for Industry
2
Advances in the assessment and control of the effector functions of therapeutic antibodies, Xu-Rong Jiang et al. Nature Reviews - Drug Discovery, 101-110 (2011)
Getting the Most Out of the Analytical Master File
The Analytical Master File provides a head start in biosimilar development so that
manufacturers can focus on cell line optimization. The selection of the clone is
the most important step in any biosimilar program since biosimilars do not
become more biosimilar through the development phases.
The Analytical Master Files can be flexed for variety of program needs with
fit-for-purpose use:
Analysis of clones to demonstrate which has the most appropriate molecular attributes
and enable a rapid go/no-go decision as to whether to re-engineer the cell line or adjust
the upstream or downstream processes.
Initial characterization of market-sourced
lots of target originator to define the
manufacturing ranges for attributes.
Analysis of externally sourced biosimilar
product for the purchaser to decide on
further investment and enable a rapid go/
no-go decision.
Access to individual methods that can be
used to fast track GMP or non-GMP CMC
analysis.
As a comprehensive package to be used
internally by the sponsor.
Ownership of the Analytical Master File
for each target biosimilar is retained by
Covance and licensed to sponsors for use
in perpetuity.
Currently Available Analytical
Master Files from Covance
Target innovators are constantly being
evaluated for Analytical Master File
development and clients are encouraged
to provide suggestions.
adalimumab
bevacizumab
nivolumab
pembrolizumab
ipilimumab
aflibercept
tocilizumab
atezolizumab
secukinumab
daratumumab
vedolizomab