Biosimilar development is the work required to understand a biologic, reproduce it as closely as possible and build a manufacturing process that can deliver the same result batch after batch.

This matters because biosimilars are not assessed only by their final profile. Their quality also depends on how well the development and manufacturing process has been built, controlled and reproduced over time.

The biosimilar development process starts with a detailed analysis of the reference product. Teams study its structure, biological activity, purity profile and critical quality attributes to define the target they need to match.

It’s crucial to understand the original medicine in depth before trying to develop a highly similar version of it. This stage provides the foundation for the full program of biosimilar development.

Once the target profile is defined, developers create and select the cell line that will produce the biosimilar candidate. In other words, here is where we choose the biological “factory” that will make the molecule.

The selected clone needs to support stable expression, reproducibility and long-term performance. Because biologics are made by living cells, choosing the right cell line is one of the earliest and most important decisions in the whole program.

After clone selection, the production system is secured through cell banking, usually with master and working cell banks.

These banks carefully store cell stocks used to make sure future batches start from the same controlled source. That consistency matters because even small biological differences can affect how a product performs.

With the cell line in place, teams develop the manufacturing process itself.

In upstream process development, they define how cells grow and produce the molecule. In downstream process development, they recover and purify the product after it has been produced. Together, these stages shape the manufacturing route and begin to establish the process conditions that influence product quality.

Once the initial process is established, it has to be studied in greater detail. Teams need to learn which process conditions really matter, how much flexibility the process allows and where tighter control is needed. For that, teams assess how key parameters affect performance, consistency and critical quality attributes. The result is the definition of operating ranges, identification of critical process parameters and the improvement of robustness.

Analytical method development provides the tools used to evaluate the product throughout development and manufacturing.

These methods are used to assess identity, purity, potency, stability and other critical quality attributes. Strong analytical methods help teams monitor consistency and generate reliable data across the biosimilar development pathway.

Analytical comparability is one of the central stages of biosimilar development. At this point, the biosimilar candidate is compared with the reference product through a broad analytical package.

The purpose is to demonstrate a high degree of similarity in structural and functional attributes. In practice, this is one of the clearest ways to answer the question “how are biosimilars developed?”: they are developed by building a product and process that can support a robust comparability exercise.

A process that performs well in development still needs to show that it can work under larger-scale manufacturing conditions. Scale-up helps teams understand how the process behaves as systems, equipment and operating conditions change.

This stage also supports GMP readiness. Process understanding, documentation, control strategy and manufacturing fit all become more important as the program moves closer to GMP execution.

This is often the point where development work is tested under more realistic production conditions.

As the program advances, the biosimilar is manufactured under GMP conditions for the activities needed to support the next phase of development.

Depending on the program, this can include clinical supply, engineering batches or validation-related work. By this stage, the process needs to perform consistently and the quality system needs to support reliable execution.

The final stage is commercial batch production. This is where cell line stability, process development, analytical control and GMP manufacturing all have to work together in a repeatable way.

A commercial batch reflects the quality of the full biosimilar development process. It shows whether the earlier stages were strong enough to support long-term manufacturing consistency.

At mAbxience, biosimilars development is approached as a connected path from early scientific work to manufacturing readiness. That approach reflects our broader mission: expanding access to high-quality biologic treatments through strong science, reliable development and consistent manufacturing.