How to Achieve Platformisation with So Many Molecular Types?-Newsroom

Preface

The core concept of a "platformisation" strategy is to achieve uniformity, standardisation, and compatibility. However, there is an unspoken understanding among R&D professionals when advancing platformisation – the pursuit of "flexibility."

In China, the process development for antibodies was once likened to "crossing the river by feeling the stones." In less than a decade, antibody-fusion proteins emerged from the complex antibody field. We have witnessed a series of innovative antibody structures, including bispecific antibodies, multispecific antibodies, single-chain antibodies, and nanobodies. The successive advent of these formats has provided a real-world testing ground for the flexibility of process development platforms, allowing us to observe and validate a platform's adaptability and innovation capability in meeting diverse needs.

150+ Molecules, 50+ Structures

Intellective Bio's debut project involved a bispecific antibody IND application. The team possesses profound technical expertise in handling complex antibody processes. Over the past six years, Intellective Bio has successfully addressed numerous challenges in process development. To date, the professional team has undertaken and completed over 150 projects, covering comprehensive needs from pre-clinical stages through process validation and post-approval process changes, involving more than 50 different molecular types.

How is Platformisation Achieved with So Many Molecular Types?

Intellective Bio has extensive downstream process development experience, having developed processes for over 100 projects. This includes 40+ mAb projects, 30+ bispecific/multispecific antibody projects, 12 fusion protein projects and 15 untagged recombinant protein projects. Based on this experience, four distinct purification platforms have been established.

Development Complexity by Antibody Type

• Monoclonal Antibodies (mAbs): As mainstream antibody-based drugs, many have advanced to Phase III or commercial stages. Process development thus focuses more on cost control and quality comparability. Challenges include controlling charge variants, high-concentration ultrafiltration and resin lifespan.

• Bispecific/Multispecific Antibodies: Their different antigen-binding sites offer significant therapeutic potential but pose substantial downstream challenges, such as product stability and removal of product-related impurities (aggregates, mispaired species, half-antibodies, etc.).

• Fusion Proteins: Often characterised by large molecular weight or low pI, which can lead to non-specific adsorption during chromatography, posing challenges such as difficult HCP removal and poor stability.

• Untagged Recombinant Proteins: Offer advantages such as simple molecular design, low immunogenicity and low cost, finding wide application in recombinant vaccines, thrombin and collagen. However, the lack of an affinity chromatography step often presents challenges in achieving high purity and effective HCP removal.

Our Strategies

1. High-Throughput Screening Strategy

Rapidly and efficiently screen resins from different vendors with different matrices and ligands, followed by DOE to identify and optimise the best process parameters.

Case 1: A commercial project faced short affinity resin lifespan. Using HTP screening, Intellective Bio identified an improved cleaning method, extending resin lifespan to 1.5 times the original and reducing associated costs to 34% of the original process.

2. HCP Removal Strategy

Leveraging experience from 11 challenging HCP removal projects, this strategy adjusts parameters such as resin selection, chromatography pH, salt concentration, additives and temperature to effectively remove HCP that binds non-specifically or has a pI close to the target protein.

Case 2: An IND project involved an Fc fusion protein with low pI. HCP contained lipases causing polysorbate degradation. Using the HCP removal platform strategy, HCP levels were reduced to 1/30 of the original process while maintaining yield, monomer purity increased by 2%, and material costs decreased to 63%.

3. Charge Variant Control Strategy

Drawing from over five charge variant challenge projects, this strategy optimises parameters (resin selection, pH, salt concentration, additives, temperature) to control charge variants within comparable ranges and remove new variants arising from changes.

Case 3: A commercial mAb project showed a >5% increase in acidic variants after a post-approval change. Using the charge variant control strategy, two process options were provided to the client, increasing acidic variant removal capability by over 5-fold post-change. 

4. Developing Novel Formulation Technologies

Exploring new formulation technologies, such as nanotechnology or liposomes, to enhance the stability and bioavailability of complex antibodies.

References

[1] Li Zhi, Zhuge Xin, Chen Zijuan. A method for eluting asymmetric bispecific antibodies in anion exchange chromatography. CN117362442A, 2024-01-09.
[2] Li Zhi, Zhuge Xin, Chen Zijuan. A special wash buffer system for significantly removing Fc fusion protein degradation fragments. CN117820414A, 2024-04-05.
[3] Li Zhi, Zhuge Xin, Chen Zijuan. A virus filtration method for very large molecules. CN116854809A, 2023-10-10.
[4] A-Mab: A Case Study in Bioprocess Development. 2009 Oct, CMC Biotech Working Group.
[5] Levine H L, Cooney C L. The Development of Therapeutic Monoclonal Antibody Products - A Comprehensive Guide to CMC Activities from Clone to Clinic. BioProcess Technology Consultants, Inc. 2017 Jun.