【Case Analysis】Ion Exchange and Hydroxyapatite Media in ADC Purification

Antibody-Drug Conjugates (ADCs) are a novel class of biopharmaceuticals that combine monoclonal antibodies with cytotoxic drugs via chemical linkers. They offer the dual advantages of high targeting specificity of monoclonal antibodies and high cytotoxicity of the payload in tumor tissues, making them one of the fastest-growing drug classes in targeted cancer therapy.

Figure 1. Schematic diagram of ADC structure

Challenges in ADC Purification

In addition to mAb production, ADC manufacturing requires the preparation of small molecule toxins and the conjugation step. Conjugation introduces impurities such as organic reagents, conjugation enzymes, and derivatives. Therefore, an additional purification step is required after conjugation to remove process- and product-related impurities.

Figure 2. ADC purification process flow diagram

NanoMicro ADC Purification Platform

NanoMicro offers a comprehensive portfolio of chromatography resins that fully address the needs for naked antibody purification, small molecule toxin purification, and DAR value control. Our technology platform is designed to deliver tailored purification solutions for ADC manufacturing, ensuring efficient and precise separation at every step.

ADC Purification Case Studies

Case 1. Purification of an ADC using Protein A + CEX + AEX

The mAb was captured from upstream harvest using Protein A affinity resin NMab Pro. After GSH reduction, cation exchange resin NanoGel-50SP HP was used to remove antibody aggregates, fragments, and excess GSH. Anion exchange chromatography with NanoGel-50Q was then employed for polishing to removetrace impurities.

Figure 3. NMab Pro affinity capture of mAb

Figure 4. NanoGel-50SP HP CEX purification of mAb

Figure 5. NanoGel-50Q AEX purification of mAb

The crude ADC conjugated with Linker-Payload was purified by NanoGel-50SP HP to remove free small molecules, followed by UF/DF to obtain the final ADC product meeting customer requirements for purity and yield.

Figure 6. NanoGel-50SP HP CEX purification of ADC

Case 2. HAPcera Type I hydroxyapatite media for removal of mAb aggregates

HAPcera Type I is a ceramic hydroxyapatite multimodal chromatography resin with metal affinity and cation exchange functionalities, enabling efficient removal of antibody aggregates, fragments, and other impurities. In an ADC project, the initial naked antibody purity was 96%. After HAPcera Type I hydroxyapatite chromatography, monomer purity was increased to over 99% with a recovery of greater than 90%.

Figure 7. HAPcera Type I hydroxyapatite purification of an ADC naked antibody

Summary

Chromatography resins play a critical role in the downstream manufacturing of ADCs. NanoMicro offers a comprehensive range of resins specifically designed for the purification of naked antibodies, small molecule toxins, and ADCs, enabling precise control of key quality attributes including the removal of aggregates, fragments, and small molecule toxins, as well as DAR value modulation. Our ADC purification process is not only simple and efficient but also delivers high purity and excellent recovery, providing a comprehensive solution for ADC purification. This one-stop service greatly simplifies the production process and enhances manufacturing efficiency.