Antibody-Drug Conjugates (ADCs) are a class of therapeutic compounds designed to target cancer cells. They combine the cancer-killing (oncolytic) properties of potent cytotoxic drugs with the targeting capabilities of monoclonal antibodies, meaning that the drug can be delivered to diseased tissue and not to healthy cells, limiting the customary side effects that are traditionally associated with anti-cancer therapies while also extending the therapeutic window.
Due to the complex and sensitive nature of antibodies and the potent nature of cytotoxic drugs, together with the requirement to maintain the structural “linker” between these 2 components when they are conjugated together in an ADC, it is easy to understand how such a chemical entity may not possess significant levels of stability in an aqueous solution for injection, or during the traditional – and usually aggressive – drying methods that are often used to create a powder suitable for tableting.
Stabilizing ADCs with lyophilisation
Freeze-drying has long since been used on antibodies and cytotoxic drugs, and can be used to stabilise ADCs in order to provide a longer shelf life; however, with the freeze-concentration effects that occur during lyophilisation, and the potential sensitivity of molecules to dehydration, it is unlikely that suitable combination of formulation and process conditions will be hit upon by trial and error.