Perks and Pitfalls of Antibody Drug Conjugates: Lessons Learned with Charlie Johnson

Charlie Johnson has kept his eye on the antibody drug conjugate (ADC) field since its early days and was involved in developing the process for one of the first ADCs to hit the market, as well as helping to establish Avecia’s ADC manufacturing operations. Today, he is CEO of ADC Bio. Here, he talks about the ups and downs of the ADC market, and shares the lessons he has learned as ADC Bio gears up to jump into GMP manufacturing.

New classes of therapeutics take time to find their feet

I’ve always been fascinated by ADCs. In many ways, ADCs combine the best of both worlds: the potency of cytotoxic agents with the specificity of antibodies. The targeting ability has been of particular interest to drug developers working on cancer therapeutics. But although the industry has been talking about ADCs for years, approvals have been thin on the ground. ADCs have shown promising data in terms of having an effect on tumor cells, but there have also been unintended side effects as the target antigen on the tumor may also be present in healthy tissue. The translational science of ADCs has been very challenging, but a lot of it comes down to choosing the right targets. Right now, there is a great deal of attention being paid to more exquisite targeting; for example, using bispecific ADCs.

It is normal for new areas of science and drug development to suffer some setbacks, but there is now a renaissance in the ADC area, thanks to growing understanding and experience with ADCs. Two new products were approved in 2017 and there are over 80 ADCs in clinical development, as well as thousands of patents filed. And new research is being published constantly as the community strives to improve safety and efficacy (for just some example papers published in 2019, see the sidebar). Oncology remains the top area for ADC drug development, but other areas are also being explored, such as inflammatory diseases and even bacterial infections.