ADC Biotechnology said it is developing a new downstream bioconjugation method that will present a new paradigm in antibody drug conjugate (ADC) development and manufacturing. In contrast to the existing approaches, which undertake bioconjugation after both the mAb and cytotoxic have been manufactured, this new approach moves the conjugation step into the later stages of the downstream processing (DSP), with conjugation and antibody purification carried out concurrently.

“The major benefit, and the reason this approach will prove so disruptive, is that it will save several months of manufacturing time and up to 25% of the overall costs,” said Charlie Johnson, chief executive officer, ADC Bio. “But it will require much of the industry, with its current ingrained manufacturing methods, to reevaluate exactly how it structures the supply chain that often uses three contract manufacturing organizations (CMOs).”

Using this downstream bioconjugation approach potentially means less time at the antibody manufacturer (i.e. less time in traditional downstream processing), with the remaining downstream processing and conjugation service both transferring to the bioconjugation CMO. The result is a refined, simpler and much more efficient system-saving up to three months of development time and resources plus creating large cost savings.

Under the company’s new process, the starting point for the conjugation will no longer be post-creation of purified antibodies and will instead begin with antibody supernatants. This approach forgoes the need for extensive chromatographic purification techniques to deliver purified antibody, according to the company.

The company’s new production technique, yet to be formally named, would also remove the need for expensive Protein A resins, instead replacing them with capture resins that are at the heart of the company’s core ‘Lock-Release’ technology. In ADC manufacturing, the Protein A capture step is the most costly in downstream processing, delivering semi-purified antibody. Now, starting from antibody supernatant, ADC Bio’s approach will see their patented Lock-Release technology facilitate both the antibody capture step and subsequent conjugation to the ADC payload-essentially replacing the Protein A resin and assembling the ADC in an efficient manner. The subsequent viral inactivation, removal and polishing will then occur post-conjugation.


“In essence, we are telescoping antibody DSP and conjugation, providing just one set of analytical development and release processes, while bringing in the use of much more cost effective and safer resins,” said Mr. Johnson. “We have already successfully piloted our new development process in a number of applications.”

The company has just launched its Specialist Process Innovation Group, which will be responsible for fostering all further technological innovations moving forwards. Its first project is to validate ADC’s new downstream conjugation approach over the course of the next 18 months.