The move was expected; it follows Sterling’s strategic investment in the ADC Bio business back in December 2020, with the CDMO indicating then the possibility it would take on full ownership of the UK firm in early 2021, subject to due diligence.
ADC Bio have been at the forefront of antibody-drug bioconjugation and process development in recent years. Its Deeside, Wales, UK facility will rebrand to become part of the Sterling Pharma Solutions international network.
A multi-million sterling pound investment will support the further growth of ADC Bio’s capabilities, which will include growing and developing its existing bioconjugation technical services team and expanding the analytical services cohort, particularly in the cGMP area.
Spotlight on ADCs
ADC drugs combine the cell killing activity of a cytotoxic drug payload with the targeting ability of an antibody. They have been generating a lot of buzz in recent years, given the scale of some of the ADC deals of late such as the alliance between AstraZeneca and Daiichi and, in what was the largest deal in its 33-year history, in September 2020, Gilead Sciences agreeing to pay US$21bn to acquire Immunomedics and its recently-approved ADC, Trodelvy.
Pyxis Oncology is also moving into this area. Through a licensing deal with Pfizer, announced last month, the biotech gets two ADCs from the pharma giant, along with a toolkit to develop additional ADC candidates. That followed a deal to license another ADC from South Korea’s LegoChem Biosciences at the end of 2020. The financial details of the agreement with Pfizer were not revealed but Pyxis paid out US$9.5m upfront for the LegoChem ADC, with a further US$280m in potential milestones.
Challenges with ADCs
Challenges do exist with ADCs though. They can range from toxic side-effects, limited flexibility, and the resulting limitations in the range of cancers that can be treated, restricting the field and caused many clinical programs to stall, said the team from Spirea, a University of Cambridge spinout, when talking to this publication late last year.
Spirea said its technology overcomes a lot of those issues by offering high drug-to-antibody ratio (DAR) and a design flexibility which enables the development of differentiated ADCs with improved efficacy and safety. Because the technology allows more drug to be loaded onto the targeting antibody whilst maintaining drug stability, payloads can also be customized to the target, enabling flexibility in payload potencies, creative drug combinations and novel modes of action to serve a wider patient group, it added.
Sunil Shah, CEO at o2h Ventures, said Spirea’s potentially "transformative approach" to addressing the common obstacles faced in ADC development could disrupt the field entirely.
The company has also reported the successful in vivo validation of its platform in proof-of-concept studies using a cancer xenograft model.
Spirea’s technology can be applied to a wide range of solid and blood cancers, Dr Myriam Ouberai, CEO of Spirea, told us. But the company sees particular potential for its approach in significant subsets of cancers where current ADC approach cannot be used because of toxicity issues. “This might include tumors where the expression of the tumor target/marker protein is relatively low,” she said.