Spirea secures more capital to develop next generation ADC cancer therapeutics

The investment will be used to enable Spirea’s ADC therapeutic programs ahead of a significant seed funding round anticipated in 2021.

ADC drugs combine the cell killing activity of a cytotoxic drug payload with the targeting ability of an antibody. However, toxic side-effects, limited flexibility, and the resulting limitations in the range of cancers that can be treated have restricted the field and caused many clinical programs to stall.

Spirea says its technology overcomes these 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.

In respect of that development, Dr Myriam Ouberai, CEO of Spirea, told this publication: “We have demonstrated in vivo efficacy with Spirea high DAR ADC platform technology using a model system (anti-HER2 trastuzumab as antibody and MMAE as drug payload). The data show dose response efficacy for Spirea ADC, avg DAR 16, in a high HER2 expressing gastric cancer xenograft model with tumor with regression and complete inhibition of tumor growth observed at 4mg/kg.”​

Spirea’s technology can be applied to a wide range of solid and blood cancers, she said. 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,”​ said Ouberai.

Product pipeline 

The company is building a pipeline of therapeutic products based on its validated technology.  

“We plan to formally initiate our inhouse programs in 2021 once we have completed our next financing round but planning for these programs is already well underway. We have chosen targets and indications where we see the greatest potential for differentiation combined with a significant unmet medical need.​

“Our technology specifically addresses the problem of drug toxicity and narrow therapeutic index observed with many current ADCs, so there is considerable opportunity to work with validated tumor targets and validated lower potency payloads and still achieve differentiation because of the novel way that our technology allows us to construct our proprietary ADCs,​” said the CEO.

Spirea has previously received investment from Jonathan Milner, Start Codon, Innovate UK, IP Group and Cambridge Enterprise and is supported by a number of successful, high-profile board members from the life sciences including Jane Dancer (former chief business officer at F-star), Gaynor Fryers (former VP of business development at AstraZeneca) and Christine Martin (deputy head of seed funds at Cambridge Enterprise).

The company also benefits from being part of the healthcare business accelerator Start Codon and the Cambridge Judge Business School Entrepreneurship Centre's Accelerator, Accelerate Cambridge.