Merck & Co has signed a deal with private US biotech Arvinas buying into technology that could churn out new drug targets not attainable through more traditional techniques.

Arvinas’ novel technology creates proteolysis-targeting chimeras, bifunctional small molecules that target proteins for degradation and removal from a cell. PROTACs induce a cell’s internal quality control mechanism to ‘label’ it for degradation, thus removing a protein from the system.

This contrasts to the traditional drug development approaches that either inhibit or boost proteins, though this can only target about 25% of the body’s 20,000 proteins. Arvinas says its method of protein degradation can reach some of these previously unattainable targets.

Financial specifics of the deal were largely kept under wraps, except that Arvinas will receive an up-front payment and funding from Merck, and could earn up to $434 million if all research, development, regulatory and commercial milestone payments are paid for products against all the targets initially selected, as well as tiered royalties. 

Merck also has the option of expanding the collaboration to include additional disease targets, which would trigger an additional one-time payment as well as milestones and royalties.