Inhibition of protein-protein interactions (PPIs) by small molecules historically has been challenging because interactions between proteins usually involve large, complementary binding areas that lack features that would allow for small molecules to selectively bind and directly block the PPI. Antibodies can overcome this limitation due to the large nature of their complementary binding areas, but their large size makes them unsuitable for oral administration as they are not absorbed in the gut. Currently available biologics have transformed the inflammatory disease landscape, but are not ideally suited for chronic treatment and face challenges including administration through injections or intravenous infusions and regular patient monitoring. There remains a strong preference among many patients and clinicians for orally-administered therapeutics.
We believe that the best opportunities for orally-dosed, small molecule inhibitors of PPIs are presented by targets that are dimeric (having two discrete components) or trimeric (having three discrete components). At DICE, we believe there is a significant unmet medical need for convenient oral therapies in chronic immunological diseases that offer the therapeutic benefits of systemic biologics. We are leveraging our DELSCAPE platform to discover selective oral small molecules with the potential to modulate PPIs as effectively as systemic biologics.
Our approach to drug discovery and development leverages the capabilities of DELSCAPE to determine feasibility, optimize the design of and generate families of specific and potentially potent therapeutic compounds that we consider ideal for advancement to clinical development. We combine this approach with an assessment of attractive, validated market opportunities, informed by our expertise in the field of immunology, to determine our priority targets. We have used this approach to discover and develop therapeutic candidates in our pipeline.
We utilize our proprietary DNA-encoded library (DEL) chemistry to accelerate the hit-to-lead phase of compound optimization. We use DEL in a novel way, producing libraries that incorporate known binders—often with poor potency, selectivity or drug-like properties—into the library design, greatly increasing the percentage of hits and thus the depth of structure-activity relationships (SAR) we can obtain from a single experiment. With our proprietary approach, we generate smaller, targeted libraries, typically between 100,000 and 1 million discrete compounds, and obtain data that enables both quantitative and qualitative assessment of a landscape of small molecule hits. We therefore do not need to aim for the massive diversity (billion to trillions of compounds) reported by companies that conventionally utilize unbiased DELs for hit-finding and, importantly, not for the hit-to-lead phase of compound optimization. Our approach can extend well beyond binding optimization to further produce insights into functional activity and selectivity. We think of this process as performing medicinal chemistry but on a very large scale, in parallel, and it is what allows us to accelerate this phase of drug discovery against these difficult PPI targets.