Unlike GLP-1s, PCSK9 inhibitors are a near "free lunch." Discovered from a genetic mutation in a population with virtually no heart disease, these drugs dramatically lower bad cholesterol with minimal trade-offs, making them an ideal preventative tool.

In selecting targets for its macrocyclic peptide platform, Merck strategically prioritizes two factors: 1) extracellular targets that don't require difficult cell penetration, and 2) disease areas where existing options are only injectable. This creates a clear path to differentiation and addresses high unmet patient needs.

The debate isn't about peptides replacing antibodies but about combining them. The future lies in hybrid therapeutics, such as grafting peptides into antibody CDRs or creating fusions that use a peptide for optimal target binding and an antibody scaffold for effector functions, half-life extension, and stability.

The company positions its peptide platform as the ideal middle ground in drug development. They aim to create medicines that are functionally like highly selective, less toxic large biologics (e.g., antibodies) but are structurally designed for the convenience of an oral pill, combining the best attributes of both major drug classes.

Despite promising preclinical data, most at Merck were skeptical the complex molecule would be orally bioavailable. The pivotal "aha" moment wasn't in the lab but when Phase 1 clinical data showed oral absorption and profound cholesterol reduction in humans, instantly validating the decade-long effort.

Unlike traditional small molecules that need a pocket on a target protein, molecular glues work by changing the surface of an E3 ligase. This modified surface then perfectly matches and binds the target protein, enabling its degradation without requiring a direct drug-to-target binding site.

While biologics get much attention, a significant investment opportunity lies in next-generation small molecules like degraders and hetero-bifunctional molecules. These advanced chemistries allow companies to target known, de-risked biological pathways in novel ways, hitting previously 'undruggable' targets and creating powerful new drugs.

Mini-proteins are framed as a superior drug modality that merges the key strengths of traditional therapies. They possess the high selectivity characteristic of biologics like antibodies, while also having the stability and formulation advantages of small-molecule drugs. This combination allows them to precisely target difficult receptors while avoiding common off-target effects or instability issues.

CEO Jonathan Steckbeck simplifies a complex topic by describing peptides as a "Goldilocks modality." They sit between small molecules (good access, poor specificity) and biologics (poor access, good specificity), ideally offering the best of both worlds for targeted drug delivery.