Biocatalytic cascades enable manufacture of the macrocyclic peptide enlicitide

Historically, many compelling therapeutic targets have been accessible only by injectable biologic drugs. Macrocyclic peptides, such as the proprotein convertase subtilisin/kexin type 9 inhibitor enlicitide for the treatment of atherosclerotic cardiovascular disease, are beginning to unlock these targets to orally administered therapies to enable broader patient access. We report the convergent biocatalytic assembly of enlicitide from simple building blocks enabled by a suite of engineered enzymes to catalyze selective peptide fragment formation, coupling, and macrocyclization in a protecting group–free manner. Together with efficient crystallizations that obviate the need for chromatography, this approach reduces the number of steps by greater than half compared with prior state-of-the-art methods, addressing long-standing synthetic challenges and offering a sustainable blueprint for the scalable development of complex peptide therapeutics.