Daily digest — 2026-10-31

Does the cage truly reproduce the ortho exit vectors, or only the silhouette? Matching activity in two known drugs is encouraging, but the chiral, strained core worries me: stereochemistry, and stability under metabolic and acidic conditions. The patent-free angle is the selling point, provided the building blocks scale beyond a one-off route.

Binding potency is the easy part here; charge and efflux are what have sunk P2Y12 tracers. A neutral, compact imidazopyrazolone is a sensible escape from the acid-bearing, clopidogrel-type chemistry, but nothing yet shows it evades efflux or crosses into the brain, and that is the data that would make this interesting.

A heterobivalent ligand only earns its keep if both pharmacophores stay engaged, and the weaker NTSR1 binding hints that the peptide arm is the one compromising. The linker and albumin-binding tolyl may be crowding the neurotensin pocket. It is also a hefty conjugate to make; a comparison with a mixture of single-target ligands, plus kidney and salivary uptake, would show whether the SAR holds.

One non-conserved cysteine looks like a thin basis for selectivity, yet an acrylamide on an azetidine linker reaching Cys545 is a clean way to tell paralogs apart, and the alkyne probe with kinome profiling suggests the warhead is not simply promiscuous. Still open: GSH reactivity, protein turnover for a platelet target, and how this stacks up against reversible FAK/Pyk2 chemotypes.

It is a pleasant surprise to see a kinase-inspired scaffold this clean on a GPCR. If selectivity holds in orthogonal assays, the roscovitine-derived core is an easily decorated starting point, and three-vector SAR on a triazolopyridazine is cheap to run. The pose shared with IB-MECA comes from docking alone, so I would hold off until mutagenesis or a structure backs it.

Locking the hinge-binding pharmacophore into a tricycle is a sensible way out of the crowded diaminopyrimidine carboxamide space. Rigidifying the core should pay the conformational penalty up front and help kinome selectivity, which matters because MAP4K relatives are the usual liability. Exposure data and the ring-fused synthetic route would decide how excited I get.

A two-day cycle per analogue is only the bottleneck on a kinase hit if the benzodiazepine core hides real selectivity levers. The traceless triazene handle for late diazonium diversification is the genuinely useful part, since it opens aryl vectors that amide-coupling libraries never reach. Until I see CDK11B selectivity against other CDKs, I'd hold the early SAR loosely.

The non-substrate binding pose is the part I care about: it means the series is not just a steroid mimic that gets sulfonated, which should buy metabolic stability. But steroid-like scaffolds invite off-target worries against other SULTs and nuclear receptors, so I would want a broad selectivity panel and a look at tumor exposure before believing the immune story.

Beta-lactones are a red flag for stability and off-target acylation, so the chloroacetamide follow-up is the more interesting chemotype: tunable warhead reactivity, easy synthesis. Hitting a catalytic cysteine in PqsC is plausible, but I'd want proteome-wide selectivity data before trusting a pathoblocker label.

The neat part is that the E3 recruiter is just a small tetrazine conjugate, so the bulky, greasy half of a PROTAC never has to travel through the body in one piece. Whether it works on a crowded nanoparticle surface is another matter: I'd like to see how much ternary complex actually forms there, and whether the hook effect appears at this ligand density.