Science: p53 Y220C engagement, covalent macrocycle libraries, methyl-mimic bioisosteres, a fluorinated apoptosis scaffold, and cell-penetrating poly(disulfide)s. Business: trial wins for Roche's enicepatide, Vertex's inaxaplin, Roche/Ionis's sefaxersen, and Amgen's dazodalibep, capped by the EU's first CETP-inhibitor approval, obicetrapib.
2026-09-26 · ⚗️Cell-penetrating poly(disulfide) delivery vehicles — macromolecular drug delivery modality · Angewandte Chemie International Edition (Wiley)
- Poly(disulfide)s are dynamic-covalent polymers whose guanidinium-rich chains cross cell membranes via thiol-mediated uptake, engaging surface thiols rather than classical endocytosis.
- This study probes the chemical basis of that uptake, linking polymer structure and disulfide exchange to membrane translocation and cytosolic release.
- It reinforces poly(disulfide)s as a macromolecular delivery modality for proteins, antibodies, and nucleic acids, bypassing lysosomal degradation.
💡 PointsSkipping endocytosis entirely is the real prize: LNPs and most CPPs still have to escape an endosome, and that's where most of your payload dies. A dynamic-covalent scaffold means guanidinium density and disulfide exchange rate are dial-in knobs, not a peptide sequence you're stuck re-screening. Worth revisiting for antibody or siRNA payloads where endosomal escape is currently the bottleneck.
The Nature of Cell‐Penetrating Poly(disulfide)s ↗
2026-09-26 · ⚗️Covalent genetically-encoded peptide macrocycle libraries (cGELs) — a DEL-adjacent hit-finding platform for covalent ligand discovery · Journal of the American Chemical Society (ACS)
- A two-step route builds covalent genetically-encoded macrocycle libraries (cGELs): cysteines form the macrocycle via a diketone linchpin, then a separate Knorr-pyrazole step adds the electrophilic warhead.
- Separating cyclization (basic pH) from warhead installation (acidic pH) avoids the regioisomer mixtures that limited earlier one-pot chemical modification methods.
- This lets more diverse, reactive electrophiles be used safely, broadening covalent chemotypes accessible for selections against protein targets in DEL-style screens.
💡 PointsRegioisomer scrambling in one-pot warhead installation is exactly what kills confidence when you're deconvoluting covalent DEL hits — you can't tell if a signal is real or an artifact of a messy electrophile mixture. Decoupling cyclization from Knorr-pyrazole warhead chemistry means finally screening exotic, more reactive electrophiles beyond the usual acrylamide/chloroacetamide workhorses without second-guessing every hit's identity.
A Two-Step Synthesis of Covalent Genetically Encoded Libraries of Peptide-Derived Macrocycles Enables the Use of Electrophiles with Diverse Reactivity ↗
2026-09-26 · ⚗️Fluorinated 4-methylideneisoxazolidin-5-one scaffold — apoptosis-inducing antiproliferative small molecules (specific molecular target not confirmed from available sources) · ACS Medicinal Chemistry Letters (ACS)
- A new series of fluorinated 4-methylideneisoxazolidin-5-one derivatives adds fluorine substituents onto the exocyclic methylidene-lactone-type isoxazolidinone core.
- The fluorinated analogs showed antiproliferative activity against cancer cell lines, with the reported cell-death mechanism attributed to induction of apoptosis.
- Structure-activity comparisons across the fluorinated series highlighted substitution patterns linked to improved potency and selectivity relative to non-fluorinated parent compounds.
💡 PointsAn exocyclic methylidene lactone is a classic Michael acceptor shape — before crediting fluorination for the potency gain, I'd rule out plain thiol-reactive cytotoxicity masquerading as 'apoptosis.' Fluorination itself is a cheap, tractable SAR handle for potency/metabolic stability, but with no confirmed target, this stays a phenotypic hit until a pulldown or competition assay lands the binding site.
Fluorinated 4-Methylideneisoxazolidin-5-ones: Synthesis and Apoptosis-Inducing Antiproliferative Activity ↗
2026-09-26 · ⚗️Bioisosteres for methylated-lysine/arginine PTM mimics (epigenetic reader/PPI ligand design, cell-penetrating peptides) · Journal of the American Chemical Society (ACS)
- Imidazolium amino acids are proposed as cationic bioisosteres mimicking the size and charge of trimethyllysine, dimethylarginine, and arginine side chains.
- Binding to methyl-lysine reader domains is evaluated to see how closely the surrogates reproduce native residue recognition and selectivity.
- Cell assays indicate the charged isosteres can still traverse membranes, and SAR trends tie ring substitution to the affinity-permeability tradeoff for reader ligands and CPPs.
💡 PointsA non-hydrolyzable Kme3/Rme2 mimic solves a genuine headache—native methylated peptides get erased by demethylases or clipped by proteases mid-assay, muddying SAR. If ring substitution tunes affinity without killing permeability, this is a genuine alternative scaffold for reader-domain PPI inhibitors and arginine-free CPPs, not just another quaternary-ammonium curiosity—worth testing against our own Kme3 reader panel.
Evaluation of Binding and Cell Penetration of Imidazolium Amino Acids as Novel Bioisosteres for Trimethyllysine, Dimethylarginine, and Arginine ↗
2026-09-26 · ⚗️p53 Y220C (mutant p53 reactivator/stabilizer) · Journal of Medicinal Chemistry (ACS)
- Researchers built a live-cell NanoBRET assay to test whether reported p53 Y220C ligands truly engage the mutant protein inside intact cells.
- The BRET-based readout gives a cell-based engagement ranking for known Y220C stabilizer/reactivator compounds, complementing prior biochemical binding data.
- Such cellular validation checks permeability and intracellular target occupancy, a key hit-to-lead checkpoint for this hard-to-drug p53 cavity mutant.
💡 PointsCompounds that light up beautifully in DSF or ITC routinely stall out crossing a membrane into that buried, polar cavity — a cell-based BRET ranking is built to catch precisely that failure mode before a Y220C hit gets pushed into SAR. I'd still want it cross-referenced against a functional readout like p21 induction or apoptosis, and benchmarked directly against rezatapopt's (PC14586) cellular engagement window before trusting the ranking over biochemical Kd.
NanoBRET Target Engagement Enables Validation of p53 Y220C Ligands in a Cellular Context ↗
2026-09-23 · 🏢trial result · Endpoints News · Ionis Pharmaceuticals / Roche
- Sefaxersen, Ionis's antisense oligonucleotide suppressing liver complement factor B, met the primary endpoint of Roche's Phase 3 IMAgINATION trial in high-risk primary IgA nephropathy.
- A prespecified interim analysis of 459 patients (1:1 randomized) showed statistically significant, clinically meaningful proteinuria reduction (24-hour UPCR) vs. placebo at week 37.
- The once-monthly, self-administered subcutaneous drug could support accelerated approval in a crowded IgAN market that already includes sparsentan.
💡 PointsComplement factor B suppression becomes a third distinct mechanism validated in IgA nephropathy, joining sparsentan's endothelin/AT1 blockade and the B-cell/APRIL plays from atacicept and sibeprenlimab; convergent proteinuria data across mechanisms suggests the market fragments by dosing convenience, not efficacy. Once-monthly self-injection undercuts daily oral and infused rivals on adherence, while Ionis banks another platform-licensing win validating its originate-and-out-license model.
Roche kidney drug's Phase 3 win sets up path to accelerated approval ↗
2026-09-22 · 🏢trial result · Endpoints News · Amgen
- Dazodalibep is a CD40 ligand (CD40L) antagonist fusion protein that blocks a key costimulatory signal between T cells, B cells and antigen-presenting cells implicated in Sjögren's disease.
- The Phase 3 OASIZ 301 trial randomized about 621 adults with moderate-to-severe systemic Sjögren's disease (ESSDAI ≥5) to dazodalibep or placebo.
- The study met its primary endpoint, showing a statistically significant and clinically meaningful reduction in ESSDAI disease-activity scores at Week 48, with benefit emerging as early as Week 4.
- No imbalance in blood clots or opportunistic infections was reported, a closely watched safety signal for this drug class; a second Phase 3 trial, OASIZ 303, in patients with lower systemic disease activity is due to complete in Q4 2026.
💡 PointsNo imbalance in blood clots or infections is the headline that matters most: CD40L antagonists carry a long history of thromboembolic failures, so this clean safety data de-risks the whole mechanism, not just Amgen's asset. It also finally validates the $27.8B Horizon buy, giving Amgen the first credible disease-modifying candidate in a zero-approved-therapy indication—with a second Phase 3 in a milder segment positioning it to own both ends of the severity spectrum.
Amgen's Phase 3 Sjögren's win; Novartis' $900M radioligand deal ↗
2026-09-22 · 🏢trial result · Fierce Biotech · Roche
- Enicepatide (CT-388), Roche's dual GLP-1/GIP receptor agonist, met both primary endpoints in a Phase II trial in type 2 diabetes with overweight or obesity.
- At 48 weeks, the top 24 mg dose drove dose-dependent weight loss near 15% with no plateau, plus strong glycemic improvement.
- Most high-dose patients reached near-normal HbA1c, and Roche is now advancing Phase III programs (ENITH-1, ENITH-2) plus a glycemic-control study.
💡 PointsRoche just cashed in its $2.7B Carmot acquisition: a 15% weight-loss curve still climbing at 48 weeks puts enicepatide in contention with Lilly's retatrutide and Novo's CagriSema, not just chasing tirzepatide. More importantly, it hands Roche a credible re-entry into metabolic disease after sitting out the incretin boom — Phase III now becomes the real test of manufacturing and commercial scale-up against entrenched leaders.
Roche's GLP-1/GIP drug hits in phase 2 diabetes trial, fueling best-in-disease hopes ↗
2026-09-22 · 🏢trial result / pipeline progress · Fierce Biotech · Vertex Pharmaceuticals
- Vertex's oral APOL1 inhibitor inaxaplin met Phase 2b AMPLIFIED goals in two new AMKD populations beyond the original cohort.
- Among 41 patients, Week 13 UACR fell 42.7% with modest proteinuria (n=23) and 17.3% with AMKD plus type 2 diabetes (n=18).
- This broadens inaxaplin's market as pivotal AMPLITUDE trial enrollment completes, with interim data due early 2027.
💡 PointsAPOL1-mediated kidney disease has essentially no targeted competition — a genetically defined, high-unmet-need population overwhelmingly of African ancestry that mainstream nephrology has largely ignored — and Vertex is quietly building the second pillar of its post-CF story there. Widening efficacy into milder-proteinuria and diabetic AMKD subgroups ahead of AMPLITUDE's 2027 readout meaningfully expands the addressable market and de-risks the label.
Vertex's midstage data amplify kidney disease market opportunity ↗
2026-09-21 · 🏢regulatory approval · FiercePharma · NewAmsterdam Pharma / Menarini Group
- The European Commission approved obicetrapib, an oral once-daily CETP (cholesteryl ester transfer protein) inhibitor, marking the first-ever regulatory approval anywhere in the world for this drug class.
- Two products were cleared for hypercholesterolemia, including heterozygous familial and mixed dyslipidemia: monotherapy Ubeslo and a fixed-dose combination with ezetimibe, Evlarco.
- Approval rests on three NewAmsterdam Pharma trials showing LDL cholesterol reductions of up to roughly 40% with monotherapy and about 50% with the combination versus placebo.
- Menarini Group holds exclusive commercialization rights across Europe under its licensing agreement with NewAmsterdam, which stands to receive tiered royalties and milestone payments.
💡 PointsCETP inhibitors were pharma's most notorious graveyard — torcetrapib killed patients, evacetrapib and anacetrapib flamed out on efficacy — so obicetrapib's clearance is a rare mechanism resurrection, not just another lipid drug. The Menarini licensing deal also shows how a small biotech de-risks European commercialization: NewAmsterdam banks royalties and milestones while Menarini fronts sales infrastructure against entrenched PCSK9 and statin-ezetimibe incumbents.
Regulatory tracker: FDA updates for Merck's Winrevair, Nuvation's Ibtrozi lead regulatory deluge (item: Menarini's obicetrapib products Evlarco and Ubeslo receive EU nod) ↗