Peptide News Digest

JAMA on Gray-Market Retatrutide and Zenagamtide, Icotyde Two-Year ICONIC-LEAD Data, Melflufen Crosses the Blood-Brain Barrier

JAMA examines online sales of unapproved retatrutide and zenagamtide, Icotyde holds psoriasis clearance at two years, and melflufen reaches brain tumors.

6 stories · Covering regulatory, clinical-trials, research

Editor's Note

Friday's news was light on GLP-1 science and heavy on peptides elsewhere. A JAMA news report found dozens of websites selling Lilly's retatrutide and Novo's zenagamtide, two drugs no regulator has approved, and Australian tests showing one vial of supposed retatrutide held semaglutide instead. J&J reported that most psoriasis patients on its peptide pill Icotyde kept clear or almost clear skin through two years, though the release does not say how dropouts were counted. Oncopeptides said its peptide-drug conjugate melflufen reached brain tumors in the first three surgical patients of a small study, a test of delivery rather than benefit, and BioMarin filed to extend its growth peptide Voxzogo to a second form of short stature. Two lab papers rounded out the day: red blood cells coated with disease peptides calmed a multiple sclerosis-like disease in mice, and a corn fungus was found to use a hidden peptide to sense that it has entered a plant.

Regulatory

JAMA Finds Dozens of Websites Selling Unapproved Retatrutide and Zenagamtide, With Lab Tests Showing Wrong Doses and a Vial That Held Semaglutide

A JAMA Medical News report published October 9, 2026 found dozens of websites, promoted by TikTok and Instagram influencers, selling Eli Lilly's investigational triple agonist retatrutide and Novo Nordisk's GLP-1 and amylin drug zenagamtide, often labeled "for research purposes only" while giving dosing instructions. Neither drug is approved anywhere. Australia's drug regulator found a product labeled retatrutide that contained a high dose of semaglutide instead, and University of Queensland tests of three 10 mg vials found doses from about half to about twice the label; the FDA has sent 21 warning letters to retatrutide sellers since December 2024, according to the report.

#retatrutide #zenagamtide #gray-market #fda-warning-letter
Clinical Trials

J&J Reports Two-Year ICONIC-LEAD Data: At Least 70% of Icotyde Patients Kept Clear or Almost Clear Skin From Week 64 Through Week 112

Johnson & Johnson said on October 9, 2026, at the Fall Clinical Dermatology Conference, that in the Phase 3 ICONIC-LEAD trial of its oral IL-23 receptor-blocking peptide Icotyde (icotrokinra) in 684 people aged 12 and older with moderate to severe plaque psoriasis, at least 70% of treated patients had clear or almost clear skin, at least 44% had completely clear skin by PASI 100, and at least 72% reached PASI 90 at week 112. Among people who reached PASI 90, stopped the drug at week 24, and later restarted it, 85% regained that response within 24 weeks. The release does not say how patients who left the study were counted, and J&J reported no new safety signals.

#icotrokinra #psoriasis #johnson-johnson #oral-peptide
Clinical Trials

Oncopeptides Says Its Peptide-Drug Conjugate Melflufen Reached Brain Tumor Tissue in the First Three Glioblastoma Surgery Patients

Oncopeptides reported on October 9, 2026 that in the open-label INSULA window-of-opportunity study at Oslo University Hospital, active drug was found in resected tumor tissue from the first three patients with recurrent glioblastoma given melflufen, its EMA-approved peptide-drug conjugate, before surgery, meeting the study's primary goal of showing the drug crosses the blood-brain barrier. The company said tumor drug levels matched what animal studies predicted but gave no numbers, and the study is not designed to show clinical benefit. It plans to enroll about 10 patients and will discuss the data in an investor webcast on October 12.

#oncopeptides #melflufen #glioblastoma #blood-brain-barrier #peptide-drug-conjugate
Regulatory

BioMarin Files to Extend Voxzogo, Its CNP Peptide Growth Drug, to Hypochondroplasia and Brings Phase 3 Data to ASBMR 2026

BioMarin said on October 9, 2026 that it has submitted a supplemental application to the FDA for Voxzogo (vosoritide), a C-type natriuretic peptide analog approved for achondroplasia, in hypochondroplasia, a milder genetic form of short stature, with filings in Europe and other regions on track and a possible 2027 launch if approved. Phase 3 results showing faster growth in children with hypochondroplasia are among 13 studies the company is presenting at the ASBMR meeting in Boston, though the release gives no growth figures. A separate application with long-term achondroplasia data has an FDA decision date of February 28, 2027.

#vosoritide #biomarin #hypochondroplasia #achondroplasia #cnp
Research

Zurich Study Finds Liver Kupffer Cells Drive the Immune Tolerance Created by Peptide-Coated Red Blood Cells in a Mouse Model of Multiple Sclerosis

University of Zurich researchers reported in Science Advances on October 9, 2026 that red blood cells coupled to the disease-inducing peptide prevented experimental autoimmune encephalomyelitis, a mouse model of multiple sclerosis, when given beforehand and eased symptoms when given after onset. The effect was specific to the coupled peptide and depended on both cell and peptide dose. Kupffer cells, immune cells in the liver that swallowed the coated red cells, were required for tolerance. The authors describe red cells coupled to a cocktail of multiple sclerosis peptides as a promising approach for patients, but these results are from mice.

#immune-tolerance #peptide-coupled-cells #preclinical
Research

Corn Smut Fungus Uses a Peptide Hidden Inside Its Own Protein, Released by Plant Enzymes, to Sense It Has Entered a Host

Researchers reported in Nature Communications on October 9, 2026 that the corn pathogen Ustilago maydis secretes a protein, Pit2, that plant enzymes cut to release a hidden peptide, which then activates the fungal receptor Gpe1 and promotes fungal growth after the fungus enters plant tissue. Mutations that disrupted the peptide-receptor contact reduced virulence, and the system is conserved in related fungi. The authors note mechanistic similarities to mammalian GPCRs, the receptor family targeted by many peptide drugs.

#peptide-signaling #fungal-pathogens #plant-disease

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