May 21, 2026

Retatrutide TRIUMPH-1 Phase 3 Topline 28.3% Weight Loss, ASCO 2026 Abstract Release, Regeneron-Parabilis $2.325B Antibody-Helicon Conjugate, AMAZE-12 Amycretin Phase 3, FDA Jixianglong Warning

Retatrutide TRIUMPH-1 Phase 3 hits 28.3% weight loss + 30.3% extension, ASCO 2026 abstracts release, Regeneron-Parabilis $2.325B Helicon deal, AMAZE-12 amycretin Phase 3.

10 stories · Covering clinical-trials, industry, regulatory, research

Editor's Note

Thursday digest anchored on the single largest obesity-pharmacology data event of 2026 to date. Eli Lilly released TRIUMPH-1 Phase 3 topline this morning: retatrutide produced 28.3% mean weight loss at 12 mg over 80 weeks in 2,339 adults with obesity and without diabetes (25.9% at 9 mg, 19.0% at 4 mg, vs 2.2% placebo), with 45.3% of participants reaching ≥30% weight loss — territory previously reserved for bariatric surgery outcomes. A 104-week extension in the BMI ≥35 subgroup pushed mean loss to 30.3% (85.0 lbs). All three doses met the primary and key secondary endpoints. Discontinuation rates ran 4.1%, 6.9%, and 11.3% across 4, 9, and 12 mg arms versus 4.9% placebo; the hepatic-enzyme signal that surfaced in TRIUMPH-4 reappeared as transient ALT elevations that normalized by week 24. Full data lands at ADA 2026 in New Orleans starting June 5. Independently, the ASCO 2026 abstract embargo lifted at 5 PM ET — the peptide-oncology slate landed simultaneously with Bicycle Therapeutics' Duravelo-2 interim data (zelenectide pevedotin + pembrolizumab in 1L urothelial), Avacta's AVA6000 Phase 1b in salivary gland cancers (90% combined disease control rate including 2 confirmed partial responses and 7 minor responses across 30 Phase 1b patients), BriaCell's final Phase 2 Bria-IMT survival data, and BioVaxys's MVP-S PESCO trial release. On the deal side, Regeneron and Parabilis Medicines announced May 18 a strategic collaboration worth up to $2.325 billion ($50M upfront, $75M equity, $2.2B milestones) to develop antibody-Helicon conjugates across five initial targets using Parabilis's stabilized helical peptide platform. Novo Nordisk started recruiting AMAZE-12, the Phase 3 weight-maintenance trial of amycretin (dual GLP-1/amylin receptor agonist), on the same day. FDA enforcement landed in the supply chain: a warning letter to Harbin Jixianglong Biotech for shipping semaglutide API sourced from a non-green-list facility while labeled as produced at its own green-listed plant. Off the GLP-1 axis, a Science magazine May 8 feature highlighted iRGD as the tumor-penetrating peptide that could shift how cancer drug-delivery strategies are designed.

Clinical Trials

Eli Lilly TRIUMPH-1 Phase 3 Topline (May 21): Retatrutide Delivers 28.3% Weight Loss at 12 mg / 25.9% at 9 mg / 19.0% at 4 mg Over 80 Weeks, 45.3% Reach ≥30% Loss, 30.3% in BMI ≥35 Extension at 104 Weeks

Eli Lilly announced TRIUMPH-1 topline results May 21 from the 80-week Phase 3 registrational trial of retatrutide — a first-in-class GIP/GLP-1/glucagon triple-receptor agonist — in 2,339 adults with obesity or overweight and at least one weight-related comorbidity, without diabetes. Mean body weight loss was 28.3% (70.3 lbs) at 12 mg, 25.9% at 9 mg, and 19.0% at 4 mg, all versus 2.2% on placebo. All three doses met the primary and key secondary endpoints. 45.3% of participants achieved ≥30% weight loss — bariatric-surgery territory. A 104-week extension in adults with baseline BMI ≥35 saw mean weight loss reach 30.3% (85.0 lbs) on 12 mg. Full data presentation is scheduled for ADA 2026 in New Orleans (June 5-8). Lilly's NDA filing follows the TRIUMPH-2 (obesity + T2D) and TRIUMPH-3 (obesity + established cardiovascular disease) readouts expected later in 2026.

#retatrutide #triumph-1 #eli-lilly #phase-3 #obesity #triple-agonist #ada-2026

Clinical Trials

TRIUMPH-1 Safety Profile: 4.1% / 6.9% / 11.3% Discontinuation on 4 / 9 / 12 mg Retatrutide vs 4.9% Placebo; Transient ALT Elevations Normalize by Week 24

TRIUMPH-1's safety profile landed alongside the efficacy headline. Discontinuation rates due to adverse events were 4.1%, 6.9%, and 11.3% on retatrutide 4 mg, 9 mg, and 12 mg respectively, versus 4.9% on placebo. The most common adverse events were nausea, diarrhea, constipation, and vomiting — generally mild-to-moderate, concentrated during dose escalation, and decreasing over time. The hepatic-enzyme signal that appeared in TRIUMPH-4 (December 2025) reappeared as transient ALT elevations in a subset of participants on 9 mg and 12 mg dosing, normalizing by week 24. Liver fat dropped >80% on 8-12 mg dosing, supporting the interpretation that the transient transaminitis reflects hepatic triglyceride mobilization rather than hepatotoxicity. The 12 mg discontinuation rate at 11.3% sits modestly above tirzepatide 15 mg in SURMOUNT-1 (~7%) and Wegovy 2.4 mg in STEP 1 (~6.5%) — a tolerability gap that prescribers and patients will weigh against the efficacy gain.

#retatrutide #triumph-1 #safety-profile #alt-elevation #discontinuation #tolerability

Industry

Regeneron and Parabilis Medicines Announce $2.325B Antibody-Helicon Conjugate Collaboration (May 18) — $50M Upfront + $75M Equity + $2.2B Milestones Across Five Initial Targets

Regeneron Pharmaceuticals and Parabilis Medicines announced May 18 a strategic research collaboration to discover and develop antibody-Helicon conjugates (AHCs) — a novel modality combining Regeneron's antibody platform with Parabilis's Helicon stabilized helical peptide technology. Deal structure: $50M upfront, $75M equity commitment, and up to $2.2B in development and regulatory milestones across an initial five targets, plus tiered royalties. The Helicon platform locks peptides into their bioactive helical conformation, enabling targeting of historically undruggable protein-protein interaction surfaces that small molecules cannot access. The conjugate format pairs antibody-mediated tissue homing with peptide payload delivery — an extension of the broader peptide-drug-conjugate field that included Bicycle Therapeutics' bicyclic peptide-MMAE conjugates and Avacta's FAP-activated PDCs. The deal is the largest single peptide-platform partnership announced in 2026.

#regeneron #parabilis-medicines #helicon #antibody-peptide-conjugate #stabilized-peptide #platform-deal #undruggable-targets

Clinical Trials

Novo Nordisk AMAZE-12 Phase 3 Amycretin Trial Begins Recruitment May 18 — Dual GLP-1/Amylin Receptor Agonist for Weight Maintenance

Novo Nordisk's AMAZE-12 Phase 3 trial of amycretin — a dual GLP-1 and amylin receptor agonist — began recruiting on May 18, 2026. The trial evaluates amycretin specifically for weight maintenance after initial weight loss, distinguishing it from AMAZE-1 (which measures body weight change over 84 weeks). The amycretin clinical rationale rests on Phase 1 weekly subcutaneous dosing producing 22% weight reduction at 36 weeks and oral formulation producing 13.1% at 12 weeks — both reported in the Lancet earlier in 2026. Amycretin sits within Novo's next-generation pipeline alongside CagriSema (cagrilintide + semaglutide, FDA filing under review with decision expected late 2026) and the orexin-related pipeline acquired via Centessa. The amycretin program is structurally Novo's most direct response to Lilly's retatrutide.

#novo-nordisk #amycretin #amaze-12 #phase-3 #amylin #weight-maintenance #dual-agonist

Industry

ASCO 2026 Abstracts Released May 21 5 PM ET — Peptide Oncology Slate Lands Across Bicycle, Avacta, BioVaxys, BriaCell, Crinetics, and Pfizer

ASCO 2026 abstract text released at 5 PM ET Thursday, ahead of the May 29-June 2 Chicago meeting. The peptide-oncology data landed simultaneously across the previously-announced slate. Bicycle Therapeutics released Duravelo-2 Phase 2/3 interim data on zelenectide pevedotin (BT8009) plus pembrolizumab in 1L locally advanced/metastatic urothelial cancer. Avacta released AVA6000 Phase 1b data in salivary gland cancers. BriaCell released final Phase 2 Bria-IMT survival data plus biomarker analyses from the ongoing Phase 3. BioVaxys's MVP-S PESCO Phase 1B/2 ovarian cancer abstract landed. Crinetics CRN09682 SSTR2 NDC BRAVESST2 abstract emerged. Pfizer released 40+ company-sponsored, investigator-sponsored, and collaborative oncology abstracts including three late-breaking sessions. The peptide-oncology cohort is the largest single ASCO presence in recent meeting history.

#asco-2026 #abstract-release #peptide-oncology #bicycle-therapeutics #avacta #biovaxys #briacell #embargo-lift

Clinical Trials

Avacta AVA6000 ASCO 2026 Salivary Gland Cancer Data (May 21): 90% Combined Disease Control, 2 Confirmed Partial Responses + 7 Minor Responses in 30 Phase 1b Patients

Avacta's AVA6000 — a fibroblast activation protein (FAP)-activated peptide-drug conjugate releasing doxorubicin selectively in the tumor microenvironment — released Phase 1a/1b data at ASCO 2026 in salivary gland cancers. Of 30 patients in the Phase 1b cohort treated at 250 mg/m² and above, two experienced confirmed partial responses (>30% tumor shrinkage) and seven experienced minor responses (10-30% shrinkage). The combined Phase 1a + 1b disease control rate reached 90%. Phase 1a data in 11 patients at the same dose range showed 1 confirmed partial response, 4 minor responses, 1 progression, and 5 stable disease — a 91% disease control rate. The favorable safety profile continued versus conventional doxorubicin, with no severe cardiac toxicity events. The data anchors Avacta's planned Phase 2/3 expansion in adenoid cystic carcinoma — the most common salivary gland cancer subtype, with no FDA-approved systemic therapy.

#avacta #ava6000 #fap-dox #salivary-gland-cancer #asco-2026 #peptide-drug-conjugate #phase-1b

Clinical Trials

Bicycle Therapeutics Duravelo-2 ASCO 2026 Data (May 21): Zelenectide Pevedotin + Pembrolizumab in 1L Urothelial — Oral Presentation Monday June 1, Abstract 4516

Bicycle Therapeutics released Duravelo-2 Phase 2/3 interim analysis data at ASCO 2026 — zelenectide pevedotin (BT8009, a Nectin-4-targeting bicyclic peptide-MMAE conjugate) plus pembrolizumab in previously untreated locally advanced or metastatic urothelial cancer. The full data presentation is scheduled for Monday June 1, 8:30-8:36 AM CT in the GU Cancers oral session (Abstract 4516). The Duravelo-1 monotherapy comparator anchor — 65% ORR (13/20) in cisplatin-ineligible 1L mUC at 5 mg/m² + pembrolizumab combination, with median DOR 11.1 months in the monotherapy expansion — sets the bar for what the Duravelo-2 combination interim must clear. Bicycle's five-abstract ASCO package includes the oral Duravelo-2 piece plus four posters covering Duravelo-1 monotherapy update, BT5528 EphA2 monotherapy and combination cohorts, and BT8009 second-line urothelial data.

#bicycle-therapeutics #zelenectide-pevedotin #bt8009 #duravelo-2 #urothelial-cancer #asco-2026 #nectin-4

Clinical Trials

BriaCell ASCO 2026 Final Phase 2 Bria-IMT Survival Data (May 21): Cell-Immunotherapy + Checkpoint Inhibitor in Heavily Pretreated Metastatic Breast Cancer

BriaCell released final randomized Phase 2 Bria-IMT survival and quality-of-life data at ASCO 2026 alongside biomarker analyses from the ongoing Phase 3 study. Bria-IMT — a whole-cell allogeneic peptide-and-cell immunotherapy combined with checkpoint inhibitor — has been studied in heavily pretreated metastatic breast cancer patients who have failed antibody-drug conjugate, checkpoint, and CDK4/6 inhibitor therapy. The Phase 2 data set covers 12- and 24-month survival, treatment tolerability, and circulating-tumor-cell biomarker work. The Phase 3 program added Penn Medicine's Abramson Cancer Center as a site on May 13, joining Smilow Cancer Hospital at Yale New Haven and the Los Angeles Cancer Network. The six-abstract BriaCell package at ASCO 2026 — three poster presentations and three publication-only abstracts — establishes the company as the largest peptide-immunotherapy presence at this year's meeting.

#briacell #bria-imt #metastatic-breast-cancer #asco-2026 #cell-immunotherapy #phase-2-survival #phase-3-biomarkers

Regulatory

FDA Warning Letter to Harbin Jixianglong Biotech (May 20): Chinese GLP-1 Supplier Shipped Semaglutide API Sourced From Non-Green-List Facility Under Misleading Label

The FDA sent a warning letter to Harbin Jixianglong Biotech disclosed May 20 after inspectors discovered a compliance failure at the company's manufacturing facility two months after the firm had been added to the FDA's green list to export GLP-1 drugs to the US. Jixianglong allegedly bought semaglutide active pharmaceutical ingredient from a facility not on the green list, labeled the API as manufactured at its own plant (implying the green-listed origin), and shipped the batch to US customers. The FDA framed the labeling as an apparent attempt to circumvent import-alert safeguards. The agency's March 11 enforcement report had previously listed Jixianglong recalls of semaglutide for compounding use only, attributed to failing to complete process validation and bacterial endotoxin method validation before distribution. The action is part of the broader FDA Pharmaceutical Quality / GLP-1 supply-chain enforcement cycle, including the April 30 503B bulks-list proposal closing June 29.

#fda #warning-letter #harbin-jixianglong #semaglutide-api #import-alert #compounded-glp-1 #supply-chain

Research

Science Magazine Feature (May 8): iRGD Tumor-Penetrating Peptide Could Reshape Cancer Drug Delivery if Safety and Efficacy Pan Out

A Science magazine feature published May 8 highlighted iRGD — a 9-amino-acid tumor-penetrating peptide originally identified by Erkki Ruoslahti's group at Sanford Burnham Prebys — as a candidate to improve delivery of cancer chemotherapy and immunotherapy into solid tumors. iRGD binds α-v integrins overexpressed on tumor vasculature, then is proteolytically processed to expose a cryptic CendR motif that engages neuropilin-1 and triggers a transient tumor-vascular permeability burst. Co-administered with chemotherapy, iRGD increases drug penetration into the tumor without covalent conjugation. Early clinical studies in pancreatic cancer combining iRGD with nab-paclitaxel and gemcitabine showed improved tumor response and progression-free survival; later-stage development continues through DrugCendR (the Ruoslahti lab spinout) and academic-industrial partnerships. The Science piece frames iRGD as a complementary technology to antibody-drug conjugates and peptide-drug conjugates — a co-administered delivery enhancer rather than a covalent payload carrier.

#irgd #tumor-penetrating-peptide #science-magazine #cancer-drug-delivery #neuropilin-1 #alpha-v-integrin #drugcendr