Peptide News Digest

Circle Pharma CID-078 Clinical Plenary at AACR 2026, Bicycle BT5528 Head-Neck Data, Fedora FPI-2119 at ESCMID, Nature Biomed HMD-AMP AI Discovery

Circle Pharma's CID-078 macrocyclic peptide debuts at AACR clinical plenary; Bicycle's BT5528 HNSCC data; Fedora's FPI-2119 bactericidal profile at ESCMID; HMD-AMP AI finds 37M+ AMPs.

10 stories · Covering clinical-trials, research, industry

Editor's Note

Today's digest is dominated by parallel AACR 2026 in San Diego and ESCMID Global 2026 in Munich, with peptide-based therapeutics delivering some of the highest-profile data readouts. The headline event is Circle Pharma's unveiling of first Phase 1 clinical activity data for CID-078, a macrocyclic peptide cyclin A/B RxL inhibitor, in the coveted Clinical Trials Plenary Session — a major validation moment for the macrocyclic peptide modality in oncology. Bicycle Therapeutics presents preclinical anti-tumor data for BT5528 (nuzefatide pevedotin), its EphA2-targeting bicyclic peptide drug conjugate, in head-and-neck squamous cell carcinoma models. The AACR Opening Plenary — 'Precision, Partnership, Purpose' — features Carl June on CAR-T for solid tumors alongside Regina Barzilay, Charles Sawyers, and Georg Winter. Beyond oncology, Fedora Pharmaceuticals drops positive bactericidal data on FPI-2119, a first-in-class lactivicin antibiotic, at ESCMID, while a Nature Biomedical Engineering paper unveils HMD-AMP, a protein language model that screened 37 million+ antimicrobial peptide candidates across nine mammalian host and gut microbiomes — a major AI milestone for AMR research. Molecular Partners, Leukogene, Cogent, and Verismo round out the day's slate with novel modalities spanning DARPin T-cell engagers, MHC class II engagers, pan-KRAS inhibitors, and KIR-CAR-T platforms.

Circle Pharma Unveils First Phase 1 Clinical Activity Data for CID-078 Macrocyclic Peptide at AACR 2026 Clinical Trials Plenary

Circle Pharma presents early clinical data for CID-078 in the AACR 2026 Clinical Trials Plenary (Sunday, April 19, 1:00-3:00 PT). CID-078 is a first-in-class orally bioavailable macrocyclic peptide cyclin A/B RxL inhibitor evaluated in a Phase 1 multicenter trial (NCT06577987) for advanced solid tumors with RB1 alterations. The plenary slot — a coveted showcase for private biotechs — tests whether macrocyclic peptides can establish themselves as a third modality alongside small molecules and biologics.

Bicycle Therapeutics Presents BT5528 Bicyclic Peptide Drug Conjugate Anti-Tumor Data in HNSCC Xenograft Models at AACR 2026

Bicycle Therapeutics delivers an oral presentation (Sunday, April 19, 4:05-4:20 PT) on preclinical activity of BT5528 (nuzefatide pevedotin), its EphA2-targeting bicycle drug conjugate, in cell-line-derived xenograft models of head and neck squamous cell carcinoma. Lukas Stanczuk, Ph.D. leads the presentation under abstract 1325. The HNSCC program complements ongoing Phase 1/2 clinical work combining BT5528 with nivolumab in advanced solid tumors.

AACR 2026 Opening Plenary: Carl June on CAR-T Solid Tumor Progress, Regina Barzilay on AI, Charles Sawyers on Precision Oncology

The AACR 2026 Opening Plenary Session — 'Precision, Partnership, Purpose: Advancing Cancer Science to Save Lives Globally' — runs Sunday April 19, 9:30-11:30 a.m. PT. Cochaired by Paul Mischel (Stanford) and Alice Shaw (Dana-Farber), speakers include Carl June (Penn, armored CAR-T for solid tumors, glioblastoma), Georg Winter (AITHYRA), Regina Barzilay (MIT), and Charles Sawyers (MSK). The program sets the tone for a meeting in which peptide-based modalities, ADCs, and PDCs are taking center stage.

Molecular Partners Announces Three AACR 2026 Posters Including First Switch-DARPin T-Cell Engager MP0632 Preclinical Data

Molecular Partners presents three posters at AACR 2026 announcing MP0632 as the first logic-gated Switch-DARPin T-cell engager candidate, targeting MSLN/EpCAM-expressing solid tumors. MP0632 showed tumor regression in dual-antigen preclinical models with limited activity on single-antigen tumors, supporting a favorable therapeutic window. The company also presented updated data for Radio-DARPin MP0712, currently in a US Phase 1/2a trial for DLL3-expressing tumors.

Fedora Pharmaceuticals: FPI-2119 Lactivicin-Class Antibiotic Shows Potent Bactericidal Activity at ESCMID 2026

Fedora Pharmaceuticals presented eight posters at ESCMID Global 2026 in Munich today highlighting FPI-2119, a first-in-kind derivative of the lactivicin class for Gram-negative infections. As a non-β-lactam antibiotic, FPI-2119 is not susceptible to β-lactamases. Posters demonstrated concentration-dependent bactericidal activity and low resistance frequency against Pseudomonas aeruginosa, maintained activity against β-lactamase-expressing E. coli strains, and activity against resistant Campylobacter, Salmonella, and Shigella.

Leukogene Therapeutics Highlights MHC Class II-Engager Platform in AACR 2026 Presentations for AML and Pancreatic Cancer

Leukogene Therapeutics presents two posters at AACR 2026 showcasing its proprietary M2T platform, designed to harness MHC class II-engaging mechanisms to redirect immune response against acute myeloid leukemia and pancreatic cancer. CEO Sandeep Gupta framed the platform as targeting two of the most lethal and treatment-resistant cancers. Posters appear in the Bi- and Tri-Specific Antibody Therapies session on April 21.

Cogent Biosciences' CGT1263 Pan-KRAS(ON) Inhibitor and CNS-Penetrant ErbB2 Inhibitor CGT4255 Preclinical Data at AACR 2026

Cogent Biosciences presents preclinical data for its novel pan-KRAS(ON) inhibitor CGT1263 and selective ErbB2 inhibitor CGT4255 at AACR 2026. CGT1263 shows best-in-class cellular potency with a kinase selectivity advantage that could mitigate skin toxicity plaguing multi-RAS inhibitors. CGT4255 is designed with best-in-class CNS penetration to address HER2+ brain metastases, with preclinical synergy data with a HER2 ADC suggesting re-sensitization after ADC resistance.

Verismo Therapeutics Secures $28M From HLB Innovation Ahead of AACR 2026 Late-Breaking KIR-CAR Clinical Debut

Verismo Therapeutics announced a $28 million investment from HLB Innovation to accelerate clinical development of its KIR-CAR platform, timed to the company's first-ever presentation of SynKIR-110 Phase 1 (STAR-101) multi-chain KIR-CAR clinical data in the AACR 2026 Late-Breaking Clinical Trials plenary (April 20). Verismo is a Penn/Carl June spinout using a modified NK-cell-derived receptor and DAP12 pairing to improve T-cell persistence.

Nature Biomedical Engineering: HMD-AMP Protein Language Model Screens 37 Million+ Antimicrobial Peptide Candidates From Mammalian Microbiomes

A new Nature Biomedical Engineering paper introduces HMD-AMP, a protein language model-based approach that outperforms prior methods at identifying evolutionarily distant antimicrobial peptides. Applied to host and gut microbiome genomes of nine mammals, HMD-AMP revealed over 37 million predicted AMPs. Of 91 experimentally validated high-confidence sequences, 74 showed strong antibacterial activity and 48 were evolutionarily remote from known AMPs, including four with broad-spectrum activity at low toxicity.

Medical Xpress / San Raffaele Study: AI Dietary Tracking Reveals GLP-1 Users Get Only 0.6 g/kg/day Protein — 88% Below Recommendations

A study published in Medical Xpress analyzed 5,741 days of AI-powered dietary-tracking data from 332 adults with overweight or obesity. GLP-1 users consumed significantly less energy (1,102 vs 1,281 kcal/day) and protein (53.8 vs 62.0 g/day) than non-users. Weight-adjusted daily protein intake was 0.6 g/kg/day among GLP-1 users, with 88% falling below the Italian national 0.9 g/kg/day recommendation. IRCCS San Raffaele researchers warn of nutritional deficiencies and muscle-health risks during GLP-1 therapy.