AACR 2026 — the American Association for Cancer Research annual meeting in April — produced a heavy load of peptide-related abstracts. The conference is the central venue for peptide-drug conjugates, peptide cancer vaccines, neoantigen platforms, and PRRT-style radioligand therapies.
Notable threads from this site's coverage: Bicycle Therapeutics' BT5528 in EphA2-positive solid tumors; CID-078 (a cyclin-targeted bicyclic peptide) in RB1-deficient tumors; ELI-002 amphiphile-peptide and EVX-01 in cancer-vaccine sessions; new peptide-drug conjugate work from Merck, AstraZeneca, and Avacta; Verismo Therapeutics' KIR-CAR program; and an opening plenary on AI-designed cyclic peptides hitting undruggable intracellular targets.
Use this tag to scan AACR readouts as they appear. For deeper threads, see #peptide-vaccine, #peptide-drug-conjugate, and #bicycle-therapeutics.
BriaCell announced April 21 preclinical results from its next-generation Bria-OTS+ personalized peptide immunotherapy at the AACR 2026 Annual Meeting. The platform pairs HLA-matched whole-cell allogeneic immunotherapy with peptide-mediated antigen targeting, building on the Bria-IMT clinical foundation in heavily pretreated metastatic breast cancer. Based on the preclinical anti-cancer activity, BriaCell plans to enter the clinic for metastatic breast cancer and prostate cancer indications later in 2026, with lung cancer and melanoma planned for 2027. The program adds to a peptide-immuno-oncology pipeline that includes the Bria-IMT Phase 3 and the company's six accepted ASCO 2026 presentations covering survival data, biomarkers, and quality-of-life endpoints.
On the final day of AACR 2026, the German Cancer Consortium presented first-in-human imaging data for EphA2 BIA — a gallium-68-labeled bicyclic peptide targeting EphA2 — in pancreatic ductal adenocarcinoma patients. Seven patients underwent PET/CT imaging up to three hours post-injection, with rapid tumor uptake and primarily renal excretion in six of seven. The tracer successfully detected liver, bone, lymph node, and peritoneal metastases in 15 of 18 patients imaged to date, validating bicyclic peptides as a radioconjugate imaging modality.
The AACR Annual Meeting 2026 concluded April 22 in San Diego after six days featuring unprecedented peptide-oncology visibility. Macrocyclic peptide drug conjugate (PDC) pipelines across Circle Pharma, Bicycle Therapeutics, Oncopeptides, and SignaBlok drew regulatory and venture attention; peptide-targeting radioligand data from Perspective Therapeutics, Bicycle, and AlphaGen signaled maturation of the peptide-radioconjugate subcategory. AACR Advances sessions throughout the meeting featured targeted protein degradation and novel tumor-selective modalities, with peptide-based approaches competing directly with antibody drug conjugates in Phase 1/2 readouts.
Lirum Therapeutics announced preclinical data at AACR 2026 demonstrating antitumor activity of LX-101, an IGF-1R–targeted peptide-payload conjugate, in Ewing sarcoma patient-derived xenograft models. As a monotherapy, LX-101 showed meaningful single-agent activity and demonstrated synergy when combined with PI3K or mTOR inhibition. The compound was previously granted FDA "Study May Proceed" authorization for inclusion in the RAPID platform clinical trial for relapsed/refractory Ewing sarcoma and desmoplastic small round cell tumor (DSRCT).
Avacta Therapeutics presented April 21 data at AACR 2026 showing its FAP-enabled peptide-drug conjugate AVA6103, which delivers exatecan via the pre|CISION® platform, achieved a Tumor Selectivity Index three times higher than marketed ADC Enhertu in preclinical models, with tumor Cmax more than one log higher. AVA6103 entered the Phase 1 FOCUS-01 trial (NCT07454642) in March 2026 with initial clinical readout expected later this year.
Evaxion's AI-designed personalized neoantigen peptide vaccine EVX-01 combined with Keytruda produced a 75% objective response rate at 2 years in advanced melanoma patients, with 86% of vaccine targets triggering de novo T-cell responses. Data were presented April 22 at AACR 2026; 3-year follow-up expected in H2 2026. The 86% target-hit rate demonstrates AI-designed peptide neoantigen selection maturing for cancer vaccines.
AlphaGen Therapeutics presented preclinical data at AACR 2026 (April 22) showing its novel macrocyclic peptide-based alpha-emitter radioligand [212Pb]Pb-AG1206 binds fibroblast activation protein with picomolar affinity, achieving rapid tumor accumulation, renal clearance, and a high tumor-to-kidney ratio. A sister candidate [212Pb]Pb-AG1002 targets SSTR2 as a non-agonist alpha therapy for neuroendocrine tumors.
Perspective Therapeutics' [212Pb]VMT-α-NET, a first-in-class alpha-emitter peptide radionuclide therapy targeting SSTR2, achieved objective responses in 10 of 23 (43%) Cohort 2 patients with metastatic neuroendocrine tumors in Phase 1/2a data presented at AACR 2026. 18 of 25 patients (72%) remained alive without progression; no dose-limiting toxicities or Grade 4/5 adverse events observed.
Sapience Therapeutics presented first Phase 2 clinical data from ST316, a first-in-class β-catenin/BCL9 antagonist SPEAR peptide, in second-line metastatic colorectal cancer at AACR 2026. Dose expansion showed a well-tolerated safety profile with no dose-limiting toxicities or related SAEs, significant knockdown of Wnt-related signatures in tumor cells, and dose-proportional PK achieving predicted efficacious exposures.
Bicycle Therapeutics presented first clinical experiences of a phage-display-derived EphA2-specific bicyclic peptide PET imaging agent in the Diagnostic Biomarkers 2 session at AACR. The imaging agent complements Bicycle's EphA2-targeted therapeutic pipeline (including nuzefatide pevedotin) and could enable patient selection for EphA2-targeted bicyclic peptide drug conjugates across multiple tumor types.
Novigenix presented first human clinical data at AACR 2026 from its LITOSeek AI-enabled liquid biopsy platform showing dynamic immune-transcriptomic responses in metastatic GEP-NET patients treated with either [212Pb]DOTAMTATE (AlphaMedix) alpha-emitter PRRT or [177Lu]DOTATATE (Lutathera) beta-emitter PRRT. The platform may enable treatment stratification between alpha- and beta-emitter radionuclide therapies.
Bicycle's EphA2-targeting bicyclic peptide-drug conjugate nuzefatide pevedotin (BT8009) at 6.5 mg/m² Q2W plus nivolumab achieved 40% confirmed ORR (4/10) in metastatic urothelial patients who had progressed on checkpoint inhibitors, and 100% (3/3) in MMAE-naive EphA2+ patients. No Grade ≥3 treatment-related adverse events of clinical interest. Presented at AACR 2026 on April 20.
Greenwich LifeSciences presented FLAMINGO-01 Phase III open-label data at AACR 2026 showing GLSI-100 (the 9-amino-acid GP2 HER2 peptide plus GM-CSF adjuvant) produced a ~4x increase in delayed-type hypersensitivity to GP2 across 247 non-HLA-A*02 patients — from 5.2% at baseline to 20.4% at months 4-6 (p<0.001). GP2 is the C-terminal transmembrane fragment of the HER2/neu protein.
BriaCell's Bria-IMT + checkpoint inhibitor combination preserved overall health status and key functional quality-of-life measures in its pivotal Phase 3 study in heavily pretreated metastatic breast cancer patients who had failed ADC, CPI, and CDK4/6 inhibitor therapy. Phase 2 biomarker analyses identified mitotic circulating tumor cells as prognostic and PD-L1 in tumor-macrophage fusion cells as predictive of checkpoint benefit. Presented at AACR April 20.
Enara Bio presented ENA101 at AACR 2026 on April 20, a first-in-class bispecific T-cell engager targeting DARKFOX — a novel cancer-specific 'dark antigen' peptide presented by HLA-A*03:01 and expressed in multiple solid tumors. Preclinical data showed low-picomolar potency and complete tumor regression in xenograft models with once-weekly dosing. IND submission planned for 2H 2026.
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 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.
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.