ADC Trials to Watch at ASCO 2026: A Patient Preview

ASCO is where Phase 3 readouts land. Here's what's maturing into ASCO 2026 (May 29 – June 2, Chicago) on the antibody-drug conjugate side — and what patients seeking trials should be asking before the talks drop.

Published May 23, 2026 • ~8 min read • Pre-conference preview

TL;DR: Six weeks after AACR showcased novel ADC designs, ASCO 2026 (May 29 – June 2, Chicago) is where the field's Phase 3 readouts and registrational data land. The headline ADC readouts confirmed for the meeting program include DESTINY-Breast09 (trastuzumab deruxtecan + pertuzumab as 1L treatment for HER2-positive metastatic breast cancer, Rapid Oral Abstract #1021) and TROPION-Breast02 (datopotamab deruxtecan as 1L treatment for triple-negative breast cancer in patients ineligible for PD-1/PD-L1 inhibitors, Oral Abstract). Expected updates also span EGFR-ADCs (MRG003, BL-B01D1) in nasopharyngeal and gastric cancer, B7-H3 ADCs in lung, and the first ADC + checkpoint-immunotherapy combinations entering 1L treatment. Bispecific ADCs stay in earlier-phase readouts, but ASCO is where the established ADCs (Enhertu, Trodelvy, Padcev, Datroway) expand into earlier lines and broader tumor types.
Confirmed ASCO 2026 ADC abstracts (as of May 23, 2026):

More abstracts will be confirmed as sponsor portfolio press releases are published in the days leading up to the May 31 LBA release date.

Why ASCO 2026 Matters for ADC-Trial Patients

The American Society of Clinical Oncology (ASCO) Annual Meeting is the largest oncology conference of the year. Where AACR (held April 17–22, 2026 in San Diego) showcased earlier-stage research and novel drug designs, ASCO is where Phase 3 confirmatory data lands — the readouts that change FDA approvals, the trials that change first-line standards, the registrational datasets that move drugs from "promising" to "available." For patients, ASCO timing matters because:

What's Different in 2026 vs Prior ASCOs

Three structural shifts in the ADC landscape going into ASCO 2026:

  1. EGFR-ADCs have matured. Going into ASCO 2026, MRG003 / Becotatug Vedotin and BL-B01D1 (EGFR × HER3 bispecific ADC) are in active Phase 3 trials in nasopharyngeal carcinoma and head-and-neck cancers. ASCO is where the first registrational-quality readouts from these regional Phase 3 trials are likely to be presented.
  2. ADC + checkpoint-immunotherapy combinations are entering 1L. Several Phase 3 trials combine an ADC with a PD-1 or PD-L1 inhibitor in previously-untreated metastatic cancer. The 2026 readouts move ADCs from late-line salvage into the front-line conversation.
  3. Bispecific ADC clinical data continues to expand. BL-B01D1 (EGFR × HER3 bispecific ADC, Sichuan Baili) is already the most clinically-advanced bispecific ADC, with Phase 3 trials across NSCLC, NPC, ESCC, and breast cancer; expect further data updates at ASCO 2026. AACR 2026 also showcased earlier-stage bispecific ADC designs (NEOK001, NEOK002, ATG-125, VBC108) moving toward Phase 1 / 2 starts.

ADC Readouts to Watch by Cancer Type

Nasopharyngeal Carcinoma (NPC)

NPC has emerged as one of the most active ADC-development settings in 2026. Going into ASCO:

What patients should ask: if you have recurrent/metastatic NPC after platinum, ADC trials are now multi-Phase 3. Eligibility shifts quickly as new lines of therapy become standard. See current recruiting NPC trials.

Breast Cancer (the headline ADC story this year)

Breast cancer is where the most-confirmed ASCO 2026 ADC abstracts sit. Two are already on the program:

Additional likely topics on the program based on the active Phase 3 trial landscape:

See current recruiting breast cancer trials.

Gastric and Gastroesophageal Cancer

HER2+ gastric cancer was where trastuzumab deruxtecan first received FDA approval after gastric-specific trials. ASCO 2026 watch:

See current recruiting gastric cancer trials.

Lung Cancer (NSCLC and SCLC)

The lung-cancer ADC space has matured into multiple competing classes:

See NSCLC trials | See SCLC trials.

Cholangiocarcinoma

HER2-directed ADC activity in HER2-expressing biliary tract cancers centers on trastuzumab deruxtecan, often combined with chemotherapy or immunotherapy. (Note: zanidatamab is a naked HER2 × HER2 bispecific antibody, not an ADC; the ADC version, zanidatamab-zovodotin / ZW49, is at earlier development.) ASCO 2026 watch: T-DXd combination trial updates and Phase 2 expansion data in HER2-expressing biliary subsets. See cholangiocarcinoma trials.

Other Cancer Types

ADC + Immunotherapy: The Front-Line Question

Perhaps the most consequential question going into ASCO 2026: do ADC + PD-1/PD-L1 combinations beat chemotherapy + PD-1/PD-L1 in front-line metastatic disease? Multiple Phase 3 trials across breast, lung, gastric, and head-and-neck cancers are testing exactly this comparison. Positive readouts would move ADCs from "after progression" to "from day 1" — a major shift in eligibility for downstream lines.

What patients should know:

What This Means for Patients Seeking Trials

  1. Biomarker testing is the gate. Most 2026 ADC trials require specific marker confirmation on tumor tissue. The common tests are IHC (immunohistochemistry — a stain that grades protein expression as 0, 1+, 2+, or 3+) and FISH (fluorescence in situ hybridization — a test for gene amplification, used for HER2). Markers in active 2026 ADC trials include HER2 (by IHC and FISH; plus the newer HER2-low and HER2-ultra-low designations), TROP2 IHC, B7-H3 IHC, CLDN18.2, CLDN6, PSMA, Nectin-4, and FOLR1. Ask your oncologist for comprehensive testing on archival or fresh biopsy material before evaluating trials.
  2. Re-biopsy on progression matters. HER2 status changes in 10–20% of patients between primary tumor and metastasis. A fresh biopsy can open ADC trials your initial pathology would have excluded.
  3. Trial timing peaks at progression. The strongest post-platinum / post-IO enrollment window is right at progression, before too many lines of therapy reduce eligibility. Worth asking about trial options at each decision point, not just at the end.
  4. ASCO data triggers eligibility shifts. Some trials reset their eligibility criteria within weeks of positive ASCO data — either tightening (to be more selective for the new standard arm) or loosening (to expand into the validated patient population). Check trial postings again 2–3 weeks after the conference.
  5. Most trials don't mean "placebo or nothing." Phase 3 ADC trials almost always test the new drug added to standard care, or compare two active options head-to-head. You're typically getting at least the standard backbone.

ClinTrialFinder helps you find ADC and other clinical trials matched to your cancer type, biomarkers, and treatment history.

Find ADC Trials for Your Cancer

Disease-Specific Trial Pages

Browse recruiting trials for cancers with active ADC development:

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This article previews publicly-anticipated topics for the ASCO 2026 Annual Meeting (May 29 – June 2, Chicago) based on the active Phase 3 trial landscape going into the conference. Specific abstract details will be added after the embargo lifts. This is intended for educational purposes and does not constitute medical advice. Always discuss treatment options with your oncologist.