Claudin 18.2 in Upper GI Cancer: New Target, New Challenges

ASCO 2026: GI Oncology Abstracts to Look Forward To.

With the 2026 ASCO Annual Meeting just days away, Drs. Nicholas Hornstein, Timothy Brown, and Udhayvir Grewal sit down for a rapid-fire, "mouth-to-butt" preview of the most practice-altering abstracts hitting the floor in Chicago. Armed with top-line press releases and early data, the team highlights their top three high-stakes selections across the entire GI tract. Key previews include: * The Upper GI Blockbusters (Tim’s Picks): Updated HORIZON-GEA data showing why HER2/PD-1 bispecific synergy doesn't care about baseline PD-L1 expression; a compliance deep-dive from the Matterhorn trial; and the arrival of IsaBrin (an EGFR/HER3 bispecific ADC) moving the needle in second-line squamous cell esophageal cancer. * The Midgut & Plenary Hype (Udhayvir’s Picks): Front-row seats for RESOLUTE-302, the monumental plenary session showcasing deruxantrib doubling overall survival (13 months vs. 6.7 months) in second-line RAS-mutant pancreatic cancer. Plus, the PHITE-302 trial proving frontline pemigatinib works for FGFR2-rearranged cholangiocarcinoma despite notorious accrual challenges. * Below-the-Belt Tech & Wild West De-escalation (Nick’s Picks): The highly anticipated late-breaking PUMP trial testing adjuvant hepatic artery infusion (HAI) pumps for colorectal liver metastases. Then, a massive look at China's Abstract 3502, confirming that MSI-High colorectal patients who hit a Complete Clinical Response can safely stop maintenance immunotherapy and maintain a 100% 3-year overall survival rate. * The Sci-Fi Future: A look outside the box at the Archer trial in lung cancer—utilizing a prophylactic peptide vaccine to train the immune system to short-circuit targeted therapy resistance mutations before they occur. Chapters: (00:00) Welcome and ASCO Preview (00:46) Top Three Picks Setup (01:28) HORIZON GEA HER2 Triplet (03:55) Matterhorn DFLOT Completion (06:11) IsaBrin for ESCC Second Line (08:10) RESOLUTE-302 RAS Inhibitor (13:12) PHITE 302 Pemigatinib Frontline (20:10) PUMP Trial Hepatic Infusion (24:02) MSI-High CRC Stop PD-1 (29:15) Archer Vaccine vs Resistance (33:30) Closing Thoughts and Chicago   You can find us on X: Gut Onc Lab (@TheGutOncLab) / X [https://x.com/TheGutOncLab]

Organ Preservation in Upper GI Cancers

In this landmark fifth episode of The Gut Onc Lab, Drs. Nicholas Hornstein and Timothy Brown welcome their first guest, radiation oncologist Dr. Nina Sanford, to discuss one of the most significant shifts in modern oncology: Organ Preservation. Historically, esophageal and gastric cancers have required highly morbid, "life-changing" surgeries. Today, the team explores how we can leverage advanced imaging, radiation, and immunotherapy to potentially spare the organ without sacrificing survival.   Key highlights include: * Defining Organ Preservation: Why avoiding esophagectomy or gastrectomy is the goal, provided we maintain oncologic outcomes. * The SANO Trial Deep Dive: A look at the Phase 3 data establishing "Watch and Wait" as a non-inferior strategy for complete responders, and the modeling studies that suggest where surgery might still pull ahead long-term. * The MSI-High Exception: How medical oncology is leading the way with chemo-free immunotherapy (PD-1 and CTLA-4 doublets) to achieve near-miraculous clinical complete responses in a subset of patients. * Radiation as a Biological Tool: Dr. Sanford explains why "one-size-fits-all" radiation is a thing of the past. * The Burden of Surveillance: A realistic look at "Time Toxicity"—the intensive endoscopy, PET, and CT schedules required to safely manage patients who forgo surgery. * Multidisciplinary Buy-In: Why organ preservation isn't just about biology; it’s about having a surgical team ready for "salvage" and a GI team dedicated to frequent monitoring. Whether you're curious about the biological "Magic Rays" of radiation or the latest "Infinity" and "NEONIKA" trial results, this episode defines the current frontier of upper GI sparing.   Chapters: (00:00) Why Organ Preservation Matters (03:48) Immunotherapy Enters the Chat (06:45) Key Evidence for Watch and Wait (09:45) Quality of Life and Long Term Tradeoffs (13:10) Radiation Dose and Adaptive Future (17:32) Cross vs FLOT and RT in Gastric (20:38) MSI High Chemo Free Pathway (26:48) Surveillance Protocols and Logistics (28:23) Ideal Candidates and Feasibility (31:43) Infrastructure for Community Practice (33:03) Final Takeaways and Wrap Up   You can find us on X: Gut Onc Lab (@TheGutOncLab) / X [https://x.com/TheGutOncLab]

MSI-High in GI Oncology: When Biology Opens the Door

In this episode of The GutOnc Lab, Drs. Nicholas Hornstein, Timothy Brown, and Udhayvir Grewal break down MSI-High GI cancers. A cancer diagnosis is never good news—but this is a setting where tumor biology meaningfully changes what’s possible, with immunotherapy offering real potential for durable responses and even cure.    Key discussion points include: * MMR vs. MSI: A diagnostic primer on the difference between IHC (protein) and NGS/PCR (molecular), including how to handle the discordance. * The “Parachute” Data: Breaking down the practice-changing CheckMate 8HW results—and why a hazard ratio of 0.21 is hard to ignore. Nick walks through why nivo/ipi is increasingly his frontline default. * The COMMIT Curveball: Why the COMMIT trial data didn’t deliver—and what it may tell us about PD-L1 vs PD-1 strategies in colorectal cancer. * Pseudoprogression vs Hyperprogression: Tim shares practical, in-the-clinic ways to tell whether a scan is showing immune infiltration… or true disease acceleration. * ctDNA at 6 Weeks: How Nick uses early ctDNA dynamics as a real-time readout of response—especially when you’re pushing toward non-operative management. * When IO Fails: What next? From CTLA-4 “immune salvage” approaches to where targeted therapy (including BRAF-directed options) fits. Whether you’re screening for Lynch or choosing between single-agent PD-1 and dual checkpoint blockade, this episode covers how we’re actually managing dMMR/MSI-H disease right now.   Chapters: (00:00) MSI High Basics (02:31) MSI vs MMR Methods (05:12) Choosing Tests in Practice (09:59) TMB Pitfalls (12:14) Pivotal Immunotherapy Trials (15:13) CheckMate 8HW Results (21:03) Biomarkers for Ipi Nivo (25:47) PD1 vs PDL1 Debate (31:52) Using ctDNA in Practice (34:42) How Long to Treat   You can find us on X: Gut Onc Lab (@TheGutOncLab) / X [https://x.com/TheGutOncLab]

Pancreatic Cancer Breakthrough: The Pan-RAS Inhibition Era

Drs. Nicholas Hornstein, Timothy Brown, and Udhayvir Grewal break down the blockbuster press release from Revolution Medicine regarding their Phase 3 trial, RASOLUTE 302. For years, KRAS was the "compact, smooth" molecule that defied targeted therapy, but the era of the molecular glue has officially arrived.               Understanding the Breakthrough: The hosts emphasize the shift from "OFF" inhibitors to "ON" inhibitors. The following visual concept illustrates how these new molecular glues utilize a chaperone to finally lock onto the active state of the KRAS protein.   Chapters: 00:00 Press Release Breakthrough 01:21 Why KRAS Was Undruggable 03:14 Limits of G12C Inhibitors 08:43 Trial Results 13:58 What It Means for Patients 20:30 Oncoderm and Support Team 20:56 Whats Next in Trials   You can find us on X: Gut Onc Lab (@TheGutOncLab) / X [https://x.com/TheGutOncLab]

Claudin 18.2 in Upper GI Cancer: New Target, New Challenges

Drs. Hornstein, Brown, and Grewal discuss how Claudin 18.2 has quickly become an important actionable biomarker in upper GI cancers, with zolbetuximab now entering frontline treatment for selected HER2-negative, microsatellite-stable patients. They review the key phase 3 data supporting its use, while emphasizing that the major challenge in practice is managing the significant nausea and vomiting seen early in treatment. The conversation also highlights how biomarker sequencing now shapes therapy selection and how future strategies, including ADCs, CAR T-cell therapy, and immunotherapy combinations, may further expand the role of Claudin 18.2 targeting.