OncLive Polls Reveal Picks for Top Gastrointestinal Cancer Abstracts at ASCO 2025

Gastrointestinal Cancer |
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With the 2025 ASCO Annual Meeting just one week away, interest in gastrointestinal (GI) cancer research continues to climb, with several late-breaking abstracts already generating discussion among oncology professionals. To gauge which datasets are most anticipated, OncLive® conducted informal social media polls of GI oncologists across X and LinkedIn.

Among 28 respondents on X, the phase 3 MATTERHORN trial (NCT05161580) evaluating perioperative durvalumab (Imfinzi) plus chemotherapy in resectable gastric/gastroesophageal junction (GEJ) adenocarcinoma emerged as the most highly anticipated abstract, receiving 60.7% of the vote. The phase 3 ATOMIC study (NCT02912559) evaluating adjuvant mFOLFOX6 with or without atezolizumab (Tecentriq) in stage III microsatellite instability–high (MSI-H)–high/DNA mismatch repair deficient (dMMR) colon cancer was the next highest study of interest (17.9%), with the phase 3 PANOVA-3 (NCT03377491) and DESTINY-Gastric04 (NCT04704934) trials subsequently receiving 14.3% and 7.1% of the vote, respectively.

Conversely, among 48 LinkedIn respondents, DESTINY-Gastric04—a study of fam-trastuzumab deruxtecan-nxki (T-DXd; Enhertu) vs chemotherapy in HER2-positive gastric/GEJ cancer—led with 49% of the vote. However, MATTERHORN was identified as the second most anticipated abstract in this poll (33%), followed by PANOVA-3 (11%), which is exploring tumor treating fields (TTFields) in combination with nab-paclitaxel (Abraxane) and gemcitabine for locally advanced pancreatic ductal adenocarcinoma (PDAC), and ATOMIC (7%).

Clinicians were also asked to identify the GI cancer subtype they were most interested in ahead of ASCO. On X, 39.3% of 61 respondents selected colorectal cancer (CRC), followed by gastric cancer (27.9%), pancreatic cancer (19.7%), and hepatocellular carcinoma (13.1%).

On LinkedIn, however, pancreatic cancer led at 31% of responses, followed by gastric cancer (28%), CRC (26%), and HCC (14%).

Based on these insights, OncLive has compiled a list of the most closely followed GI abstracts being presented at the 2025 ASCO Annual Meeting, including trial design, prior findings, and potential implications for practice. Read on for a closer look at each study.

LBA5: Event-free survival (EFS) in MATTERHORN: A randomized, phase 3 study of durvalumab plus 5-fluorouracil, leucovorin, oxaliplatin and docetaxel chemotherapy (FLOT) in resectable gastric/gastroesophageal junction cancer (GC/GEJC).

Session time: Monday, June 1st, 1:00 PM – 4:00PM CDT

The phase 3 MATTERHORN trial evaluated the addition of durvalumab to standard perioperative FLOT chemotherapy (fluorouracil, leucovorin, oxaliplatin, and docetaxel) in patients with resectable stage II to IVA gastric/GEJ adenocarcinoma.1,2 This global, randomized, double-blind, placebo-controlled study enrolled 948 patients across 20 countries.Patients received either durvalumab at a fixed dose of 1500 mg or placebo every 4 weeks, combined with FLOT every 2 weeks, for 4 cycles prior to surgery.2 Postoperative treatment included 2 additional doses of durvalumab or placebo plus 4 doses of FLOT, followed by 10 doses of maintenance durvalumab or placebo.

Previously reported data from the first interim analysis of the study showed that durvalumab plus FLOT (n = 474) elicited a pathologic complete response (pCR) rate of 19% by central review vs 7% with placebo plus FLOT (n = 474; difference, 12%; odds ratio [OR], 3.08; 95% CI, 2.03-4.67; P < .00001).2 The combined pCR/near-pCR rate was also higher in the durvalumab arm at 27% vs 14% in the placebo arm, respectively (difference, 12%; OR, 2.19; 95% CI, 1.58-3.04; P < .00001).

Findings from an interim analysis reported in March 2025 revealed a statistically significant and clinically meaningful improvement in event-free survival for durvalumab plus FLOT vs FLOT alone, meeting the trial’s primary end point.1 The safety profile of durvalumab combined with FLOT was consistent with known profiles, and no new safety signals were reported.1 The trial continues to monitor overall survival (OS) as a key secondary end point, with a strong trend favoring the durvalumab-based regimen observed.

LBA 4002: Trastuzumab deruxtecan (T-DXd) vs ramucirumab (RAM) + paclitaxel (PTX) in second-line treatment of patients (pts) with human epidermal growth factor receptor 2-positive (HER2+) unresectable/metastatic gastric cancer (GC) or gastroesophageal junction adenocarcinoma (GEJA): Primary analysis of the randomized, phase 3 DESTINY-Gastric04 study.

Session time: Sunday, May 31, 3:00 PM – 6:00 PM CDT

DESTINY-Gastric04 evaluated the efficacy and safety of T-DXd compared with ramucirumab (Cyramza) plus paclitaxel in patients with HER2-positive unresectable or metastatic gastric or GEJ adenocarcinoma who had progressed following a trastuzumab (Herceptin)-containing regimen.3

This global, open-label study enrolled 494 patients across Asia, Europe, and South America. Patients were randomly assigned 1:1 to receive either T-DXd at 6.4 mg/kg every 3 weeks or ramucirumab at 8 mg/kg on days 1 and 15 plus paclitaxel at 80 mg/m² on days 1, 8, and 15 of a 28-day cycle. The primary end point was OS, with secondary end points including progression-free survival (PFS), objective response rate (ORR), duration of response, disease control rate, and safety.

In a planned interim analysis reported in March 2025, T-DXd demonstrated a statistically significant and clinically meaningful improvement in OS vs ramucirumab plus paclitaxel regimen, meeting the trial's primary end point.4 Notably, the independent data monitoring committee recommended unblinding the study due to the clear efficacy benefit observed with T-DXd. The safety profile of T-DXd was consistent with previous studies, with no new safety signals identified.

According to the press release, these results represent the first demonstration of a HER2-directed therapy providing an OS benefit in the second-line treatment of HER2-positive gastric or GEJ adenocarcinoma.

LBA4005: PANOVA-3: Phase 3 study of tumor treating fields (TTFields) with gemcitabine and nab-paclitaxel for locally advanced pancreatic ductal adenocarcinoma (LA-PAC).

Session time: Sunday, May 31, 3:00 PM – 6:00 PM CDT

The prospective, randomized, open-label, controlled PANOVA-3 study evaluated the efficacy and safety of adding TTFields therapy to standard frontline gemcitabine and nab-paclitaxel in patients with locally advanced PDAC. A total of 571 patients were randomly assigned 1:1 to receive either gemcitabine plus nab-paclitaxel with TTFields or chemotherapy alone. OS served as the primary end point, with PFS, ORR, and safety as secondary measures.5

Topline results shared in December 2024 showed that the study met its primary end point with a median OS of 16.2 months with TTFields plus chemotherapy vs 14.2 months in the control arm (HR, 0.819; P = 0.039). Notably, the 12-month OS rate improved by 13%, and the 24-month OS rate improved by 33% in the TTFields group. The safety profile of TTFields in combination with chemotherapy was consistent with prior studies, with the most common device-related adverse effects being localized skin irritation.

LBA1: Randomized trial of standard chemotherapy alone or combined with atezolizumab as adjuvant therapy for patients with stage III deficient DNA mismatch repair (dMMR) colon cancer (Alliance A021502; ATOMIC).

Session time: Monday, June 1, 1:00 PM – 4:00 PM CDT

The ATOMIC trial is a randomized study evaluating the addition of atezolizumab to standard adjuvant chemotherapy with mFOLFOX6 in patients with curatively resected stage III MSI-H colon cancer with evidence of dMMR via immunohistochemistry.6

The study planned to enroll 700 patients, who would be randomly assigned to receive either mFOLFOX6 alone every 14 days for up to 12 cycles or mFOLFOX6 combined with atezolizumab, followed by 13 additional cycles of atezolizumab monotherapy. Treatment continued until disease progression or unacceptable toxicity.7

Disease-free survival served as the study’s primary end point, with secondary end points including OS, safety, and quality of life assessments. The study is active but no longer recruiting.

Want to learn more about why these abstracts are generating buzz? Check out this preview article featuring exclusive expert insights and visit our conference coverage page for real-time updates on these presentations and more throughout the meeting.

References

1. Imfinzi-based regimen demonstrated statistically significant and clinically meaningful improvement in event-free survival in resectable early-stage gastric and gastroesophageal junction cancers. News release. AstraZeneca. March 7, 2025. Accessed May 22, 2025. https://www.astrazeneca.com/media-centre/press-releases/2025/imfinzi-improved-efs-in-early-stage-gastric-cancer.html
2. Janjigian YY, Al-Batran S-E, Wainberg ZA, et al. Pathological complete response (pCR) to durvalumab plus 5-fluorouracil, leucovorin, oxaliplatin and docetaxel (FLOT) in resectable gastric and gastroesophageal junction cancer (GC/GEJC): interim results of the global, phase III MATTERHORN study. Ann Oncol. 2023;34(suppl 2):S1315-S1316. doi:10.1016/j.annonc.2023.10.074
3. Trastuzumab deruxtecan for subjects with HER2-positive gastric cancer or gastro-esophageal junction adenocarcinoma after progression on or after a trastuzumab-containing regimen (DESTINY-Gastric04). ClinicalTrials.gov. Updated October 24, 2024. Accessed May 21, 2025. https://clinicaltrials.gov/study/NCT04704934
4. Enhertu demonstrated statistically significant and clinically meaningful improvement in overall survival in patients with HER2 positive metastatic gastric cancer at interim analysis of DESTINY-Gastric04 phase 3 trial. News release. Daiichi Sankyo. March 3, 2025. Accessed May 21, 2025 https://www.daiichisankyo.com/files/news/pressrelease/pdf/202503/20250303_E.pdf
5. Novocure announces positive topline results from phase 3 PANOVA-3 clinical trial of tumor treating fields (TTFields) therapy for pancreatic cancer. News release. Novocure. December 2, 2024. Accessed May 22, 2025. https://www.novocure.com/novocure-announces-positive-topline-results-phase-3-panova-3-clinical-trial-tumor-treating-fields
6. Randomized trial of standard chemotherapy alone or combined with atezolizumab as adjuvant therapy for patients with stage III colon cancer and deficient mismatch repair (ATOMIC, Alliance A021502). J Clin Oncol. 2019;37(suppl 2):S1315-S1316. doi:10.1200/JCO.2019.37.15_suppl.e15169
7. Combination chemotherapy with or without atezolizumab in treating patients with stage III colon cancer and deficient DNA mismatch repair. ClinicalTrials.gov. Updated May 14, 2025. Accessed May 22, 2025. https://clinicaltrials.gov/study/NCT02912559