IntroductionThe 5-year follow-up results of KEYNOTE-177 [1] established pembrolizumab as a standard first-line (1L) treatment for deficient mismatch repair (dMMR) metastatic colorectal cancer (mCRC), demonstrating improved response rates, progression-free survival (PFS) and tolerability over chemotherapy. Pembrolizumab became available as a 1L option in Australia following government reimbursement in August 2021. Real-world treatment patterns and outcomes since then have not previously been reported. Patients and methodsPatients with dMMR mCRC diagnosed 1/8/2021-30/5/2025 were analysed using data from TRACC and TRACC-SELECT, Australian multi-site prospective registries. Clinicopathologic characteristics, treatment patterns, and outcomes were examined. Survival outcomes for 1L pembrolizumab-treated patients were analysed using Kaplan-Meier. ResultsFrom 36 sites, 120 dMMR mCRC patients were identified; 109 (91%) received any systemic treatment. 1L treatment included pembrolizumab (n=103, 94%), clinical trial enrolment (n=4,4%), and chemotherapy (n=2,2%). Among pembrolizumab-treated patients, the median age was 76 years, 49% had a BRAFV600E mutation, and 17% had an ECOG performance status ≥ 2. Median follow-up was 25.8 months. The clinician-assessed response rate was 58%, while 17% had progressive disease as best response. Median duration of therapy was 15.2 months. Of 74 patients who discontinued pembrolizumab, 21 (28%) completed the 2-year course, 28 (38%) had progressive disease, 11 (15%) discontinued due to toxicity, 6 (8%) had a complete response before 2 years, and 8 (11%) had other reasons. Median PFS was 37.9 months. Median overall survival (OS) was not reached; 12- and 24-month OS rates were 88% and 77%, respectively. ConclusionIn this real-world cohort, patients were older and had higher rates of BRAFV600E mutation and poorer ECOG performance status than those in KEYNOTE-177. There has been rapid and wide uptake of pembrolizumab as a new standard of care, with promising outcomes. Ongoing data collection and analyses will evaluate predictors of immunotherapy response and real-world second-line treatment patterns and outcomes.

Triple M syndrome is a rare and life-threatening overlap presentation of myocarditis, myositis and myasthenia gravis, secondary to immune checkpoint inhibition. We report a case of an 80-year-old female with metastatic cholangiocarcinoma, presenting with progressive asthenia, ptosis and dysphagia, following completion of six cycles of combination chemotherapy and immunotherapy, durvalumab. Her symptoms emerged 2 weeks after the commencement of maintenance therapy with immune checkpoint inhibitor, durvalumab, and poly(ADP-ribose) polymerase inhibitor, olaparib. Biochemical investigations were suspicious for myocarditis, myositis and type 2 respiratory failure due to myasthenic crisis. Clinical findings supported the diagnosis of triple M syndrome, and she was treated with high-dose steroids, intravenous immunoglobulin and supported with non-invasive ventilation. The patient initially improved; however, her admission was complicated by a fatal retroperitoneal haemorrhage. Our case highlights the need to consider serious immune-related adverse events and escalate prompt management for overlap syndromes in the context of immunotherapy and poly(ADP-ribose) polymerase inhibitors.Trial RegistrationClinicalTrials.gov identifier: NCT06441747

INTRODUCTION:Early detection of peritoneal disease, especially micro-metastases, in patients with gastroesophageal adenocarcinoma is critical as it alters therapeutic intent, providing a vital opportunity to personalise treatment. However, our ability to accurately stage the peritoneum is inadequate. Tumour-derived DNA in peritoneal lavage fluid (ptDNA) has been suggested to be more sensitive than current methods to stage the peritoneum. Accordingly, this study will determine whether ptDNA is a biomarker of peritoneal micro-metastasis and evaluate its prognostic value in patients with gastroesophageal adenocarcinoma undergoing curative-intent treatment. METHODS AND ANALYSIS:This will be an Australian multi-centre prospective observational cohort study enrolling patients undergoing routine staging laparoscopy and subsequent curative-intent treatment (either upfront surgery or perioperative chemo-/radiotherapy and surgery) for gastric and gastroesophageal junction adenocarcinoma. Tumour biopsies, blood and peritoneal lavage fluid will be collected at the time of staging laparoscopy for all patients. A subset of patients will have blood and peritoneal fluid collected at the time of surgical resection, and blood collected at the first post-operative clinic. These biospecimens will undergo genomic and methylomic analysis to detect tumour DNA. ptDNA status will be correlated to disease free survival, peritoneal-specific event free survival, overall survival, sites of treatment failure, histopathological features, and peritoneal lavage cytology status. REGISTRATION:This study is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12624000451505p).

Adjuvant chemotherapy in stage III colon cancer provides uncertain benefit at the individual level. Circulating tumor DNA (ctDNA) may help refine risk-adjusted treatment selection. In this multicenter, randomized, phase 2/3 trial, patients with stage III colon cancer underwent ctDNA testing 5-6 weeks after surgery and were assigned (1:1) to ctDNA-guided or standard management. In the ctDNA-guided arm, patients negative for ctDNA received de-escalated therapy, whereas ctDNA-positive patients received escalated therapy. Clinicians prespecified the standard regimen. Primary endpoints were 3-year recurrence-free survival (RFS) for ctDNA-negative patients and 2-year RFS for ctDNA-positive patients. Secondary endpoints included treatment-related hospitalization and ctDNA clearance. Among 968 evaluable patients, 702 (72.5%) were ctDNA negative. With a median follow-up of 47 months, ctDNA-negative patients experienced significantly fewer recurrences than ctDNA-positive patients (3-year RFS 87% versus 49%; P < 0.001). In ctDNA-negative patients, de-escalation reduced oxaliplatin use (34.8% versus 88.6%) and hospitalizations (8.5% versus 13.2%) but yielded slightly lower RFS than standard management (85.3% versus 88.1%), not meeting the non-inferiority margin. In ctDNA-positive patients, higher ctDNA burden correlated with recurrence risk (3-year RFS 77% to 23% across quartiles; P < 0.001). Escalated therapy did not improve outcomes over standard management (2-year RFS 51% versus 61%). There was no unexpected toxicity. Persistent ctDNA after treatment predicted markedly worse prognosis (3-year RFS 14% versus 79%). ctDNA is validated as a strong prognostic classifier. ctDNA-guided de-escalation reduced oxaliplatin exposure and adverse events with outcomes approaching standard of care, whereas exploratory chemotherapy intensification conferred no RFS benefit, suggesting a need for novel strategies in ctDNA-positive disease.Australian New Zealand Clinical Trials Registry Identifier: ACTRN12617001566325 .

INTRODUCTION:Neoadjuvant therapy has been proposed as a safe and effective treatment option for resectable colon cancer, providing several advantages over the current standard adjuvant protocol. AREAS COVERED:This review summarizes the recent developments in neoadjuvant strategies for resectable colon cancer, highlighting key clinical trial data, current and emerging challenges, and the role of precision medicine in guiding treatment. Sources for this review were obtained through searches of PubMed, ClinicalTrials.gov, and relevant conference abstracts. EXPERT OPINION:Neoadjuvant therapy is emerging as a promising approach for treating colon cancer, especially for dMMR/MSI-H colon cancer where neoadjuvant immunotherapy have shown exceptional complete pathologic response rates and durable responses. Ongoing trials are focused on identifying optimal treatment approaches that balance oncological efficacy with the minimization of toxicity. A reliable multimodal evaluation framework incorporating advanced staging techniques and biomarkers such as circulating tumor DNA is essential to guide treatment and improve patient selection.

Oncolytic viruses have emerged as promising therapeutic agents to selectively infect and destroy cancer cells while synergizing with checkpoint inhibitors to increase efficacy of immunotherapy. IVX037 is a novel bio-selected, receptor targeted, non-genetically modified, naturally occurring oncolytic strain of a human enteric RNA picornavirus. IVX037 challenge can induce selective in vitro tumor cell lytic infection via specific viral capsid cellular receptor interactions in cell cultures of human colorectal, gastric, ovarian and hepatocellular (HCC) cancers. Significant anti-tumor activity was displayed by intratumoral (IT) injections of IVX037 in human xenografts of microsatellite stable colorectal (MSS-CRC), gastric, HCC and ovarian cancers in SCID mice. In vivo human MSS-CRC xenograft studies in mice, revealed that IT administration of IVX037 induced elevated levels of γ-INF response genes (CXCL10, RIG-I) and up-regulated expression of a key immune-checkpoint molecule, PD-L1, indicating an inflammation phenotype within the treated tumor microenvironment (TME). In the Phase 1a monotherapy clinical study, multiple IT administrations of IVX037 were generally well tolerated with no Gr 3 or higher TRAE’s or DLTs seen. The most common Gr 1 and Gr 2 TRAE’s were injection site pain (44%) and fatigue (22%), respectively. Of the 9 patients (pts) administered IVX037 in Phase 1a, one MSS, KRAS G12D mutant CRC pt achieved a biopsy confirmed complete response at day 262 after six IT doses. Two MSS-CRC pts displaying injected lesion reductions also exhibited decreases in serum CEA levels. Serum biomarker analysis highlighted IVX037-mediated induction of potentially beneficial inflammatory cytokines/chemokines (ie.CXCL10) at day 8 for future enhancement of combination Phase 1b CPI therapy (Wong.,et al. AGITG ASM, 2024). This is a Phase 1b, first-in-human, open-label, non-randomized, multi-center clinical trial of IT IVX037 in combination with an intravenous (IV) immune checkpoint inhibitor, sintilimab (anti-PD1) in patients with advanced MSS-CRC, gastroesophageal or ovarian cancer. Pts must have at least one injectable tumour. A total of 45 participants (15 from each of the three tumor types) will be enrolled and receive IT doses of IVX037 administered on Days 1,15, 29,43,57,71 and 85 at dose of up to 7.5 x 108 TCID50 (a dosage level deemed safe during the Phase 1a study), sintilimab administration will commence on Study Day 8 and be administered every 3 weeks at 200 mg/dose through to Study Day 344. The primary objective is to determine the feasibility, safety and tolerability of IT IVX037 in combination with sintilimab including the incidence of dose-limiting toxicities (DLT). Tumor response will be assessed using iRECIST, with the first response assessment occurring at Day 43. Several biomarker effects of IVX037 administration in peripheral blood and tumor tissue addressing tumor infiltrating lymphocytes and cellular target expression levels for immune checkpoint therapies will be assessed. ctDNA levels will also be monitored. Pt recruitment commenced in October 2024, with currently 4 MSS-CRC pts enrolled and no DLT’s. The Phase 1b trial is continuing as planned. NCT05427487 Mark Wong, Niall Tebbutt, Tim Price, Shehara Mendis, Rafid Al-Asady, Eugene Hsu, Darren Shafren, Oksana Zdanska, Jia Liu. Phase 1b open-label, non-randomized, multi-center clinical trial of intratumoral IVX037 in combination with sintilimab (anti-PD1) in patients with advanced microsatellite stable (MSS) colorectal,gastroesophageal or ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_2):Abstract nr CT115.

Supplementary figure 2 shows the effect of trametinib plus panobinostat on colony formation in HCT 116 cells

Differentiation grade of colorectal cancers (CRC) is histologically defined by the proportion of the tumour which retains the glandular architecture of the normal colon. Poorly differentiated CRCs display loss of glandular architecture and canonical markers of colonic differentiation and are associated with increased metastatic capacity and poorer prognosis. It is currently unclear whether poorly differentiated cells within a heterogeneous primary tumour are more likely to establish metastases and if this cellular trait is conserved in the secondary tumours, or whether metastasis is largely stochastic, with most cells in the primary tumour harboring metastatic potential. To explore this, we examined the concordance in histological grade, expression of markers of colonic differentiation, and epithelial to mesenchymal transition (EMT) in 67 matched primary and metastatic CRCs. Tumour differentiation grade was scored categorically, and expression of differentiation and EMT markers were scored as continuous variables. In matched primary-metastatic pairs, tumour grade was concordant in 88% of cases (59/67 pairs), irrespective of the site of metastasis. In tumour pairs with discordant grade (n = 8), tumour grade was higher in the metastatic lesion in 6/8 (75%) cases. Consistent with the histological concordance, expression of the key driver of colonic differentiation (CDX2); colonic lineage-specific markers (VIL1, MUC2, SYN and CHG); and the markers of epithelial-to-mesenchymal transition (E-Cadherin and Vimentin) were highly concordant between matched primary and metastatic lesions. Finally, no staining of the squamous lineage marker Cytokeratin5/6 was observed in either primary or metastatic tumours. Tumour grade assessed histologically or using expression of markers of colonic differentiation or epithelial to mesenchymal transition was largely concordant between primary and metastatic CRC. These findings complement previously reported genomic similarities between primary and metastatic lesions and demonstrate that the histological grade of a primary tumour can in most cases inform the differentiation grade of associated metastatic lesions.

Supplementary figure 4 shows phosphorylated ERK staining in an adenoma from a ACDX2 mouse

INTRODUCTION:Resection of primary tumor and liver metastases is the gold standard for colorectal cancer with liver-only metastases (CRLM). Although treatment options have expanded to enable conversion of unresectable to resectable CRLM, about 40% of patients will have definitively unresectable disease. Major advances in surgical techniques, immunosuppressive protocols and patient selection criteria for liver transplantation have resulted in improved outcomes. AREAS COVERED:A literature search has been conducted in Pubmed for articles published between 2014 and 2024. This review paper comments on current liver-directed treatment options for CRLM: resection, percutaneous ablation, conversion-chemotherapy, TACE, SIRT, and SABR. We explore evidence for liver transplantation in patients with unresectable CRLM, comment on possible limitations for implementation in clinical practice and give an overview of the current guidelines on liver transplantation in the USA, Europe, the United Kingdom, and Australia/New Zealand. EXPERT OPINION:The recent randomized TRANSMET trial, investigating liver transplantation versus chemotherapy in unresectable CRLM, shows promising 5-year OS reaching similar values as for other accepted liver transplantation indications. Further investigations with RCTs to investigate reproducibility and feasibility in clinical practice are needed. Before liver transplantation can be implemented as a standard treatment option, reorganizations at federal, regional and hospital levels would be required.

Supplementary Figure 1 shows the synergistic effect of trametinib plus panobinostat in CRC cell lines and PDTO's

Supplementary figure 3 shows combining trametinib with different classes of HDAC inhibitors in COLO 201 cells

BACKGROUND:Gastric cancer has a risk of early transcoelomic spread. Despite perioperative chemotherapy and surgery, peritoneal recurrence is a frequent contributor to mortality. The addition of neoadjuvant normothermic intraperitoneal chemotherapy (IPC) allows early treatment of microscopic disease. Our study aims to systematically evaluate the safety and efficacy of neoadjuvant IPC in patients with gastric cancer who are at high risk of peritoneal recurrence. METHODS:A systematic review was conducted according to the PRISMA guidelines. Embase, PubMed, Web of Science and Scopus were searched for relevant papers. The primary outcomes were the rates of disease-free (DFS) and overall survival (OS) among patients treated with neoadjuvant IPC. Secondary outcomes focused on adverse effects and toxicity. RESULTS:Overall, 562 manuscripts were screened and 7 papers were included, totalling 158 patients. For cytology-positive patients, the addition of IPC led to a conversion to negative cytology and radical surgery in 78-89 %. This was associated with relatively high DFS and OS. Peritoneal-specific recurrence was higher in cohorts who initially had cytology-positive disease (63-69 %) compared to those who did not (0-29 %). Our data suggest that OS is lower in patients who were initially cytology-positive compared to cytology-negative disease. Importantly, neoadjuvant IPC did not appear to significantly increase treatment-related adverse events. CONCLUSION:Our results suggest that the neoadjuvant IPC has efficacy and is safe, with high rates of cytology conversion (in cytology-positive disease), low rates of peritoneal recurrence (in locally advanced disease). This was associated with substantial improvements in DFS and OS, compared to current standard treatment regimens.

728 Background: Gemcitabine (GEM) plus nab-paclitaxel (NAB-PAC) is a standard first-line chemotherapy regimen for advanced/metastatic pancreatic ductal adenocarcinoma (PDAC), with median Progression Free Survival (mPFS) and Overall Survival (mOS) of 5.5 & 8.7 in the MPACT trial and 5.6 & 9.2 months (mo) in the NAPOLI 3 trial, respectively. Certepetide (formerly LSTA1 or CEND-1) is a novel cyclic peptide that improves targeted penetration of co-administered drugs into tumor and stroma, leading to potentially increased anti-neoplastic activity. ASCEND is a randomized phase II trial designed to investigate the impact of adding certepetide to GEM/NAB-PAC. (NCT05042128). Methods: Eligible participants (pts) with histologically confirmed advanced PDAC and ECOG 0-1 were randomized 2:1 to receive GEM/NAB-PAC plus certepetide (3.2 mg/kg) or placebo (PLA) on days 1, 8, & 15 of a 28-day cycle. Stratification was by age (<65/≥65 years), ECOG (0/1), presence of liver metastasis (Y/N) and trial site. The primary objective was to determine the effect of adding certepetide to GEM/NAB-PAC on PFS. Objective tumor response rate (OTRR), safety and OS were secondary objectives. This non-comparative phase II design targeted a PFS increase of 17% at 6 mo from 47% to 63%. A sample size of 65 patients in the certepetide arm was expected to have 80% power, with 95% confidence to exclude an uninteresting 6-mo PFS rate of 47%. Results: 95 pts (66 certepetide, 29 PLA) were enrolled between May 2022 to December 2023. 6-mo PFS in the certepetide and PLA groups was 49.0% (95% CI 36.4%, 60.5%) and 40.8 (95% CI 22.6%, 58.3%) respectively, with mPFS of 5.5 mo in both groups. mOS was 12.42 mo for the certepetide and 9.72 mo for the PLA. An OTRR of 38.3% (certepetide) and 26.9% (PLA) was observed. Of note, 4 complete responses were observed in the certepetide group vs. 0 in PLA group. In subjects with ECOG 0, 6 mo PFS was 68.1% (95% CI 48.7%, 81.4%) in the certepetide compared to 36.4% (95% CI 11.2%, 62.7%) in the PLA. Grade ≥3 toxicities were similar in both groups at 16% (certepetide) and 15% (PLA). Conclusions: The addition of certepetide is safe and despite showing no improvement in 6-mo PFS, a possible signal of benefit in OS and OTRR, including the 4 complete responses was observed, warranting further investigation. A further cohort of the ASCEND study evaluating the addition of a second dose of certepetide is ongoing. Clinical trial information: NCT05042128 .

PURPOSE:Several lines of treatment can be used sequentially in patients with metastatic colorectal cancer. We investigated the evolution of patient/tumor characteristics and their prognostic impact across treatment lines to develop an overall prognostic score (OPS). PATIENTS AND METHODS:Individual patient data from 48 randomized trials were analyzed. The end point was overall survival (from random assignment to death). Missing data were imputed. The complete data set was then separated into construction (80%) and validation sets (20%). The Cox's model was used to define risk groups for survival using the OPS. The discrimination capability was assessed in each treatment-line via bootstrapping to obtain optimism-corrected calibration and discrimination C-indices. Internal validation was done in the validation set. RESULTS:A total of 37,560 patients (26,974 in first-line [1L], 7,693 in second-line [2L], and 2,893 in third-line [3L]) were analyzed. Some clinical, biological, and molecular characteristics of patients/tumors included in therapeutic trials evolve over the lines. Seven independent prognostic variables were retained in the final multivariate model common to all lines: Eastern Cooperative Oncology Group performance status, hemoglobin, platelet count, WBC/absolute neutrophil count ratio, lactate dehydrogenase, alkaline phosphatase, and the number of metastatic sites. The OPS was used to define four patient subgroups with significantly different prognoses in 1L, 2L, and 3L, separately, with adequate C-indices: 0.65, 0.66, and 0.69 in the construction set and 0.65, 0.66, and 0.68 in the validation set, respectively. The OPS was not predictive, with 3L drugs (v placebo) or subsequent line (2L/1L or 3L/2L) extending survival in all prognostic groups. CONCLUSION:The same prognostic model using practical variables can be used before all treatment lines. The OPS could better stratify patients in future clinical trials and help to therapeutic decision in routine practice.

Supplementary figure 5 shows mouse weight during treatment in two of the mouse studies