Rectal Cancer PatientsPhase 2NCT07314528
Evaluating the Impact of GLP-1 Receptor Agonists With Total Neoadjuvant Therapy in Rectal Cancer
A Phase 2 study testing GLP-1 receptor agonist and Total neoadjuvant therapy (TNT) in people with Rectal Cancer Patients and Obesity &Amp; Overweight, run by St. James's Hospital, Ireland.
Trial summary
The goal of this clinical trial is to see if adding a weight loss medication (GLP-1 receptor drug) to patients with an increased BMI receiving treatment for rectal cancer prior to surgery (total neoadjuvant chemoradiotherapy) improves cancer outcomes. The main questions it aims to answer is 1. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Rectal Cancer Patients, Obesity &Amp; Overweight, Locally Advanced Rectal Cancer (LARC)
- What is being tested?
- GLP-1 receptor agonist and Total neoadjuvant therapy (TNT)
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 42 participants
- Where
- No sites listed yet
- Study dates
- Apr 2026to Sep 2028
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Written informed consent according to local guidelines obtained prior to any study-related activities.
- Histologically confirmed mismatch repair protein proficient adenocarcinoma of the rectum.
- BMI ≥25 kg/m²
- Radiological confirmed >T2, Node positive, Threatened Surgical Margin and/or EMVI+ by MRI
- Imaging available for radiomics analysis
- Absence of metastatic disease at registration.
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- Adequate renal function is defined as calculated creatinine clearance (CrCl) >50ml/min.
- ANC > 1.5 cells/mm3, HGB > 8.0 gm/dl, PLT > 150,000/mm3, total bilirubin ≤ 1.5 x ULN (except in patients with Gilbert's Syndrome who must have total bilirubin ≤ 3.0 x ULN), AST≤ 3 x ULN, ALT ≤ 3 x ULN
- Able to tolerate medication.
- ECOG 0-2
Who cannot join
- Received prior chemotherapy or radiotherapy
- Previous or concurrent active malignancy ≤ 5 years prior to registration, with the exception of non-melanotic skin cancer or carcinoma in situ of any type, or other cancers that the treating investigator does not feel will impact the study objectives.
- Locally advanced disease T3N+ or T4 disease.
- Recurrent rectal cancer
- Metastatic disease at presentation
- Patients unable to undergo MRI
- Patients having already received weight-loss intervention (pharmacological or surgical)
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: A Phase II Multi-institutional Randomized Trial Evaluating the Impact of GLP-1 Receptor Agonists in Combination With Total Neoadjuvant Therapy for Locally Advanced Rectal Cancer
The goal of this clinical trial is to see if adding a weight loss medication (GLP-1 receptor drug) to patients with an increased BMI receiving treatment for rectal cancer prior to surgery (total neoadjuvant chemoradiotherapy) improves cancer outcomes. The main questions it aims to answer is
- Does the drug increase weight loss in rectal cancer patients with a high BMI
- Does the drug improve response rates to chemotherapy and radiotherapy
- Does the drug improve survival outcomes and if cancer returns
Read more
Researchers will compare this drug in one group against a group of patients receiving preoperative total neoadjuvant chemoradiotherapy without the drug
Patients will be required to
- take the GLP-1 receptor agonist drug during TNT or just having TNT alone as per standard hospital protocols
Body weight will be measured at three predefined time points:
- Baseline: Prior to initiation of semaglutide or TNT
- Pre-TNT: Start of TNT (for the intervention arm, this is 4 weeks after semaglutide initiation)
- Post-TNT: Within 7 days following completion of TNT and prior to definitive surgery
Patients will complete their treatment and go on to have surgery as per standard methods for treating rectal cancer
Read the detailed description
This Phase II multicentre, open-label randomized controlled trial aims to determine whether adding a GLP-1 receptor agonist (GLP-1RA) to standard Total Neoadjuvant Therapy (TNT) improves oncological outcomes in Locally Advanced Rectal Cancer (LARC). We will evaluate whether metabolic modulation through GLP-1RA increases pathological complete response (pCR) rates, accelerates the clearance of circulating tumour DNA (ctDNA), and reduces the risk of recurrence. Secondary outcomes include toxicity profiles, surgical parameters and outcomes, ctDNA dynamics, and 2-year disease-free (DFS) and overall survival (OS). By combining innovative metabolic therapy with biomarker-driven monitoring, this study pioneers a precision oncology approach in the management of LARC.
Immune metabolism refers to the bioenergetic and biosynthetic processes that support immune cell function. Obesity significantly alters this metabolic programming. Obesity has a significant impact on cancer development and progression, in part due to its effects on the tumour microenvironment (TME) and immune metabolism. Understanding this connection is key in cancer biology and can also inform therapeutic strategies. There are many consequences of obesity-induced TME alterations, including immune suppression, increased tumour progression, metastasis, and resistance to immunotherapy.
Obesity is linked to an increased risk of developing 13 different cancers, including CRC cancer. 1 The mechanisms are complex, but elevated systemic inflammation and dysregulated immunity are major factors. Emerging evidence is beginning to show the potential benefits of GLP-1 therapies in cancer treatment; since this class of medications improves obesity, they might also help improve cancer outcomes. In a large retrospective cohort study with a 15-year follow-up, GLP-1 medication use was associated with a significant risk reduction in 10 of the 13 obesity-related cancers. 1 Mechanistically, the reasons for this reduction are unknown, but decreased inflammation and immune dysregulation are likely key factors in lowering this risk.
Our research group has extensively documented the harmful effects of obesity on the immune system, including its impact on anti-cancer immunity. Additionally, we have provided clinical and experimental evidence that GLP-1 therapy reduces inflammation and can significantly enhance anti-tumor immune cell populations. In this study, we will precisely assess the effects of two specific interventions-either TNT combined with GLP-1 RA (intervention group) or TNT alone (control group)-on the systemic inflammatory profile and circulating/tumor immune phenotype in stage III rectal cancer.
GLP-1-based treatments originally developed for type 2 diabetes and obesity, are now gaining attention for their potential impact on immune metabolism and even cancer therapy. There has been direct links between GLP-1 treatment and immune metabolism, with GLP reducing inflammation and improving systemic metabolism enhancing immune fitness. Some studies have also shown that GLP treatment can also indirectly modulate the TME by lowering leptin and insulin levels, reducing tumour-promoting signalling and reducing immunosuppressive cells in the TME. It is important to note that different cancers may respond differently to GLP-1 modulation based on the complexity, composition and level of immune infiltration. In this current study, we will profile the metabolic profiles and inflammatory profiles in the complex TME across the two defined interventions (either TNT + GLP-1 RA (intervention group) or TNT alone (control group)) in stage III rectal cancer patents enrolled in the trial.
GLP-1 receptor agonists (GLP-1 RAs), such as semaglutide, have demonstrated strong effects on weight loss in individuals with obesity. In the STEP 1 trial, semaglutide led to an average weight loss of 14.9%, compared to 2.4% with placebo, over 68 weeks. Recent epidemiologic data also suggest a link between GLP-1 RA use and a reduced incidence of obesity-related cancers, including colorectal cancer. 3 Additionally, GLP-1 RAs may have anti-inflammatory and metabolic effects that could be beneficial in the context of cancer therapy.
Total neoadjuvant therapy (TNT) is increasingly utilized in managing locally advanced rectal cancer (LARC) to improve pathological complete response (pCR) rates, facilitate surgical downstaging, and support organ preservation. This trial aims to determine whether combining GLP-1 RAs with TNT leads to meaningful weight loss and better oncological outcomes compared to TNT alone in patients with BMI ≥30 and LARC.
- Conditions
- Rectal Cancer Patients, Obesity &Amp; Overweight, Locally Advanced Rectal Cancer (LARC), Total Neoadjuvant Therapy, GLP-1
- Being tested
- GLP-1 receptor agonist, Total neoadjuvant therapy (TNT)
- Keywords
- Locally Advanced Rectal Cancer, Total Neoadjuvant Therapy, GLP-1 Receptor Agonist
- Medical subject headings
- Obesity, Overweight
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
GLP-1 receptor agonistDrug
All patients will receive standard total neoadjuvant therapy for rectal cancer as per local standards. One group will receive a GLP-1 rector agonist in addition to the standard treatment for rectal cancer
Total neoadjuvant therapy (TNT)Drug
Total ne-adjuvant therapy is standard treatment for locally advanced rectal cancer
| Study group | Role | What they receive |
|---|---|---|
| Total Neoadjuvant Therapy and GLP-1 Receptor Agonist | Experimental | This arm will have patients with increased BMI and locally advanced rectal cancer having total neoadjuvant chemoradiotherapy. This arm will be given a GLP-1 receptor agonist Receives: Drug: GLP-1 receptor agonist; Drug: Total neoadjuvant therapy (TNT) |
| Locally advanced rectal cancer and total neoadjuvant therapy alone | Active comparator | Patients with a high BMI and locally advanced rectal cancer undergoing total neoadjuvant therapy with not receiving a GLP-1 receptor agonist Receives: Drug: Total neoadjuvant therapy (TNT) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Weight Loss
Change in weight loss (Kilograms) between groups at 2 time points
- Baseline
- Pre TNT starting
- Post TNT starting
Measured: 6 months
Metabolic Profile of the Tissue
Using a human ex vivo explant model (3D), we will assess in real time the metabolic profiles of the tissues from patents in the control and interventions groups. Detailed metabolic profiling data using Seahorse technology. These metabolic profile data will be correlated with detailed clinical, pathology and outcome data for each patient in the trial.
Measured: From enrolment to operation within 1 year
Inflammatory Mediators
Using human ex vivo explant model (3D) system, we will profile the secretions of inflammatory mediators from the TME and how these cross talks to immune cells. This data will be directly correlated with the detailed metabolic signatures.
Measured: From enrolment to surgical resection within 1 year
GLP-1 effects on mitochondrial fitness
Determine of GLP-1 treatment alters mitochondrial fitness ex vivo in explants by assessing ATP levels (Relative Light Units), stress responses and adaptations to metabolic demands using tissues from both arms of the trial.
Measured: From enrolment to surgical resection within 1 year
Mapping systemic inflammatory profiles
To definitively map the systemic inflammatory profile, we will investigate matched plasma samples (baseline and post-intervention) using a high dimensional approach (e.g Olink Target-96 Immunoncology panel or Olink Explore-396 inflammatory profile). Samples will be taken at the time of diagnosis and the time of surgery
Measured: From enrolment to surgical resection within 1 year
Mapping circulating immune systems
Map the circulating immune system using spectral flow cytometry to include cell frequencies (e.g. T cells, Innate T cells, NK cells, Monocytes and DC subsets), activation/exhaustion phenotype (e.g. CD69, PD-1, TIM-3 etc) and cytokine profiles (e.g. interleukin (IL)-2, 4, 10 \& 17, interferon gamma, tumour necrosis factor, granzymes etc). Samples will be taken from pre treatment biopsies and from the tumour itself when removed at surgery.
Measured: From enrolment to surgical resection within 1 year
Mapping tumour resident immune system
Map the tumour resident immune system using MACsima spatial imaging platform and their 61- parameter immuno-oncology antibody panel (which includes T cells, NK cells, Macrophages \& DCs plus tumour specific markers). Using this platform, in addition to deep immunopheotyping, we will allow perform neighbour analysis to determine cell-cell interactions. Tissue will be taken from pre treatment biopsies and from the tumour itself when removed at surgery.
Measured: From enrolment to surgical resection within 1 year
Secondary outcomes (16)
Oncological outcomes
To compare pathological complete response (pCR) rates at the time of surgical resection.
To assess overall survival (OS) at 3 and 5 years post-treatment. To assess disease-free survival (DFS) at 3 and 5 years post-treatment. To evaluate local recurrence rates at 1, 3 and 5 years
Measured: 5 years
Surgical Outcomes
To compare operative complexity (e.g., operative time, blood loss (millilitres), conversion rates).
Measured: Enrolment to surgical intervention and 30 days post discharge
Metabolic and Physiologic Outcomes:
To measure changes in BMI, waist circumference, and visceral fat volume using imaging modalities. (kg/m2)
Measured: From enrolment to surgical resection within 1 year
Treatment Tolerability and Safety:
To compare the incidence and severity of adverse events (graded by CTCAE v5.0). This will be assessed while on treatment and post surgery for 30-days To assess treatment compliance and any dose modifications or interruptions due to toxicity. This will be measured continually during treatment To evaluate GLP-1 RA-related side effects, particularly gastrointestinal symptoms and hypoglycemia. This will be assessed at the end of treatment
Measured: 1 year
Patient-Reported Outcomes:
To compare quality of life (QoL) scores using validated instruments (e.g., EORTC QLQ-C30). This will happen at 3 monthly intervals from starting treatment To assess patient-reported functional status, fatigue, and appetite changes. This will happen at 3 monthly intervals from starting treatment To evaluate psychological well-being (e.g., depression, anxiety scores) in the context of body weight changes and cancer therapy.
Measured: 2 years
Translational Component: to investigate the molecular and cellular effects of GLP-1 RA therapy during TNT through analysis of tissue and blood biomarkers.
To evaluate changes in tumor microenvironment, including immune cell infiltration (e.g., CD8+ T-cells, macrophages) via immunohistochemistry or multiplex immunofluorescence.
Measured: From enrolment to surgical resection within 1 year
Radiomics
Standardize imaging and segmentation across sites with centralized protocols and ROI annotation for tumor and mesorectal fat.
Extract baseline and post-TNT radiomic features and calculate delta-radiomics, alongside CT-based body composition measures.
Develop predictive models combining radiomics with clinical and metabolic data to correlate with pCR, survival, and treatment toxicity.
Measured: From enrolment to surgical resection within 1 year
Circulating Tumor DNA (ctDNA)
Longitudinal sampling: Plasma will be collected at baseline, mid-TNT, preoperatively, and postoperatively at defined follow-up intervals.
Analytical methods: ctDNA will be quantified and profiled using next-generation sequencing (NGS)-based assays to detect mutations, copy number variations, and methylation patterns relevant to rectal cancer.
Endpoints: Dynamics of ctDNA clearance and re-emergence will be evaluated as biomarkers of treatment response, minimal residual disease, and early recurrence.
Integration: ctDNA data will be correlated with radiomic signatures, metabolic changes, and pathological outcomes to explore composite biomarker models that predict pCR, DFS, and OS.
Measured: From enrolment to surgical resection within 1 year
Surgical Outcomes
To assess postoperative complications, including anastomotic leak, wound infection, and ileus (Clavien-Dindo classification).
Measured: 30 days
Surgical Outcomes
To evaluate length of hospital stay and 30-day readmission rates
Measured: 30 days
Metabolic and Physiologic Outcomes:
To assess changes in insulin sensitivity, lipid profile, and inflammatory markers (e.g., CRP, IL-6).
Measured: From enrolment to 1 year
Metabolic and Physiologic Outcomes:
To evaluate resting metabolic rate (RMR) and body composition (e.g., lean mass vs. fat mass if DEXA or BIA is used).
Measured: Enrolment to 1 year
Translational Component: to investigate the molecular and cellular effects of GLP-1 RA therapy during TNT through analysis of tissue and blood biomarkers.
To assess systemic inflammatory and metabolic markers, such as IL-6, TNF-α, adiponectin, leptin, and CRP, at baseline and post-TNT.
Measured: From enrolment to1 year
Translational Component: to investigate the molecular and cellular effects of GLP-1 RA therapy during TNT through analysis of tissue and blood biomarkers.
To perform gene expression profiling of tumor samples (pre- and post-TNT) to identify signatures associated with treatment response or resistance.
Measured: Enrolment to 1 year
Translational Component: to investigate the molecular and cellular effects of GLP-1 RA therapy during TNT through analysis of tissue and blood biomarkers.
To explore gut microbiome composition in relation to treatment arm and metabolic outcomes, using fecal metagenomic sequencing.
Measured: Enrolment to 1 year
Translational Component: to investigate the molecular and cellular effects of GLP-1 RA therapy during TNT through analysis of tissue and blood biomarkers.
To assess circulating tumor DNA (ctDNA) dynamics pre-, during, and post-TNT as a potential predictor of minimal residual disease and recurrence.
Measured: Enrolment to 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Jan 2026
- Study startApr 2026 (estimated)
- Primary completionSep 2028 (estimated)
- Study completionSep 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (13)Papers the sponsor has linked to this study.
- Other trials for Rectal Cancer PatientsStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 42 participants (estimated)
Sponsor and investigators
- Lead sponsor
- St. James's Hospital, Ireland
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Ben Creavin, St. James's Hospital, Ireland
- Investigators
- Michael Kelly, MB BAO BCH PHD FRCSI, Principal investigator, St. James Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07314528
- Sponsor's protocol ID
- 435911714
- Status last verified
- Dec 2025
- First submitted
- 28 Aug 2025
- Last updated
- 2 Jan 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: De identified data will not be available to anyone outside the study. This is in line with our ethics department and GDPR
Publications
Kazi T, McKechnie T, Lee Y, Alsayari R, Talwar G, Doumouras A, Hong D, Eskicioglu C. The impact of obesity on postoperative outcomes following surgery for colorectal cancer: analysis of the National Inpatient Sample 2015-2019. ANZ J Surg. 2024 Jul-Aug;94(7-8):1305-1312. doi: 10.1111/ans.19135. Epub 2024 Jun 18.
PubMed 38888262Martin-Carnicero A, Ramalle-Gomara E, Rubio-Mediavilla S, Alonso-Lago M, Zorrilla-Larraga M, Manrique-Abos I, de Las Heras-Duena ME, Larrayoz IM, Martinez A. Prognostic and Predictive Biomarkers in Patients with Locally Advanced Rectal Cancer (LARC) Treated with Preoperative Chemoradiotherapy. J Clin Med. 2022 Oct 16;11(20):6091. doi: 10.3390/jcm11206091.
PubMed 36294412Dizdarevic E, Hansen TF, Jakobsen A. The Prognostic Importance of ctDNA in Rectal Cancer: A Critical Reappraisal. Cancers (Basel). 2022 Apr 30;14(9):2252. doi: 10.3390/cancers14092252.
PubMed 35565381Chen C, Douglas MP, Ragavan MV, Phillips KA, Jansen JP. Clinical Validity and Utility of Circulating Tumor DNA (ctDNA) Testing in Advanced Non-small Cell Lung Cancer (aNSCLC): A Systematic Literature Review and Meta-analysis. Mol Diagn Ther. 2024 Sep;28(5):525-536. doi: 10.1007/s40291-024-00725-x. Epub 2024 Aug 2.
PubMed 39093546Ryan EJ, Creavin B, Sheahan K. Delivery of Personalized Care for Locally Advanced Rectal Cancer: Incorporating Pathological, Molecular Genetic, and Immunological Biomarkers Into the Multimodal Paradigm. Front Oncol. 2020 Aug 14;10:1369. doi: 10.3389/fonc.2020.01369. eCollection 2020.
PubMed 32923389Silverii GA, Marinelli C, Bettarini C, Del Vescovo GG, Monami M, Mannucci E. GLP-1 receptor agonists and the risk for cancer: A meta-analysis of randomized controlled trials. Diabetes Obes Metab. 2025 Aug;27(8):4454-4468. doi: 10.1111/dom.16489. Epub 2025 May 29.
PubMed 40437949Ochiai K, Bhutiani N, Ikeda A, Uppal A, White MG, Peacock O, Messick CA, Bednarski BK, You YN, Skibber JM, Chang GJ, Konishi T. Total Neoadjuvant Therapy for Rectal Cancer: Which Regimens to Use? Cancers (Basel). 2024 May 31;16(11):2093. doi: 10.3390/cancers16112093.
PubMed 38893212Johnson GGRJ, Park J, Helewa RM, Goldenberg BA, Nashed M, Hyun E. Total neoadjuvant therapy for rectal cancer: a guide for surgeons. Can J Surg. 2023 Apr 21;66(2):E196-E201. doi: 10.1503/cjs.005822. Print 2023 Mar-Apr.
PubMed 37085291Lin A, Ding Y, Li Z, Jiang A, Liu Z, Wong HZH, Cheng Q, Zhang J, Luo P. Glucagon-like peptide 1 receptor agonists and cancer risk: advancing precision medicine through mechanistic understanding and clinical evidence. Biomark Res. 2025 Mar 27;13(1):50. doi: 10.1186/s40364-025-00765-3.
PubMed 40140925Miousse IR. GLP-1 receptor agonists in the context of cancer: the road ahead. Am J Physiol Cell Physiol. 2025 Jun 1;328(6):C1822-C1828. doi: 10.1152/ajpcell.00245.2025. Epub 2025 Apr 26.
PubMed 40285503Wilding JPH, Batterham RL, Calanna S, Davies M, Van Gaal LF, Lingvay I, McGowan BM, Rosenstock J, Tran MTD, Wadden TA, Wharton S, Yokote K, Zeuthen N, Kushner RF; STEP 1 Study Group. Once-Weekly Semaglutide in Adults with Overweight or Obesity. N Engl J Med. 2021 Mar 18;384(11):989-1002. doi: 10.1056/NEJMoa2032183. Epub 2021 Feb 10.
PubMed 33567185Wang L, Xu R, Kaelber DC, Berger NA. Glucagon-Like Peptide 1 Receptor Agonists and 13 Obesity-Associated Cancers in Patients With Type 2 Diabetes. JAMA Netw Open. 2024 Jul 1;7(7):e2421305. doi: 10.1001/jamanetworkopen.2024.21305.
PubMed 38967919Temperley HC, Coalter M, Creavin B, Jordan P, Hogan A, O'Sullivan J, O'Shea D, McCormick PH, Harrold E, Kelly ME. Evaluating the impact of GLP-1 receptor agonists in combination with total neoadjuvant therapy for locally advanced rectal cancer. Br J Surg. 2026 Apr 9;113(4):znag029. doi: 10.1093/bjs/znag029.
PubMed 41806363
Study at a glance
From the registry record, last updated by the sponsor on 2 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase II Multi-institutional Randomized Trial Evaluating the Impact of GLP-1 Receptor Agonists in Combination With Total Neoadjuvant Therapy for Locally Advanced Rectal Cancer
- ClinicalTrials.gov ID
- NCT07314528
- Acronym / sponsor ID
- 435911714
- Conditions
- Rectal Cancer Patients, Obesity &Amp; Overweight, Locally Advanced Rectal Cancer (LARC), Total Neoadjuvant Therapy, GLP-1
- Keywords
- Locally Advanced Rectal Cancer, Total Neoadjuvant Therapy, GLP-1 Receptor Agonist
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 42 participants (estimated)
- Lead sponsor
- St. James's Hospital, IrelandUniversity, hospital or other
- Study start
- Apr 2026 (estimated)
- Primary completion
- Sep 2028 (estimated)
- Study completion
- Sep 2028 (estimated)
- First posted
- 2 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this clinical trial is to see if adding a weight loss medication (GLP-1 receptor drug) to patients with an increased BMI receiving treatment for rectal cancer prior to surgery (total neoadjuvant chemoradiotherapy) improves cancer outcomes. The main questions it aims to answer is
- Does the drug increase weight loss in rectal cancer patients with a high BMI
- Does the drug improve response rates to chemotherapy and radiotherapy
- Does the drug improve survival outcomes and if cancer returns
Researchers will compare this drug in one group against a group of patients receiving preoperative total neoadjuvant chemoradiotherapy without the drug
Patients will be required to
- take the GLP-1 receptor agonist drug during TNT or just having TNT alone as per standard hospital protocols
Body weight will be measured at three predefined time points:
- Baseline: Prior to initiation of semaglutide or TNT
- Pre-TNT: Start of TNT (for the intervention arm, this is 4 weeks after semaglutide initiation)
- Post-TNT: Within 7 days following completion of TNT and prior to definitive surgery
Patients will complete their treatment and go on to have surgery as per standard methods for treating rectal cancer
Detailed description
This Phase II multicentre, open-label randomized controlled trial aims to determine whether adding a GLP-1 receptor agonist (GLP-1RA) to standard Total Neoadjuvant Therapy (TNT) improves oncological outcomes in Locally Advanced Rectal Cancer (LARC). We will evaluate whether metabolic modulation through GLP-1RA increases pathological complete response (pCR) rates, accelerates the clearance of circulating tumour DNA (ctDNA), and reduces the risk of recurrence. Secondary outcomes include toxicity profiles, surgical parameters and outcomes, ctDNA dynamics, and 2-year disease-free (DFS) and overall survival (OS). By combining innovative metabolic therapy with biomarker-driven monitoring, this study pioneers a precision oncology approach in the management of LARC.
Immune metabolism refers to the bioenergetic and biosynthetic processes that support immune cell function. Obesity significantly alters this metabolic programming. Obesity has a significant impact on cancer development and progression, in part due to its effects on the tumour microenvironment (TME) and immune metabolism. Understanding this connection is key in cancer biology and can also inform therapeutic strategies. There are many consequences of obesity-induced TME alterations, including immune suppression, increased tumour progression, metastasis, and resistance to immunotherapy.
Obesity is linked to an increased risk of developing 13 different cancers, including CRC cancer. 1 The mechanisms are complex, but elevated systemic inflammation and dysregulated immunity are major factors. Emerging evidence is beginning to show the potential benefits of GLP-1 therapies in cancer treatment; since this class of medications improves obesity, they might also help improve cancer outcomes. In a large retrospective cohort study with a 15-year follow-up, GLP-1 medication use was associated with a significant risk reduction in 10 of the 13 obesity-related cancers. 1 Mechanistically, the reasons for this reduction are unknown, but decreased inflammation and immune dysregulation are likely key factors in lowering this risk.
Our research group has extensively documented the harmful effects of obesity on the immune system, including its impact on anti-cancer immunity. Additionally, we have provided clinical and experimental evidence that GLP-1 therapy reduces inflammation and can significantly enhance anti-tumor immune cell populations. In this study, we will precisely assess the effects of two specific interventions-either TNT combined with GLP-1 RA (intervention group) or TNT alone (control group)-on the systemic inflammatory profile and circulating/tumor immune phenotype in stage III rectal cancer.
GLP-1-based treatments originally developed for type 2 diabetes and obesity, are now gaining attention for their potential impact on immune metabolism and even cancer therapy. There has been direct links between GLP-1 treatment and immune metabolism, with GLP reducing inflammation and improving systemic metabolism enhancing immune fitness. Some studies have also shown that GLP treatment can also indirectly modulate the TME by lowering leptin and insulin levels, reducing tumour-promoting signalling and reducing immunosuppressive cells in the TME. It is important to note that different cancers may respond differently to GLP-1 modulation based on the complexity, composition and level of immune infiltration. In this current study, we will profile the metabolic profiles and inflammatory profiles in the complex TME across the two defined interventions (either TNT + GLP-1 RA (intervention group) or TNT alone (control group)) in stage III rectal cancer patents enrolled in the trial.
GLP-1 receptor agonists (GLP-1 RAs), such as semaglutide, have demonstrated strong effects on weight loss in individuals with obesity. In the STEP 1 trial, semaglutide led to an average weight loss of 14.9%, compared to 2.4% with placebo, over 68 weeks. Recent epidemiologic data also suggest a link between GLP-1 RA use and a reduced incidence of obesity-related cancers, including colorectal cancer. 3 Additionally, GLP-1 RAs may have anti-inflammatory and metabolic effects that could be beneficial in the context of cancer therapy.
Total neoadjuvant therapy (TNT) is increasingly utilized in managing locally advanced rectal cancer (LARC) to improve pathological complete response (pCR) rates, facilitate surgical downstaging, and support organ preservation. This trial aims to determine whether combining GLP-1 RAs with TNT leads to meaningful weight loss and better oncological outcomes compared to TNT alone in patients with BMI ≥30 and LARC.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Total Neoadjuvant Therapy and GLP-1 Receptor Agonist | Experimental | Drug: GLP-1 receptor agonist, Drug: Total neoadjuvant therapy (TNT)This arm will have patients with increased BMI and locally advanced rectal cancer having total neoadjuvant chemoradiotherapy. This arm will be given a GLP-1 receptor agonist |
| Locally advanced rectal cancer and total neoadjuvant therapy alone | Active comparator | Drug: Total neoadjuvant therapy (TNT)Patients with a high BMI and locally advanced rectal cancer undergoing total neoadjuvant therapy with not receiving a GLP-1 receptor agonist |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (10 listed)
- Written informed consent according to local guidelines obtained prior to any study-related activities.
- Histologically confirmed mismatch repair protein proficient adenocarcinoma of the rectum.
- BMI ≥25 kg/m²
- Radiological confirmed >T2, Node positive, Threatened Surgical Margin and/or EMVI+ by MRI
- Imaging available for radiomics analysis
Key exclusion criteria (7 listed)
- Received prior chemotherapy or radiotherapy
- Previous or concurrent active malignancy ≤ 5 years prior to registration, with the exception of non-melanotic skin cancer or carcinoma in situ of any type, or other cancers that the treating investigator does not feel will impact the study objectives.
- Locally advanced disease T3N+ or T4 disease.
- Recurrent rectal cancer
- Metastatic disease at presentation
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| GLP-1 receptor agonistAll patients will receive standard total neoadjuvant therapy for rectal cancer as per local standards. One group will receive a GLP-1 rector agonist in addition to the standard treatment for rectal cancer | Drug | Total Neoadjuvant Therapy and GLP-1 Receptor Agonist |
| Total neoadjuvant therapy (TNT)Total ne-adjuvant therapy is standard treatment for locally advanced rectal cancer | Drug | Locally advanced rectal cancer and total neoadjuvant therapy alone, Total Neoadjuvant Therapy and GLP-1 Receptor Agonist |
Primary outcome
Weight Loss
Time frame: 6 months
Change in weight loss (Kilograms) between groups at 2 time points * Baseline * Pre TNT starting * Post TNT starting
Metabolic Profile of the Tissue
Time frame: From enrolment to operation within 1 year
Using a human ex vivo explant model (3D), we will assess in real time the metabolic profiles of the tissues from patents in the control and interventions groups. Detailed metabolic profiling data using Seahorse technology. These metabolic profile data will be correlated with detailed clinical, pathology and outcome data for each patient in the trial.
Inflammatory Mediators
Time frame: From enrolment to surgical resection within 1 year
Using human ex vivo explant model (3D) system, we will profile the secretions of inflammatory mediators from the TME and how these cross talks to immune cells. This data will be directly correlated with the detailed metabolic signatures.
GLP-1 effects on mitochondrial fitness
Time frame: From enrolment to surgical resection within 1 year
Determine of GLP-1 treatment alters mitochondrial fitness ex vivo in explants by assessing ATP levels (Relative Light Units), stress responses and adaptations to metabolic demands using tissues from both arms of the trial.
Mapping systemic inflammatory profiles
Time frame: From enrolment to surgical resection within 1 year
To definitively map the systemic inflammatory profile, we will investigate matched plasma samples (baseline and post-intervention) using a high dimensional approach (e.g Olink Target-96 Immunoncology panel or Olink Explore-396 inflammatory profile). Samples will be taken at the time of diagnosis and the time of surgery
Mapping circulating immune systems
Time frame: From enrolment to surgical resection within 1 year
Map the circulating immune system using spectral flow cytometry to include cell frequencies (e.g. T cells, Innate T cells, NK cells, Monocytes and DC subsets), activation/exhaustion phenotype (e.g. CD69, PD-1, TIM-3 etc) and cytokine profiles (e.g. interleukin (IL)-2, 4, 10 \& 17, interferon gamma, tumour necrosis factor, granzymes etc). Samples will be taken from pre treatment biopsies and from the tumour itself when removed at surgery.
Mapping tumour resident immune system
Time frame: From enrolment to surgical resection within 1 year
Map the tumour resident immune system using MACsima spatial imaging platform and their 61- parameter immuno-oncology antibody panel (which includes T cells, NK cells, Macrophages \& DCs plus tumour specific markers). Using this platform, in addition to deep immunopheotyping, we will allow perform neighbour analysis to determine cell-cell interactions. Tissue will be taken from pre treatment biopsies and from the tumour itself when removed at surgery.
16 secondary outcomes
Oncological outcomes
Time frame: 5 years
Surgical Outcomes
Time frame: Enrolment to surgical intervention and 30 days post discharge
Metabolic and Physiologic Outcomes:
Time frame: From enrolment to surgical resection within 1 year
Treatment Tolerability and Safety:
Time frame: 1 year
Patient-Reported Outcomes:
Time frame: 2 years
Translational Component: to investigate the molecular and cellular effects of GLP-1 RA therapy during TNT through analysis of tissue and blood biomarkers.
Time frame: From enrolment to surgical resection within 1 year
Radiomics
Time frame: From enrolment to surgical resection within 1 year
Circulating Tumor DNA (ctDNA)
Time frame: From enrolment to surgical resection within 1 year
Surgical Outcomes
Time frame: 30 days
Surgical Outcomes
Time frame: 30 days
Metabolic and Physiologic Outcomes:
Time frame: From enrolment to 1 year
Metabolic and Physiologic Outcomes:
Time frame: Enrolment to 1 year
Translational Component: to investigate the molecular and cellular effects of GLP-1 RA therapy during TNT through analysis of tissue and blood biomarkers.
Time frame: From enrolment to1 year
Translational Component: to investigate the molecular and cellular effects of GLP-1 RA therapy during TNT through analysis of tissue and blood biomarkers.
Time frame: Enrolment to 1 year
Translational Component: to investigate the molecular and cellular effects of GLP-1 RA therapy during TNT through analysis of tissue and blood biomarkers.
Time frame: Enrolment to 1 year
Translational Component: to investigate the molecular and cellular effects of GLP-1 RA therapy during TNT through analysis of tissue and blood biomarkers.
Time frame: Enrolment to 1 year
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Jan 2026.
- Results publication: PubMed 38888262Kazi T, McKechnie T, Lee Y, Alsayari R, Talwar G, Doumouras A, Hong D, Eskicioglu C. The impact of obesity on postoperative outcomes following surgery for colorectal cancer: analysis of the National Inpatient Sample 2015-2019. ANZ J Surg. 2024 Jul-Aug;94(7-8):1305-1312. doi: 10.1111/ans.19135. Epub 2024 Jun 18.
- Results publication: PubMed 36294412Martin-Carnicero A, Ramalle-Gomara E, Rubio-Mediavilla S, Alonso-Lago M, Zorrilla-Larraga M, Manrique-Abos I, de Las Heras-Duena ME, Larrayoz IM, Martinez A. Prognostic and Predictive Biomarkers in Patients with Locally Advanced Rectal Cancer (LARC) Treated with Preoperative Chemoradiotherapy. J Clin Med. 2022 Oct 16;11(20):6091. doi: 10.3390/jcm11206091.
- Results publication: PubMed 35565381Dizdarevic E, Hansen TF, Jakobsen A. The Prognostic Importance of ctDNA in Rectal Cancer: A Critical Reappraisal. Cancers (Basel). 2022 Apr 30;14(9):2252. doi: 10.3390/cancers14092252.
- Results publication: PubMed 39093546Chen C, Douglas MP, Ragavan MV, Phillips KA, Jansen JP. Clinical Validity and Utility of Circulating Tumor DNA (ctDNA) Testing in Advanced Non-small Cell Lung Cancer (aNSCLC): A Systematic Literature Review and Meta-analysis. Mol Diagn Ther. 2024 Sep;28(5):525-536. doi: 10.1007/s40291-024-00725-x. Epub 2024 Aug 2.
- Results publication: PubMed 32923389Ryan EJ, Creavin B, Sheahan K. Delivery of Personalized Care for Locally Advanced Rectal Cancer: Incorporating Pathological, Molecular Genetic, and Immunological Biomarkers Into the Multimodal Paradigm. Front Oncol. 2020 Aug 14;10:1369. doi: 10.3389/fonc.2020.01369. eCollection 2020.
- Results publication: PubMed 40437949Silverii GA, Marinelli C, Bettarini C, Del Vescovo GG, Monami M, Mannucci E. GLP-1 receptor agonists and the risk for cancer: A meta-analysis of randomized controlled trials. Diabetes Obes Metab. 2025 Aug;27(8):4454-4468. doi: 10.1111/dom.16489. Epub 2025 May 29.
- Results publication: PubMed 38893212Ochiai K, Bhutiani N, Ikeda A, Uppal A, White MG, Peacock O, Messick CA, Bednarski BK, You YN, Skibber JM, Chang GJ, Konishi T. Total Neoadjuvant Therapy for Rectal Cancer: Which Regimens to Use? Cancers (Basel). 2024 May 31;16(11):2093. doi: 10.3390/cancers16112093.
- Results publication: PubMed 37085291Johnson GGRJ, Park J, Helewa RM, Goldenberg BA, Nashed M, Hyun E. Total neoadjuvant therapy for rectal cancer: a guide for surgeons. Can J Surg. 2023 Apr 21;66(2):E196-E201. doi: 10.1503/cjs.005822. Print 2023 Mar-Apr.
- Results publication: PubMed 40140925Lin A, Ding Y, Li Z, Jiang A, Liu Z, Wong HZH, Cheng Q, Zhang J, Luo P. Glucagon-like peptide 1 receptor agonists and cancer risk: advancing precision medicine through mechanistic understanding and clinical evidence. Biomark Res. 2025 Mar 27;13(1):50. doi: 10.1186/s40364-025-00765-3.
- Results publication: PubMed 40285503Miousse IR. GLP-1 receptor agonists in the context of cancer: the road ahead. Am J Physiol Cell Physiol. 2025 Jun 1;328(6):C1822-C1828. doi: 10.1152/ajpcell.00245.2025. Epub 2025 Apr 26.
- Results publication: PubMed 33567185Wilding JPH, Batterham RL, Calanna S, Davies M, Van Gaal LF, Lingvay I, McGowan BM, Rosenstock J, Tran MTD, Wadden TA, Wharton S, Yokote K, Zeuthen N, Kushner RF; STEP 1 Study Group. Once-Weekly Semaglutide in Adults with Overweight or Obesity. N Engl J Med. 2021 Mar 18;384(11):989-1002. doi: 10.1056/NEJMoa2032183. Epub 2021 Feb 10.
- Results publication: PubMed 38967919Wang L, Xu R, Kaelber DC, Berger NA. Glucagon-Like Peptide 1 Receptor Agonists and 13 Obesity-Associated Cancers in Patients With Type 2 Diabetes. JAMA Netw Open. 2024 Jul 1;7(7):e2421305. doi: 10.1001/jamanetworkopen.2024.21305.
- Individual participant dataSharing planned: No. De identified data will not be available to anyone outside the study. This is in line with our ethics department and GDPR
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Michael Kelly, MB BAO BCH PHD FRCSI principal investigator
St. James Hospital
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing GLP-1 receptor agonist and Total neoadjuvant therapy (TNT) in people with Rectal Cancer Patients and Obesity &Amp; Overweight, run by St. James's Hospital, Ireland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 10 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 2 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Michael Eamon Kelly, MB BAO BCH PhD FRCSI (00353876638956, kellym11@tcd.ie), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Weight Loss (time frame: 6 months). The study lists 7 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07314528, which also lists 13 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Jan 2026.