Colorectal CancerPhase 2NCT05678257
A Study of NUC-3373 in Combination With Other Agents in Patients With Colorectal Cancer
A Phase 2 study testing Fosifloxuridine Nafalbenamide, Leucovorin and Irinotecan in people with Colorectal Cancer and Colorectal Neoplasms, run by NuCana plc at 59 sites in 6 countries.
Trial summary
This is a randomized, open-label, dose/schedule optimization study comparing NUC-3373/leucovorin (LV)/irinotecan plus bevacizumab (NUFIRI-bev) to 5-FU/LV/irinotecan plus bevacizumab (FOLFIRI-bev) for the treatment of patients with unresectable metastatic colorectal cancer. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Colorectal Cancer, Colorectal Neoplasms, Colorectal Adenocarcinoma
- What is being tested?
- Fosifloxuridine Nafalbenamide, Leucovorin and Irinotecan
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 180 participants
- Where
- 59 sitesin 6 countries
- Study dates
- 18 Apr 2023to 29 Aug 2024
- Phase
- Phase 2
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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
- Provision of written informed consent.
- Histological or cytological confirmation of colorectal adenocarcinoma (excluding appendiceal and anal canal cancers, as well as signet-ring cell carcinoma) that is unresectable and metastatic.
- Measurable disease (as defined by RECIST v1.1).
- Received ≥2 months of a first-line fluoropyrimidine and oxaliplatin-containing regimen for metastatic disease or relapsed within 6 months of completing a fluoropyrimidine and oxaliplatin-containing neoadjuvant/adjuvant therapy. Previous treatment with standard of care chemotherapy regimens in combination with molecular targeted therapies (e.g., VEGF and EGFR pathway inhibitors and immuno-oncology agents) is permitted. Previous treatment with maintenance therapy (e.g., capecitabine) is also allowed. Patients who started on a fluoropyrimidine and oxaliplatin-containing regimen in any setting but must discontinue the oxaliplatin due to.toxicity or allergy (and are now unable to receive oxaliplatin) are considered eligible regardless of the number of cycles of oxaliplatin they received.
- Known RAS and BRAF status. Patients with wild-type RAS tumours must have received prior treatment with an EGFR inhibitor, unless this was not standard of care according to relevant region-specific treatment recommendations.
- Known UGT1A1 status, or patient consents to UGT1A1 status testing if unknown.
Show all 17Show fewer
- Known DPD activity status, or patient consents to DPD status testing if unknown. See exclusion criterion 1.
- Age ≥18 years.
- Minimum life expectancy of ≥12 weeks.
- Eastern Cooperative Oncology Group (ECOG) Performance status 0 or 1.
- Adequate bone marrow function as defined by: absolute neutrophil count (ANC) ≥1.5 × 109/L, platelet count ≥100 × 109/L, and haemoglobin ≥9 g/dL. Patients with benign neutropenia may be discussed on a case-by-case basis with the medical monitor.
- Adequate liver function, as defined by: serum total bilirubin ≤1.5 × ULN), AST and ALT ≤2.5 × ULN (or ≤5 × ULN if liver metastases are present).
- Adequate renal function assessed as serum creatinine <1.5 × ULN and glomerular filtration rate ≥50 mL/min (calculated by the Cockcroft-Gault method).
- Serum albumin ≥3 g/dL.
- Ability to comply with protocol requirements.
- Female patients of child-bearing potential must have a negative serum pregnancy test within 7 days prior to the first study drug administration. This criterion does not apply to patients who have had a previous hysterectomy or bilateral oophorectomy. Male patients and female patients of child-bearing potential must agree to practice true abstinence (defined in Section 10.3.1) or to use two forms of contraception, one of which must be highly effective. These forms of contraception must be used from the time of signing consent, throughout the treatment period, and for 6 months following the last dose of any study medication. Oral or injectable contraceptive agents cannot be the sole method of contraception
- Patients must have been advised to take measures to avoid or minimize exposure of the skin and eyes to UV light, including avoiding sunbathing and solarium use, for the duration of study participation and for a period of 4 weeks following the last dose of study medication
Who cannot join
- History of hypersensitivity or current contra-indications to 5-FU, FUDR, or capecitabine.
- History of hypersensitivity or current contra-indication to any of the combination agents required for the study.
- History of allergic reactions attributed to components of the NUC-3373 drug product formulation.
- History of hypersensitivity to Chinese Hamster Ovary (CHO) cell products or other recombinant human or humanised antibodies.
- History of or known central nervous system or leptomeningeal metastases.
- Symptomatic ascites, ascites currently requiring drainage procedures or ascites requiring drainage over the prior 3 months.
Show all 31Show fewer
- Mutant BRAF V600E status.
- MSI high or dMMR.
- Prior treatment with irinotecan.
- Chemotherapy, hormonal therapy, radiotherapy (other than a short cycle of palliative radiotherapy [e.g., for bone pain]*), immunotherapy, biological agents, or exposure to another investigational agent within 21 days (or four times the half-life for molecular targeted agents, whichever is shorter) of first administration of study treatment:
- Residual toxicities from prior chemotherapy or radiotherapy which have not regressed to Grade ≤1 severity (CTCAE v5.0), except for alopecia and residual Grade 2 neuropathy.
- History of other malignancies, except adequately treated non-melanoma skin cancer, curatively treated in situ cancer of the cervix, surgically excised or potentially curatively treated ductal carcinoma in situ of the breast, or low-grade prostate cancer or patients after prostatectomy. Patients with previous invasive cancers are eligible if treatment was completed >3 years prior to initiating the current study treatment, and the patient has had no evidence or recurrence since then.
- Presence of an active bacterial or viral infection (including SARS-CoV-2, Herpes Zoster, Varicella Zoster or chickenpox), known Human Immunodeficiency Virus (HIV) positive or known active hepatitis B or C.
- Presence of any uncontrolled concurrent serious illness, medical condition or other medical history, including laboratory results, which, in the Investigator's opinion, would be likely to interfere with the patient's ability to participate in the study or with the interpretation of the results (refer to protocol for further details).
- Any condition that, in the judgment of the Investigator, may affect the patient's ability to provide informed consent and undergo study procedures.
- Patients with a history of haemoptysis (1/2 teaspoon or more of red blood) within 6 months prior to enrolment.
- Wound healing complications or surgery within 28 days of starting bevacizumab (wound healing must have been fully completed before starting bevacizumab). Investigators may allow patients to initiate treatment with the other study drugs (i.e., NUC-3373/5-FU, LV and irinotecan) on C1D1 but withhold bevacizumab for at least 15 days, but no longer than 28 days, to allow completion of wound healing in patients who would otherwise be eligible for the study, in line with standard local practice and after discussion with the Medical Monitor. Patients who have not received bevacizumab by C2D1 must be replaced.
- Unhealed wound, active gastric or duodenal ulcer, or bone fracture.
- Serious thromboembolic event in the 6 months before inclusion.
- Patients with a history of haemorrhage within 6 months prior to enrolment.
- Known inherited or acquired bleeding disorders.
- Red blood cell (RBC) transfusion dependence, defined as requiring more than 2 units of packed RBC transfusions during the 4-week period prior to screening.
- Uncontrolled hypertension.
- Severe proteinuria or nephrotic syndrome.
- Acute intestinal obstruction or sub-obstruction, history of inflammatory intestinal disease or extended resection of the small intestine. Presence of a colic prosthesis.
- History of abdominal fistulas, trachea-oesophageal fistulas, any other Grade 4 gastrointestinal perforations, non-gastrointestinal fistulas, or intra-abdominal abscesses 6 months prior to screening.
- Currently pregnant, lactating or breastfeeding.
- Required concomitant use of brivudine, sorivudine and analogues.
- Required concomitant use of St John's Wort.
- Required concomitant use of drugs known to prolong QT/QTc interval.
- Required concomitant use of strong CYP3A4 inducers or strong CYP3A4 inhibitors. The use of strong CYP3A4 inducers within 2 weeks of first receipt of study drug or the use of strong CYP3A4 inhibitors within 1 week of first receipt of study drug is also excluded.
Trial locations and contacts
59 sites in 6 countries.
59 sites in 6 countries
United States16 sites
Boston Medical Center
Boston, Massachusetts, 02118
The Christ Hospital Cancer Center
Cincinnati, Ohio, 45219
Texas Oncology - Baylor Charles A. Sammons Cancer Center
Dallas, Texas, 75246
University of Texas Southwestern Medical Center
Dallas, Texas, 75390
Barbara Ann Karmanos Cancer Institute
Detroit, Michigan, 48201
University of Florida Health Medical Oncology - Davis Cancer Pavilion
Gainesville, Florida, 32610
University of Iowa Hospitals and Clinics
Iowa City, Iowa, 52242
Fred Hutchinson Cancer Center at Evergreen Health
Kirkland, Washington, 98034
Norton Cancer Institute
Louisville, Kentucky, 40202
Morristown Medical Center
Morristown, New Jersey, 07960
Helen F. Graham Cancer Center
Newark, Delaware, 19713
USOR - Texas Oncology Northeast Texas
Tyler, Texas, 75702
Northwest Cancer Specialists, P.C. dba Compass Oncology - Vancouver Cancer Center
Vancouver, Washington, 98684
Georgetown University Medical Center
Washington D.C., District of Columbia, 20007
Cancer Center of Kansas
Wichita, Kansas, 67214
University of Massachusetts Worcester
Worcester, Massachusetts, 01655
Spain14 sites
Hospital Universitario Fundación Alcorcón
Alcorcón, Madrid, 28922
Institut Català d'Oncologia - ICO Badalona - Hospital Universitari Germans Trias i Pujol
Badalona, Barcelona, 08916
Hospital de la Santa Creu i Sant Pau
Barcelona, 08041
Hospital Universitari Vall d'Hebrón
Barcelona, 8035
Hospital Duran i Reynals
Barcelona, 8908
Hospital de León
León, 24008
Hospital Universitari Arnau de Vilanova
Lleida, 25198
Hospital General Universitario Gregorio Marañón
Madrid, 28007
MD Anderson Cancer Center Madrid
Madrid, 28033
Hospital Universitario 12 de Octubre
Madrid, 28041
Hospital Universitario Puerta de Hierro
Majadahonda, Madrid, 28222
Hospital Universitario Virgen de la Victoria
Málaga, 29010
Complejo Hospitalario Universitario de Santiago (CHUS)
Santiago de Compostela, La Coruña, 15706
Hospital Universitario Virgen del Rocío
Seville, 41013
France9 sites
Centre Hospitalier Régional et Universitaire de Besançon - Hôpital Jean-Minjoz
Besançon, Doubs, 25000
Institut Bergonié
Bordeaux, Gironde, 33076
Centre Georges-François Leclerc
Dijon, Bourgogne-Franche-Comté, 21079
Hôpital Européen Marseille
Marseille, Bouches-du-Rhône, 13003
Centre Hospitalier UniversitaireNantes - Hôtel Dieu
Nantes, 44000
Hôpital Européen Georges-Pompidou
Paris, Île-de-France Region, 75015
Centre Hospitalier Universitaire de Poitiers
Poitiers, Vienne, 86000
Strasbourg Oncology Liberale - Clinique Sainte-Anne
Strasbourg, Alsace, 67000
Hôpital Foch
Suresnes, Île-de-France Region, 92150
Italy8 sites
Azienda Ospedaliero Universitaria Ospedali Riuniti di Ancona
Ancona, 60126
Ospedale Santa Maria delle Croci di Ravenna
Faenza, Ravenna, 48121
Azienda Ospedaliero Universitaria Careggi
Florence, Tuscany, 50134
Fondazione IRCCS Istituto Nazionale dei Tumori
Milan, Lombardy, 20133
Azienda Socio Sanitaria Territoriale Grande Ospedale Metropolitano Niguarda
Milan, 20162
Azienda Ospedaliera Universitaria - Università degli Studi della Campania Luigi Vanvitelli
Naples, Campania, 80131
Istituto Oncologico Veneto - IRCCS
Padova, Veneto, 35128
Azienda Ospedaliera Regionale San Carlo
Potenza, 85100
United Kingdom8 sites
Velindre University NHS Trust
Cardiff, CF14 2TL
NHS Greater Glasgow and Clyde
Glasgow, G51 4TF
University College London Hospitals NHS Foundation Trust
London, Greater London, NW1 2PG
Royal Free London NHS Foundation Trust
London, Greater London, NW3 2QG
Guy's and Saint Thomas' NHS Foundation Trust
London, Greater London, SE1 9RT
The Christie NHS Foundation Trust
Manchester, Lancashire, M20 4BX
Mount Vernon Cancer Centre - East and North Hertfordshire NHS Trust
Northwood, Middlesex, HA6 2RN
Queen's Hospital
Romford, Essex, RM7 OAG
Germany4 sites
Charité Campus Virchow-Klinikum
Berlin, 13353
Krankenhaus Nordwest
Frankfurt am Main, Hesse, 60488
München Klinik Neuperlach
München, Bavaria, 81737
Universitätsklinik Ulm - Oberen Eselsberg
Ulm, Tübingen, 89081
About this study
Official title: A Randomised, Open-label, Phase II, Dose/Schedule Optimisation Study of NUC-3373/Leucovorin/Irinotecan Plus Bevacizumab (NUFIRI-bev) Versus 5-FU/Leucovorin/Irinotecan Plus Bevacizumab (FOLFIRI-bev) for the Treatment of Patients With Previously Treated Unresectable Metastatic Colorectal Cancer
This is a randomized, open-label, dose/schedule optimization study comparing NUC-3373/leucovorin (LV)/irinotecan plus bevacizumab (NUFIRI-bev) to 5-FU/LV/irinotecan plus bevacizumab (FOLFIRI-bev) for the treatment of patients with unresectable metastatic colorectal cancer.
A total of 171 patients will be randomized 1:1:1 to either NUFIRI-bev on a weekly NUC-3373 schedule, NUFIRI-bev based on an alternate weekly NUC-3373 schedule, or FOLFIRI bev on an alternate weekly schedule. The main objectives are to assess and compare the efficacy and safety of the 3 regimens. Pharmacokinetics will be assessed on the 2 NUFIRI arms.
- Conditions
- Colorectal Cancer, Colorectal Neoplasms, Colorectal Adenocarcinoma, Colorectal Cancer Metastatic, Neoplasm, Colorectal
- Being tested
- Fosifloxuridine Nafalbenamide, Leucovorin, Irinotecan, Bevacizumab, 5-FU
- Keywords
- Relapsed metastatic adenocarcinoma of colon/rectum, NUC-3373, Fosifloxuridine nafalbenamide, Leucovorin, Irinotecan, Bevacizumab, Antineoplastic agents, Chemotherapy, Second-line chemotherapy, Locally advanced cancer, Metastatic cancer, Neoplasm, 5-FU
- Medical subject headings
- Colorectal Neoplasms, Colonic Neoplasms, Neoplasm Metastasis, Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Fosifloxuridine NafalbenamideDrug
Also called NUC-3373, Nucleotide analogue
Intravenous infusion
LeucovorinDrug
Also called Folinic acid, LV
Intravenous infusion
IrinotecanDrug
Also called Campto, Camptosar
Intravenous infusion
BevacizumabBiological
Also called Avastin, Zirabev
Intravenous infusion
5-FUDrug
Also called 5FU, 5-fluorouracil, Fluorouracil
Intravenous infusion
| Study group | Role | What they receive |
|---|---|---|
| NUFIRI-bev on a Q1W NUC-3373 schedule | Experimental | Arm A: Study treatment will be administered in 28-day cycles as follows:
1. Bevacizumab 5 mg/kg on Days 1 and 15:
* 90 minutes for the first dose
* 60 minutes for the second dose (if first dose is tolerated)
* 30 minutes for subsequent doses (if second dose is tolerated)
2. LV 400 mg/m2 (or equivalent levo-LV) over 120 minutes on Days 1, 8, 15, and 22.
3. Irinotecan 180 mg/m2 over 90 minutes (concurrently with the LV infusion) on Days 1 and 15.
4. NUC-3373 1500 mg/m2 over 120 minutes on Days 1, 8, 15, and 22. Receives: Drug: Fosifloxuridine Nafalbenamide; Drug: Leucovorin; Drug: Irinotecan; Biological: Bevacizumab |
| NUFIRI-bev on a Q2W NUC-3373 schedule | Experimental | Arm B: Study treatment will be administered in 28-day cycles as follows:
1. Bevacizumab 5 mg/kg on Days 1 and 15:
* 90 minutes for the first dose
* 60 minutes for the second dose (if first dose is tolerated)
* 30 minutes for subsequent doses (if second dose is tolerated)
2. LV 400 mg/m2 (or equivalent levo-LV) over 120 minutes on Days 1 and 15.
3. Irinotecan 180 mg/m2 over 90 minutes (concurrently with the LV infusion) on Days 1 and 15.
4. NUC-3373 1500 mg/m2 over 120 minutes on Days 1 and 15. Receives: Drug: Fosifloxuridine Nafalbenamide; Drug: Leucovorin; Drug: Irinotecan; Biological: Bevacizumab |
| FOLFIRI-bev on a Q2W schedule | Active comparator | Arm C: Study treatment will be administered in 28-day cycles as follows:
1. Bevacizumab 5 mg/kg on Days 1 and 15:
* 90 minutes for the first dose
* 60 minutes for the second dose (if first dose is tolerated)
* 30 minutes for subsequent doses (if second dose is tolerated)
2. LV 400 mg/m2 (or equivalent levo-LV) over 120 minutes on Days 1 and 15.
3. Irinotecan 180 mg/m2 over 90 minutes (concurrently with the LV infusion) on Days 1 and 15.
4. 5-FU 400 mg/m2 bolus on Days 1 and 15.
5. 5-FU 2400 mg/m2 infusion over 46 hours on Days 1 and 15. Receives: Drug: Leucovorin; Drug: Irinotecan; Biological: Bevacizumab; Drug: 5-FU |
What is being measured
The primary outcome is the main question the study is designed to answer.
Median Progress-free Survival (PFS)
PFS assessed according to Response Evaluation Criteria in Solid Tumours (RECIST) v1.1, defined as the time from randomisation to the first observation of objective tumour progression or death from any cause. Progression was defined as a 20% increase in the sum of the longest diameter of target lesions, or a measurable increase in non-target lesions, or the appearance of new lesions.
Measured: Assessed from baseline to 30 days after last dose of study drug, up to 16 months
Secondary outcomes (2)
Number of Patients Achieving a Reduction in Tumour Volume
Objective response rate, defined as the percentage of patients achieving a complete (CR) or partial response (PR) to treatment. Response was measured by MRI scan and assessed per Response Evaluation Criteria in Solid Tumors (RECIST v1.1) criteria:
CR= disappearance of all target lesions PR= at least a 30% decrease in the sum of the longest diameter of target lesions
Measured: Assessed from baseline to 30 days after last dose of study drug, up to 16 months
Number of Patients Achieving Disease Control
Disease control rate, defined as the number of patients achieving a response (CR or PR) or stable disease (SD) as their best overall response. Disease control was measured by MRI scan and assessed using Response Evaluation Criteria in Solid Tumors (RECIST v1.1) criteria:
CR= disappearance of all target lesions PR= at least a 30% decrease in the sum of the longest diameter of target lesions SD= neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for progressive disease
Measured: Assessed from baseline to 30 days after last dose of study drug, up to 16 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Jan 2023
- Study start18 Apr 2023
- Primary completion29 Aug 2024
- Study completion29 Aug 2024
Why it stopped: A pre-planned initial analysis concluded that the study was unlikely to achieve its primary objective of demonstrating superior progression-free survival. Based on the Steering Committee's recommendation, the Sponsor has closed the study.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Colorectal CancerStudies 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
- 180 participants (actual)
Sponsor and investigators
- Lead sponsor
- NuCana plc
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Elisabeth Oelmann, MD, PhD, Study director, NuCana plc
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05678257
- Sponsor's protocol ID
- NuTide:323
- Other IDs
- 2022-001459-17
- Status last verified
- Aug 2025
- First submitted
- 22 Dec 2022
- Last updated
- 12 Sep 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 12 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Randomised, Open-label, Phase II, Dose/Schedule Optimisation Study of NUC-3373/Leucovorin/Irinotecan Plus Bevacizumab (NUFIRI-bev) Versus 5-FU/Leucovorin/Irinotecan Plus Bevacizumab (FOLFIRI-bev) for the Treatment of Patients With Previously Treated Unresectable Metastatic Colorectal Cancer
- ClinicalTrials.gov ID
- NCT05678257
- Acronym / sponsor ID
- NuTide:323
- Conditions
- Colorectal Cancer, Colorectal Neoplasms, Colorectal Adenocarcinoma, Colorectal Cancer Metastatic, Neoplasm, Colorectal
- Keywords
- Relapsed metastatic adenocarcinoma of colon/rectum, NUC-3373, Fosifloxuridine nafalbenamide, Leucovorin, Irinotecan, Bevacizumab, Antineoplastic agents, Chemotherapy
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: A pre-planned initial analysis concluded that the study was unlikely to achieve its primary objective of demonstrating superior progression-free survival. Based on the Steering Committee's recommendation, the Sponsor has closed the study.
- Enrolment
- 180 participants (actual)
- Lead sponsor
- NuCana plcUniversity, hospital or other
- Study start
- 18 Apr 2023 (actual)
- Primary completion
- 29 Aug 2024 (actual)
- Study completion
- 29 Aug 2024 (actual)
- First posted
- 10 Jan 2023 (actual)
- Results
- Posted 12 Sep 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a randomized, open-label, dose/schedule optimization study comparing NUC-3373/leucovorin (LV)/irinotecan plus bevacizumab (NUFIRI-bev) to 5-FU/LV/irinotecan plus bevacizumab (FOLFIRI-bev) for the treatment of patients with unresectable metastatic colorectal cancer.
A total of 171 patients will be randomized 1:1:1 to either NUFIRI-bev on a weekly NUC-3373 schedule, NUFIRI-bev based on an alternate weekly NUC-3373 schedule, or FOLFIRI bev on an alternate weekly schedule. The main objectives are to assess and compare the efficacy and safety of the 3 regimens. Pharmacokinetics will be assessed on the 2 NUFIRI arms.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| NUFIRI-bev on a Q1W NUC-3373 schedule | Experimental | Drug: Fosifloxuridine Nafalbenamide, Drug: Leucovorin, Drug: Irinotecan, Biological: BevacizumabArm A: Study treatment will be administered in 28-day cycles as follows: 1. Bevacizumab 5 mg/kg on Days 1 and 15: * 90 minutes for the first dose * 60 minutes for the second dose (if first dose is tolerated) * 30 minutes for subsequent doses (if second dose is tolerated) 2. LV 400 mg/m2 (or equivalent levo-LV) over 120 minutes on Days 1, 8, 15, and 22. 3. Irinotecan 180 mg/m2 over 90 minutes (concurrently with the LV infusion) on Days 1 and 15. 4. NUC-3373 1500 mg/m2 over 120 minutes on Days 1, 8, 15, and 22. |
| NUFIRI-bev on a Q2W NUC-3373 schedule | Experimental | Drug: Fosifloxuridine Nafalbenamide, Drug: Leucovorin, Drug: Irinotecan, Biological: BevacizumabArm B: Study treatment will be administered in 28-day cycles as follows: 1. Bevacizumab 5 mg/kg on Days 1 and 15: * 90 minutes for the first dose * 60 minutes for the second dose (if first dose is tolerated) * 30 minutes for subsequent doses (if second dose is tolerated) 2. LV 400 mg/m2 (or equivalent levo-LV) over 120 minutes on Days 1 and 15. 3. Irinotecan 180 mg/m2 over 90 minutes (concurrently with the LV infusion) on Days 1 and 15. 4. NUC-3373 1500 mg/m2 over 120 minutes on Days 1 and 15. |
| FOLFIRI-bev on a Q2W schedule | Active comparator | Drug: Leucovorin, Drug: Irinotecan, Biological: Bevacizumab, Drug: 5-FUArm C: Study treatment will be administered in 28-day cycles as follows: 1. Bevacizumab 5 mg/kg on Days 1 and 15: * 90 minutes for the first dose * 60 minutes for the second dose (if first dose is tolerated) * 30 minutes for subsequent doses (if second dose is tolerated) 2. LV 400 mg/m2 (or equivalent levo-LV) over 120 minutes on Days 1 and 15. 3. Irinotecan 180 mg/m2 over 90 minutes (concurrently with the LV infusion) on Days 1 and 15. 4. 5-FU 400 mg/m2 bolus on Days 1 and 15. 5. 5-FU 2400 mg/m2 infusion over 46 hours on Days 1 and 15. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (17 listed)
- Provision of written informed consent.
- Histological or cytological confirmation of colorectal adenocarcinoma (excluding appendiceal and anal canal cancers, as well as signet-ring cell carcinoma) that is unresectable and metastatic.
- Measurable disease (as defined by RECIST v1.1).
- Received ≥2 months of a first-line fluoropyrimidine and oxaliplatin-containing regimen for metastatic disease or relapsed within 6 months of completing a fluoropyrimidine and oxaliplatin-containing neoadjuvant/adjuvant therapy. Previous treatment with standard of care chemotherapy regimens in combination with molecular targeted therapies (e.g., VEGF and EGFR pathway inhibitors and immuno-oncology agents) is permitted. Previous treatment with maintenance therapy (e.g., capecitabine) is also allowed. Patients who started on a fluoropyrimidine and oxaliplatin-containing regimen in any setting but must discontinue the oxaliplatin due to.toxicity or allergy (and are now unable to receive oxaliplatin) are considered eligible regardless of the number of cycles of oxaliplatin they received.
- Known RAS and BRAF status. Patients with wild-type RAS tumours must have received prior treatment with an EGFR inhibitor, unless this was not standard of care according to relevant region-specific treatment recommendations.
Key exclusion criteria (31 listed)
- History of hypersensitivity or current contra-indications to 5-FU, FUDR, or capecitabine.
- History of hypersensitivity or current contra-indication to any of the combination agents required for the study.
- History of allergic reactions attributed to components of the NUC-3373 drug product formulation.
- History of hypersensitivity to Chinese Hamster Ovary (CHO) cell products or other recombinant human or humanised antibodies.
- History of or known central nervous system or leptomeningeal metastases.
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 |
|---|---|---|
| Fosifloxuridine NafalbenamideAlso: NUC-3373, Nucleotide analogueIntravenous infusion | Drug | NUFIRI-bev on a Q1W NUC-3373 schedule, NUFIRI-bev on a Q2W NUC-3373 schedule |
| LeucovorinAlso: Folinic acid, LVIntravenous infusion | Drug | FOLFIRI-bev on a Q2W schedule, NUFIRI-bev on a Q1W NUC-3373 schedule, NUFIRI-bev on a Q2W NUC-3373 schedule |
| IrinotecanAlso: Campto, CamptosarIntravenous infusion | Drug | FOLFIRI-bev on a Q2W schedule, NUFIRI-bev on a Q1W NUC-3373 schedule, NUFIRI-bev on a Q2W NUC-3373 schedule |
| BevacizumabAlso: Avastin, ZirabevIntravenous infusion | Biological | FOLFIRI-bev on a Q2W schedule, NUFIRI-bev on a Q1W NUC-3373 schedule, NUFIRI-bev on a Q2W NUC-3373 schedule |
| 5-FUAlso: 5FU, 5-fluorouracil, FluorouracilIntravenous infusion | Drug | FOLFIRI-bev on a Q2W schedule |
Primary outcome
Median Progress-free Survival (PFS)
Time frame: Assessed from baseline to 30 days after last dose of study drug, up to 16 months
PFS assessed according to Response Evaluation Criteria in Solid Tumours (RECIST) v1.1, defined as the time from randomisation to the first observation of objective tumour progression or death from any cause. Progression was defined as a 20% increase in the sum of the longest diameter of target lesions, or a measurable increase in non-target lesions, or the appearance of new lesions.
2 secondary outcomes
Number of Patients Achieving a Reduction in Tumour Volume
Time frame: Assessed from baseline to 30 days after last dose of study drug, up to 16 months
Number of Patients Achieving Disease Control
Time frame: Assessed from baseline to 30 days after last dose of study drug, up to 16 months
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 12 Sep 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: No
Related trials for Colorectal Cancer
Not yet recruitingPhase 1
Hepatic Artery Infusion of Carfilzomib in Participants With Liver Metastatic Disease Previously Treated With Hepatic Artery Infusion Pump Therapy
Colorectal Neoplasms, Neoplasms
Active, not recruiting
Streamlined Geriatric and Oncological Evaluation Based On IC Technology
Breast Cancer, Comorbidities and Coexisting Conditions
RecruitingObservational study
Pre- and On-treatment Multi-omics Profiling of Locally Advanced Rectal Cancer
Rectal Neoplasms
Enrolling by invitationObservational study
Natural History Study of Early Life Exposures in Agriculture (ELEA)
Prostate Cancer, Leukemia
RecruitingPhase 2
Tislelizumab in People With Colorectal Cancer
Colorectal Cancer
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. This study is not recruiting at the moment.
Elisabeth Oelmann, MD, PhD study director
NuCana plc
59 sites in 6 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Fosifloxuridine Nafalbenamide, Leucovorin and Irinotecan in people with Colorectal Cancer and Colorectal Neoplasms, run by NuCana plc at 59 sites in 6 countries.
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 17 inclusion and 31 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: stopped early, as of the sponsor's last update on 12 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 59 sites in United States, Spain, France, Italy, United Kingdom and 1 more country. Whether a site is taking part right now should be confirmed with that site. See every site.
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?
Yes. Results are posted in the registry (first posted 12 Sep 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Median Progress-free Survival (PFS) (time frame: Assessed from baseline to 30 days after last dose of study drug, up to 16 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 12 Sep 2025.