ClinicalTrials.gg
Not yet recruitingNCT07779694Updated Sep 8, 2026

16-Hour Fasting Plus Serplulimab and CAPEOX as Neoadjuvant Therapy in pMMR/MSS Advanced Mid-to-Low Rectal Cancer

A Phase 2 interventional study of 16-Hour Fasting and Serplulimab + chemotherapy in pMMR/MSS, Locally Advanced Rectal Carcinoma and Fasting, Intermittent, sponsored by Zhejiang University. Not yet recruiting. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-09-08.

Sponsored by Zhejiang University · Phase 2, Interventional, and Treatment

Phase
Phase 2
Study type
Interventional
Enrollment
51
Allocation
Not applicable
Ages
18 Years to 75 Years
Sex
All
01

Study summary

Although standard neoadjuvant chemoradiotherapy (nCRT) for locally advanced rectal cancer (LARC) effectively reduces local recurrence, radiotherapy-related toxicities and surgical complications severely impair patients' quality of life, making a radiotherapy-free strategy urgently needed. However, chemotherapy alone yields a pathological complete response (pCR) rate of only 6.6%-15%, which is far from satisfactory.

The pMMR/MSS subtype, accounting for 90% of rectal cancers, is "immune-cold" and shows almost no response to PD-1 monotherapy; nonetheless, chemotherapy can reshape the tumor immune microenvironment, and multiple studies have demonstrated that combining chemotherapy with PD-1 inhibitors (without radiotherapy) can elevate pCR rates to 26.8%-42.9%, yet further improvement remains desirable. A recent mechanistic study published in Cell Metabolism (2026) revealed that a single 16-hour fasting episode before treatment promotes isoleucine accumulation in the tumor microenvironment, which enhances CD8+T-cell cytotoxic function and reduces exhaustion through acetyl-CoA metabolism and epigenetic reprogramming, thereby significantly sensitizing PD-1 inhibitors-and this intervention is non-invasive, low-cost, and easily adoptable by patients.

Based on the above evidence, we hypothesize that the neoadjuvant triple-combination regimen of "16-hour fasting + chemotherapy + PD-1 inhibitor" (radiotherapy-free) in pMMR/MSS locally advanced mid-to-low rectal cancer may further increase pCR rates and tumor regression, offering a novel, highly effective, and low-toxicity therapeutic option for LARC patients.

02

Conditions studied

  • pMMR/MSS
  • Locally Advanced Rectal Carcinoma
  • Fasting, Intermittent

Keywords

  • Rectal cancer
  • Serplulimab
  • CAPEOX
  • neoadjuvant therapy
  • 16-hour fasting
03

In context

Intermittent Fasting

333 studies on the registry are indexed under Intermittent Fasting; 99 are open to participants now.

This study's planned enrollment of 51 is close to the median of 50 across 320 interventional studies indexed under Intermittent Fasting.

Browse Intermittent Fasting studies →

Lead sponsor

Zhejiang University is the lead sponsor of 356 studies on the registry; 166 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 75 Years
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  1. Willing and able to provide written .
  2. Male or female subjects ≧ 18 years ≦ 75 of age.
  3. Histological or cytological documentation of adenocarcinoma of the rectum.
  4. No previous any systemic anticancer therapy for rectal cancer disease.
  5. The primary rectal tumor is assessed as likely to be R0 resectable by a multidisciplinary colorectal cancer collaborative team, comprising at least 2 gastrointestinal surgeons and 1 radiologist.
  6. The lower margin of the tumor is less than 10cm from the anus verge.
  7. cT2N1-2M0, cT3N0-2M0, cT4N0-1M0 MSS with MRF(-) assessed by MRI.
  8. Primary tumor can be detected by CT or MRI.
  9. (ECOG) performance status of 0 or 1.
  10. Eligible tumor tissues were identified for MSI/MMR assays.
  11. Surface Antigen (HBsAg) (-).
  12. If HBsAg (+) , HBV-DNA must be less than 2500 copies/mL or 500 IU/mL to be enrolled.
  13. Patients with antibody (-) or HCV-RNA negative can be enrolled. (AST) must be ≤ 3 x for the lab. If HCV-RNA is positive, patients with both alanine aminotransferase (ALT) and aspartate aminotransferase (AST) performed ≤3×ULN could be enrolled. Patients infected with both hepatitis B virus and hepatitis C virus should be excluded (positive for HBsAg or HBcAb and positive for HCV antibodies).

Exclusion criteria

Exclusion Criteria:

  1. Patients with recurrent rectal cancer or a history of pelvic radiotherapy.
  2. Patients with a history of inflammatory bowel disease.
  3. Patients with acquired immunodeficiency syndrome (AIDS-related illnesses) or known (HIV) disease (HIV1 antibody, HIV2 antibody, HTLV1 antibody positive) should be excluded.
  4. Patients who are preparing for or have previously received an organ or bone marrow transplant.
  5. History of myocardial infarction, poorly controlled arrhythmias (including ≥470 ms in women) in the 6 months prior to enrollment (QTc interval calculated by Fridericia formula).
  6. According to New York College of Cardiology () standards for Grade III-IV cardiac insufficiency or cardiac color ultrasound: (LVEF) \<50%.Poor hypertension control (systolic blood pressure ≥150 mmHg and/or diastolic blood pressure ≥100 mmHg), a past hypertensive crisis or hypertensive encephalopathy.
  7. Poor hypertension control (systolic blood pressure ≥150 mmHg and/or diastolic blood pressure ≥100 mmHg), a past hypertensive crisis or hypertensive encephalopathy.
  8. Patients had undergone major surgery within 28 days prior to enrollment. Patients with tumor or lymph node dissection biopsy were admitted. Patients undergoing enterostomy due to intestinal obstruction were admitted.
  9. The patients had previously been treated with other antibodies/drugs that target immune checkpoints, such as , PD-L1, and cytotoxic T lymphocyte-associated Antigen 4 (CTLA-4).
  10. Patients are participating in other clinical studies, or plan to start this study treatment less than 14 days from the end of the previous clinical study.
  11. Uncontrolled tumor-related pain.
  12. A known history of severe allergy to any monoclonal antibody.
  13. Known to be allergic or intolerance to any oxaliplatin and capecitabine ingredients.
  14. Pregnant or lactating women.
  15. The investigators determined that the patient had other factors that might have led to the early termination of the study.
Terms in these criteria, in plain language(12)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

ECOG performance status

A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.

0
Fully active, no restrictions.
1
Limited in strenuous activity, but walking and able to do light work, such as housework or office work.
2
Walking and able to look after yourself, but unable to work; up and about more than half of waking hours.
3
Able to look after yourself only in part; in bed or a chair more than half of waking hours.
4
Unable to look after yourself at all; in bed or a chair all day.

Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.

Hepatitis B tests

Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.

Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.

Hepatitis C tests

Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.

After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.

ALT and AST (liver enzymes)

Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.

Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.

ULN (upper limit of normal)

The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.

“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.

HIV

The human immunodeficiency virus, which weakens the immune system.

Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.

QT and QTc

On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.

The study may name a correction formula and a limit in milliseconds, often around 450–480.

NYHA class (heart failure)

The New York Heart Association’s four classes of how much heart failure limits physical activity.

I
No limits: ordinary activity causes no undue tiredness or breathlessness.
II
Slight limits: comfortable at rest, ordinary activity causes symptoms.
III
Marked limits: comfortable at rest, less than ordinary activity causes symptoms.
IV
Symptoms even at rest; any activity makes them worse.

Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.

LVEF (left ventricular ejection fraction)

The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.

Biopsy and archival tissue

A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.

Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.

PD-1, PD-L1 and checkpoint inhibitors

PD-1, PD-L1 and CTLA-4 are proteins that act as brakes on the immune system. Checkpoint inhibitors, such as pembrolizumab or nivolumab, block them so the immune system can attack a cancer.

PD-L1 can also be measured in a tumour sample. Some scores count stained tumour cells only (TPS); others also count certain immune cells (CPS). The study names the score and the minimum it uses.

05

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
51 participants (estimated)

Study arms

  • Experimental
    16-Hour Fasting + Serplulimab + CAPEOX

    Patients enrolled in the study are required to fast for 16 hours prior to the administration of serplulimab in combination with CAPEOX. Serplulimab: 300 mg, IV, d1, q3w. CAPEOX regimen: Oxaliplatin(130mg/m2) on day 1 of each cycle and Capecitabine, 1000mg/m2, PO, BID, day1-14, q3w. Treatment repeats every 3 weeks for 4 cycles followed by surgery (total mesorectal excision, TME).

    Behavioral: 16-Hour Fasting · Drug: Serplulimab + chemotherapy

Interventions

  • Behavioral16-Hour Fasting

    Patients begin fasting at 20:00 on the day prior to immunotherapy (only plain water is allowed) and continue until 10:00 the next morning, when serplulimab is administered. Fasting is maintained until 12:00 noon, after which normal diet may be resumed.

  • DrugSerplulimab + chemotherapy

    Drug page: Serplulimab

    Serplulimab is an innovative monoclonal antibody targeting PD-1, developed by Shanghai Henlius Biotech, Inc. 300 mg, IV, d1, q3w. CAPEOX regimen: Oxaliplatin(130mg/m2) on day 1 of each cycle and Capecitabine, 1000mg/m2, PO, BID, day1-14, q3w. 4 cycles

06

What researchers measure

Primary outcomes

  1. Pathological complete response rates

    Proportion of participants achieving pathological complete response (pCR) after neoadjuvant therapy.

    Time frame: 10 days after surgery

Secondary outcomes

  1. Rate of clinical complete response rate(cCR)

    Proportion of participants achieving clinical complete response (cCR) after neoadjuvant therapy.

    Time frame: 1 year

  2. R0 resection rates

    Proportion of patients achieved a complete resection with negative margin

    Time frame: 10 days after surgery

  3. Disease Free Survival

    Defined as the interval from enrollment to locoregional or metastatic recurrence or the appearance or a secondary colorectal cancer or death, whichever occurs first

    Time frame: 3 years

  4. Event free survival

    Defined as the time from enrollment to the first occurrence of any of the following events: tumor disease progression on imaging as assessed by RECIST 1.1; tumor recurrence, including local recurrence or distant recurrence, as assessed on imaging or tissue biopsy transfer; death from any cause.

    Time frame: 3 years

  5. Overall survival (OS)

    Defined as the time between the date of enrollment and death from any cause.

    Time frame: 3 years

  6. Treatment-related adverse events

    Assessed by evaluation of treatment-related adverse events.

    Time frame: 1 year

  7. Single-Cell RNA Sequencing (scRNA-seq) of Tumor Microenvironment

    Use single cell sequence to describe changes in the microenvironment of rectal cancer before and after treatment.

    Time frame: 1 year

  8. Spatial Transcriptomics Profiling of Tumor and Stroma

    Explore spatial organization of gene expression within the tumor microenvironment and its association with treatment response using spatial transcriptomics.

    Time frame: 1 year

07

Study locations

No study locations are listed for this record.

08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Sep 8, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT07779694
Responsible party
Ding Ke-Feng (Professor, Zhejiang University) — Principal investigator
First posted
Aug 21, 2026
Start date
Oct 1, 2026 (estimated)
Primary completion
Dec 31, 2028 (estimated)
Completion
Dec 31, 2029 (estimated)
Last update
Sep 8, 2026

Study contacts

feng Ke Ding
Contact
dingkefeng@zju.edu.cn
+86 13588425440

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is not yet recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.

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Studies of the drug tested here: Serplulimab

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