A Phase 1/2 interventional study of Serine/Glycine-Restricted Diet and CAPOX Chemotherapy in Locally Advanced Rectal Cancer (LARC), sponsored by Xuelei Ma MD. Not yet recruiting at 1 site in China. Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-09-09.
Sponsored by Xuelei Ma MD · Phase 1/2, Interventional, and Treatment
This is a Phase Ib/II seamless, open-label, randomized controlled trial evaluating the safety and efficacy of a serine/glycine-restricted diet combined with neoadjuvant chemoradiotherapy and immunotherapy in patients with locally advanced rectal cancer (LARC).
The study consists of two phases. Phase Ib is a non-randomized, single-arm safety run-in phase enrolling 6 patients, all of whom will receive the experimental regimen (serine/glycine-restricted diet plus CAPOX chemotherapy, PD-1 inhibitor, and short-course radiotherapy). The primary objective of Phase Ib is to assess safety, tolerability, and dietary compliance. If the safety criteria are met (≥3 grade diet-related adverse event rate ≤20% and compliance rate ≥70%), the study will proceed to Phase II.
Phase II is a randomized, open-label, parallel-controlled phase in which 134 additional patients will be randomized in a 1:1 ratio to either the experimental group (serine/glycine-restricted diet plus standard neoadjuvant chemoradiotherapy and immunotherapy) or the control group (standard neoadjuvant chemoradiotherapy and immunotherapy alone). The total enrollment is 140 patients (6 in Phase Ib + 134 in Phase II).
The primary endpoint is the complete response rate (pCR + cCR). Secondary endpoints include major pathological response (MPR) rate, R0 resection rate, mrTRG regression grade, event-free survival (EFS), progression-free survival (PFS), overall survival (OS), adverse event profile, changes in serum amino acid levels, quality of life (EORTC QLQ-C30), and nutritional status. Exploratory endpoints include gut microbiome diversity and tumor immune microenvironment changes.
2,400 studies on the registry are indexed under Rectal Neoplasms; 587 are open to participants now.
This study's planned enrollment of 140 is above the median of 65 across 1,751 interventional studies indexed under Rectal Neoplasms.
Browse Rectal Neoplasms studies →Xuelei Ma MD is the lead sponsor of 4 studies on the registry; 4 are open to participants now.
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≥ 1.5×10⁹/L (without G-CSF support within 14 days); count ≥ 100×10⁹/L; ≥ 9 g/dL (without transfusion or erythropoietin use within 7 days); Serum albumin ≥ 3.0 g/dL; Total ≤ 1.5× ; and ALT ≤ 2.5× ULN; ≥ 50 mL/min (Cockcroft-Gault formula) or serum creatinine ≤ 1.5× ULN; ≤ 1.5× ULN, PT and APTT ≤ 1.5× ULN; Urine protein \< 2+ (if ≥2+, 24-hour urine protein \< 2.0 g required for enrollment); Cardiac enzymes within normal range (isolated laboratory abnormalities without clinical significance permitted).
Exclusion Criteria:
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.
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.
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
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.
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.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
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.
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.
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
The US National Cancer Institute’s scale of how severe an adverse event is — any unwanted medical event during a study, such as a symptom, an illness or an abnormal test result, whether or not a treatment caused it. Whether it did is judged separately.
“Side effects of earlier treatment resolved to grade 1 or less” means they have settled to mild or gone.
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
A “mini-stroke”: temporary stroke-like symptoms caused by reduced blood flow to part of the brain, spinal cord or eye, without signs of a new stroke on a scan.
Stroke symptoms need emergency care at once, even if they go away.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
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.
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.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Histologically or cytologically confirmed
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Absolute neutrophil count (ANC)
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Creatinine clearance (CrCl)
How quickly the kidneys clear creatinine, a waste product, from the blood. A study may estimate it from a blood test with age, weight and sex (often by the Cockcroft–Gault formula), or measure it using blood and urine collected over a set time. Given in mL/min; higher is better.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
INR, PT and aPTT (clotting tests)
Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.
Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
CTCAE grade
The US National Cancer Institute’s scale of how severe an adverse event is — any unwanted medical event during a study, such as a symptom, an illness or an abnormal test result, whether or not a treatment caused it. Whether it did is judged separately.
“Side effects of earlier treatment resolved to grade 1 or less” means they have settled to mild or gone.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Excipients
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
TIA (transient ischaemic attack)
A “mini-stroke”: temporary stroke-like symptoms caused by reduced blood flow to part of the brain, spinal cord or eye, without signs of a new stroke on a scan.
Stroke symptoms need emergency care at once, even if they go away.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Dietary Supplement: Serine/Glycine-Restricted Diet · Drug: CAPOX Chemotherapy · Drug: PD-1 Inhibitor · Radiation: Short-Course Radiotherapy
Drug: CAPOX Chemotherapy · Drug: PD-1 Inhibitor · Radiation: Short-Course Radiotherapy
A specialized liquid nutritional powder free of serine and glycine, supplemented with a list of permitted low-serine/glycine foods. Patients receive 30 kcal/kg/day energy and 1.5 g/kg/day protein for 4 weeks during the neoadjuvant treatment period.
Drug pages: Capecitabine · Oxaliplatin
Oxaliplatin 130 mg/m² IV on day 1 of each 3-week cycle, plus capecitabine 1000 mg/m² orally twice daily on days 1-14 of each cycle, for a total of 6 cycles.
PD-1 inhibitor administered intravenously every 3 weeks in combination with CAPOX chemotherapy as part of the neoadjuvant regimen.
25 Gy delivered in 5 fractions (5 Gy/fraction) over 1 week, administered during the second week of Cycle 1 (C2, Week 1), concurrent with capecitabine.
Complete Response Rate (pCR + cCR)
Time frame: At the time of surgery, approximately 6-8 weeks after completion of all 6 cycles of neoadjuvant chemoradiotherapy and immunotherapy
Major Pathological Response (MPR) Rate
Time frame: At the time of radical surgery, approximately 24 weeks after initiation of neoadjuvant treatment.
R0 Resection Rate
Time frame: At the time of radical surgery, approximately 24 weeks after initiation of neoadjuvant treatment.
mrTRG Regression Grade
Time frame: Up to approximately 24 weeks after initiation of neoadjuvant treatment (at the time of pre-surgery imaging assessment).
Event-Free Survival (EFS)
Time frame: Up to 5 years after randomization.
Progression-Free Survival (PFS)
Time frame: Up to 5 years after randomization.
Overall Survival (OS)
Time frame: Up to 5 years after randomization.
Incidence of Adverse Events
Time frame: From the start of study treatment through 30 days after the last dose of study treatment (approximately up to 22 weeks for the active treatment phase).
Changes in Serum Amino Acid Levels
Time frame: Baseline and at cycles 1, 2, and 3 (weeks 3, 6, and 9) during the intervention phase.
Quality of Life (EORTC QLQ-C30)
Time frame: Baseline, at cycles 1, 2, 3, 4, 5, 6 (weeks 3, 6, 9, 12, 15, 18), and at 30-day safety follow-up.
Nutritional Status
Time frame: Baseline, at cycles 1, 2, and 3 (weeks 3, 6, and 9), and at surgery.
Change in Gut Microbiome Diversity as Assessed by Metagenomic Sequencing
Time frame: Baseline and at the end of the dietary intervention period (week 4).
Changes in Tumor-Infiltrating CD8⁺ T Cell Density and PD-L1 Expression as Assessed by Multiplex Immunohistochemistry
Time frame: At the time of radical surgery, approximately 24 weeks after initiation of neoadjuvant treatment.
Plan to share: Undecided
No publications or documents are linked to this record.
Start is estimated for Aug 2026; primary completion for Jan 2027, 5 months later.
Of 37 phase 1/2 interventional studies under Rectal Neoplasms, half reached primary completion within 75 months of starting (the median), counting those still running; a quarter within 36 and three quarters within 106. This study's planned 5 months is below that.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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Xuelei Ma MD