Locally Advanced Rectal AdenocarcinomaPhase 2SIB-NCRTNCT07200141

Simultaneous Boost in Neoadjuvant Radiotherapy for Rectal Cancer

A Phase 2 study testing GTV 58.75 Gy/25 fractions(Simultaneous Integrated Boost), GTV 50 Gy/25 fractions(Simultaneous Integrated Boost) and Concurrent Chemotherapy in people with Locally Advanced Rectal Adenocarcinoma, run by Peking Union Medical College Hospital at 1 site in China.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts

Official record

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Trial summary

The goal of this clinical trial is to learn whether new adjuvant radiotherapy with gross tumor volume(GTV) escalated to 58.75 Gy can improve complete response (CR) rates compared with GTV dose of 50 Gy in adult patients (18-79 years) with locally advanced rectal adenocarcinoma (T3-T4/N+, M0) located ≤10 cm from the… Read more about this study

Who is it for?: Ages 18 to 80 years
Conditions the study is for: Locally Advanced Rectal Adenocarcinoma
What is being tested?: GTV 58.75 Gy/25 fractions(Simultaneous Integrated Boost), GTV 50 Gy/25 fractions(Simultaneous Integrated Boost) and Concurrent Chemotherapy
Type of treatment: Surgery or procedure
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 156 participants
Where: 1 siteChina
Study dates: 1 Oct 2025to 1 Dec 2028
Phase: Phase 2

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 to 80 years
All sexes
No healthy volunteers
Adult, Older adult

Who may be able to join

Age ≥18 and <80 years
Histologically confirmed rectal adenocarcinoma
Tumor located within 10 cm from the anal verge
MRI staging: T3-T4 and/or N+, M0 (AJCC 8th edition)
ECOG performance status 0-2
Adequate bone marrow function: WBC ≥3×10⁹/L, ANC ≥1.5×10⁹/L, PLT ≥100×10⁹/L, Hb ≥90 g/L

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Adequate liver function: TBIL ≤1.5 × ULN, ALT/AST ≤2.5 × ULN
Adequate renal function: Cr ≤1.5 × ULN or CCr ≥60 mL/min
Signed informed consent

Who cannot join

Prior rectal cancer surgery
Prior induction chemotherapy, immunotherapy, or pelvic radiotherapy
History of other malignancies
History of chronic colitis, ulcerative colitis, or nonspecific proctitis
Pregnant or breastfeeding women
Active infection or fever
Severe uncontrolled comorbidities (e.g., unstable heart disease, renal disease, chronic hepatitis, uncontrolled diabetes, psychiatric disorders)
Inability to comply with study protocol

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

ke hu contact

86-010-69155482

huke8000@126.com

China1 site, 1 recruiting

Peking Union Medical College Hospital
Beijing
ke hu, huke8000@126.com
Recruiting

Other trials in China

About this study

Official title: Simultaneous Boost in Neoadjuvant Radiotherapy for Rectal Cancer：A Phase 2, Randomized Controlled Study

Does GTV simultaneously boost to 58.75 Gy/25f increase complete response (pCR or cCR) compared with 50 Gy/25f?
How do the two regimens differ in terms of progression-free survival (PFS), pelvic local control (LC), tumor regression grade (TRG), organ preservation, and treatment-related toxicity? Researchers will compare GTV 58.75 Gy/25f (experimental arm) versus GTV 50 Gy/25f (control arm) to see if dose escalation improves tumor response rate.

Participants will:

Receive neoadjuvant radiotherapy with one of the two PGTV dose escalated regimens (with concurrent chemotherapy: oral capecitabine or XELOX).
Undergo restaging with imaging and clinical assessment before surgery or observation.
Proceed to total mesorectal excision (TME), local excision, or "watch-and-wait" strategy depending on treatment response and patient preference.
Be followed regularly with clinical exams, imaging, endoscopy, and laboratory tests to assess efficacy, safety, and long-term outcomes.

Read the detailed description

This study is a randomized controlled trial designed to evaluate the clinical efficacy and safety of simultaneous integrated boost (SIB) dose escalation in the neoadjuvant treatment of locally advanced rectal cancer (LARC).Standard neoadjuvant chemoradiotherapy (nCRT) typically utilizes a dose of 50 Gy to the gross tumor volume (GTV). This trial investigates whether escalating the radiation dose specifically to the GTV to 58.75 Gy, delivered in 25 fractions, can significantly enhance tumor downstaging and increase the rates of pathologic complete response (pCR) or sustained clinical complete response (cCR).Study Arms and Radiation Technique:Participants are randomized into two arms. Both arms receive intensity-modulated radiation therapy (IMRT) or volumetric-modulated arc therapy (VMAT) with concurrent fluoropyrimidine-based chemotherapy.Experimental Arm: The planned target volume of the GTV (PGTV) receives a total dose of 58.75 Gy in 25 fractions ($2.35 \text{ Gy/fraction}$), while the elective lymphatic drainage areas (PTV) receive 45-50 Gy.Control Arm: The PGTV receives a total dose of 50 Gy in 25 fractions ($2.0 \text{ Gy/fraction}$), consistent with standard-of-care protocols.Clinical Workflow:Following the completion of neoadjuvant therapy, patients will undergo a mandatory restaging assessment 6-12 weeks post-radiation. This evaluation includes digital rectal examination (DRE), pelvic multiparametric MRI (mpMRI), and endoscopy.Surgical Intervention and Organ Preservation:Patients achieving a cCR may be offered a "Watch-and-Wait" (W\&W) strategy with intensive surveillance, aiming for organ preservation.Patients with a good but incomplete response may undergo local excision (LE) or total mesorectal excision (TME).The primary endpoint is the combined complete response (CR) rate, defined as pCR for those undergoing surgery and cCR (sustained for at least 6 months) for those entering the W\&W protocol.Secondary Objectives:The study will also perform a comparative analysis of progression-free survival (PFS), local control (LC) rates, and the distribution of Tumor Regression Grade (TRG). Safety profiles will be rigorously monitored using the Common Terminology Criteria for Adverse Events (CTCAE), focusing on acute and late gastrointestinal and genitourinary toxicities.

Conditions: Locally Advanced Rectal Adenocarcinoma
Being tested: GTV 58.75 Gy/25 fractions(Simultaneous Integrated Boost), GTV 50 Gy/25 fractions(Simultaneous Integrated Boost), Concurrent Chemotherapy, Total mesorectal excision (TME) surgery or non-operative management
Keywords: locally advanced rectal cancer, Neoadjuvant Chemoradiotherapy, Dose Escalation, Simultaneous Integrated Boost

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

GTV 58.75 Gy/25 fractions(Simultaneous Integrated Boost)Radiation
Patients will receive neoadjuvant long course radiotherapy using VMAT or IMAT with daily image guided.
Gross tumor volume (GTV): A total dose of 58.75Gy delivered in 25 fractions using a simultaneous integrated boost approach; CTV: 45Gy/25f; Mesorectum lymph node(GTVnd1):58.75Gy/25f ; Lateral lymph node（GTVnd2）：60Gy/25f;
GTV 50 Gy/25 fractions(Simultaneous Integrated Boost)Radiation
Patients will receive neoadjuvant radiotherapy with GTV 50 Gy in 25 fractions , delivered with IMRT or VMAT technique.
CTV: 45Gy/25f; Mesorectum lymph node(GTVnd1):58.75Gy/25f; Lateral lymph node（GTVnd2）
Concurrent ChemotherapyDrug
Concurrent administration of capecitabine (825 mg/m² twice daily, 5 days per week) or XELOX regimen during radiotherapy.
Total mesorectal excision (TME) surgery or non-operative managementProcedure or surgery
After treatment, patients will undergo restaging and proceed to total mesorectal excision (TME) or non-operative management ("watch-and-wait") depending on response and clinical assessment.

Study groups in NCT07200141
Study group	Role	What they receive
Experimental Arm (GTV 58.75 Gy/25f)	Experimental	Radiotherapy: long course simultaneous integrated boost radiotherapy * Gross tumor volume (GTV): A total dose of 58.75Gy delivered in 25 fractions using a simultaneous integrated boost approach. * CTV: 45Gy/25f * Mesorectum lymph node(GTVnd1):58.75Gy/25f * Lateral lymph node（GTVnd2）：60Gy/25f Concurrent Chemotherapy: Concurrent administration of capecitabine (825 mg/m² twice daily, 5 days per week) or XELOX regimen during radiotherapy After treatment, patients will undergo restaging and proceed to total mesorectal excision (TME) or non-operative management ("watch-and-wait") depending on response and clinical assessment. Receives: Radiation: GTV 58.75 Gy/25 fractions(Simultaneous Integrated Boost); Drug: Concurrent Chemotherapy; Procedure: Total mesorectal excision (TME) surgery or non-operative management
Control Arm (PGTV 50 Gy/25f)	Active comparator	Radiotherapy: long course simultaneous integrated boost radiotherapy Gross tumor volume (GTV): A total dose of 50Gy delivered in 25 fractions using a simultaneous integrated boost approach. CTV: 45Gy/25f Mesorectum lymph node(GTVnd1):58.75Gy/25f Lateral lymph node（GTVnd2）：60Gy/25f Concurrent Chemotherapy: Concurrent administration of capecitabine (825 mg/m² twice daily, 5 days per week) or XELOX regimen during radiotherapy After treatment, patients will undergo restaging and proceed to total mesorectal excision (TME) or non-operative management ("watch-and-wait") depending on response and clinical assessment. Receives: Radiation: GTV 50 Gy/25 fractions(Simultaneous Integrated Boost); Drug: Concurrent Chemotherapy; Procedure: Total mesorectal excision (TME) surgery or non-operative management

What is being measured

The primary outcome is the main question the study is designed to answer.

CR
primary tumor achieved pathological complete response or clinical complete response.
Measured: 1 year

Secondary outcomes (5)

3-year disease free suvival rate
The proportion of patients from the initiation of surgery to tumor recurrence or death within 3 years
Measured: 3 years
3-year local control rate
The proportion of patients absence of pelvic tumor progression, including primary tumor regrowth or regional lymph node progression, within 3 years after randomization.
Measured: 3 years
Tumor Regression Grade
Pathological tumor regression grade (TRG) according to CAP criteria.
Measured: 1 year
Number of participants with treatment-related adverse events as assessed by CTCAE v5.0
Acute and late adverse events will be graded according to Common Terminology Criteria for Adverse Events (CTCAE) version 5.0.
Measured: 3 years
Organ Preservation Rate
The proportion of patients who retain anal sphincter function without permanent stoma, including watch-and-wait, Dixon procedure or sphincter-preserving resection.
Measured: 1 year

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

1 Oct 20251 Dec 2028

First posted30 Sep 2025
Study start1 Oct 2025
Primary completion1 Dec 2026 (estimated)
Study completion1 Dec 2028 (estimated)

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Other trials for Locally Advanced Rectal AdenocarcinomaStudies of the same condition, open and under way.
More trials run by Peking Union Medical College HospitalThe sponsor's other registered studies.
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: Triple blind
Who is masked: Participant, Investigator, Outcomes assessor
Enrolment: 156 participants (estimated)

IDs, dates and publications

ClinicalTrials.gov ID: NCT07200141
Sponsor's protocol ID: I-25PJ2066
Acronym: SIB-NCRT
Status last verified: Sep 2025
First submitted: 22 Sep 2025
Last updated: 21 Sep 2026
Results posted: No
Data monitoring committee: Yes
FDA-regulated drug: No
FDA-regulated device: No

Interested in taking part?

ke hu

86-010-69155482

huke8000@126.com

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See sites and contacts

Active, not recruitingPhase 2
Testing Nivolumab and Ipilimumab With Short-Course Radiation in Locally Advanced Rectal Cancer
Locally Advanced Rectal Adenocarcinoma, Stage II Rectal Cancer AJCC v8
Active, not recruitingPhase 2/3
Testing the Addition of an Anti-Cancer Drug, Irinotecan, to the Standard Chemotherapy Treatment (FOLFOX) After Long-Course Radiation Therapy for Advanced-Stage Rectal Cancers to Improve the Rate of Complete Response and Long-Term Rates of Organ Preservation and Continuing Response
Stage II Rectal Cancer AJCC v8, Stage III Rectal Cancer AJCC v8
Active, not recruitingObservational study
Circulating Tumor Cells in Patients With Locally Advanced Rectal Cancer
Locally Advanced Rectal Adenocarcinoma, Metastatic Rectal Adenocarcinoma
RecruitingPhase 2
Single-arm, Phase II Clinical Study Evaluating the Safety and Efficacy of Sintilimab Combined With IBI-310 and Chemotherapy as Neoadjuvant Therapy for Locally Advanced Rectal Cancer
MSI-H/dMMR Locally Advanced Rectal Adenocarcinoma
Not yet recruitingPhase 2
ctDNA-Informed Management of Early-Stage Rectal Cancer
Rectal Adenocarcinoma, Rectal Cancer

All Locally Advanced Rectal Adenocarcinoma trials