Rectum Cancer, AdenocarcinomaPhase 1ARBORNCT07221058
Adaptive Radiation Boost for Rectal Cancer
A Phase 1 study testing Adaptive Radiotherapy Boost in people with Rectum Cancer, Adenocarcinoma, run by Fox Chase Cancer Center at 1 site in United States.
Trial summary
The goal of this clinical trial is to find out if giving extra adaptive radiation therapy after standard chemoradiation treatment is safe and helpful for people with rectal cancer. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Rectum Cancer, Adenocarcinoma
- What is being tested?
- Adaptive Radiotherapy Boost
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 37 participants
- Where
- 1 siteUnited States
- Study dates
- 24 Oct 2025to 1 Nov 2029
- Phase
- Phase 1
- 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
- Subjects must have histologically or cytologically confirmed rectal adenocarcinoma.
- Subjects must have T2-3, N0-1, M0 rectal cancer. Staging will be done by MRI pelvis and CT chest and abdomen with contrast. PET-CT will be an acceptable alternative for the CT chest and abdomen.
- Subjects must be willing to undergo MRI scans.
- Age ≥18 years.
- ECOG performance status 0 or 1.
- Estimated survival of ≥ 12 months.
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- Subjects must have normal organ and marrow function as defined below
- Absolute neutrophil count > =1,000/mcL
- Platelets >= 75,000/mcL
- Total bilirubin < 3 mg/dL
- Subjects must be able to tolerate the chemotherapy regimens outlined in the treatment plan (Section 5.0), both before and after ART.
- Before ART: Capecitabine at a dose of 825 mg/m²
- After ART: FOLFOX combination chemotherapy, or 5-FU, or capecitabine
- Subjects must possess the ability to understand and willingness to sign a written informed consent and HIPAA consent document. Translation services including translation of informed consent documents will be provided, as feasible, to encourage diversity of inclusion of eligible patients.
Who cannot join
- Subjects who have been previously treated for rectal cancer are excluded.
- Subjects with rectal cancer involving the anal canal are excluded. (Rectal cancer abutting the anal canal will be allowed.)
- Subjects must not be receiving any other investigational agents.
- Subjects may not have had prior pelvic radiation.
- Subjects should not have had a cancer actively treated within the last 3 years, excluding non-melanoma skin cancer.
- Subjects must not have uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements.
- Any condition or significant co-morbidity that prevents safe delivery of ART per the discretion of the treating physician(s).
- Subjects must not be pregnant or breast-feeding.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Fox Chase Cancer Center
Philadelphia, Pennsylvania, 19111
Joshua Meyer, MD, 267-449-1431, Joshua.Meyer@fccc.edu
Jianli Hu, MD, PhD, 2674491431, Jianli.Hu@fccc.edu
About this study
Official title: Adaptive Radiation BOost for Rectal Cancer: a Phase I Dose Escalation Study (ARBOR)
The goal of this clinical trial is to find out if giving extra adaptive radiation therapy after standard chemoradiation treatment is safe and helpful for people with rectal cancer.
The main questions the study aims to answer are:
Read more
- Can this approach help target the most aggressive cancer cells more accurately, while protecting nearby healthy tissue?
- Can it reduce the side effects that people may experience during treatment?
Participants will:
- First receive standard treatment: radiation (45 Gy in 25 sessions) along with a chemotherapy pill called capecitabine.
- Then get extra radiation using MRI scans every two weeks to adjust the treatment based on how the tumor responds.
- Use a small balloon during treatment to help aim the radiation and protect healthy areas.
- Finally, receive additional chemotherapy (such as FOLFOX) for four months.
- Conditions
- Rectum Cancer, Adenocarcinoma
- Being tested
- Adaptive Radiotherapy Boost
- Keywords
- Adaptive Radiation Therapy, Rectum Cancer, Adenocarcinoma, Organ Preservation, Total Mesorectal Excision
- Medical subject headings
- Rectal Neoplasms, Adenocarcinoma
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Adaptive Radiotherapy BoostRadiation
Patients will receive one boost fraction every two weeks, targeting the primary tumor within the rectum plus a 2 mm Planning Target Volume (PTV) margin. Any regional lymph nodes that measure at least 5 mm in short axis on the day of treatment will receive treatment with the ART dose being given to the primary rectal tumor.
| Study group | Role | What they receive |
|---|---|---|
| Adaptive Radiotherapy Boost Following Standard Pelvic Chemoradiation | Experimental | Adaptive Radiotherapy Receives: Radiation: Adaptive Radiotherapy Boost |
What is being measured
The primary outcome is the main question the study is designed to answer.
MTD will be evaluated by monitoring the rate of dose limiting toxicities (DLTs) defined as acute Grade 2+ gastrointestinal toxicity probably or definitely related to radiation.
Measured: From the initiation of rectal adaptive radiotherapy boost to 90 days after the last dose of boost, for a total of ~ 120 days.
Feasibility of a rectal boost that targets at least 90% of the rectal planning tumor volume with the 80% prescribed dose while limiting the outer 3 mm of the rectal wall to no more than 50% of the prescription dose delivered to 0.1cc.
Feasibility will be determined based on successful implementation and completion of standard chemoradiotherapy followed by experimental rectal adaptive radiotherapy boost utilizing CT-MR fusion that targets at least 90% of the rectal PTV_Eval with the 80% prescribed dose while limiting the outer 3 mm of the rectal wall to no more than 50% of the prescription dose delivered to 0.1cc in ≥ 70% of ART fractions for the patient population enrolled in the study. This will be assessed at the MTD.
Measured: From the ART boost initiation to the end of the ART boost, for a period of ~ 5 weeks
Secondary outcomes (4)
Estimate the efficacy of bi-weekly adaptive radiotherapy boost fractions by complete response rate, near complete response rate, and incomplete response rate as per Memorial Sloan Kettering Cancer Center (MSKCC) criteria.
Measured: From the end of rectal adaptive radiotherapy boost to the end of study, for a total of ~ 5 years.
Estimate total mesorectal excision (TME) free survival following treatment with the study regimen.
Measured: From the end of treatment to the end of the study, for a total of up to 5 years.
Estimate overall survival (OS) following treatment with the study regimen.
Measured: From the end of treatment to the end of study, for a total of up to 5 years.
Estimate early and late toxicity following treatment with the study regimen.
Measured: From the initiation of rectal radiation boost treatment to the end of the study, for a total of ~ 5 years.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Oct 2025
- Study start24 Oct 2025
- Primary completion1 Nov 2028 (estimated)
- Study completion1 Nov 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Rectum Cancer, AdenocarcinomaStudies 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 1
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 37 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Fox Chase Cancer Center
- Sponsor type
- University, hospital or other
- Collaborators
- Varian Medical Systems
- Responsible party
- Sponsor
- Investigators
- Joshua Meyer, Principal investigator, Fox Chase Cancer Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07221058
- Sponsor's protocol ID
- RT-231
- Other IDs
- 25-1024
- Acronym
- ARBOR
- Status last verified
- Dec 2025
- First submitted
- 22 Oct 2025
- Last updated
- 9 Dec 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 9 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Adaptive Radiation BOost for Rectal Cancer: a Phase I Dose Escalation Study (ARBOR)
- ClinicalTrials.gov ID
- NCT07221058
- Acronym / sponsor ID
- ARBOR / RT-231
- Conditions
- Rectum Cancer, Adenocarcinoma
- Keywords
- Adaptive Radiation Therapy, Rectum Cancer, Adenocarcinoma, Organ Preservation, Total Mesorectal Excision
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 37 participants (estimated)
- Lead sponsor
- Fox Chase Cancer CenterUniversity, hospital or other
- Collaborators
- Varian Medical Systems
- Study start
- 24 Oct 2025 (actual)
- Primary completion
- 1 Nov 2028 (estimated)
- Study completion
- 1 Nov 2029 (estimated)
- First posted
- 27 Oct 2025 (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 find out if giving extra adaptive radiation therapy after standard chemoradiation treatment is safe and helpful for people with rectal cancer.
The main questions the study aims to answer are:
- Can this approach help target the most aggressive cancer cells more accurately, while protecting nearby healthy tissue?
- Can it reduce the side effects that people may experience during treatment?
Participants will:
- First receive standard treatment: radiation (45 Gy in 25 sessions) along with a chemotherapy pill called capecitabine.
- Then get extra radiation using MRI scans every two weeks to adjust the treatment based on how the tumor responds.
- Use a small balloon during treatment to help aim the radiation and protect healthy areas.
- Finally, receive additional chemotherapy (such as FOLFOX) for four months.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Adaptive Radiotherapy Boost Following Standard Pelvic Chemoradiation | Experimental | Radiation: Adaptive Radiotherapy BoostAdaptive Radiotherapy |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (14 listed)
- Subjects must have histologically or cytologically confirmed rectal adenocarcinoma.
- Subjects must have T2-3, N0-1, M0 rectal cancer. Staging will be done by MRI pelvis and CT chest and abdomen with contrast. PET-CT will be an acceptable alternative for the CT chest and abdomen.
- Subjects must be willing to undergo MRI scans.
- Age ≥18 years.
- ECOG performance status 0 or 1.
Key exclusion criteria (8 listed)
- Subjects who have been previously treated for rectal cancer are excluded.
- Subjects with rectal cancer involving the anal canal are excluded. (Rectal cancer abutting the anal canal will be allowed.)
- Subjects must not be receiving any other investigational agents.
- Subjects may not have had prior pelvic radiation.
- Subjects should not have had a cancer actively treated within the last 3 years, excluding non-melanoma skin cancer.
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 |
|---|---|---|
| Adaptive Radiotherapy BoostPatients will receive one boost fraction every two weeks, targeting the primary tumor within the rectum plus a 2 mm Planning Target Volume (PTV) margin. Any regional lymph nodes that measure at least 5 mm in short axis on the day of treatment will receive treatment with the ART dose being given to the primary rectal tumor. | Radiation | Adaptive Radiotherapy Boost Following Standard Pelvic Chemoradiation |
Primary outcome
MTD will be evaluated by monitoring the rate of dose limiting toxicities (DLTs) defined as acute Grade 2+ gastrointestinal toxicity probably or definitely related to radiation.
Time frame: From the initiation of rectal adaptive radiotherapy boost to 90 days after the last dose of boost, for a total of ~ 120 days.
Feasibility of a rectal boost that targets at least 90% of the rectal planning tumor volume with the 80% prescribed dose while limiting the outer 3 mm of the rectal wall to no more than 50% of the prescription dose delivered to 0.1cc.
Time frame: From the ART boost initiation to the end of the ART boost, for a period of ~ 5 weeks
Feasibility will be determined based on successful implementation and completion of standard chemoradiotherapy followed by experimental rectal adaptive radiotherapy boost utilizing CT-MR fusion that targets at least 90% of the rectal PTV_Eval with the 80% prescribed dose while limiting the outer 3 mm of the rectal wall to no more than 50% of the prescription dose delivered to 0.1cc in ≥ 70% of ART fractions for the patient population enrolled in the study. This will be assessed at the MTD.
4 secondary outcomes
Estimate the efficacy of bi-weekly adaptive radiotherapy boost fractions by complete response rate, near complete response rate, and incomplete response rate as per Memorial Sloan Kettering Cancer Center (MSKCC) criteria.
Time frame: From the end of rectal adaptive radiotherapy boost to the end of study, for a total of ~ 5 years.
Estimate total mesorectal excision (TME) free survival following treatment with the study regimen.
Time frame: From the end of treatment to the end of the study, for a total of up to 5 years.
Estimate overall survival (OS) following treatment with the study regimen.
Time frame: From the end of treatment to the end of study, for a total of up to 5 years.
Estimate early and late toxicity following treatment with the study regimen.
Time frame: From the initiation of rectal radiation boost treatment to the end of the study, for a total of ~ 5 years.
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 9 Dec 2025.
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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.
Joshua Meyer principal investigator
Fox Chase Cancer Center
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Adaptive Radiotherapy Boost in people with Rectum Cancer, Adenocarcinoma, run by Fox Chase Cancer Center at 1 site in United States.
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 14 inclusion and 8 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: looking for participants now, as of the sponsor's last update on 9 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. 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 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
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 Joshua Meyer, MD (215-728-2667, Joshua.Meyer@fccc.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
MTD will be evaluated by monitoring the rate of dose limiting toxicities (DLTs) defined as acute Grade 2+ gastrointestinal toxicity probably or definitely related to radiation. (time frame: From the initiation of rectal adaptive radiotherapy boost to 90 days after the last dose of boost, for a total of ~ 120 days.). The study lists 2 primary outcomes in all. 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 9 Dec 2025.