for people ages 18 years and up (full criteria)
at Orange, California and other locations
study started
completion around
Principal Investigator
by May Cho, M.D.



The purpose of this research study is to evaluate epacadostat when given with routine radiation therapy and chemotherapy (capecitabine and oxaliplatin) to treat rectal cancer before routine surgery is performed to remove the tumor.

The Phase II portion of the trial has not started recruiting.

Official Title

Phase I/II Study of Epacadostat (INCB024360) Added to Preoperative Chemoradiation in Patients With Locally Advanced Rectal Cancer


Based on preclinical data from Ciorba Lab (WUSM) the investigators hypothesize that "SCRT is a foundational regimen to examine adjunctive immunotherapy in LARC and that inhibition of IDO1 mediated tryptophan metabolism will safely improve anti-tumor immunity and therapeutic response to SCRT based therapy." In this multi-center phase II clinical trial, first 20 patients will be randomized to either Treatment Cohort or Biomarker Cohort. Patients on Biomarker Cohort will undergo standard SCRT and CAPOX chemotherapy, and provide research biopsies before and after SCRT, and at the time of surgery. Patients on Treatment Cohort will receive epacadostat 400mg twice daily, along with standard SCRT and CAPOX chemotherapy. After the first 20 patients, additional patients will be enrolled to Treatment Cohort until 27 patients who are evaluable for the primary endpoint are enrolled. Patients will be assessed for clinical outcomes including response to therapy as measured by neoadjuvant rectal score (NAR score), local and distant control of their disease, toxicities and survival. Up to 37 evaluable patients (27 patients in treatment cohort and 10 patients in biomarker cohort) of any gender, race, or ethnicity with locally advanced rectal cancer will be included in this clinical trial. Tumor and blood samples will be collected for analyses to determine factors that underlie treatment response or resistance.


Rectal Cancer, Immunotherapy, Kynurenine, Colon, Indoleamine 2,3 dioxygenase, IDO1, Rectal Neoplasms, Epacadostat, Short-course radiation, CAPOX chemotherapy


You can join if…

Open to people ages 18 years and up

  • Newly diagnosed locally advanced rectal cancer with pathology confirmation with plans to proceed with neoadjuvant short course radiation and chemotherapy as confirmed by treating physician
  • At least 18 years of age.
  • ECOG performance status ≤ 1
  • Normal bone marrow and organ function as defined below:
    • Absolute neutrophil count ≥ 1,500/mcl
    • Platelets ≥ 100,000/mcl
    • Hemoglobin > 9 g/dL
    • Total bilirubin ≤ IULN
    • AST(SGOT)/ALT(SGPT) ≤ 2.5 x IULN
    • Serum creatinine < 1.5 x IULN OR measured or calculated creatinine clearance ≥ 50 mL/min/1.73 m2
    • INR or PT ≤ 1.5 x IULN unless patient is receiving anticoagulant therapy as long as INR or PTT is within therapeutic range of intended use of anticoagulants
    • aPTT ≤ 1.5 x IULN unless patient is receiving anticoagulant therapy as long as INR or PTT is within therapeutic range of intended use of anticoagulants
  • Applicable to subjects enrolled at Washington University and Dana Farber Cancer

    Institute only: Willing to undergo study-related biopsies subject to accessibility of tumor, appropriateness of biopsy (not contraindicated), and continued subject consent.

  • Women of childbearing potential and men must agree to contraceptive methods as described in protocol prior to study entry, for the duration of study participation, and for 120 days after the last dose of study treatment. Should a woman become pregnant or suspect she is pregnant while participating in this study, she must inform her treating physician immediately.
  • Able to understand and willing to sign an IRB approved written informed consent document (or that of legally authorized representative, if applicable).

You CAN'T join if...

  • Received prior anti-cancer therapy for rectal cancer.
  • Prior treatment with an anti-PD-1, anti-PD-L1, anti-PD-L2, anti-CD137, or anti-cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) antibody (including ipilimumab or any other antibody or drug specifically targeting T-cell co-stimulation or checkpoint pathways) or other agents targeting IDO pathway (including indoximod)
  • Previous radiotherapy in the pelvic region or previous rectal surgery (e.g. TEM) or any investigational treatment for rectal cancer within the past month.
  • A history of prior malignancy active within the previous 3 years except for locally curable cancers that have been apparently cured, including, but not limited to, basal or squamous cell skin cancer, superficial bladder cancer, or carcinoma in situ of the prostate, cervix, or breast.
  • Currently receiving any other investigational agents.
  • Extensive growth into cranial part of the sacrum (above S3) or the lumbosacral nerve roots indicating that surgery will never be possible even if substantial tumor downsizing is seen.
  • Presence of metastatic disease or recurrent rectal tumor.
  • Diagnosis of Familial Adenomatosis Polyposis coli (FAP), Hereditary Non-Polyposis Colorectal Cancer (HNPCC), active Crohn's disease, or active ulcerative colitis.
  • A history of allergic reactions attributed to compounds of similar chemical or biologic composition to epacadostat, pembrolizumab, 5-FU, oxaliplatin, or other agents used in the study.
  • Has an active infection requiring systemic therapy.
  • Warfarin (Coumadin): patients currently on warfarin are excluded. Patients who go off warfarin and have INR within normal limits have no washout period.
  • Any history of serotonin syndrome (SS) after receiving serotonergic drugs. This syndrome has been most closely associated with the use of MAOIs, meriperidine, linezolid, or methylene blue; all of these agents are prohibited during the study
  • Uncontrolled intercurrent illness including, but not limited to symptomatic congestive heart failure, unstable angina pectoris, or cardiac arrhythmia.
  • Has an active or inactive autoimmune disease or syndrome (i.e. rheumatoid arthritis, moderate or severe psoriasis, multiple sclerosis, inflammatory bowel disease) that has required systemic treatment in the past 2 years or is receiving systemic therapy for an autoimmune or inflammatory disease (i.e. with use of modifying agents, corticosteroids, or immunosuppressive drugs). Exceptions include subjects with vitiligo or resolved childhood asthma/atopy, hypothyroidism stable on hormone replacement, controlled asthma, Type I diabetes, Graves' disease, or Hashimoto's disease.
  • An abnormal screening ECG that, in the investigator's opinion, is clinically meaningful.
  • Presence of a gastrointestinal condition that may affect drug absorption.
  • Receipt of live attenuated vaccine within 30 days before the first dose of study treatment. Examples of live vaccines include, but are not limited to, the following: measles, mumps, rubella, chicken pox, yellow fever, rabies, Bacillus Calmette-Guérin (BCG), and typhoid vaccine. Seasonal influenza vaccines for injection are generally killed virus vaccines and are allowed; however, intranasal influenza vaccines (e.g. FluMist) are live attenuated vaccines and are not allowed.
  • Pregnant and/or breastfeeding. Women of childbearing potential must have a negative pregnancy test within 72 hours of cycle 1 day 1.
  • Evidence of interstitial lung disease or active, non-infectious pneumonitis including symptomatic and/or pneumonitis requiring treatment
  • Known presence of active TB.
  • Known active hepatitis B (e.g. HBsAg reactive or HBV DNA detected) or hepatitis C (e.g. HCV RNA [qualitative] is detected) infection. Testing at screening is required (Serology testing with HBsAg, HBsAb, and HCV Ab are required; HBV DNA or HCV RNA are only required in the setting of serology tests compatible with possible active infection.).
  • Known microsatellite instability- high (MSI-H) or mismatch repair deficient rectal cancer.


  • University of California Irvine not yet accepting patients
    Orange California 92868 United States
  • Washington University School of Medicine accepting new patients
    Saint Louis Missouri 63110 United States
  • Henry Ford Cancer Institute not yet accepting patients
    Detroit Michigan 48202 United States
  • Dana Farber Cancer Institute not yet accepting patients
    Boston Massachusetts 02215 United States

Lead Scientist at UC Irvine


accepting new patients at some sites,
but this study is not currently recruiting here
Start Date
Completion Date
Washington University School of Medicine
Alvin J. Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine
Phase 1/2 research study
Study Type
Expecting 39 study participants
Last Updated