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OnTARGET: A Phase 3 Multicenter, Randomized, Double-Blind Placebo-Controlled Trial Evaluating Crofelemer for the Prophylaxis of Diarrhea in Adult Patients with Solid Tumors Receiving Targeted-Cancer Therapies with or Without Standard Chemotherapy Regimen


General Information

Age Group




Protocol Number


Background Information

Studies have shown that certain types of targeted cancer therapies and standard chemotherapy drugs can result in diarrhea, which is defined as the passage of one or more loose and/or watery stool while you are being treated for cancer. The frequency of such diarrhea has been reported in greater than 50% of people who receive targeted cancer therapy with or without standard chemotherapy drugs. It is likely diarrhea will develop at some point while on a targeted cancer therapy regimen with or without the use of chemotherapy drugs to treat the cancer. Currently, there is no effective way to prevent diarrhea or to reduce or lessen the frequency of the diarrhea receiving targeted cancer therapy.

This study will help determine if a drug called crofelemer (MytesiTM) will prevent or decrease the incidence of diarrhea and the frequency of loose/watery stools while receiving targeted cancer therapy and/or chemotherapy drugs. Crofelemer is currently a U.S. Food and Drug Administration (FDA) approved drug for treating chronic non-infectious diarrhea in people with HIV/AIDS who are receiving anti-retroviral therapy (ART). Mytesi has been shown to be effective in reducing the frequency of loose/watery stools in people with HIV/AIDS receiving crofelemer along with their ART. Crofelemer works by regulating the movement of water and salts in your gut to decrease the likelihood of diarrhea. Mytesi is not approved for use in people who have diarrhea due to cancer therapy.

The use of crofelemer is what is being studied. Mytesi (Crofelemer 125 mg delayed-release) tablets are manufactured at Patheon Inc (Cincinnati, OH) for the Sponsor of this study, Napo Pharmaceuticals, Inc. Mytesi, will be used as the study drug in this clinical study. Crofelemer is available as a tablet that you take by mouth with or without food, twice daily. All subjects will be randomly assigned (like the toss of a coin) to either one 125 mg tablet of crofelemer (active drug) or one 125 mg matching placebo tablet (non-active tablet, as it contains no crofelemer), to be taken two times a day, with or without food, for up to 24 weeks.

Offered At

Inova Schar Cancer Institute
8081 Innovation Park Drive
Fairfax, VA 22031

A department of Inova Fairfax Hospital

Inova Schar Cancer Institute
3580 Joseph Siewick Dr.
Fairfax, VA 22033

A department of Inova Fair Oaks Hospital

Eligibility Information

  • Participants to receive targeted cancer therapy drugs that have a reported incidence of all grade diarrhea in at least 50% of patients (e.g., tyrosine kinase inhibitors, cdk inhibitors, anti-EGFR, etc.) for the treatment of solid tumors.
  • Men and women ≥18 years of age.
  • Pathologically and/or radiologically confirmed diagnosis of solid tumors scheduled to receive targeted cancer therapy.
  • Participants eligible to receive targeted cancer therapy per NCCN guidelines and/or standard-of-care practice, with or without cycle chemotherapy.
  • Patient can receive concomitant cycle [standard] chemotherapy agents together with their targeted cancer therapy treatment regimens.
  • Additional eligibility in protocol.

Ineligibility Information

  • Patients receiving any type of immunotherapy including but not limited to, immune checkpoint inhibitors that inhibit negative regulatory components of immune response such as cytotoxic Tlymphocyte associated antigen 4 (CTLA-4) and the programmed cell death protein-1 and its ligand (PD1/ PDL1) and IL-2 cancer immunotherapy.
  • Any cancer therapy for which antidiarrheal (antimotility) medications in the prophylaxis setting is mandatory, including but not limited to patients receiving neratinib and irinotecan.
  • Ongoing irritable bowel syndrome (IBS) or colitis (including but not limited to ulcerative colitis, Crohn’s disease, microscopic colitis, etc.).
  • Ongoing diarrhea and/or diarrheal episodes within the previous 7 days prior to randomization into the study.
  • Laxative use within 7 days prior to randomization or a history of constipation requiring the use of laxatives for more than ≥ 30 consecutive days.
  • Inadequate organ function, which may include, but is not limited to, the following laboratory results within 28 days prior to signing consent: Total bilirubin > upper limit of normal (ULN), AST (SGOT) and ALT (SPGT) > 2.5 ULN (unless the participant has documented Gilbert’s syndrome, hepatocellular carcinoma or hepatic metastases), serum creatinine > 2.0 mg/dL or 177 μmol/L.
    • a. NOTE: Investigator discretion will determine continued eligibility after randomization occurs in the event the liver function results are greater than (>) the proposed upper limit of normal.
  • Use of other investigational drugs within 4 weeks of signed informed consent or foreseen use during the study.
  • Use of antibiotics within the past 7 days (up to 2 prophylactic doses of antibiotic for procedures, including but not limited to port placement, is permitted) prior to randomization.
  • Total colectomy and/or any type of gastrointestinal ostomy.
  • Major abdominal or pelvic surgery within the past 3 months.
  • Previous (within 1 month) or planned abdominal and/or pelvic radiation.
  • Additional ineligibility in protocol.

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