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Protocol Details

Phase I Trial of 4'-thio-2'-deoxycytidine (TdCyd) in Patients With Advanced Solid Tumors

This study is NOT currently recruiting participants.

Summary | Eligibility | Citations | Contacts




Sponsoring Institute

National Cancer Institute (NCI)

Recruitment Detail

Type: Clinical hold/Recruitment or enrollment suspended
Gender: Male & Female
Min Age: 18 Years
Max Age: N/A

Referral Letter Required


Population Exclusion(s)



DNA Methylation;
Nucleoside Analog;

Recruitment Keyword(s)



Solid Tumors

Investigational Drug(s)


Investigational Device(s)



Drug: TdCyd

Supporting Site

National Cancer Institute


- Genes are made up of DNA and are the instruction book for cells. When people have cancer, some of the genes that might have slowed the growth of tumor cells were turned off. Researchers think a drug called TdCyd might help to turn these genes back on. This may slow the growth of tumors in people with cancer.


- To test the safety of TdCyd and to find out how it works. Also, to find out the dose of the drug that can be safely given to humans.


- Adults 18 years and older who have advanced cancer that has progressed after standard treatment, or for which no effective therapy exists.


- Participants will take TdCyd by mouth. The drug is given in 21-day cycles. TdCyd is taken once a day during week 1 for 5 days. Then for 2 days participants do not take the drug. Then they take it for 5 days during week 2. No TdCyd is taken during week 3.

- Participants will keep a diary of their study drug doses.

- Participants will have tests about every 3 weeks to see how the study drugs are affecting their body. They will have blood and urine tests, a medical history, and physical exams. They may have computed tomography (CT) scans to measure their tumors. They may have an electrocardiogram, which measures the heart electrical activity.

- If participants develop any side effects, they may be asked to visit more often.

- Participants will stay in the study as long as they are tolerating TdCyd and their tumors are either stable or getting better. One month after stopping the drug, they will have a follow-up phone call.

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-Patients must have histologically documented solid tumors whose disease has progressed on standard therapy or for which there is no available standard therapy.

-Patients must have measurable or evaluable disease.

-Age greater than or equal to 18 years of age.

-ECOG performance status less than or equal to 2.

-Life expectancy > 3 months.

-Patients must have normal organ and marrow function as defined below:

a. absolute neutrophil count greater than or equal to 1,500/mcL

b. platelets greater than or equal to 100,000/mcL

c. total bilirubin less than or equal to 1.5 times institutional upper limit of normal

d. AST(SGOT)/ALT(SGPT) less than or equal to 3 times institutional upper limit of normal

e. creatinine less than or equal to 1.5 times institutional upper limit of normal


e. creatinine clearance greater than or equal to 60 mL/min/1.73 m(2) for patients with creatinine levels above 1.5 times institutional normal

-Because nucleoside analogs are known to be teratogenic, women of child-bearing potential and men must agree to use two forms of contraception (hormonal or barrier method of birth control; abstinence; sterilization) prior to study entry, for the duration of study participation, and for 3 months after completing study treatment. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately. Men treated or enrolled on this protocol must also agree to use two forms of contraception prior to the study, for the duration of study participation, and for 3 months after completion of administration of TdCyd.

-Patients must have completed any chemotherapy, radiation therapy, or biologic therapy greater than or equal to 4 weeks or 5 half-lives (whichever is shorter) (6 weeks for nitrosoureas or mitomycin C) prior to entering the study. Patients must be greater than or equal to 2 weeks since any prior administration of a study drug in a phase 0 or equivalent study and be greater than or equal to 2 weeks since any prior palliative radiation or cyberknife therapy. Patients must have recovered to grade 1 from prior toxicity or adverse events. Patients with bone metastases or hypercalcemia on intravenous bisphosphonate treatment prior to study entry may continue this treatment.

-Ability to understand and the willingness to sign a written informed consent document.

-Willingness to provide blood and urine samples for research purposes.

-Ability to swallow pills/capsules.


-Patients who are receiving any other investigational agents.

-Pregnant women and women who are breastfeeding are excluded from this study.

-Patients with clinically significant illnesses which would compromise participation in the study, including, but not limited to active or uncontrolled infection, immune deficiencies, known HIV infection requiring protease inhibitor therapy, Hepatitis B, Hepatitis C, uncontrolled diabetes, uncontrolled hypertension, symptomatic congestive heart failure, unstable angina pectoris, myocardial infarction within the past 6 months, uncontrolled cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements.

-Patients with known brain metastases or carcinomatous meningitis are excluded from this clinical trial, with the exception of patients whose brain metastatic disease status has remained stable for greater than or equal to 1 month after treatment of the brain metastases. Patients should not be on anti-seizure medications. These patients may be enrolled at the discretion of the Principal Investigator.

-Malabsorption syndrome or other conditions that would interfere with intestinal absorption.


Both men and women of all races and ethnic groups are eligible for this trial.

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Cowan LA, Talwar S, Yang AS. Will DNA methylation inhibitors work in solid tumors? A review of the clinical experience with azacitidine and decitabine in solid tumors. Epigenomics. 2010 Feb;2(1):71-86. doi: 10.2217/epi.09.44.

Thottassery JV, Sambandam V, Allan PW, Maddry JA, Maxuitenko YY, Tiwari K, Hollingshead M, Parker WB. Novel DNA methyltransferase-1 (DNMT1) depleting anticancer nucleosides, 4'-thio-2'-deoxycytidine and 5-aza-4'-thio-2'-deoxycytidine. Cancer Chemother Pharmacol. 2014 Aug;74(2):291-302. doi: 10.1007/s00280-014-2503-z. Epub 2014 Jun 8.

Kumar S, Horton JR, Jones GD, Walker RT, Roberts RJ, Cheng X. DNA containing 4'-thio-2'-deoxycytidine inhibits methylation by HhaI methyltransferase. Nucleic Acids Res. 1997 Jul 15;25(14):2773-83.

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Principal Investigator

Referral Contact

For more information:

James H. Doroshow, M.D.
National Cancer Institute (NCI)
(240) 781-3320

Ashley B. Bruns
National Cancer Institute (NCI)
National Institutes of Health
Building 10
Room 8D53
10 Center Drive
Bethesda, Maryland 20892
(240) 858-3162

NCI Referral Office
National Institute of Health Clinical Center (CC), 9000 Rockville Pike, Bethesda, Maryland 20892, United States: NCI Clinical Trials Referral Office

Clinical Trials Number:


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