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RecruitingNCT03099356Updated Jul 31, 2026

Cyclophosphamide and Sirolimus for the Treatment of Metastatic, RAI-refractory, Differentiated Thyroid Cancer

A Phase 2 interventional study of Cyclophosphamide and Sirolimus in Metastatic Thyroid Cancer, sponsored by University of Michigan Rogel Cancer Center. Recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-07-31.

Sponsored by University of Michigan Rogel Cancer Center · Phase 2, Interventional, and Treatment

From the registry’s dates

  • Started Apr 2017; still recruiting 9 years 6 months later.
Phase
Phase 2
Study type
Interventional
Enrollment
22
Allocation
Not applicable
Ages
18 Years and older
Sex
All
01

Study summary

This study will be a non-randomized pilot trial using Cyclophosphamide and Sirolimus for the treatment of metastatic differentiated thyroid cancer. Patients will be treated with Sirolimus 4 mg, PO, days 1-28 as well as Cyclophosphamide 100 mg, PO, days 1-5 and 15-19. Cycle length will be 28 days. Patients will be monitored closely for toxicity and undergo imaging to evaluate efficacy once every 2 cycles.

02

Conditions studied

  • Metastatic Thyroid Cancer

Browse trials for

03

In context

Thyroid Neoplasms

785 studies on the registry are indexed under Thyroid Neoplasms; 204 are open to participants now.

This study's planned enrollment of 22 is below the median of 53 across 520 interventional studies indexed under Thyroid Neoplasms.

Browse Thyroid Neoplasms studies →

Lead sponsor

University of Michigan Rogel Cancer Center is the lead sponsor of 323 studies on the registry; 47 are open to participants now.

Of its 46 completed or terminated interventional studies of FDA-regulated products, 31 (67%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • documented differentiated thyroid cancer with or without , not amenable to curative treatment; or the patient has documented refusal of curative treatment
  • (>10 mm) and have progression of disease based on criteria. Previously irradiated tumor lesions are not considered measurable unless they have progressed since radiation.
  • Previous failure of Iodine-131 (131I) therapy or not candidates to receive 131I as assessed by treating physician.
  • Age ≥ 18 years
  • (Eastern Cooperative Oncology Group) performance status 0-2
  • Life expectance of ≥ 12 weeks
  • 131I therapy not allowed within 24 weeks before entry (4 weeks if negative post-treatment scan)
  • Adequate organ and marrow function
  • Women of must have a negative serum or urine pregnancy test within 3 days prior to treatment
  • Signed and dated document indicating that the patient (or legally acceptable representative) has been informed of all pertinent aspects of the trial prior to enrollment
  • Willingness and ability to comply with scheduled visits, treatment plans, including willingness to take study medication, laboratory tests, and other study procedures

Exclusion criteria

Exclusion Criteria:

  • Inability to obtain Foundation One testing on , or, lack of previous Next Generation Sequencing
  • Chemotherapy, tyrosine kinase inhibitor, or radiation therapy within 4 weeks
  • Prior experimental therapy within 4 weeks of planned start of this trial
  • 131I therapy within 24 weeks before entry (4 weeks if negative post-treatment scan)
  • Previous treatment with an mTOR inhibitor
  • Patients who are currently receiving treatment with strong inhibitors or inducers of or P-glycoprotein that cannot be discontinued at least one week prior to the start of treatment with Cyclophosphamide and Sirolimus
  • Impairment of GI (gastrointestinal) function or GI disease that may significantly alter the absorption of study medications (e.g., ulcerative diseases, uncontrolled nausea, vomiting, diarrhea, malabsorption syndrome, small bowel resection) including dependence on a G-Tube for administration of medications.
  • A serious uncontrolled medical disorder or active infection that would impair their ability to receive study treatment
  • Patients with known sensitivities to either cyclophosphamide and/or sirolimus
  • Patients with known urinary outflow obstruction
  • Dementia or significantly altered mental status that would prohibit the understanding or rendering of and compliance with the requirements of this protocol
  • Patients (male and female) having procreative potential who are not willing or not able to use adequate or practicing abstinence
  • Women who are pregnant or breast-feeding
  • Patients residing in prison
Terms in these criteria, in plain language(10)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Histologically or cytologically confirmed

The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).

Your pathology report is the document that shows this.

Metastases

Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.

Measurable disease

The amount of disease can be tracked with a defined measurement, so the study can see whether it shrinks or grows. It might be a tumour measured on a scan or, in some blood cancers such as myeloma, a marker measured in blood or urine.

The criteria or the study team say which measurement counts — having no tumour visible on a scan does not by itself rule you out.

RECIST

The standard rules for measuring tumours on CT or MRI scans, to tell whether a cancer is shrinking, stable or growing during treatment.

“Measurable disease per RECIST 1.1” usually means at least one tumour 10 mm or more at its longest on a CT scan, or a lymph node 15 mm or more across its short axis.

ECOG performance status

A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.

0
Fully active, no restrictions.
1
Limited in strenuous activity, but walking and able to do light work, such as housework or office work.
2
Walking and able to look after yourself, but unable to work; up and about more than half of waking hours.
3
Able to look after yourself only in part; in bed or a chair more than half of waking hours.
4
Unable to look after yourself at all; in bed or a chair all day.

Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.

Childbearing potential

Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).

Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Biopsy and archival tissue

A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.

Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.

CYP3A (CYP3A4) inhibitors and inducers

CYP3A is a group of enzymes, mainly CYP3A4, in the liver and gut that break down many medicines. Some medicines, supplements and foods (grapefruit, St John’s wort) slow them down or speed them up, which changes how much of a study drug stays in the body.

Studies list them so they can be avoided or switched; bring a list of everything you take, including supplements.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

05

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
22 participants (estimated)

Study arms

  • Experimental
    Cyclophosphamide and Sirolimus

    Sirolimus 4 mg, PO, days 1-28 as well as Cyclophosphamide 100 mg, PO, days 1-5 and 15-19

    Drug: Cyclophosphamide · Drug: Sirolimus

Interventions

06

What researchers measure

Primary outcomes

  1. Percentage of patients that respond to treatment

    The primary measure of efficacy will be the overall response rate (ORR) which is defined as those achieving either complete response (CR) or partial response (PR). Partial response is defined as at least a 30% decrease in the sum of the longest diameter (LD) of target lesions. Complete response is defined as Disappearance of all target lesions, determined by two separate observations conducted not less than 4 weeks apart (there can be no appearance of new lesions) and the disappearance of all non-target lesions and normalization of tumor marker level.

    Time frame: Patients will be followed for response until progression or up to 2 Years

Secondary outcomes

  1. The number of patients that experience toxicity

    The number of patients that experience toxicity by type will be reported.

    Time frame: Patients are followed for toxicity up to 30 days after the last dose of study drug

  2. Median overall survival time

    The median duration of time from start of treatment until death

    Time frame: Patients will be followed until death or up to 2 years

  3. Median progression free survival time

    The median duration of time from start of treatment until progression. Progression is defined as at least a 20% increase in the sum of the LD (longest diameter) of target lesions, taking as reference the smallest sum LD recorded since the treatment started, or the appearance of one or more new lesions and/or unequivocal progression of existing non-target lesions.

    Time frame: Patients will be followed for response until progression or up to 2 Years

07

Study locations

1 of 1 sites recruiting
08

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jul 31, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
09

Registry details

Key details

Study ID
NCT03099356
Responsible party
Sponsor
First posted
Apr 4, 2017
Start date
Apr 27, 2017
Primary completion
Dec 2026 (estimated)
Completion
Dec 2026 (estimated)
Last update
Jul 31, 2026

Study contacts

Cancer AnswerLine
Contact
canceranswerline@umich.edu
1-800-865-1125
Paul Swiecicki, M.D.
Contact
pswiecic@med.umich.edu
Paul Swiecicki, M.D.
principal investigator · University of Michigan Rogel Cancer Center

Oversight

Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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Studies of the drugs tested here: Cyclophosphamide · Sirolimus

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