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AMT-PET in Monitoring Telotristat Etiprate Treatment in Participants With MetastaticNeuroendocrine Neoplasm

Monitoring Telotristat Ethyl Inhibition of Tryptophan Hydroxylase (TPH) in Neuroendocrine Tumors Using ?-[11C]Methyl-L-tryptophan (AMT)-PET

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03453489
Enrollment
4
Registered
2018-03-05
Start date
2018-06-20
Completion date
2020-10-15
Last updated
2025-04-10

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Carcinoid Syndrome, Metastatic Nonfunctional Well Differentiated Neuroendocrine Neoplasm

Brief summary

This pilot trial studies how well telotristat etiprate works in treating participants with well differentiated neuroendocrine neoplasm that has spread to other places in the body and monitored by carbon C 11 alpha-methyltryptophan (AMT)-emission tomography (PET). Telotristat etiprate may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Studying the changes within the tumor cells via AMT-PET may help doctors better understand how tumors respond to treatment with telotristat etiprate.

Detailed description

PRIMARY OBJECTIVES: I. To evaluate the effect of telotristat etiprate (telotristat ethyl) treatment in patients with advanced neuroendocrine tumors (NETs) using carbon C 11 alpha-methyltryptophan (alpha-\[11C\]methyl-?L-?tryptophan) (AMT)-?positron emission tomography (PET) as measured by changes in tumor maximum standardized uptake value (SUVmax). SECONDARY OBJECTIVES: I. Show that NETs will have increased AMT uptake on PET, as compared to surrounding non-tumor tissue at baseline. II. Use compartmental modeling (in tumors with the left ventricle of the heart in the field-of-view) to measure change in AMT retention. III. Measure change in AMT retention as mean standardized uptake value (SUVmean). OUTLINE: Participants undergo AMT-PET within 7 days prior to, and 9-14 days after start of telotristat etiprate treatment. Participants receive telotristat etiprate orally (PO) three times a day (TID) for 9-14 days. After completion of study treatment, participants are followed up for 3 months.

Interventions

OTHERLaboratory Biomarker Analysis

Correlative studies

PROCEDUREPositron Emission Tomography

Undergo AMT-PET

Sponsors

National Cancer Institute (NCI)
CollaboratorNIH
Barbara Ann Karmanos Cancer Institute
Lead SponsorOTHER

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Histopathologically confirmed, well-differentiated metastatic NETs * Receiving stable-dose somatostatin analog (long-acting release \[LAR\], depot) for \> 3 months before enrollment. * Patients with 5-HIAA levels above or below the upper limit of normal range and those with unknown values at baseline are allowed to participate. * Able to lie within the PET scanner for at least 70 minutes while undergoing scanning. * ECOG performance status of 2 or better. * Physical exam, CBC and Multiphasic (including electrolytes, BUN, creatinine, total bilirubin, AST, and ALT) must be done within 28 days of PET imaging and demonstrate adequate renal and liver function. Creatinine ≤ 2.5, total bilirubin ≤ 1.5 x upper limit of normal (ULN). AST and ALT ≤ 2.5 ULN. * Patient must have a least one lesion greater than 2 cm on standard imaging (CT, MR, octreotide, or dotatate imaging within 8 weeks of the start of the study) that is judged amenable to AMT-PET. * Women of child bearing potential must not be pregnant or breastfeeding. A negative urine or blood pregnancy test must be obtained in women with child bearing potential. Men and women with reproductive potential must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) on study entry and for the duration of study participation. * Eligible and consent signed for imaging with AMT PET under protocol 2011-053.

Exclusion criteria

* Patients experiencing more than 12 watery bowel movements per day associated with volume contraction, dehydration, or hypotension, or showing evidence of enteric infection are excluded * Patients are excluded if they had undergone tumor-directed therapy within 3 months * Patients cannot be on a targeted agent (e.g., sunitinib or everolimus) or receiving cytotoxic chemotherapy (e.g., capecitabine or temozolomide); they cannnot be on telotristat ethyl; previous use is acceptable if the patient has been off for over one month

Design outcomes

Primary

MeasureTime frameDescription
The Proportion of Patients Who Achieved SUVmax Reduction of 20% or More Between Baseline and Follow up ScanBaseline up to follow up, assessed up to 3 monthsThe proportion of patients who achieved maximum standardized uptake value (SUVmax) reduction of 20% or more between baseline and follow up scan. It will be reported with a one-sided, 90% confidence limit.

Secondary

MeasureTime frameDescription
Change in Mean Standardized Uptake Value (SUVmean)Baseline up to 3 monthsWill be reported as percent change with two-sided 95% confidence intervals. Paired t test will be used for pre-and post-treatment SUVs if normality assumption holds.
Neuroendocrine Tumors VisibilityAt baselineProportion of patients with visible neuroendocrine tumors at baseline out of total number of patients. The outcome will be reported as proportion and 95% CI
Difference in SUVmax of AMT Uptake Between the Tumor Mass and Background at BaselineBaselineDifference will be reported as percent of (SUVmax.tumor - SUVmax.background)/SUVmax.background in the baseline scan with 95% Confidence Interval

Countries

United States

Participant flow

Participants by arm

ArmCount
Treatment (AMT-PET, Telotristat Etiprate)
Participants undergo AMT-PET within 7 days prior to, and 9-14 days after start of telotristat etiprate treatment. Participants receive telotristat etiprate PO TID for 9-14 days. Carbon C 11 Alpha-methyltryptophan: Undergo AMT-PET Laboratory Biomarker Analysis: Correlative studies Positron Emission Tomography: Undergo AMT-PET Telotristat Etiprate: Given PO
4
Total4

Baseline characteristics

CharacteristicTreatment (AMT-PET, Telotristat Etiprate)
Age, Categorical
<=18 years
0 Participants
Age, Categorical
>=65 years
2 Participants
Age, Categorical
Between 18 and 65 years
2 Participants
Age, Continuous61 years
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
Race (NIH/OMB)
Asian
0 Participants
Race (NIH/OMB)
Black or African American
1 Participants
Race (NIH/OMB)
More than one race
0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
Race (NIH/OMB)
Unknown or Not Reported
1 Participants
Race (NIH/OMB)
White
2 Participants
Region of Enrollment
United States
4 participants
Sex: Female, Male
Female
1 Participants
Sex: Female, Male
Male
3 Participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
0 / 4
other
Total, other adverse events
0 / 4
serious
Total, serious adverse events
0 / 4

Outcome results

Primary

The Proportion of Patients Who Achieved SUVmax Reduction of 20% or More Between Baseline and Follow up Scan

The proportion of patients who achieved maximum standardized uptake value (SUVmax) reduction of 20% or more between baseline and follow up scan. It will be reported with a one-sided, 90% confidence limit.

Time frame: Baseline up to follow up, assessed up to 3 months

ArmMeasureValue (NUMBER)
Treatment (AMT-PET, Telotristat Etiprate)The Proportion of Patients Who Achieved SUVmax Reduction of 20% or More Between Baseline and Follow up Scan0 Proportion of participants
Secondary

Change in Mean Standardized Uptake Value (SUVmean)

Will be reported as percent change with two-sided 95% confidence intervals. Paired t test will be used for pre-and post-treatment SUVs if normality assumption holds.

Time frame: Baseline up to 3 months

ArmMeasureValue (MEAN)
Treatment (AMT-PET, Telotristat Etiprate)Change in Mean Standardized Uptake Value (SUVmean)46.01 Percentage change
p-value: 0.837t-test, 2 sided
Secondary

Difference in SUVmax of AMT Uptake Between the Tumor Mass and Background at Baseline

Difference will be reported as percent of (SUVmax.tumor - SUVmax.background)/SUVmax.background in the baseline scan with 95% Confidence Interval

Time frame: Baseline

ArmMeasureValue (MEAN)
Treatment (AMT-PET, Telotristat Etiprate)Difference in SUVmax of AMT Uptake Between the Tumor Mass and Background at Baseline451.90 Percentage
Secondary

Neuroendocrine Tumors Visibility

Proportion of patients with visible neuroendocrine tumors at baseline out of total number of patients. The outcome will be reported as proportion and 95% CI

Time frame: At baseline

ArmMeasureValue (NUMBER)
Treatment (AMT-PET, Telotristat Etiprate)Neuroendocrine Tumors Visibility1 Proportion of participants

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026