A Phase 2 interventional study of Carbon C 11 Alpha-methyltryptophan and Laboratory Biomarker Analysis in Carcinoid Syndrome and Metastatic Nonfunctional Well Differentiated Neuroendocrine Neoplasm, sponsored by Barbara Ann Karmanos Cancer Institute. Completed at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-04-10.
Sponsored by Barbara Ann Karmanos Cancer Institute · Phase 2, Interventional, and Treatment
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.
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.
Exclusion Criteria:
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.
Other: Carbon C 11 Alpha-methyltryptophan · Other: Laboratory Biomarker Analysis · Procedure: Positron Emission Tomography · Drug: Telotristat Etiprate
Undergo AMT-PET
Also known as: 11C-alpha-methyltryptophan, 11C-AMT, [11C] AMT, alpha-[11C]methyl-L-tryptophan
Correlative studies
Undergo AMT-PET
Also known as: Medical Imaging, Positron Emission Tomography, PET, PET Scan, Positron Emission Tomography Scan, Positron-Emission Tomography, proton magnetic resonance spectroscopic imaging
Given PO
Also known as: LX1032 Hippurate, LX1606, LX1606 Hippurate, TPH Inhibitor LX1606, Tryptophan Hydroxylase Inhibitor LX1032, Tryptophan Hydroxylase Inhibitor LX1606
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
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
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
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
| Milestone | Treatment (AMT-PET, Telotristat Etiprate) |
|---|---|
| Started | 4 |
| Completed | 4 |
| Not completed | 0 |
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.
| Proportion of participants | Treatment (AMT-PET, Telotristat Etiprate) |
|---|---|
| The Proportion of Patients Who Achieved SUVmax Reduction of 20% or More Between Baseline and Follow up Scan | 0 (0 to 1) |
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.
| Percentage change | Treatment (AMT-PET, Telotristat Etiprate) |
|---|---|
| Change in Mean Standardized Uptake Value (SUVmean) | 46.01 (-56.06 to 148.08) |
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
| Proportion of participants | Treatment (AMT-PET, Telotristat Etiprate) |
|---|---|
| Neuroendocrine Tumors Visibility | 1 (0.51 to 1) |
Difference will be reported as percent of (SUVmax.tumor - SUVmax.background)/SUVmax.background in the baseline scan with 95% Confidence Interval
| Percentage | Treatment (AMT-PET, Telotristat Etiprate) |
|---|---|
| Difference in SUVmax of AMT Uptake Between the Tumor Mass and Background at Baseline | 451.90 (271.21 to 632.60) |
Collected over From the date of informed consent until 4 weeks after the treatment completion, up to 3 months.. Non-serious events are listed at a 5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Treatment (AMT-PET, Telotristat Etiprate) | 0/4 (0%) | 0/4 (0%) | 0/4 (0%) |
| Age, Categorical(Participants) | Treatment (AMT-PET, Telotristat Etiprate) |
|---|---|
| <=18 years | 0 |
| Between 18 and 65 years | 2 |
| >=65 years | 2 |
| Age, Continuous(years) | Treatment (AMT-PET, Telotristat Etiprate) |
|---|---|
| Median | 61 (57 to 80) |
| Sex: Female, Male(Participants) | Treatment (AMT-PET, Telotristat Etiprate) |
|---|---|
| Female | 1 |
| Male | 3 |
| Race (NIH/OMB)(Participants) | Treatment (AMT-PET, Telotristat Etiprate) |
|---|---|
| American Indian or Alaska Native | 0 |
| Asian | 0 |
| Native Hawaiian or Other Pacific Islander | 0 |
| Black or African American | 1 |
| White | 2 |
| More than one race | 0 |
| Unknown or Not Reported | 1 |
| Region of Enrollment(participants) | Treatment (AMT-PET, Telotristat Etiprate) |
|---|---|
| United States | 4 |
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Barbara Ann Karmanos Cancer Institute