Low Grade GliomaPhase 2NCT07735819
Positron Emission Tomography/Computed Tomography (PET/CT) Imaging in Patients Diagnosed With a Glioma
A Phase 2 study testing Minocycline 200mg/day and [18F]FETrp PET/CT in people with Low Grade Glioma and Glioblastoma, run by Barbara Ann Karmanos Cancer Institute at 1 site in United States.
Trial summary
The goal of this clinical trial is to evaluate Positron emission tomography/computed tomography (PET/CT) imaging with the radiotracer 1-(2-[18F]fluoroethyl)-l-tryptophan ([18F]FETrp) in patients diagnosed with a glioma. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Low Grade Glioma, Glioblastoma
- What is being tested?
- Minocycline 200mg/day and [18F]FETrp PET/CT
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 61 participants
- Where
- 1 siteUnited States
- Study dates
- Sep 2026to 30 Jun 2031
- Phase
- Phase 2
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age =18 years.
- Patient is able to lie in the PET/CT scanner for at least 60 minutes while undergoing scanning.
- Patient is willing and able to review, understand, and provide written consent for the study procedures and indicates that they are aware of the investigational nature of this study.
- Histopathology/cytopathological diagnosis of a glioblastoma without a history of radiation.
- The tumor is deemed amenable for radiation treatment (pre-radiation planning MRI can be done before or after the PET scan).
- ADDITIONAL CRITERIA FOR ARM 2:
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- Previous histopathology/cytopathological diagnosis of glioblastoma.
- History of glioma radiation.
- Presence of a new or progressing enhancing brain lesion on follow-up clinical MRI suspicious for post-radiation glioma progression or late radiation-induced MRI changes (i.e., radiation injury), at least 7 mm in bidirectional diameter.
- The most recent MRI, used for comparison with the PET/CT, is performed within 4 weeks of the planned PET scan.
- ADDITIONAL CRITERIA FOR ARM 3
- MRI diagnosis of a brain tumor, previously verified to be a low-grade (WHO grade 2, IDH (isocitrate dehydrogenase) mutant glioma, based on histopathology from biopsy or resection.
- The detected mass on the most recent clinical MRI is at least 7 mm in bidirectional diameter (i.e., twice the PET scanner resolution).
- The tumor does not require urgent (within 1 month) resection, steroid treatment, or radiation.
- The most recent MRI, used for comparison with the PET/CT, is performed within 4 weeks.
- Patient agrees to have a baseline and follow-up PET/CT scan (approximately 1 month later) and interval oral treatment with 200mg/day minocycline.
- Due to planned minocycline treatment, patients will need to have adequate renal function
Who cannot join
- Patients who are pregnant or lactating are excluded. Premenopausal women (defined per institutional guidelines) must have a negative pregnancy test (urine or serum) within 7 days of the PET scan.
- Severe increased intracranial pressure, status epilepticus, or other severe or progressing clinical symptoms requiring urgent intervention in the opinion of the treating
- Karnofsky performance score <60, as determined by one of the clinician co- investigators.
- ADDITIONAL CRITERIA FOR ARM 1:
- Active connective tissue disorders, such as lupus or scleroderma.
- History of allergic reaction to minocycline or any tetracyclines.
- Ongoing treatment with warfarin with INR > 1.5.
- History of colitis during antibiotics treatment.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site
Karmanos Cancer Institute
Detroit, Michigan, 48201
Csaba Juhasz, M.D., Ph.D, 1-800-527-6266
About this study
Official title: Tryptophan-kynurenine Pathway PET Imaging in Human Gliomas
The goal of this clinical trial is to evaluate Positron emission tomography/computed tomography (PET/CT) imaging with the radiotracer 1-(2-[18F]fluoroethyl)-l-tryptophan ([18F]FETrp) in patients diagnosed with a glioma. This study has 3 aims:
- to assess if the [18F]FETrp PET/CT can outperform Magnetic Resonance Imaging (MRI) by providing a better treatment target volume in newly diagnosed Stage 4 glioma patients
- better differentiate tumor progression from radiation induced MRI changes in post treatment stage 4 gliomas
- by giving a drug that can inhibit a pathway to allow objective assessment of treatment effects in low grade gliomas
- Conditions
- Low Grade Glioma, Glioblastoma
- Being tested
- Minocycline 200mg/day, [18F]FETrp PET/CT
- Medical subject headings
- Glioblastoma
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Minocycline 200mg/dayDrug
Minocycline 200mg orally daily to start within 14 days of the first [18F]FETrp PET/CT and taken until the second [18F]FETrp PET/CT obtained 25-44 days after the start of the Minocycline in Arm 3
[18F]FETrp PET/CTDiagnostic test
[18F]FETrp PET/CT used in all three arms
| Study group | Role | What they receive |
|---|---|---|
| [18F]FETrp PET/CT in newly diagnosed grade 4 glioma prior to radiation | Experimental | Arm 1. [18F]FETrp PET prior to radiotherapy in newly diagnosed grade 4 glioblastoma to provide a better treatment target volume Receives: Diagnostic Test: [18F]FETrp PET/CT |
| [18F]FETrp PET/CT in previously treated gliomas with post radiation progression | Experimental | Arm 2. [18F]FETrp PET to differentiate post-treatment glioma progression from radiation-induced MRI changes Receives: Diagnostic Test: [18F]FETrp PET/CT |
| [18F]FETrp PET/CT pre and post Minocycline 200mg/day | Experimental | Arm 3. Minocycline orally 200mg/day administered between the first [18F]FETrp PET scan and the month follow up [18F]FETrp scan to determine if pharmacologic inhibition of the kynurenine pathway will reduce tumoral tryptophan metabolic rates in low-grade gliomas Receives: Drug: Minocycline 200mg/day; Diagnostic Test: [18F]FETrp PET/CT |
What is being measured
The primary outcome is the main question the study is designed to answer.
Difference Between Dice Similarity Coefficients (DSC) of Position Emission Tomography (PET) High K Tumor Volume and DSC of MRI-based Tumor Volume (d-PETk-MRI) in Arm 1
A comparative evaluation of the predictive accuracy of pre-radiotherapy imaging modalities (V1) in forecasting the spatial location of future tumor progression (V2) defined by RANO (Response Assessment in Neuro-Oncology) 2.0 criteria. For each participant, two separate Dice Similarity Coefficients (DSC) will be calculated against the final progression volume (V2): one using the pre-radiotherapy PET High K influx map volume (V1_PETk) and one using the structural MRI target volume (V1_MRI). The primary endpoint (d-PETk-MRI) is the absolute difference calculated per patient as DSC_PETk minus DSC_MRI. The resulting continuous score ranges from -1 to +1. A positive score indicates that the novel kinetic PET parameter is a spatially superior predictor of subsequent localized tumor recurrence compared to standard clinical MRI planning fields.
Measured: From the time of the pre-radiotherapy scans (Baseline) up to tumor progression or study completion, assessed at a maximum follow-up of 2 years.
Sensitivity of [18F]FETrp PET Kinetic Influx Rate (PETk) with a predefined L/C ratio threshold of 1.60 in differentiating Tumor Progression from Radiation Injury in Arm 2
The diagnostic sensitivity of PETk post-radiation (T2) (PETk-T2) with a predefined L/C ratio threshold of 1.60 to correctly identify true glioblastoma progression. The true disease status (ground truth) is defined by follow-up serial MRIs using RANO 2.0 criteria or histopathologic evidence from surgical re-resection. Sensitivity is calculated as the proportion of true-positive tumor progression cases correctly identified by PETk out of all true-positive cases.
Measured: From the date of the [18F]FETrp PET/CT scan up to the date of confirmed ground truth designation via histopathology or serial MRI follow-up, assessed over a maximum period of 1 year per participant.
Change in [18F]FETrp Kinetic Influx Rate (K) Values Following One Month of Standard of Care Plus Indoleamine 2,3-dioxygenase (IDO) Inhibitor Treatment (d-PETK) in Arm 3
The quantitative change in [18F]FETrp PET K values evaluated within the MRI-defined tumor mass from baseline to post treatment. The primary analysis will be performed on the per-protocol population, defined as participants who completed both pre- and post-treatment PET scans and demonstrated at least 80% drug compliance via pill counts and paper diaries. Changes will be calculated as post-treatment minus baseline values, with a negative value indicating a reduction in tumoral tryptophan metabolic rates resulting from kynurenine pathway inhibition.
Measured: From Baseline (within 2 weeks prior to treatment initiation) to 1-month post-treatment (30 days ± 5 days, up to 44 days).
Secondary outcomes (8)
Difference Between Dice Similarity Coefficients (DSC) of PET High Standardized Uptake Value (SUV) Tumor Volume and DSC of MRI-based Tumor Volume (d-PETsuv-MRI) in Arm 1
A comparative evaluation of the predictive accuracy of pre-radiotherapy imaging modalities (V1) in forecasting the spatial location of future tumor progression (V2) defined by RANO 2.0 criteria. For each participant, two separate Dice Similarity Coefficients (DSC) will be calculated against the final progression volume (V2): one using the pre-radiotherapy PET High SUV volume (V1_PETsuv) and one using the structural MRI target volume (V1_MRI). The primary endpoint (d-PETk-MRI) is the absolute difference calculated per patient as DSC_PETsuv minus DSC_MRI. The resulting continuous score ranges from -1 to +1. A positive score indicates that the novel kinetic PET parameter is a spatially superior predictor of subsequent localized tumor recurrence compared to standard clinical MRI planning fields.
Measured: From the time of the pre-radiotherapy scans (Baseline) up to tumor progression or study completion, assessed at a maximum follow-up of 2 years.
Hazard Ratio for Progression-Free Survival Based on Pre-Radiotherapy (T1) [18F]FETrp PET High K Tumor Volume (PETk-T1) in Arm 1
Assessment of pre-radiotherapy metabolic tumor volume (PETk-T1, in cm³) as an independent prognostic predictor of progression-free survival (PFS). A multivariable Cox proportional hazards regression model will calculate the adjusted hazard ratio (HR) and 95% confidence interval for PFS per unit increase in PETk-T1 volume. The model will adjust for baseline clinical covariates. PFS is defined as time from the date of diagnosis to the first documented and verified disease progression (defined by the RANO 2.0 criteria9). Patients who are lost to follow-up or without disease progression at time of data cut off are censored at the time of last known disease progression follow-up.
Measured: From date of initial diagnosis up to first documented RANO 2.0 disease progression, death, or study closure, assessed up to a maximum of 2 years.
Specificity of [18F]FETrp PET Kinetic Influx Rate (PETk) with a predefined L/C ratio threshold of 1.60 in differentiating Tumor Progression from Radiation Injury in Arm 2
The diagnostic specificity of PETk post-radiation (T2) (PETk-T2) with a predefined L/C ratio threshold of 1.60 to correctly identify true glioblastoma progression. The true disease status (ground truth) is defined by follow-up serial MRIs using RANO 2.0 criteria or histopathologic evidence from surgical re-resection. Specificity is calculated as the proportion of true-negative cases (radiation injury) correctly identified by PETk out of all true-negative cases.
Measured: From the date of the [18F]FETrp PET/CT scan up to the date of confirmed ground truth designation via histopathology or serial MRI follow-up, assessed over a maximum period of 1 year per participant.
Positive Predictive Value (PPV) of [18F]FETrp PET K L/C Ratio for Glioblastoma Progression in Arm 2
The proportion of participants with a positive [18F]FETrp PET K L/C ratio (≥ 1.60) who are confirmed to have true tumor progression via the composite ground truth reference standard (RANO 2.0 MRI follow-up or histopathology).
Measured: From the date of the [18F]FETrp PET/CT scan up to the date of confirmed ground truth designation via histopathology or serial MRI follow-up, assessed over a maximum period of 1 year per participant.
Negative Predictive Value (NPV) of [18F]FETrp PET K L/C Ratio for Glioblastoma Progression in Arm 2
The proportion of participants with a negative [18F]FETrp PET K L/C ratio (< 1.60) who are confirmed to have radiation-induced injury via the composite ground truth reference standard (RANO 2.0 MRI follow-up or histopathology).
Measured: From the date of the [18F]FETrp PET/CT scan up to the date of confirmed ground truth designation via histopathology or serial MRI follow-up, assessed over a maximum period of 1 year per participant.
Overall Diagnostic Accuracy of [18F]FETrp PET K L/C Ratio for Differentiating Tumor Progression From Radiation Injury in Arm 2
The total proportion of correctly classified cases (true positives plus true negatives) using the [18F]FETrp PET K L/C ratio threshold of 1.60 divided by the total number of evaluable suspicious contrast-enhancing lesions.
Measured: From the date of the [18F]FETrp PET/CT scan up to the date of confirmed ground truth designation via histopathology or serial MRI follow-up, assessed over a maximum period of 1 year per participant.
Partial Area Under the Receiver Operating Characteristic Curve (pAUC) for [18F]FETrp PET K L/C Ratios in Arm 2
The partial area under the receiver operating characteristic (ROC) curve generated by varying the continuous [18F]FETrp PET K L/C ratio values to assess overall classification performance across a clinically relevant range of specificities, utilizing the composite ground truth reference standard.
Measured: From the date of the [18F]FETrp PET/CT scan up to the date of confirmed ground truth designation via histopathology or serial MRI follow-up, assessed over a maximum period of 1 year per participant.
Change in [18F]FETrp PET Kinetic Influx Rate (K) Lesion-to-Contralateral (L/C) Ratios Following One Month of Standard of Care Plus IDO Inhibitor Treatment in Arm 3
The change in the [18F]FETrp PET K-map lesion-to-contralateral (L/C) ratio from baseline to 1 month post-treatment. It is analyzed in the per-protocol population (at least 80% pill compliance and evaluable paired imaging).
Measured: From Baseline (within 2 weeks prior to treatment initiation) to 1-month post-treatment (30 days ± 5 days, up to 44 days).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Jul 2026
- Study startSep 2026 (estimated)
- Primary completion30 Jun 2031 (estimated)
- Study completion30 Jun 2031 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Low Grade GliomaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Diagnosis
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 61 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Barbara Ann Karmanos Cancer Institute
- Sponsor type
- University, hospital or other
- Collaborators
- Wayne State University
- Responsible party
- Principal investigator, Csaba Juhasz, Barbara Ann Karmanos Cancer Institute
- Investigators
- Csaba Juhasz, M.D.,Ph.D., Principal investigator, Wayne State University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07735819
- Sponsor's protocol ID
- 2026-055
- Status last verified
- Jul 2026
- First submitted
- 24 Jul 2026
- Last updated
- 30 Jul 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No