Metastatic Prostate CancerPhase 2NCT07723651
[18F]Fluorthanatrace - Positron Emission Tomography (FTT-PET) and ctDNA to Predict Response to PARP Inhibitor Therapy in Metastatic Prostate Cancer (mPC)
A Phase 2 study testing 1-(4-(2-Fluoroethoxy)phenyl)-8,9-dihiydro-2,7,9a-triazabenzo[cd]azulen-6(7H)-one, FTT-PET/CT and EnhanceAR-Seq in people with Metastatic Prostate Cancer and Prostate Cancer, run by Washington University School of Medicine at 3 sites in United States.
Trial summary
This multicenter center, open-label, baseline-controlled diagnostic imaging study designed to assess the use of Fluorthanatrace-Positron Emission tomography (FTT-PET) as a PARP inhibitor (PARPi) therapy predictive imaging biomarker and the use of EnhanceAR-Seq (ctDNA) in predicting response to therapy and to identify… Read more about this study
- Who is it for?
- Ages 18 years and older, men only
- Conditions the study is for
- Metastatic Prostate Cancer, Prostate Cancer
- What is being tested?
- 1-(4-(2-Fluoroethoxy)phenyl)-8,9-dihiydro-2,7,9a-triazabenzo[cd]azulen-6(7H)-one, FTT-PET/CT and EnhanceAR-Seq
- Type of treatment
- Injection or infusion, Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 75 participants
- Where
- 3 sitesUnited States
- Study dates
- 1 Nov 2026to 31 May 2032
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
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
- Men only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Adult male patients 18 years of age or older
- mCRPC with confirmed germline or somatic HRR (such as ATM, ATR, BRCA1, BRCA2, CDK12, CHEK2, FANCA, MLH1, MRE11A, NBN, PALB2, or RAD51C for Talazoparib/enzalutamide and ATMm, BRCA1m, BRCA2m, BARD1m, BRIP1m, CDK12m, CHEK1m, CHEK2m, FANCLm, PALB2m, RAD51Bm, RAD51Cm, RAD51Dm, RAD54Lm; gBRCA1m, gBRCA2m; ATMm, BRCA1m, BRCA2m for Olaparib +/- abiraterone) mutations who are scheduled for SOC PARPi therapy.
- Lesion size of at least 1.0 cm in longest dimension by imaging. If non-measurable, lesion needs to be clearly detected on other imaging studies such as bone scintigraphy, FDG-PET, PSMA-PET or MRI.
- On continuous androgen deprivation therapy (ADT) with appropriately suppressed castrate testosterone levels of < 50 ng/dL, or prior bilateral orchiectomy.
- Serum PSA of 2 ng/mL or greater.
- Eastern Cooperative Oncology Group (ECOG) performance status of 0-2.
- Able to give informed consent
Who cannot join
- Receipt of prior PARP inhibitor therapy in any disease setting.
- Patients with other invasive malignancies, with the exception of non-melanoma skin cancer, who had (or have) any evidence of the other cancer that is active at the time of enrollment.
- Unable to tolerate approximately 30 min (total time) of PET/CT imaging.
Trial locations and contacts
3 sites in 1 country. Contact the study team or a site near you to ask about taking part.
United States3 sites
University of Texas MD Anderson Cancer Center
Houston, Texas, 77030
Lilie Lin, MD, 713-792-2121
Lilie Lin, MD
University of Pennsylvania Abramson Cancer Center
Philadelphia, Pennsylvania, 19104
Nei Taunk, MD, 215-662-6515, taunk@upenn.edu
Nei Taunk, MD
Washington University School of Medicine
St Louis, Missouri, 63110
Farrokh Dehdashti, MD, 314-362-1474, dehdashtif@wustl.edu
Kooresh I Shoghi, PhD
About this study
Official title: Integration of FTT-PET and ctDNA to Predict Response to PARP Inhibitor Therapy in Metastatic Prostate Cancer (mPC)
This multicenter center, open-label, baseline-controlled diagnostic imaging study designed to assess the use of Fluorthanatrace-Positron Emission tomography (FTT-PET) as a PARP inhibitor (PARPi) therapy predictive imaging biomarker and the use of EnhanceAR-Seq (ctDNA) in predicting response to therapy and to identify genomic alterations associated with resistance. Furthermore, to correlate changes in ctDNA and imaging (FTT-PET and standard of care imaging) to understand the dynamics of tumor response.
- Conditions
- Metastatic Prostate Cancer, Prostate Cancer
- Being tested
- 1-(4-(2-Fluoroethoxy)phenyl)-8,9-dihiydro-2,7,9a-triazabenzo[cd]azulen-6(7H)-one, FTT-PET/CT, EnhanceAR-Seq
- Keywords
- PARP, FTT, PET, Prostate cancer
- Medical subject headings
- Prostatic Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
1-(4-(2-Fluoroethoxy)phenyl)-8,9-dihiydro-2,7,9a-triazabenzo[cd]azulen-6(7H)-oneDrug
Also called FTT, [18F]FluorThanatrace, [18F]FTT
[18F]fluorthanatrace (FTT) is a positron emitting radiopharmaceutical that is administered as an intravenous (IV) solution via injection at a prescribed dose of 10mCi. A lesser dose may be injected if complete imaging data could be generated.
FTT-PET/CTDevice
A small intravenous (IV) catheter will be placed in the arm vein according to site's standard practice to allow injection of FTT. Approximately sixty minutes following administration of approximately 10 mCi of the radiotracer FTT, patients will undergo standard body PET/CT imaging.
EnhanceAR-SeqDiagnostic test
Patients will undergo approximately 30 mL of peripheral blood sample collection to be used for analysis. For each sample, EnhanceAR-Seq will be performed on each of these samples, with somatic genomic alteration calling performed in plasma cell-free DNA with removal of background non-tumor variants using matched plasma-depleted whole blood germline samples.
| Study group | Role | What they receive |
|---|---|---|
| FTT-PET/CT | Experimental | Participants will undergo two FluorThanatrace (FTT) Positron Emission Tomography/Computed tomography (PET/CT) scans; one at baseline prior to starting standard of care (SOC) PARP inhibitor (PARPi) therapy and one two weeks after initiation of PARPi therapy. Each cycle of PARPi therapy is 28 days.
Blood samples for EnhanceAR-Seq ctDNA analysis will be collected from participants at baseline prior to therapy, post cycle 1,12 weeks after PARPi initiation, and at time of disease progression.
Eight participants will undergo an additional FTT-PET/CT prior to initiation of PARPi therapy. Receives: Drug: 1-(4-(2-Fluoroethoxy)phenyl)-8,9-dihiydro-2,7,9a-triazabenzo[cd]azulen-6(7H)-one; Device: FTT-PET/CT; Diagnostic Test: EnhanceAR-Seq |
What is being measured
The primary outcome is the main question the study is designed to answer.
Prediction performance of FTT-PET as measured by concordance index (C-index)
Prediction performance of FTT-PET in predicting participant response to PARPi therapy will be assessed by concordance index (C-index). The C-index is mathematically calculated as the number of concordant pairs divided by the number of comparable pairs. A C-index of 1 indicates perfect ranking, values close to 0.5 indicate random prediction, and values between 0.5 and 1 suggest some predictive ability (a value below 0.5 can be reversed by switching the response's 0 and 1 labels).
Measured: At baseline prior to PARPi therapy and post cycle 1 (estimated total time 28 days)
Prediction performance of FTT-PET as measured by area under the receiver operating characteristic (ROC) curve
Prediction performance of FTT-PET in predicting participant response to PARPi therapy will be assessed by the area under the ROC curve. The ROC curve is a graphical plot that illustrates the performance of a model at various threshold settings and the area under the curve (AUC) is a single scalar value between 0 and 1 that summarizes the model performance. A higher AUC value indicates better performance.
Measured: At baseline prior to PARPi therapy and post cycle 1 (estimated total time 28 days)
Prediction performance of EnhanceAR-Seq ctDNAas measured by concordance index (C-index)
Prediction performance of EnhanceAR-Seq ctDNA analysis in predicting participant response to PARPi therapy will be assessed by concordance index (C-index). The C-index is calculated as the number of concordant pairs divided by the number of comparable pairs. A C-index of 1 indicates perfect ranking, values close to 0.5 indicate random prediction, and values between 0.5 and 1 suggest some predictive ability (a value below 0.5 can be reversed by switching the response's 0 and 1 labels).
Measured: At baseline prior to PARPi therapy, post cycle 1 (cycle is an estimated 28 days), 12 weeks after start of PARPi therapy, and at progression if applicable (estimated total time 6 months)
Prediction performance of EnhanceAR-Seq ctDNA as measured by area under the receiver operating characteristic (ROC) curve
Prediction performance of EnhanceAR-Seq ctDNA analysis in predicting participant response to PARPi therapy will be assessed by the area under the ROC curve. The ROC curve is a graphical plot that illustrates the performance of a model at various threshold settings and the area under the curve (AUC) is a single scalar value between 0 and 1 that summarizes the model performance. A higher AUC value indicates better performance.
Measured: At baseline prior to PARPi therapy, post cycle 1 (cycle is an estimated 28 days), 12 weeks after start of PARPi therapy, and at progression if applicable (estimated total time 6 months)
Prediction performance of FTT-PET and EnhanceAR-Seq ctDNA collectively as measured by concordance index (C-index)
Prediction performance of FTT-PET and EnhanceAR-Seq ctDNA analysis collectively in predicting participant response to PARPi therapy will be assessed by concordance index (C-index). The C-index is calculated as the number of concordant pairs divided by the number of comparable pairs. A C-index of 1 indicates perfect ranking, values close to 0.5 indicate random prediction, and values between 0.5 and 1 suggest some predictive ability (a value below 0.5 can be reversed by switching the response's 0 and 1 labels).
Measured: At baseline prior to PARPi therapy, post cycle 1 (cycle is an estimated 28 days), and at progression if applicable (estimated total time 6 months)
Prediction performance of FTT-PET and EnhanceAR-Seq ctDNA collectively as measured by area under the receiver operating characteristic (ROC) curve
Prediction performance of FTT-PET and EnhanceAR-Seq ctDNA analysis collectively in predicting participant response to PARPi therapy will be assessed by the area under the ROC curve. The ROC curve is a graphical plot that illustrates the performance of a model at various threshold settings and the area under the curve (AUC) is a single scalar value between 0 and 1 that summarizes model performance. A higher AUC value indicates better performance.
Measured: At baseline prior to PARPi therapy, post cycle 1 (cycle is an estimated 28 days), and at progression if applicable (estimated total time 6 months)
Sensitivity of EnhanceAR-Seq ctDNA in identifying mPC patients who respond to PARPi therapy
Sensitivity is calculated as the proportion of true positives divided by the sum of true positives and false negatives. The area under the Receiver Operating Characteristic (ROC) curve will be calculated to identify the optimal cutpoint on the ROC corresponding to the maximized Youden index to evaluate sensitivity. The ROC curve is a graphical plot that illustrates the performance of a model at various threshold settings and the area under the curve (AUC) is a single scalar value between 0 and 1 that summarizes model performance. A higher AUC value indicates better performance.
Measured: At baseline prior to PARPi therapy, post cycle 1 (cycle is an estimated 28 days), 12 weeks after start of PARPi therapy, and at progression if applicable (estimated total time 6 months)
Specificity of EnhanceAR-Seq ctDNA in identifying mPC patients who respond to PARPi therapy
Specificity is calculated as the proportion of true negatives divided by the sum of true negatives and false positives. The area under the Receiver Operating Characteristic (ROC) curve will be calculated to identify the optimal cutpoint on the ROC corresponding to the maximized Youden index to evaluate specificity. The ROC curve is a graphical plot that illustrates the performance of a model at various threshold settings and the area under the curve (AUC) is a single scalar value between 0 and 1 that summarizes the performance of model. A higher AUC value indicates better performance.
Measured: At baseline prior to PARPi therapy, post cycle 1 (cycle is an estimated 28 days), 12 weeks after start of PARPi therapy, and at progression if applicable (estimated total time 6 months)
Positive predictive value (PPV) of EnhanceAR-Seq ctDNA in identifying mPC patients who respond to PARPi therapy
PPV is calculated as the number of true positives divided by the sum of the number of true positives and number of false positives. The area under the Receiver Operating Characteristic (ROC) curve will be calculated to identify the optimal cutpoint on the ROC corresponding to the maximized Youden index to evaluate PPV. The ROC curve is a graphical plot that illustrates the performance of a model at various threshold settings and the area under the curve (AUC) is a single scalar value between 0 and 1 that summarizes model performance. A higher AUC value indicates better performance.
Measured: At baseline prior to PARPi therapy, post cycle 1 (cycle is an estimated 28 days), 12 weeks after start of PARPi therapy, and at progression if applicable (estimated total time 6 months)
Negative predictive value (NPV) of EnhanceAR-Seq ctDNA in identifying mPC patients who respond to PARPi therapy
NPV is calculated as the number of true negatives divided by the sum of the number of true negatives and number of false negatives. The area under the Receiver Operating Characteristic (ROC) curve will be calculated to identify the optimal cutpoint on the ROC corresponding to the maximized Youden index to evaluate NPV. The ROC curve is a graphical plot that illustrates the performance of a model at various threshold settings and the area under the curve (AUC) is a single scalar value between 0 and 1 that summarizes model performance. A higher AUC value indicates better performance.
Measured: At baseline prior to PARPi therapy, post cycle 1 (cycle is an estimated 28 days), 12 weeks after start of PARPi therapy, and at progression if applicable (estimated total time 6 months)
Predictive performance improvement as measured by change in concordance index of FTT-PET and EnhanceAR-seq ctDNA compared to only FTT-PET or only EnhanceAR-seq ctDNA
Prediction performance of FTT-PET and EnhanceAR-seq ctDNA in predicting participant response to PARPi therapy will be assessed by the concordance index (C-index). The C-index is calculated as the number of concordant pairs divided by the number of comparable pairs. A C-index of 1 indicates perfect ranking, values close to 0.5 indicate random prediction, and values between 0.5 and 1 suggest some predictive ability prediction (a value below 0.5 can be reversed by switching the response's 0 and 1 labels).
Measured: At baseline prior to PARPi therapy, post cycle 1 (cycle is an estimated 28 days), 12 weeks after start of PARPi therapy, and at progression if applicable (estimated total time 6 months)
Predictive performance improvement as measured by area under the receiver operating characteristic (ROC) curve of FTT-PET and EnhanceAR-seq ctDNA compared to only FTT-PET or only EnhanceAR-seq ctDNA
Prediction performance of FTT-PET and EnhanceAR-seq ctDNA in predicting participant response to PARPi therapy will be assessed by the area under the ROC curve. The ROC curve is a graphical plot that illustrates the performance of a model at various threshold settings and the area under the curve (AUC) is a single scalar value between 0 and 1 that summarizes model performance. A higher AUC value indicates better performance.
Measured: At baseline prior to PARPi therapy, post cycle 1 (cycle is an estimated 28 days), 12 weeks after start of PARPi therapy, and at progression if applicable (estimated total time 6 months)
Secondary outcomes (10)
Test-Retest Only: Lin's intra-class correlation coefficient of FTT-PET imaging
Defined as concordance between a new test or measurement (Y) and a gold standard test or measurement (X). This statistic quantifies the agreement between these two measures of the same variable. Ranges from -1 to 1, with perfect agreement at 1.
Measured: At baseline prior to PARPi therapy, at retest scan 1-14 days after baseline scan, and post-cycle 1 (estimated total time 28 days)
Correlation between FTT-PET imaging and tumor mutation burden (TMBddr) as assessed by Spearman or Pearson correlation coefficient
TMBddr is the number of genetic mutation in tumor cells that can affect patient response and will be assessed through EnhanceAR-Seq ctDNA.
Spearman's correlation coefficient evaluates the association and the association's direction between two ranked continuous variables. Spearman's correlation coefficient ranges from -1 to 1, with a negative number indicating a negative relationship between variables and a positive number indicating a positive relationship between variables. Values closer to zero indicate a weak relationship.
Pearson's correlation coefficient is a measure that evaluates the association between two continuous variables with the assumption that the variables have a linear relationship. Pearson's correlation coefficient ranges from -1 to 1, with a negative number indicating a negative relationship between variables and a positive number indicating a positive relationship between variables. Values closer to zero indicate a weak relationship.
Measured: At baseline and post cycle 1 (estimated total time 28 days)
Correlation between FTT-PET imaging and variant allele frequency (VAF) as assessed by Spearman or Pearson correlation coefficient
VAF represents the fraction of variant sequencing reads within a genetic locus and will be assessed through EnhanceAR-Seq ctDNA.
Spearman's correlation coefficient evaluates the association and the association's direction between two ranked continuous variables. Spearman's correlation coefficient ranges from -1 to 1, with a negative number indicating a negative relationship between variables and a positive number indicating a positive relationship between variables. Values closer to zero indicate a weak relationship.
Pearson's correlation coefficient is a measure that evaluates the association between two continuous variables with the assumption that the variables have a linear relationship. Pearson's correlation coefficient ranges from -1 to 1, with a negative number indicating a negative relationship between variables and a positive number indicating a positive relationship between variables. Values closer to zero indicate a weak relationship.
Measured: At baseline and post cycle 1 (estimated total time 28 days)
Correlation between FTT-PET imaging and dynamic changes in ctDNA levels as assessed by Spearman or Pearson correlation coefficient
Dynamic changes in ctDNA refer to measurable changes in circulating tumor DNA in patient's blood over time and will be assessed through EnhanceAR-Seq ctDNA.
Spearman's correlation coefficient evaluates the association and the association's direction between two ranked continuous variables. Spearman's correlation coefficient ranges from -1 to 1, with a negative number indicating a negative relationship between variables and a positive number indicating a positive relationship between variables. Values closer to zero indicate a weak relationship.
Pearson's correlation coefficient is a measure that evaluates the association between two continuous variables with the assumption that the variables have a linear relationship. Pearson's correlation coefficient ranges from -1 to 1, with a negative number indicating a negative relationship between variables and a positive number indicating a positive relationship between variables. Values closer to zero indicate a weak relationship.
Measured: At baseline and post cycle 1 (estimated total time 28 days)
Correlation between FTT-PET imaging and prostate-specific antigen (PSA) levels as assessed by Spearman or Pearson correlation coefficient
Changes PSA levels in the blood over time will be assessed through EnhanceAR-Seq ctDNA.
Spearman's correlation coefficient evaluates the association and the association's direction between two ranked continuous variables. Spearman's correlation coefficient ranges from -1 to 1, with a negative number indicating a negative relationship between variables and a positive number indicating a positive relationship between variables. Values closer to zero indicate a weak relationship.
Pearson's correlation coefficient is a measure that evaluates the association between two continuous variables with the assumption that the variables have a linear relationship. Pearson's correlation coefficient ranges from -1 to 1, with a negative number indicating a negative relationship between variables and a positive number indicating a positive relationship between variables. Values closer to zero indicate a weak relationship.
Measured: At baseline and post cycle 1 (estimated total time 28 days)
Correlation between FTT-PET imaging and tumor mutation burden (TMBddr) as assessed by Kappa agreement coefficient
TMBddr is the number of genetic mutation in tumor cells that can affect patient response and will be assessed through EnhanceAR-Seq ctDNA.
The Kappa agreement measure is calculated to evaluated inter-rater reliability. Kappa coefficient scores range from -1 to 1 with scores closer to 0 indicate poor or little agreement and scores of 1 or -1 indicating perfect agreement.
Measured: At baseline and post cycle 1 (estimated total time 28 days)
Correlation between FTT-PET imaging and variant allele frequency (VAF) as assessed by Kappa agreement coefficient
VAF represents the fraction of variant sequencing reads within a genetic locus and will be assessed through EnhanceAR-Seq ctDNA.
The Kappa agreement measure is calculated to evaluate inter-rater reliability. Kappa coefficient scores range from -1 to 1, with scores closer to 0 indicating poor or little agreement and scores of 1 or -1 indicating perfect agreement.
Measured: At baseline and post cycle 1 (estimated total time 28 days)
Correlation between FTT-PET imaging and dynamic changes in ctDNA level as assessed by Kappa agreement coefficient
Dynamic changes in ctDNA refer to measurable changes in circulating tumor DNA in patient's blood over time and will be assessed through EnhanceAR-Seq ctDNA.
The Kappa agreement measure is calculated to evaluated inter-rater reliability. Kappa coefficient scores range from -1 to 1, with scores closer to 0 indicating poor or little agreement and scores of 1 or -1 indicating perfect agreement.
Measured: At baseline and post cycle 1 (estimated total time 28 days)
Correlation between FTT-PET imaging and prostate-specific antigen (PSA) as assessed by Kappa agreement coefficient
Changes PSA levels in the blood over time will be assessed through EnhanceAR-Seq ctDNA.
The Kappa agreement measure is calculated to evaluate inter-rater reliability. Kappa coefficient scores range from -1 to 1, with scores closer to 0 indicating poor or little agreement and scores of 1 or -1 indicating perfect agreement.
Measured: At baseline and post cycle 1 (estimated total time 28 days)
Association of FTT-PET and EnhanceAR-Seq metrics with patient response based on relative risk
Relative risk is a measure of the ratio of the risk of a certain event in an exposed group compared to the risk of the same event in a control group. A relative risk of 1.0 indicates no difference in risk between the groups, greater than 1.0 indicates increased risk in the exposed group, and less than 1.0 indicates decreased risk in the exposed group.
Measured: From enrollment to time of progression (estimated total time 6 months)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Jul 2026
- Study start1 Nov 2026 (estimated)
- Primary completion31 May 2032 (estimated)
- Study completion31 May 2032 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Metastatic Prostate CancerStudies of the same condition, open and under way.
- More trials run by Washington University School of MedicineThe sponsor's other registered studies.
- 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
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 75 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Washington University School of Medicine
- Sponsor type
- University, hospital or other
- Collaborators
- National Cancer Institute (NCI)
- Responsible party
- Sponsor
- Investigators
- Farrokh Dehdashti, MD, Principal investigator, Washington University School of Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07723651
- Sponsor's protocol ID
- 202605165
- Other IDs
- R01CA306993
- Status last verified
- Oct 2026
- First submitted
- 19 Jul 2026
- Last updated
- 21 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- Yes
- Individual data sharing
- Yes: De-identified individual participant data collected during the trial, metadata collection, and supporting files will be shared via National Cancer Institute (NCI) repositories. Deidentified clinical images will be shared through The Cancer Imaging Archive (TCIA) and the Imaging Data Commons (IDC) of NCI. Genomic data will be shared via the NCI Genomic Data Commons (GDC).
Study at a glance
From the registry record, last updated by the sponsor on 21 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Integration of FTT-PET and ctDNA to Predict Response to PARP Inhibitor Therapy in Metastatic Prostate Cancer (mPC)
- ClinicalTrials.gov ID
- NCT07723651
- Acronym / sponsor ID
- 202605165
- Conditions
- Metastatic Prostate Cancer, Prostate Cancer
- Keywords
- PARP, FTT, PET, Prostate cancer
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 75 participants (estimated)
- Lead sponsor
- Washington University School of MedicineUniversity, hospital or other
- Collaborators
- National Cancer Institute (NCI)
- Study start
- 1 Nov 2026 (estimated)
- Primary completion
- 31 May 2032 (estimated)
- Study completion
- 31 May 2032 (estimated)
- First posted
- 23 Jul 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This multicenter center, open-label, baseline-controlled diagnostic imaging study designed to assess the use of Fluorthanatrace-Positron Emission tomography (FTT-PET) as a PARP inhibitor (PARPi) therapy predictive imaging biomarker and the use of EnhanceAR-Seq (ctDNA) in predicting response to therapy and to identify genomic alterations associated with resistance. Furthermore, to correlate changes in ctDNA and imaging (FTT-PET and standard of care imaging) to understand the dynamics of tumor response.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| FTT-PET/CT | Experimental | Drug: 1-(4-(2-Fluoroethoxy)phenyl)-8,9-dihiydro-2,7,9a-triazabenzo[cd]azulen-6(7H)-one, Device: FTT-PET/CT, Diagnostic Test: EnhanceAR-SeqParticipants will undergo two FluorThanatrace (FTT) Positron Emission Tomography/Computed tomography (PET/CT) scans; one at baseline prior to starting standard of care (SOC) PARP inhibitor (PARPi) therapy and one two weeks after initiation of PARPi therapy. Each cycle of PARPi therapy is 28 days. Blood samples for EnhanceAR-Seq ctDNA analysis will be collected from participants at baseline prior to therapy, post cycle 1,12 weeks after PARPi initiation, and at time of disease progression. Eight participants will undergo an additional FTT-PET/CT prior to initiation of PARPi therapy. |
Who may qualify
- Ages
- 18 years and older
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- Adult male patients 18 years of age or older
- mCRPC with confirmed germline or somatic HRR (such as ATM, ATR, BRCA1, BRCA2, CDK12, CHEK2, FANCA, MLH1, MRE11A, NBN, PALB2, or RAD51C for Talazoparib/enzalutamide and ATMm, BRCA1m, BRCA2m, BARD1m, BRIP1m, CDK12m, CHEK1m, CHEK2m, FANCLm, PALB2m, RAD51Bm, RAD51Cm, RAD51Dm, RAD54Lm; gBRCA1m, gBRCA2m; ATMm, BRCA1m, BRCA2m for Olaparib +/- abiraterone) mutations who are scheduled for SOC PARPi therapy.
- Lesion size of at least 1.0 cm in longest dimension by imaging. If non-measurable, lesion needs to be clearly detected on other imaging studies such as bone scintigraphy, FDG-PET, PSMA-PET or MRI.
- On continuous androgen deprivation therapy (ADT) with appropriately suppressed castrate testosterone levels of < 50 ng/dL, or prior bilateral orchiectomy.
- Serum PSA of 2 ng/mL or greater.
Key exclusion criteria (3 listed)
- Receipt of prior PARP inhibitor therapy in any disease setting.
- Patients with other invasive malignancies, with the exception of non-melanoma skin cancer, who had (or have) any evidence of the other cancer that is active at the time of enrollment.
- Unable to tolerate approximately 30 min (total time) of PET/CT imaging.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| 1-(4-(2-Fluoroethoxy)phenyl)-8,9-dihiydro-2,7,9a-triazabenzo[cd]azulen-6(7H)-oneAlso: FTT, [18F]FluorThanatrace, [18F]FTT[18F]fluorthanatrace (FTT) is a positron emitting radiopharmaceutical that is administered as an intravenous (IV) solution via injection at a prescribed dose of 10mCi. A lesser dose may be injected if complete imaging data could be generated. | Drug | FTT-PET/CT |
| FTT-PET/CTA small intravenous (IV) catheter will be placed in the arm vein according to site's standard practice to allow injection of FTT. Approximately sixty minutes following administration of approximately 10 mCi of the radiotracer FTT, patients will undergo standard body PET/CT imaging. | Device | FTT-PET/CT |
| EnhanceAR-SeqPatients will undergo approximately 30 mL of peripheral blood sample collection to be used for analysis. For each sample, EnhanceAR-Seq will be performed on each of these samples, with somatic genomic alteration calling performed in plasma cell-free DNA with removal of background non-tumor variants using matched plasma-depleted whole blood germline samples. | Diagnostic test | FTT-PET/CT |
Primary outcome
Prediction performance of FTT-PET as measured by concordance index (C-index)
Time frame: At baseline prior to PARPi therapy and post cycle 1 (estimated total time 28 days)
Prediction performance of FTT-PET in predicting participant response to PARPi therapy will be assessed by concordance index (C-index). The C-index is mathematically calculated as the number of concordant pairs divided by the number of comparable pairs. A C-index of 1 indicates perfect ranking, values close to 0.5 indicate random prediction, and values between 0.5 and 1 suggest some predictive ability (a value below 0.5 can be reversed by switching the response's 0 and 1 labels).
Prediction performance of FTT-PET as measured by area under the receiver operating characteristic (ROC) curve
Time frame: At baseline prior to PARPi therapy and post cycle 1 (estimated total time 28 days)
Prediction performance of FTT-PET in predicting participant response to PARPi therapy will be assessed by the area under the ROC curve. The ROC curve is a graphical plot that illustrates the performance of a model at various threshold settings and the area under the curve (AUC) is a single scalar value between 0 and 1 that summarizes the model performance. A higher AUC value indicates better performance.
Prediction performance of EnhanceAR-Seq ctDNAas measured by concordance index (C-index)
Time frame: At baseline prior to PARPi therapy, post cycle 1 (cycle is an estimated 28 days), 12 weeks after start of PARPi therapy, and at progression if applicable (estimated total time 6 months)
Prediction performance of EnhanceAR-Seq ctDNA analysis in predicting participant response to PARPi therapy will be assessed by concordance index (C-index). The C-index is calculated as the number of concordant pairs divided by the number of comparable pairs. A C-index of 1 indicates perfect ranking, values close to 0.5 indicate random prediction, and values between 0.5 and 1 suggest some predictive ability (a value below 0.5 can be reversed by switching the response's 0 and 1 labels).
Prediction performance of EnhanceAR-Seq ctDNA as measured by area under the receiver operating characteristic (ROC) curve
Time frame: At baseline prior to PARPi therapy, post cycle 1 (cycle is an estimated 28 days), 12 weeks after start of PARPi therapy, and at progression if applicable (estimated total time 6 months)
Prediction performance of EnhanceAR-Seq ctDNA analysis in predicting participant response to PARPi therapy will be assessed by the area under the ROC curve. The ROC curve is a graphical plot that illustrates the performance of a model at various threshold settings and the area under the curve (AUC) is a single scalar value between 0 and 1 that summarizes the model performance. A higher AUC value indicates better performance.
Prediction performance of FTT-PET and EnhanceAR-Seq ctDNA collectively as measured by concordance index (C-index)
Time frame: At baseline prior to PARPi therapy, post cycle 1 (cycle is an estimated 28 days), and at progression if applicable (estimated total time 6 months)
Prediction performance of FTT-PET and EnhanceAR-Seq ctDNA analysis collectively in predicting participant response to PARPi therapy will be assessed by concordance index (C-index). The C-index is calculated as the number of concordant pairs divided by the number of comparable pairs. A C-index of 1 indicates perfect ranking, values close to 0.5 indicate random prediction, and values between 0.5 and 1 suggest some predictive ability (a value below 0.5 can be reversed by switching the response's 0 and 1 labels).
Prediction performance of FTT-PET and EnhanceAR-Seq ctDNA collectively as measured by area under the receiver operating characteristic (ROC) curve
Time frame: At baseline prior to PARPi therapy, post cycle 1 (cycle is an estimated 28 days), and at progression if applicable (estimated total time 6 months)
Prediction performance of FTT-PET and EnhanceAR-Seq ctDNA analysis collectively in predicting participant response to PARPi therapy will be assessed by the area under the ROC curve. The ROC curve is a graphical plot that illustrates the performance of a model at various threshold settings and the area under the curve (AUC) is a single scalar value between 0 and 1 that summarizes model performance. A higher AUC value indicates better performance.
Sensitivity of EnhanceAR-Seq ctDNA in identifying mPC patients who respond to PARPi therapy
Time frame: At baseline prior to PARPi therapy, post cycle 1 (cycle is an estimated 28 days), 12 weeks after start of PARPi therapy, and at progression if applicable (estimated total time 6 months)
Sensitivity is calculated as the proportion of true positives divided by the sum of true positives and false negatives. The area under the Receiver Operating Characteristic (ROC) curve will be calculated to identify the optimal cutpoint on the ROC corresponding to the maximized Youden index to evaluate sensitivity. The ROC curve is a graphical plot that illustrates the performance of a model at various threshold settings and the area under the curve (AUC) is a single scalar value between 0 and 1 that summarizes model performance. A higher AUC value indicates better performance.
Specificity of EnhanceAR-Seq ctDNA in identifying mPC patients who respond to PARPi therapy
Time frame: At baseline prior to PARPi therapy, post cycle 1 (cycle is an estimated 28 days), 12 weeks after start of PARPi therapy, and at progression if applicable (estimated total time 6 months)
Specificity is calculated as the proportion of true negatives divided by the sum of true negatives and false positives. The area under the Receiver Operating Characteristic (ROC) curve will be calculated to identify the optimal cutpoint on the ROC corresponding to the maximized Youden index to evaluate specificity. The ROC curve is a graphical plot that illustrates the performance of a model at various threshold settings and the area under the curve (AUC) is a single scalar value between 0 and 1 that summarizes the performance of model. A higher AUC value indicates better performance.
Positive predictive value (PPV) of EnhanceAR-Seq ctDNA in identifying mPC patients who respond to PARPi therapy
Time frame: At baseline prior to PARPi therapy, post cycle 1 (cycle is an estimated 28 days), 12 weeks after start of PARPi therapy, and at progression if applicable (estimated total time 6 months)
PPV is calculated as the number of true positives divided by the sum of the number of true positives and number of false positives. The area under the Receiver Operating Characteristic (ROC) curve will be calculated to identify the optimal cutpoint on the ROC corresponding to the maximized Youden index to evaluate PPV. The ROC curve is a graphical plot that illustrates the performance of a model at various threshold settings and the area under the curve (AUC) is a single scalar value between 0 and 1 that summarizes model performance. A higher AUC value indicates better performance.
Negative predictive value (NPV) of EnhanceAR-Seq ctDNA in identifying mPC patients who respond to PARPi therapy
Time frame: At baseline prior to PARPi therapy, post cycle 1 (cycle is an estimated 28 days), 12 weeks after start of PARPi therapy, and at progression if applicable (estimated total time 6 months)
NPV is calculated as the number of true negatives divided by the sum of the number of true negatives and number of false negatives. The area under the Receiver Operating Characteristic (ROC) curve will be calculated to identify the optimal cutpoint on the ROC corresponding to the maximized Youden index to evaluate NPV. The ROC curve is a graphical plot that illustrates the performance of a model at various threshold settings and the area under the curve (AUC) is a single scalar value between 0 and 1 that summarizes model performance. A higher AUC value indicates better performance.
Predictive performance improvement as measured by change in concordance index of FTT-PET and EnhanceAR-seq ctDNA compared to only FTT-PET or only EnhanceAR-seq ctDNA
Time frame: At baseline prior to PARPi therapy, post cycle 1 (cycle is an estimated 28 days), 12 weeks after start of PARPi therapy, and at progression if applicable (estimated total time 6 months)
Prediction performance of FTT-PET and EnhanceAR-seq ctDNA in predicting participant response to PARPi therapy will be assessed by the concordance index (C-index). The C-index is calculated as the number of concordant pairs divided by the number of comparable pairs. A C-index of 1 indicates perfect ranking, values close to 0.5 indicate random prediction, and values between 0.5 and 1 suggest some predictive ability prediction (a value below 0.5 can be reversed by switching the response's 0 and 1 labels).
Predictive performance improvement as measured by area under the receiver operating characteristic (ROC) curve of FTT-PET and EnhanceAR-seq ctDNA compared to only FTT-PET or only EnhanceAR-seq ctDNA
Time frame: At baseline prior to PARPi therapy, post cycle 1 (cycle is an estimated 28 days), 12 weeks after start of PARPi therapy, and at progression if applicable (estimated total time 6 months)
Prediction performance of FTT-PET and EnhanceAR-seq ctDNA in predicting participant response to PARPi therapy will be assessed by the area under the ROC curve. The ROC curve is a graphical plot that illustrates the performance of a model at various threshold settings and the area under the curve (AUC) is a single scalar value between 0 and 1 that summarizes model performance. A higher AUC value indicates better performance.
10 secondary outcomes
Test-Retest Only: Lin's intra-class correlation coefficient of FTT-PET imaging
Time frame: At baseline prior to PARPi therapy, at retest scan 1-14 days after baseline scan, and post-cycle 1 (estimated total time 28 days)
Correlation between FTT-PET imaging and tumor mutation burden (TMBddr) as assessed by Spearman or Pearson correlation coefficient
Time frame: At baseline and post cycle 1 (estimated total time 28 days)
Correlation between FTT-PET imaging and variant allele frequency (VAF) as assessed by Spearman or Pearson correlation coefficient
Time frame: At baseline and post cycle 1 (estimated total time 28 days)
Correlation between FTT-PET imaging and dynamic changes in ctDNA levels as assessed by Spearman or Pearson correlation coefficient
Time frame: At baseline and post cycle 1 (estimated total time 28 days)
Correlation between FTT-PET imaging and prostate-specific antigen (PSA) levels as assessed by Spearman or Pearson correlation coefficient
Time frame: At baseline and post cycle 1 (estimated total time 28 days)
Correlation between FTT-PET imaging and tumor mutation burden (TMBddr) as assessed by Kappa agreement coefficient
Time frame: At baseline and post cycle 1 (estimated total time 28 days)
Correlation between FTT-PET imaging and variant allele frequency (VAF) as assessed by Kappa agreement coefficient
Time frame: At baseline and post cycle 1 (estimated total time 28 days)
Correlation between FTT-PET imaging and dynamic changes in ctDNA level as assessed by Kappa agreement coefficient
Time frame: At baseline and post cycle 1 (estimated total time 28 days)
Correlation between FTT-PET imaging and prostate-specific antigen (PSA) as assessed by Kappa agreement coefficient
Time frame: At baseline and post cycle 1 (estimated total time 28 days)
Association of FTT-PET and EnhanceAR-Seq metrics with patient response based on relative risk
Time frame: From enrollment to time of progression (estimated total time 6 months)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Oct 2026.
- Alvin J. Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of MedicineLink provided by the sponsor.
- Individual participant dataSharing planned: Yes. De-identified individual participant data collected during the trial, metadata collection, and supporting files will be shared via National Cancer Institute (NCI) repositories. Deidentified clinical images will be shared through The Cancer Imaging Archive (TCIA) and the Imaging Data Commons (IDC) of NCI. Genomic data will be shared via the NCI Genomic Data Commons (GDC).
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Farrokh Dehdashti, MD principal investigator
Washington University School of Medicine
3 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing 1-(4-(2-Fluoroethoxy)phenyl)-8,9-dihiydro-2,7,9a-triazabenzo[cd]azulen-6(7H)-one, FTT-PET/CT and EnhanceAR-Seq in people with Metastatic Prostate Cancer and Prostate Cancer, run by Washington University School of Medicine at 3 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 21 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Farrokh Dehdashti, MD (314-362-1474, dehdashtif@wustl.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Prediction performance of FTT-PET as measured by concordance index (C-index) (time frame: At baseline prior to PARPi therapy and post cycle 1 (estimated total time 28 days)). The study lists 12 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Oct 2026.