Pembrolizumab TX-naive Distant Mets Melanoma and Use of (C11-AMT) PET at Baseline as Imaging Biomarker

• Sponsor: UNC Lineberger Comprehensive Cancer Center (Other)
• Overall Status: Active, not recruiting
• CT.gov ID: NCT03089606
• Collaborator: Merck Sharp & Dohme LLC (Industry)
• Enrollment: 27
• Locations: 2
• Arm: 1
• Anticipated Duration (Months): 74.4
• Patients Per Site: 13.5
• Patients Per Site Per Month: 0.2

Study Details

Study Description

Brief Summary

Explore the association between intensity of 11C-methyl-L-tryptophan (C11-AMT) positron emission tomography (PET) at baseline, as measured by mean standardized uptake value (SUVmax) at each lesion, total tumor metabolic volume, measurement of intra-tumoral and inter-lesional heterogeneity, with objective response rate (ORR) at 12 weeks (as defined via RECIST 1.1) to pembrolizumab in patients with treatment-naïve metastatic melanoma.

Condition or Disease	Intervention/Treatment	Phase
Melanoma	Diagnostic Test: FDG PET/CT scan; Diagnostic Test: C11-AMT PET scan; Drug: Pembrolizumab; Diagnostic Test: CT scan	Phase 2

Detailed Description

Objectives:

Primary Objective

Explore the association between intensity of C11-AMT PET at baseline, as measured by mean standardized uptake value (SUVmax at each lesion), total tumor metabolic volume, measurement of intra-tumoral and inter-lesional heterogeneity), with objective response rate (ORR) at 12 weeks as defined via Response evaluation criteria in solid tumors (RECIST) 1.1 to pembrolizumab in patients with Programmed Death (PD)-1 inhibitor-naïve unresectable, American Joint Committee on Cancer (AJCC) stage III or distant metastatic (stage IV) melanoma.

Secondary Objectives

Estimate ORR (CR + PR) by RECIST 1.1 at 12 weeks to pembrolizumab in patients with PD-1 inhibitor-naïve unresectable stage III or distant metastatic metastatic melanoma (AJCC stage III/IV).

Estimate progression-free survival (PFS) in patients with unresectable stage III or distant metastatic melanoma treated with pembrolizumab as front-line therapy.

Explore associations in SUVmax and other PET parameters (e.g. total tumor metabolic volume, measurement of intra-tumoral and inter-lesional heterogeneity) between C11-AMT PET and fluorodeoxyglucose (FDG)-PET at baseline.

Explore associations between SUVmax, and other PET parameters (e.g. total tumor metabolic volume, measurement of intra-tumoral and inter-lesional heterogeneity) identified at baseline C11-AMT PET imaging with expression of components of the Indoleamine-pyrrole 2,3-dioxygenase (IDO) pathway detected by immunohistochemistry (IHC) or immunofluorescence (L -type amino acid transporter 1 (LAT1), IDO, tryptophan hydroxylase (TPH1)) and lymphocyte subtypes (CD4, cluster of differentiation 8 (CD8), FoxP3, MDSC), PD-1/PD-L1, and other immune checkpoint pathways (lymphocyte-associated gene 3 (LAG3), glucocorticoid-induced tumor necrosis factor receptor (GITR), T-cell immunoglobulin and mucin domain-3 (TIM3)) in freshly acquired tumor specimens prior to treatment with pembrolizumab.

Assess metabolic changes at week 12 (or earlier, if patient progresses) following treatment with pembrolizumab using baseline and week 12 FDG PET.

Outline:

Screening:

Physical exam, medical history, and laboratory tests, as per standard of care. Brain Magnetic resonance imaging (MRI) and Whole body FDG PET/ Computed tomography (CT) scan with IV contrast will be performed at least 24 hours before C11-AMT PET scanning. Although, the FDG PET/CT scan with IV contrast is preferred the following baseline measurements may be used if they have occurred within the below specified windows:

1. Whole body FDG PET/CT scan without IV contrast, will be accepted for study purposes (i.e. correlation between baseline FDG PET scan and baseline C11-AMT scan) if it has occurred within 28 days before the C11-AMT PET scan. In this case, the patient will only be required to have a baseline CT scan of the chest, abdomen, and pelvis (also neck, if applicable) with IV contrast within 28 days of starting pembrolizumab.

2. CT scan with intravenous (IV) contrast will be accepted for study purposes (i.e. baseline tumor assessment) if it has occurred within 28 days of starting pembrolizumab. In this case, the patient will only be required to have a baseline PET scan without CT coregistration 28 days prior to C11-AMT. This is to correlate baseline FDG PET with baseline C11-AMT PET parameters.

If eligibility criteria are met, patients will proceed to Study Related Scans and Biopsy:

C11-AMT PET will be performed at least 24 hours before pembrolizumab treatment and at least 24 hours after FDG PET/CT scan. A research biopsy will be performed before pembrolizumab treatment.

After screening and study related scans and biopsy, treatment will consist of the following:

Pembrolizumab 200mg IV flat dose will be administered over 30 minutes on Day 1; Pembrolizumab dosing will be repeated every 3 weeks until progression or subject withdrawal for other reasons.

At the end of treatment:

Whole body FDG PET/CT scan with IV contrast.

Projected Accrual:

Up to 25 subjects who have not received prior therapy for their recent diagnosis of distant metastatic melanoma.

Study Design

• Study Type: Interventional
• Actual Enrollment: 27 participants
• Allocation: N/A
• Intervention Model: Single Group Assignment
• Intervention Model Description: This is a phase 2, single-arm, open-label study.This is a phase 2, single-arm, open-label study.
• Masking: None (Open Label)
• Primary Purpose: Treatment
• Official Title: Pembrolizumab in Systemic Treatment-Naïve Distant Metastatic Melanoma and Exploration of Use of Baseline 11C-methyl-L-tryptophan (C11-AMT) PET Imaging as a Predictive Imaging Biomarker of Antitumor Response
• Actual Study Start Date: Apr 19, 2017
• Actual Primary Completion Date: Apr 1, 2021
• Anticipated Study Completion Date: Jul 1, 2023

Arms and Interventions

Arm

Intervention/Treatment

Other: Single Arm This is a single arm study. All participants completed the study interventions which are pembrolizumab treatment, FDG PET, C11-AMT PET and CT scans.

Diagnostic Test: FDG PET/CT scan; 18F-fluorodeoxy glucose (FDG) positron emission tomography (PET) with intravenous (IV) contrast images are obtained before and at the end study treatment (pembrolizumab infusion).; Diagnostic Test: C11-AMT PET scan; 11C-methyl-L-tryptophan (C11-AMT) positron emission tomography (PET) images are obtained before study treatment (pembrolizumab infusion).; Drug: Pembrolizumab; 200 mg Pembrolizumab IV administered over 30 minutes on day 1. Repeat every 3 weeks for 4 cycles, until progression, or subject withdrawal for other reasons; Other Names: Keytruda ; Diagnostic Test: CT scan; Computerized tomography (CT) images are taken without IV contrast before the treatment (pembrolizumab infusion) and with IV contrast 3 months after the treatment start.

Outcome Measures

Primary Outcome Measures

1. Association of Baseline C11-AMT PET SUV Max Value With Objective Response [12 weeks]

   Association between intensity of C11-AMT PET at baseline, as measured by maximum standardized uptake value (SUV max) and objective response (OR) using computerized tomography images with intravenous contrast, as defined via RECIST v.1.1, at 12 weeks. Subject is considered responder if subject has CR or PR while subject is considered not-responder if they do not have CR or PR at 12 weeks. RECIST v.1.1: Complete Response (CR), disappearance of all target lesions; Partial Response (PR), >=30% decrease in the sum of the longest diameter of target lesions; Stable Disease (SD), no response or less response than Partial or Progressive; or Progressive Disease (PD), as a 20% increase in the sum of the longest diameter of target lesions, or a measurable increase in a non-target lesion, or the appearance of new lesions.

Secondary Outcome Measures

1. Objective Response Rate [12 Weeks]

   Objective Response Rate (ORR) is defined as the number of the subjects with a Complete Response, Partial Response, stable disease, and progressive disease according to Response Evaluation Criteria in Solid Tumors ( RECIST 1.1) at 12 weeks after starting to study treatment. RECIST v.1.1: Complete Response (CR), disappearance of all target lesions; Partial Response (PR), >=30% decrease in the sum of the longest diameter of target lesions; Stable Disease (SD), no response or less response than Partial or Progressive; or Progressive Disease (PD), as a 20% increase in the sum of the longest diameter of target lesions, or a measurable increase in a non-target lesion, or the appearance of new lesions.

2. Progression-Free Survival [3 years]

   Progression Free Sruvival (PFS) is defined time from first day of treatment until disease progression as defined by RECIST1.1.

3. Association of Baseline FDG-PET and C11-AMT PET [Baseline]

   Associations of SUVmax values between baseline FDG-PET and baseline C11-AMT PET images were examined. To objectively determine tumor regions of interest on C11-AMT and 18F FDG PET, the voxel with the highest tracer concentration (e.g., SUVmax) was determined. The voxel with the highest AMT tracer concentration (e.g., SUVmax) as well as a background region in close proximity to the location of the tumor using the MIM vista PET viewing software (MIM software Inc., Cleveland, OH, version 7.0.5).

4. Metabolic Changes [12 weeks]

   Assess metabolic changes at week 12 (or earlier, if patient progresses) following treatment with pembrolizumab using baseline and week 12 FDG PET. Each lesion is considered independently since subjects might have some lesion with SUV max value increased and another lesion with SUV max value decreased.

5. PET Parameters and IDO [Baseline]

   Associations between SUVmax and other PET parameters (e.g. total tumor metabolic volume, measurement of intra-tumoral and inter-lesional heterogeneity) identified at baseline C11-AMT PET imaging with expression of components of the indoleamine 2,3-dioxygenase (IDO) pathway detected by immunohistochemistry (IHC) or immunofluorescence (LAT1, IDO, TPH1), lymphocyte subtypes (CD4, CD8, FoxP3, MDSC), PD-1/PD-L1, and other immune checkpoint pathways (LAG3, GITR, TIM3) in freshly acquired tumor specimens prior to treatment. The single-color indoleamine 2,3-dioxygenase pathway (IHC) staining scoring, the 0, 1+ (<25% of cells with membrane or cytoplasmic stain), 2+ (25-80% of cells with membrane of cytoplasmic stain), 3+ (>80% of cells with membrane or cytoplasmic stain) semiquantitative scale (to describe the staining intensity and percentage of positive melanoma cells) was used.

Eligibility Criteria

Criteria

• Ages Eligible for Study: 18 Years and Older
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: No

Inclusion Criteria:

1. Sign written informed consent and HIPAA authorization for release of personal health information. Note: HIPAA authorization may be included in the informed consent or obtained separately.

2. Subject must be 18 years of age or more on the day of signing informed consent.

3. Have histologic or cytologic biopsy-proven diagnosis of unresectable stage III or distant metastatic melanoma, irrespective of histologic type (i.e. cutaneous, unknown primary, mucosal, or ocular). Patients with resectable bulky stage IIIB or stage IIIC melanoma (for example at least 2.5-cm in shortest diameter for lymph nodes infiltrated by tumor and at least 2-cm in longest diameter for non-lymph nodes infiltrated by tumor) can also be entered into the study at the discretion of the Principal Investigator.

4. Have measurable disease based on RECIST v1.1. for solid tumors

5. Be willing to undergo fresh tumor tissue biopsy of an accessible tumor lesion prior to pembrolizumab. A mandatory fresh biopsy will be collected following C11-AMT PET imaging. Subjects for whom fresh samples cannot be provided (e.g. inaccessible or subject safety concern) or do not agree to this fresh tumor research biopsy of accessible tumor will be deemed ineligible for study participation. Exception to the mandatory tumor tissue collection are patients with metastatic lung lesions as the only site of metastatic disease. Fresh biopsy collection from these subjects will be optional, due to high risk of pneumothorax.

6. Be willing to allow for investigators to collect archival tumor tissues from surgical procedures that may have been performed before or after enrollment into this trial for research purposes (in-house cases and/or outside cases). These samples will be obtained by study staff as long as subject continues on follow-up. Blocks of tissue will be requested, and if blocks are not able to be obtained, 5micron slides (10-15) will be sufficient.

7. Be willing to be injected with 11C-methyl-L-tryptophan (C11-AMT)

8. Have a performance status of 0 - 2 on the Eastern Cooperative Oncology Group (ECOG) Performance Scale.

9. Has not received prior therapy with cytotoxic T lymphocyte antigen (CTLA)-4, PD-1/PD-L1 inhibitors, other co-stimulatory or co-inhibitory immune checkpoint antibody therapies (e.g. LAG3, TIM3, cluster of differentiation (CD) 137, Killer immunoglobulin-like receptor (KIR3DL), cluster of differentiation (CD) 70, and CD27) for distant metastatic melanoma. Patients who have received mitogen-activated protein kinase (MAPK) inhibitors are allowed on condition that they have recovered from adverse events to at most Grade 1 by CTCAE v4.03 and at least 15 days have elapsed between last dose of MAPK inhibitors and C11-AMT imaging. Patients who have previously received CTLA-4 inhibitors in the adjuvant setting are allowed to participate as long as they discontinued CTLA-4 treatment at least 30 days ago and meet criteria outlined in inclusion #14. Patients who have previously received adjuvant PD-1 inhibitors are excluded.

10. Demonstrate adequate organ function as defined in below; all screening labs to be obtained within 14 days prior to C11-AMT PET scan:

Hematological:

Hemoglobin (Hgb) - ≥ 9 g/dL or ≥ 5.6 mmol/L without transfusion or erythropoietin (EPO) dependency (within 7 days of Hgb) Absolute Neutrophil Count (ANC) - ≥ 1,500/mm3 Platelets - ≥ 100,000/mm3

Renal:

Serum Creatinine OR Measured or calculated creatinine clearance (GFR can also be used in place of creatinine or CrCl) - ≤1.5 x ULN OR ≥ 60 mL/min using the Cockcroft-Gault formula for subject with creatinine levels > 1.5 X institutional upper limits of normal (ULN)

Hepatic:

Serum Total Bilirubin - ≤ 1.5 X ULN Aspartate aminotransferase (AST) - ≤ 2.5 X ULN OR < 5 X ULN for subjects with liver metastases Alanine aminotransferase (ALT) - ≤ 2.5 X ULN OR < 5 X ULN for subjects with liver metastases Albumin - ≥ 2.5 mg/dL

Coagulation:

International Normalized Ratio (INR) or Prothrombin Time (PT) - ≤1.5 X ULN, unless subject is receiving anticoagulant therapy as long as PT or PTT is within therapeutic range of intended use of anticoagulants Activated Partial Thromboplastin Time (aPTT) - ≤1.5 X ULN, unless subject is receiving anticoagulant therapy as long as PT or PTT is within therapeutic range of intended use of anticoagulants

1. Female subjects of childbearing potential should have a negative urine or serum pregnancy within 14 days prior to C11-AMT PET scan. If the urine test is positive or cannot be confirmed as negative, a serum pregnancy test will be required.

2. Female subjects of childbearing potential must be willing to use adequate methods of contraception as outlined - Contraception for the course of the study through 120 days after the last dose of study medication. Subjects of childbearing potential are those who have not been surgically sterilized or have not been free from menses for > 1 year.

Note: Abstinence is acceptable if this is the usual lifestyle and preferred contraception for the subject.

Male subjects should agree to use an adequate method of contraception as outlined - Contraception starting with the first dose of study therapy through 120 days after the last dose of study therapy.

Note: Abstinence is acceptable if this is the usual lifestyle and preferred contraception for the subject.

1. Patients who have received prior adjuvant high dose interferon are allowed to participate as long as the last injection was given at least 30 days prior to the C11-AMT PET scan and they have fully recovered from side effects (i.e., Grade ≤1 or permanent side effects that require hormone replacement therapy).

2. Patients on adjuvant ipilimumab are allowed to participate at least 30 days from drug discontinuation as long as they have at most Grade 1 adverse events (or grade 2 if they have to received hormone replacement therapy for their otherwise grade 1 ipilimumab-induced autoimmune endocrinopathies).

Exclusion Criteria:

1. Is currently participating and receiving study therapy for his/her advanced melanoma or has participated in a study of an investigational agent and received study therapy in the advanced melanoma setting.

2. Has received prior treatment with PD-1/PD-L1 pathway inhibitors in the adjuvant setting.

3. Has a diagnosis of immunodeficiency or is receiving systemic steroid therapy or any other form of immunosuppressive therapy within 7 days prior to C11-AMT PET Scan

4. Has a known history of active tuberculosis (Bacillus Tuberculosis)

5. Hypersensitivity to pembrolizumab or any of its excipients described

6. Has had prior monoclonal antibody (mAb) targeting immune checkpoint proteins, for distant metastatic melanoma and have progressed or have developed intolerable side effect.

7. Adjuvant anticancer treatments are allowed at least 30 days has elapsed between the infusion/injection and C11-AMT PET scan as part of this study.

8. Prior radiation therapy for metastatic melanoma is allowed as long as the patient bears measurable actively growing disease outside the previously irradiated field. Note: If subject received major surgery, they must have recovered adequately from the toxicity (i.e., all symptoms ≤ grade 1) and/or complications from the intervention prior to starting therapy.

9. History of prior malignancy, with the exception of the following:

• Non-melanoma skin cancers, non-invasive bladder cancer, and carcinoma in situ of the cervix,

• Prior history of prostate provided patient not under active systemic treatment other than hormonal therapy and with documented undetectable prostate-specific antigen (PSA) (<0.2ng/mL),

• Chronic lymphocytic leukemia (CLL)/ small lymphocytic lymphoma (SLL) provided patient has isolated lymphocytosis (Rai stage 0), and does not require systemic treatment [for "B" symptoms, Richter's transformation, lymphocyte doubling time (<6 months), lymphadenopathy or hepatosplenomegaly],

• Lymphoma or any type or hairy-cell leukemia provided patient is not on active systemic treatment and is in complete remission, as evidenced by PET/CT scans and bone marrow biopsies for at least 3 months,

• Papillary thyroid cancer. Since this malignancy very infrequently metastasizes distantly, patients with concurrent metastatic melanoma can be enrolled even if patients may: A) have just completed thyroidectomy within the last 2 years, B) have not received adjuvant radioactive iodine therapy, C) were only recently diagnosed with asymptomatic papillary thyroid cancer and their surgery is pending.

• History of malignancy provided patient has completed therapy and is free of disease for ≥ 2 years. If patient had other malignancy within the last 2 years from which he may have been completely cured by surgery alone, he may considered to be enrolled on condition that the risk of development of distant metastatic disease based on AJCC staging system is less than 30%.

1. Has known active parenchymal central nervous system (CNS) metastases that are symptomatic, and/or more than one lesions, and/or their largest diameter is > 5-mm and/or require antiepileptic drugs or corticosteroids. Patients with carcinomatous meningitis are also excluded. Exceptions are: subjects with previously treated brain metastases provided they are stable (without evidence of progression by imaging) for at least 2 weeks prior to C11-AMT and any neurologic symptoms have returned to baseline, have no evidence of new or enlarging brain metastases, and are not using ongoing steroids for at least 7 days prior to C11-AMT. Patients with active (i.e. not treated with stereotactive radiosurgery), single, asymptomatic, up to 5-mm in largest diameter brain metastases (measured either by brain MRI with IV contrast or head CT with IV contrast measured within 2 weeks prior to C11-AMT) are allowed.

2. Has active autoimmune disease that has required systemic treatment in the past 2 years (i.e. with use of disease-modifying agents, corticosteroids or immunosuppressive drugs). Replacement therapy (e.g., thyroxine, insulin, or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency, etc.) is not considered a form of systemic treatment.

3. Has known history of (non-infectious) pneumonitis that required steroids, or any evidence of current pneumonitis.

4. Has an active infection requiring systemic therapy.

5. Has a history or current evidence of any condition, therapy, or laboratory abnormality that might confound the results of the trial, interfere with the subject's participation for the full duration of the trial, or is not in the best interest of the subject to participate, in the opinion of the treating investigator.

6. Has known psychiatric or substance abuse disorders that would interfere with cooperation with the requirements of the trial.

7. Is pregnant or breastfeeding, or expecting to conceive or father children within the projected duration of the trial, starting with the pre-screening or screening visit through 120 days after the last dose of trial treatment.

8. Has a known history of Human Immunodeficiency Virus (HIV) (HIV 1/2 antibodies).

9. Has known active Hepatitis B (e.g., HBsAg reactive) or Hepatitis C virus (HCV) (e.g., HCV RNA [qualitative] is detected).

10. Has received a live vaccine within 14 days of C11-AMT PET scan. Note: Seasonal influenza vaccines for injection are generally inactivated flu vaccines and are allowed; however intranasal influenza vaccines (e.g., Flu-Mist®) are live attenuated vaccines, and are not allowed.

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Lineberger Comprehensive Cancer Center	Chapel Hill	North Carolina	United States	27599
2	UNC Rex Healthcare	Raleigh	North Carolina	United States	27607

Sponsors and Collaborators

• UNC Lineberger Comprehensive Cancer Center
• Merck Sharp & Dohme LLC

Investigators

• Principal Investigator: Stergios Moschos, MD, Department of Medicine, Division of Hematology/Oncology, University of North Carolina at Chapel Hill

Study Documents (Full-Text)

• Study Protocol and Statistical Analysis Plan - Mar 12, 2020

More Information

Additional Information:

• University of North Carolina Lineberger Comprehensive Cancer Center Clinical Trials

Publications

None provided.

• Responsible Party: UNC Lineberger Comprehensive Cancer Center
• ClinicalTrials.gov Identifier: NCT03089606
• Other Study ID Numbers: LCCC 1531
• First Posted: Mar 24, 2017
• Last Update Posted: Jul 14, 2022
• Last Verified: Jun 1, 2022

• Individual Participant Data (IPD) Sharing Statement: No
• Plan to Share IPD: No
• Studies a U.S. FDA-regulated Drug Product: Yes
• Studies a U.S. FDA-regulated Device Product: No
• Product Manufactured in and Exported from the U.S.: No
• Additional relevant MeSH terms: Melanoma; Pembrolizumab

Study Results

Participant Flow

Recruitment Details	Participants were recruited from 5/31/2017 through 10/10/2020 at two cancer centers in North Carolina.
Pre-assignment Detail	A total of thirty-three participants consented to the study, but five were deemed to be ineligible and one withdrawn the consent during screening, and therefore were not enrolled on the study.

Arm/Group Title	Single Arm
Arm/Group Description	This is a single arm study. All participants completed the study interventions which are pembrolizumab treatment, FDG PET, C11-AMT PET and CT scans.
Period Title: Overall Study
STARTED	27
COMPLETED	26
NOT COMPLETED	1

Baseline Characteristics

Arm/Group Title	Single Arm
Arm/Group Description	This is a single-arm study. All participants completed all the study interventions namely pembrolizumab treatment, FDG PET, C11-AMT PET, and CT scans.
Overall Participants	27
Age (Count of Participants)
<=18 years	0 0%
Between 18 and 65 years	16 59.3%
>=65 years	11 40.7%
Sex: Female, Male (Count of Participants)
Female	6 22.2%
Male	21 77.8%
Ethnicity (NIH/OMB) (Count of Participants)
Hispanic or Latino	0 0%
Not Hispanic or Latino	27 100%
Unknown or Not Reported	0 0%
Race (NIH/OMB) (Count of Participants)
American Indian or Alaska Native	0 0%
Asian	0 0%
Native Hawaiian or Other Pacific Islander	0 0%
Black or African American	1 3.7%
White	26 96.3%
More than one race	0 0%
Unknown or Not Reported	0 0%
Region of Enrollment (participants) [Number]
United States	27 100%

Outcome Measures

1. Primary Outcome

Title	Association of Baseline C11-AMT PET SUV Max Value With Objective Response
Description	Association between intensity of C11-AMT PET at baseline, as measured by maximum standardized uptake value (SUV max) and objective response (OR) using computerized tomography images with intravenous contrast, as defined via RECIST v.1.1, at 12 weeks. Subject is considered responder if subject has CR or PR while subject is considered not-responder if they do not have CR or PR at 12 weeks. RECIST v.1.1: Complete Response (CR), disappearance of all target lesions; Partial Response (PR), >=30% decrease in the sum of the longest diameter of target lesions; Stable Disease (SD), no response or less response than Partial or Progressive; or Progressive Disease (PD), as a 20% increase in the sum of the longest diameter of target lesions, or a measurable increase in a non-target lesion, or the appearance of new lesions.
Time Frame	12 weeks

Outcome Measure Data

Analysis Population Description

Participants who received study treatment and pretreatment C11-AMT PET scanning performed, and tumor response assessed according to RECIST v1.1. criteria based on the CT scan with IV contrast, 12 weeks after starting treatment. C11-AMT PET SUV max cut-off value = 5 was selected considering optimal cut-point analysis, based on whether participants remained free of recurrence while on study treatment or lived longer, demonstrated "higher" or "lower" C11-AMT SUV max.

Arm/Group Title	Baseline C11AMT PET SUVmax<5	Baseline C11AMT PET SUVmax>5
Arm/Group Description	Baseline 11C-methyl-L-tryptophan (C11-AMT) positron emission tomography (PET) maximum standardized uptake value (SUVmax) is less than 5.	Baseline 11C-methyl-L-tryptophan (C11-AMT) positron emission tomography (PET) maximum standardized uptake value (SUVmax) is bigger than 5.
Measure Participants	7	19
Responder	6 22.2%	6 NaN
Not-Responder	1 3.7%	13 NaN

Statistical Analysis 1

Statistical Analysis Overview	Comparison Group Selection	Baseline C11AMT PET SUVmax<5, Baseline C11AMT PET SUVmax>5
	Comments	Null hypothesis. No association between baseline C11-AMT PET SUVmax value and antitumor response to pembrolizumab.
	Type of Statistical Test	Other
	Comments	2-tailed Fisher's exact test
Statistical Test of Hypothesis	p-Value	0.08
	Comments
	Method	2-tailed Fisher's exact test
	Comments

2. Secondary Outcome

Title	Objective Response Rate
Description	Objective Response Rate (ORR) is defined as the number of the subjects with a Complete Response, Partial Response, stable disease, and progressive disease according to Response Evaluation Criteria in Solid Tumors ( RECIST 1.1) at 12 weeks after starting to study treatment. RECIST v.1.1: Complete Response (CR), disappearance of all target lesions; Partial Response (PR), >=30% decrease in the sum of the longest diameter of target lesions; Stable Disease (SD), no response or less response than Partial or Progressive; or Progressive Disease (PD), as a 20% increase in the sum of the longest diameter of target lesions, or a measurable increase in a non-target lesion, or the appearance of new lesions.
Time Frame	12 Weeks

Outcome Measure Data

Analysis Population Description

Subjects received at least one dose of the study treatment and response evaluation according to RECIST 1.1 at 12 weeks, were performed.

Arm/Group Title	Single Arm
Arm/Group Description	This is a single arm study. All participants completed the study interventions which are pembrolizumab treatment, FDG PET, C11-AMT PET and CT scans.
Measure Participants	26
Complete response	7 25.9%
Partial response	5 18.5%
Stable Disease	2 7.4%
Progressive Disease	12 44.4%

3. Secondary Outcome

Title	Progression-Free Survival
Description	Progression Free Sruvival (PFS) is defined time from first day of treatment until disease progression as defined by RECIST1.1.
Time Frame	3 years

Outcome Measure Data

Analysis Population Description

The subjects received at least one dose of the study treatment and treatments response was assessed.

Arm/Group Title	Single Arm
Arm/Group Description	This is a single arm study. All participants completed the study interventions which are pembrolizumab treatment, FDG PET, C11-AMT PET and CT scans.
Measure Participants	26
Median (Full Range) [months]	7.4

4. Secondary Outcome

Title	Association of Baseline FDG-PET and C11-AMT PET
Description	Associations of SUVmax values between baseline FDG-PET and baseline C11-AMT PET images were examined. To objectively determine tumor regions of interest on C11-AMT and 18F FDG PET, the voxel with the highest tracer concentration (e.g., SUVmax) was determined. The voxel with the highest AMT tracer concentration (e.g., SUVmax) as well as a background region in close proximity to the location of the tumor using the MIM vista PET viewing software (MIM software Inc., Cleveland, OH, version 7.0.5).
Time Frame	Baseline

Outcome Measure Data

Analysis Population Description

All the tumor lesions with measured/determined SUVmax values belong to subjects who underwent baseline C11 AMT PET and FDG PET images were included.

Arm/Group Title	FDG PET SUVmax	C11AMT PET SUVmax
Arm/Group Description	Baseline FDG PET SUVmax (ratio above background)	Baseline C11AMT PET SUVmax (ratio above background)
Measure Participants	26	26
Measure Total number of tumor lesions analyzed	61	61
Median (Full Range) [units on a scale]	8.5	5.3

5. Secondary Outcome

Title	Metabolic Changes
Description	Assess metabolic changes at week 12 (or earlier, if patient progresses) following treatment with pembrolizumab using baseline and week 12 FDG PET. Each lesion is considered independently since subjects might have some lesion with SUV max value increased and another lesion with SUV max value decreased.
Time Frame	12 weeks

Outcome Measure Data

Analysis Population Description

Tumor lesions from the subjects who participated in the trial had available FDG PET data before and after 12 weeks ofpembrolizumab treatment (or earlier, if progression). Fifty-two tumor lesions from 23 subjects were analyzed.

Arm/Group Title	SUVmax Increased	SUVmax Decreased
Arm/Group Description	Baseline FDG PET SUVmax valueincreased, at week 12.	Baseline FDG PET SUVmax valuedecreased, at week 12.
Measure Participants	23	23
Measure Number of tumor lesions	20	32
Responder	1	30
Stable	1	0
Not-Responder	18	2

6. Secondary Outcome

Title	PET Parameters and IDO
Description	Associations between SUVmax and other PET parameters (e.g. total tumor metabolic volume, measurement of intra-tumoral and inter-lesional heterogeneity) identified at baseline C11-AMT PET imaging with expression of components of the indoleamine 2,3-dioxygenase (IDO) pathway detected by immunohistochemistry (IHC) or immunofluorescence (LAT1, IDO, TPH1), lymphocyte subtypes (CD4, CD8, FoxP3, MDSC), PD-1/PD-L1, and other immune checkpoint pathways (LAG3, GITR, TIM3) in freshly acquired tumor specimens prior to treatment. The single-color indoleamine 2,3-dioxygenase pathway (IHC) staining scoring, the 0, 1+ (<25% of cells with membrane or cytoplasmic stain), 2+ (25-80% of cells with membrane of cytoplasmic stain), 3+ (>80% of cells with membrane or cytoplasmic stain) semiquantitative scale (to describe the staining intensity and percentage of positive melanoma cells) was used.
Time Frame	Baseline

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title

Arm/Group Description

Adverse Events

Time Frame	Up to 114 days.
Adverse Event Reporting Description	Adverse events were collected from day one of study drug administration to 30 days after completion of treatment.
Arm/Group Title	Single Arm
Arm/Group Description	This is a single arm study. All participants completed the study interventions which are pembrolizumab treatment, FDG PET, C11-AMT PET and CT scans.
All Cause Mortality
	Single Arm
	Affected / at Risk (%)	# Events
Total	9/27 (33.3%)
Serious Adverse Events
	Single Arm
	Affected / at Risk (%)	# Events
Total	5/27 (18.5%)
Eye disorders
Retinal detachment	1/27 (3.7%)
Investigations
Neutrophil count decreased	1/27 (3.7%)
Neoplasms benign, malignant and unspecified (incl cysts and polyps)
Neoplasms benign, malignant and unspecified	2/27 (7.4%)
Skin and subcutaneous tissue disorders
Rash maculo-papular	1/27 (3.7%)
Other (Not Including Serious) Adverse Events
	Single Arm
	Affected / at Risk (%)	# Events
Total	27/27 (100%)
Blood and lymphatic system disorders
Anemia	5/27 (18.5%)
Cardiac disorders
Cardiac disorders - Other, specify	1/27 (3.7%)
Chest pain - cardiac	1/27 (3.7%)
Ear and labyrinth disorders
Hearing impaired	1/27 (3.7%)
Vertigo	2/27 (7.4%)
Endocrine disorders
Endocrine disorders - Other, specify	1/27 (3.7%)
Hyperthyroidism	4/27 (14.8%)
Hypothyroidism	2/27 (7.4%)
Eye disorders
Blurred vision	3/27 (11.1%)
Eye disorders - Other, specify	1/27 (3.7%)
Floaters	1/27 (3.7%)
Retinal detachment	1/27 (3.7%)
Gastrointestinal disorders
Abdominal pain	3/27 (11.1%)
Constipation	5/27 (18.5%)
Diarrhea	5/27 (18.5%)
Dry mouth	1/27 (3.7%)
Gastrointestinal disorders - Other, specify	1/27 (3.7%)
Nausea	5/27 (18.5%)
Vomiting	1/27 (3.7%)
General disorders
Edema limbs	3/27 (11.1%)
Facial pain	2/27 (7.4%)
Fatigue	24/27 (88.9%)
Flu like symptoms	1/27 (3.7%)
Localized edema	2/27 (7.4%)
Pain	11/27 (40.7%)
Hepatobiliary disorders
Hepatic pain	1/27 (3.7%)
Immune system disorders
Immune system disorders - Other, specify	1/27 (3.7%)
Infections and infestations
Infections and infestations - Other, specify	2/27 (7.4%)
Papulopustular rash	1/27 (3.7%)
Injury, poisoning and procedural complications
Seroma	1/27 (3.7%)
Investigations
Alanine aminotransferase increased	5/27 (18.5%)
Alkaline phosphatase increased	1/27 (3.7%)
Aspartate aminotransferase increased	6/27 (22.2%)
Blood bilirubin increased	4/27 (14.8%)
Creatinine increased	2/27 (7.4%)
Investigations - Other, specify	3/27 (11.1%)
Lymphocyte count decreased	13/27 (48.1%)
Neutrophil count decreased	2/27 (7.4%)
Platelet count decreased	1/27 (3.7%)
White blood cell decreased	5/27 (18.5%)
Metabolism and nutrition disorders
Anorexia	1/27 (3.7%)
Dehydration	2/27 (7.4%)
Hypercalcemia	2/27 (7.4%)
Hyperglycemia	2/27 (7.4%)
Hyperkalemia	4/27 (14.8%)
Hypertriglyceridemia	1/27 (3.7%)
Hypoalbuminemia	1/27 (3.7%)
Hyponatremia	2/27 (7.4%)
Metabolism and nutrition disorders - Other, specify	2/27 (7.4%)
Obesity	1/27 (3.7%)
Musculoskeletal and connective tissue disorders
Arthralgia	4/27 (14.8%)
Arthritis	3/27 (11.1%)
Back pain	2/27 (7.4%)
Bone pain	1/27 (3.7%)
Generalized muscle weakness	2/27 (7.4%)
Musculoskeletal and connective tissue disorder - Other, specify	4/27 (14.8%)
Neck pain	1/27 (3.7%)
Pain in extremity	2/27 (7.4%)
Neoplasms benign, malignant and unspecified (incl cysts and polyps)
Neoplasms benign, malignant and unspecified (incl cysts and polyps) - Other, specify	1/27 (3.7%)
Tumor pain	2/27 (7.4%)
Nervous system disorders
Dizziness	4/27 (14.8%)
Dysesthesia	1/27 (3.7%)
Dysgeusia	1/27 (3.7%)
Headache	6/27 (22.2%)
Ischemia cerebrovascular	1/27 (3.7%)
Paresthesia	1/27 (3.7%)
Peripheral sensory neuropathy	1/27 (3.7%)
Psychiatric disorders
Anxiety	4/27 (14.8%)
Depression	1/27 (3.7%)
Insomnia	3/27 (11.1%)
Psychiatric disorders - Other, specify	1/27 (3.7%)
Renal and urinary disorders
Chronic kidney disease	1/27 (3.7%)
Renal and urinary disorders - Other, specify	1/27 (3.7%)
Urinary frequency	2/27 (7.4%)
Reproductive system and breast disorders
Reproductive system and breast disorders - Other, specify	1/27 (3.7%)
Respiratory, thoracic and mediastinal disorders
Cough	2/27 (7.4%)
Dyspnea	2/27 (7.4%)
Nasal congestion	1/27 (3.7%)
Respiratory, thoracic and mediastinal disorders - Other, specify	1/27 (3.7%)
Sinus disorder	1/27 (3.7%)
Sleep apnea	1/27 (3.7%)
Wheezing	1/27 (3.7%)
Skin and subcutaneous tissue disorders
Dry skin	3/27 (11.1%)
Pruritus	11/27 (40.7%)
Rash acneiform	1/27 (3.7%)
Rash maculo-papular	7/27 (25.9%)
Scalp pain	1/27 (3.7%)
Skin and subcutaneous tissue disorders - Other, specify	5/27 (18.5%)
Skin hypopigmentation	2/27 (7.4%)
Surgical and medical procedures
Surgical and medical procedures - Other, specify	2/27 (7.4%)
Vascular disorders
Hot flashes	2/27 (7.4%)
Hypertension	5/27 (18.5%)
Lymphedema	3/27 (11.1%)

Limitations/Caveats

[Not Specified]

More Information

Certain Agreements

All Principal Investigators ARE employed by the organization sponsoring the study.

There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.