Trial Outcomes & Findings for A Pilot Study to Evaluate PBR PET in Brain Tumor Patients Treated With Chemoradiation or Immunotherapy (NCT NCT02431572)

Last Updated: 2020-04-28

Results Overview

The change in PBR uptake in arms cohorts A and B from baseline to the start of cycle 4 for metastatic melanoma patients or cycle 3 for glioblastoma patients. The 18-kDa translocator protein (TSPO) is a protein that is expressed in mitochondria and is particularly prominently expressed by activated microglia, infiltrating macrophages, and reactive astrocytes. Thus, it is a marker of neuro-inflammation. PBR28 is a second generation PET tracer that binds to TPSO. PBR28 uptake was quantified using the standardized uptake value (SUV), which is the ratio of activity per unit volume of the region of interest (ROI) compared to cerebellum. Higher values indicate increased uptake in the ROI.

Recruitment status

COMPLETED

Study phase

Target enrollment

11 participants

Primary outcome timeframe

At baseline and 3 to 4 months post baseline

Results posted on

2020-04-28

Participant Flow

Participant milestones

Participant milestones
Measure	Metastatic Melanoma to the Brain (Cohort A) * Assess Inflammation (PBR PET) * Immunotherapy * Assess Inflammation (PBR PET) PBR PET Cancer Immunotherapy: Subjects who are to be treated with immunotherapy for glioblastoma or melanoma brain metastases will be eligible for 2 of the 3 arms.	Primary Brain Tumor (Cohort B) * Assess Inflammation (PBR PET) * Immunotherapy * Assess Inflammation (PBR PET) PBR PET Cancer Immunotherapy: Subjects who are to be treated with immunotherapy for glioblastoma or melanoma brain metastases will be eligible for 2 of the 3 arms.	Primary Brain Tumor (Cohort C) * Chemoradiation * Assess inflammation (PBR PET) * Follow Patients PBR PET Radiation and chemotherapy: Subjects with glioblastoma will receive or will have received treatment with chemotherapy and radiation per the standard of care.
Overall Study STARTED	1	1	9
Overall Study COMPLETED	0	1	9
Overall Study NOT COMPLETED	1	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

A Pilot Study to Evaluate PBR PET in Brain Tumor Patients Treated With Chemoradiation or Immunotherapy

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Metastatic Melanoma to the Brain (Cohort A) n=1 Participants * Assess Inflammation (PBR PET) * Immunotherapy * Assess Inflammation (PBR PET) PBR PET Cancer Immunotherapy: Subjects who are to be treated with immunotherapy for glioblastoma or melanoma brain metastases will be eligible for 2 of the 3 arms.	Primary Brain Tumor (Cohort B) n=1 Participants * Assess Inflammation (PBR PET) * Immunotherapy * Assess Inflammation (PBR PET) PBR PET Cancer Immunotherapy: Subjects who are to be treated with immunotherapy for glioblastoma or melanoma brain metastases will be eligible for 2 of the 3 arms.	Primary Brain Tumor (Cohort C) n=9 Participants * Chemoradiation * Assess inflammation (PBR PET) * Follow Patients PBR PET Radiation and chemotherapy: Subjects with glioblastoma will receive or will have received treatment with chemotherapy and radiation per the standard of care.	Total n=11 Participants Total of all reporting groups
Age, Continuous	80 years n=93 Participants	65 years n=4 Participants	58 years n=27 Participants	59 years n=483 Participants
Sex: Female, Male Female	0 Participants n=93 Participants	1 Participants n=4 Participants	1 Participants n=27 Participants	2 Participants n=483 Participants
Sex: Female, Male Male	1 Participants n=93 Participants	0 Participants n=4 Participants	8 Participants n=27 Participants	9 Participants n=483 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	0 Participants n=93 Participants	0 Participants n=4 Participants	1 Participants n=27 Participants	1 Participants n=483 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	1 Participants n=93 Participants	1 Participants n=4 Participants	7 Participants n=27 Participants	9 Participants n=483 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=93 Participants	0 Participants n=4 Participants	1 Participants n=27 Participants	1 Participants n=483 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=93 Participants	0 Participants n=4 Participants	0 Participants n=27 Participants	0 Participants n=483 Participants
Race (NIH/OMB) Asian	0 Participants n=93 Participants	0 Participants n=4 Participants	0 Participants n=27 Participants	0 Participants n=483 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=93 Participants	0 Participants n=4 Participants	0 Participants n=27 Participants	0 Participants n=483 Participants
Race (NIH/OMB) Black or African American	0 Participants n=93 Participants	0 Participants n=4 Participants	0 Participants n=27 Participants	0 Participants n=483 Participants
Race (NIH/OMB) White	1 Participants n=93 Participants	1 Participants n=4 Participants	8 Participants n=27 Participants	10 Participants n=483 Participants
Race (NIH/OMB) More than one race	0 Participants n=93 Participants	0 Participants n=4 Participants	1 Participants n=27 Participants	1 Participants n=483 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=93 Participants	0 Participants n=4 Participants	0 Participants n=27 Participants	0 Participants n=483 Participants
Region of Enrollment United States	1 participants n=93 Participants	1 participants n=4 Participants	9 participants n=27 Participants	11 participants n=483 Participants

PRIMARY outcome

Timeframe: At baseline and 3 to 4 months post baseline

Population: Only a baseline measurement was taken for the 1 patient in cohort A. Change in PBR was therefore not possible to calculate for that patient. PBR PET was only assessed once in cohort C and is reported separately.

Outcome measures

Outcome measures
Measure	Metastatic Melanoma to the Brain (Cohort A) * Assess Inflammation (PBR PET) * Immunotherapy * Assess Inflammation (PBR PET) PBR PET Cancer Immunotherapy: Subjects who are to be treated with immunotherapy for glioblastoma or melanoma brain metastases will be eligible for 2 of the 3 arms.	Primary Brain Tumor (Cohort B) n=1 Participants * Assess Inflammation (PBR PET) * Immunotherapy * Assess Inflammation (PBR PET) PBR PET Cancer Immunotherapy: Subjects who are to be treated with immunotherapy for glioblastoma or melanoma brain metastases will be eligible for 2 of the 3 arms.
Change in PBR Uptake (Changes in PBR Uptake by PET) Before immunotherapy	—	1.301 percent change from baseline Interval 1.301 to 1.301
Change in PBR Uptake (Changes in PBR Uptake by PET) During immunotherapy	—	1.1219 percent change from baseline Interval 1.1219 to 1.1219

PRIMARY outcome

Timeframe: At the time of suspected pseudo-progression (up to 4 weeks after consent)

The median PBR28 uptake as measured by positron emission tomography (PET) following chemo-radiation. The 18-kDa translocator protein (TSPO) is a protein that is expressed in mitochondria and is particularly prominently expressed by activated microglia, infiltrating macrophages, and reactive astrocytes. Thus, it is a marker of neuro-inflammation. PBR28 is a second generation PET tracer that binds to TPSO. PBR28 uptake was quantified using the standardized uptake value (SUV), which is the ratio of activity per unit volume of the region of interest (ROI) compared to cerebellum. Higher values indicate increased uptake in the ROI.

Outcome measures

Outcome measures
Measure	Metastatic Melanoma to the Brain (Cohort A) n=9 Participants * Assess Inflammation (PBR PET) * Immunotherapy * Assess Inflammation (PBR PET) PBR PET Cancer Immunotherapy: Subjects who are to be treated with immunotherapy for glioblastoma or melanoma brain metastases will be eligible for 2 of the 3 arms.	Primary Brain Tumor (Cohort B) * Assess Inflammation (PBR PET) * Immunotherapy * Assess Inflammation (PBR PET) PBR PET Cancer Immunotherapy: Subjects who are to be treated with immunotherapy for glioblastoma or melanoma brain metastases will be eligible for 2 of the 3 arms.
Median PBR Uptake	0.8172 Ratio Interval 0.5723 to 1.1566	—

Adverse Events

Metastatic Melanoma to the Brain (Cohort A)

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Primary Brain Tumor (Cohort B)

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Primary Brain Tumor (Cohort C)

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr. Elizabeth Gerstner

Massachusetts General Hospital

Phone: 617-724-8770

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place