This Phase 1/2 study is intended to investigate the safety, tolerability, and radiation dosimetry of 177Lu-PSMA-R2 and further assess preliminary efficacy data in patients with metastatic castration-resistant prostate cancer (mCRPC). The Phase 1 portion of the study will determine the recommended dose of 177Lu-PSMA-R2 for radio-ligand therapy (RLT) of mCRPC, and the Phase 2 portion will expand into approximately 60 patients documenting the preliminary activity (anti-tumor response) of repeated treatments administered, continuing safety assessments and collecting QoL data.
Recruitment for PROter A206T-G01-001 (NCT03490838) was halted in Phase I by sponsor decision. Phase II expansion portion of the study was never initiated. Importantly, this recruitment halt was not a consequence of any safety concern. Ongoing patients at the time of recruitment halt continued per protocol and completed the 1 year safety follow-up prior to early study termination. The primary objective of the Phase I portion of the study to assess the safety and tolerability of 177Lu-PSMA-R2 and to assess Dose Limiting Toxicities (DLTs) and determine the maximum tolerated dose (MTD) (if reached) and the recommended Phase II dose was not reached due to early recruitment halt.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
27
radio-ligand therapy
Pheonix Molecular Imaging Center
Phoenix, Arizona, United States
University of California San Francisco
San Francisco, California, United States
Stanford University Medical Center
Stanford, California, United States
Yale New Haven Children Hospital
New Haven, Connecticut, United States
Tulane Cancer Center Tulance Cancer
New Orleans, Louisiana, United States
John Hopkins University - Kimmel Comp. Cancer Center
Baltimore, Maryland, United States
National Institute of Health
Bethesda, Maryland, United States
Mount Sinai Hospital School of Medicine
New York, New York, United States
University of Wisconsin / Paul P. Carbone Comp Cancer Center
Madison, Wisconsin, United States
Hospital Vall Hebrón
Barcelona, Spain
...and 1 more locations
Phase I: Incidence of dose limiting toxicities (DLTs) during first cycle of study treatment.
A dose-limiting toxicity (DLT) is defined as any toxicity not attributable to the disease or disease-related processes under investigation, the time window for DLT assessment period is Cycle 1. To be considered a DLT, it must be related to the IP (attributions: possible, probable, and definite) while fulfilling one of the following criteria as per the NCI Common Toxicity Criteria for Adverse Events (CTCAE) version 5.0.
Time frame: Up to 8 weeks after the first 177Lu-PSMA-R2 dose
Phase II: Prostate-Specific Antigen (PSA) response rate 50
PSA response rate 50 is defined as the proportion of participants who have a greater or equal 50% in PSA from Baseline that is confirmed by a second PSA measurement 4 weeks later, as per Prostate Cancer Working Group 3 (PCWG3) criteria.
Time frame: Week 13 (12 weeks after the first 177Lu-PSMA-R2 injection)
Phase I and II: Treatment Emergent Adverse Event (TEAE) rate
The distribution of adverse events will be done via the analysis of frequencies for treatment emergent Adverse Event (TEAEs), Serious Adverse Event (TESAEs) and Deaths due to AEs, through the monitoring of relevant clinical and laboratory safety parameters.
Time frame: From randomization till 30 days safety follow-up, assessed up to 4 years (estimated final OS analysis)
Phase I and II: Objective Response Rate (ORR)
ORR is defined as the proportion of participants with Best Overall Response (BOR) of Complete Response (CR) or Partial Response (PR) per RECIST 1.1.
Time frame: From date of randomization assessed up to 4 years (estimated final OS analysis)
Phase I and II: Duration of Response (DoR)
Duration of Response (DoR) according to RECIST v1.1 is defined as the time that measurement criteria are met for objective response (CR/PR) (whichever status is recorded first) until the first date of progression or death is documented.
Time frame: From date of randomization until date of progression or date of death from any cause, whichever come first, assessed up to 4 years (estimated final OS analysis)
Phase I and II: Prostate-Specific Antigen (PSA) response rate 30
PSA response rate 30 is defined as the proportion of participants who have a greater or equal 30% in PSA from Baseline that is confirmed by a second PSA measurement 4 weeks later, as per Prostate Cancer Working Group 3 (PCWG3) criteria.
Time frame: Week 13 (12 weeks after the first 177Lu-PSMA-R2 injection)
Phase I: Prostate-Specific Antigen (PSA) response rate 50
PSA response rate 50 is defined as the proportion of participants who have a greater or equal 50% in PSA from Baseline that is confirmed by a second PSA measurement 4 weeks later, as per Prostate Cancer Working Group 3 (PCWG3) criteria.
Time frame: Week 13 (12 weeks after the first 177Lu-PSMA-R2 injection)
Phase I: 177Lu-PSMA-R2 plasma concentration
Time frame: Days 1 through 8 post-treatment
Phase I: Maximum plasma concentration (Cmax) of 177Lu-PSMA-R2
Venous whole blood samples will be collected for activity-based pharmacokinetics characterization. Cmax will be listed and summarized using descriptive statistics.
Time frame: Day 1 (before the start of infusion, at the mid-point, and just before the end of infusion, then at post infusion at approximately 5, 15, 30 minutes, 1, 2, 4, 6, 8, 24, 40 (+/- 4 hours), 48 hours), Day 4 (+2 days) and Day 8 post end of infusion
Phase I: Minimum plasma concentration (Cmin) of 177Lu-PSMA-R2
Venous whole blood samples will be collected for activity-based pharmacokinetics characterization. Cmin will be listed and summarized using descriptive statistics.
Time frame: Day 1 (before the start of infusion, at the mid-point, and just before the end of infusion, then at post infusion at approximately 5, 15, 30 minutes, 1, 2, 4, 6, 8, 24, 40 (+/- 4 hours), 48 hours), Day 4 (+2 days) and Day 8 post end of infusion
Phase I: Area under the plasma concentration-time curve (AUC) of 177Lu-PSMA-R2
Venous whole blood samples will be collected for activity-based pharmacokinetics characterization. AUC will be listed and summarized using descriptive statistics.
Time frame: Day 1 (before the start of infusion, at the mid-point, and just before the end of infusion, then at post infusion at approximately 5, 15, 30 minutes, 1, 2, 4, 6, 8, 24, 40 (+/- 4 hours), 48 hours), Day 4 (+2 days) and Day 8 post end of infusion
Phase I: Dosimetry
Radiation (Gy, Gy/MBq) update by critical organs and metastatic lesions
Time frame: Days 1 through 8 post-treatment
Phase I and II: Patient Reported Outcomes (PRO) of Mouth Dryness using Xerostomia Questionnaire
The Xerostomia questionnaire is a questionnaire used to describe mouth dryness and its effects on daily life. It consists of 8 questions with each question score ranging from 0 ("never"/"none") to 10 ("worst"). The sum of the 8 scores produces a total score (score range from 0-80). A low score corresponds to a good quality of life while a high score means a poor quality of life due to the dry mouth.
Time frame: Prior to dosing on Day 1 and every 12 weeks until 1 year after disease progression or early study termination whichever comes first
Phase I and II: Patient Reported Outcomes (PRO) of Eye Dryness using Xerophthalmia Questionnaire
The Xerophthalmia questionnaire is a questionnaire used to describe eye dryness and its effects on daily life. It consists of 3 questions. The first 2 questions scores range from 1 ("never") to 4 ("constantly") and the last question is a Yes/No question about previous dry eye diagnosis. The sum of the scores of the first 2 questions produces a total score (score range from 2-8). A low score corresponds to a good quality of life while a high score means a poor quality of life due to the dry eye.
Time frame: Prior to dosing on Day 1 and every 12 weeks until 1 year after disease progression or early study termination whichever comes first
Phase I and II: Brief Pain Inventory-short Form (PBI-SF)
The BPI-SF is a publicly available instrument to assess the pain and includes severity and interference scores. BPI-SF is an 11-item self report questionnaire that is designed to assess the severity and impact of pain on daily functions of a participant. Pain severity score is a mean value for BPI-SF questions 3, 4, 5 and 6 (questions inquiring about the extent of pain, where the extent is ranked from 0 \[no pain\] to 10 \[pain as bad as you can imagine\]). Pain severity progression is defined as an increase in score of 30% or greater from baseline without decrease in analgesic use.
Time frame: Prior to dosing on Day 1 and every 12 weeks until 1 year after disease progression or early study termination whichever comes first
Phase II: Disease Control Rate (DCR)
DCR is defined as the proportion of participants with Best Overall Response (BOR) of Complete Response (CR), Partial Response (PR), or Stable Disease (SD) per RECIST 1.1.
Time frame: From date of randomization till 30 days safety fup, assessed up to 4 years (estimated final OS analysis)
Phase II: Radiographic Progression Free Survival (rPFS)
rPFS is defined as the time to radiographic progression by PCWG3-modified RECIST v1.1 or death.
Time frame: From date of randomization until date of radiographic progression or date of death from any cause, whichever comes first, assessed up to 4 years (estimated final OS analysis)
Phase II: Overall Survival (OS)
OS is defined as the time to death for any cause.
Time frame: From date of randomization until date of death from any cause, assessed up to 4 years (estimated final OS analysis)
Phase II: Time to Prostate Specific Antigen (PSA) progression
PSA progression is defined as the time from the date of first dose of 177Lu-PSMA-R2 injection to the first date that a \>= 25% increase in PSA and an absolute increase of 2 ng/mL or more from the nadir was documented and confirmed by a second consecutive value obtained 3 or more weeks later.
Time frame: From date of randomization until date of death from any cause, assessed up to 4 years (estimated final OS analysis)
Phase II: Change from Baseline in European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C30 (EORTC QLQ-C30) Score
The EORTC QLQ-C30 contains 30 questions assessed by the participant. There are 9 multiple-item scales: 5 scales that assess aspects of functioning (physical, role functioning, cognitive, emotional, and social); 3 symptom scales (Fatigue, Pain, and Nausea and Vomiting); and a global health status/Quality of Life (QOL) scale. There are 5 single-item measures assessing additional symptoms (i.e., dyspnea, loss of appetite, insomnia, constipation, and diarrhea) and a single item concerning perceived financial impact of the disease. All but two questions have 4 point scales ranging from "Not at all" to "Very much." The two questions concerning global health status/ QOL have 7 point scales with ratings ranging from "Very poor" to "Excellent." For each of the 14 domains, final scores are transformed such that they range from 0-100, where higher scores indicate improvement.
Time frame: Prior to dosing on Day 1 and every 12 weeks until 1 year after disease progression or early study termination whichever comes first
Phase II: Change from Baseline in European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Prostate Module (EORTC QLQ-PR25) Score
The EORTC QLQ-PR25 is a prostate cancer module for the assessment of health-related quality of life (HRQoL). It consists of 25 questions distributed on 6 domains: urinary symptoms (8 items), incontinence aid (1 item), bowel symptoms (4 items), hormonal treatment-related symptoms (HTRS) (6 items), sexual activity (2 items), and sexual functioning (4 items). Questions use a 4 point scale (1 'Not at all' to 4 'Very much'). All raw domain scores are linearly transformed to a 0-100 scale, with higher scores reflecting either more symptoms (urinary, bowel, hormonal treatment-related symptoms) or higher levels of activity or functioning (sexual).
Time frame: Prior to dosing on Day 1 and every 12 weeks until 1 year after disease progression or early study termination whichever comes first
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