Prostate Cancer
Conditions
Keywords
Vismodegib, Metastatic Castration-Resistant Prostate Cancer, Accessible Metastatic Lesions for Tumor Biopsy
Brief summary
This is a single-arm pharmacodynamic study with mandatory metastatic tumor biopsies in men with castration-resistant prostate cancer. The trial will evaluate the effect of vismodegib on tumor tissue in men with metastatic CRPC by obtaining tumor biopsies at baseline and after 4 weeks of treatment with vismodegib.
Detailed description
The study will enroll 10 evaluable patients. Patients will receive a 30-day supply of 150 mg of vismodegib on day one of each cycle daily by mouth, beginning on Day 1, and continuously until one of the following occurs: Disease progression, intolerable toxicity most probably attributable to vismodegib or withdrawal from the study. Tumor biopsies (nodal or visceral), skin biopsies, and CTCs will be obtained at baseline and after 4 weeks of treatment. PSA evaluations will be conducted every 4 weeks, imaging assessments (CT and Bone scan) will be conducted every 12 weeks and routine labs (blood counts and chemistry panel) will be conducted every 4 weeks. The investigator's intent is to examine the fold change in GLI1 expression in each man following exposure to drug (comparing pre-treatment and on-treatment core biopsy samples). As secondary endpoints, the investigator will also explore clinical response (PSA responses, progression-free survival \[PFS\], radiographic responses), safety, and will examine changes from baseline in Gli2, PTCH1, and AKT1 mRNA levels by qRT-PCR, in situ GLI1 expression in tissue sections by mRNA in situ hybridization, and GLI1 expression in isolated circulating tumor cells (CTCs).
Interventions
Sponsors
Study design
Eligibility
Inclusion criteria
* Men with metastatic castration-resistant prostate cancer (mCRPC), with accessible metastatic soft-tissue lesions for tumor biopsy * Greater than 18 years of age * Evidence of disease progression (PSA progression, or radiographic/clinical progression \[PCWG2\]) * PSA progression is defined as at least two consecutive rises in serum PSA, obtained at a minimum of 1-week intervals, and each value ≥ 2.0 ng/mL. * Radiographic progression is defined for soft tissue lesions using RECIST criteria, i.e. an increase greater than 20% in the sum of the longest diameter of all target lesions based on the smallest sum longest diameter since treatment started or the appearance of one of more new lesions with a confirmatory scan 6 or more weeks later. Radiographic progression will be defined for bone lesions as the appearance of two new lesions with a confirmatory scan performed 6 or more weeks later that shows at least 2 or more additional new lesions. * Presence of ≥1 metastatic site (nodal, visceral) that is amenable to core biopsy * Castrate serum testosterone (\<50 ng/dL) * Prior anti-androgens are permitted but not required (2 week washout from anti-androgens) * Prior abiraterone and enzalutamide are permitted (2 week washout for both agents) * Prior immunotherapy (e.g. sipuleucel-T), and chemotherapy are permitted (4 week washout period from chemotherapy) * Bisphosphonates and denosumab are permitted, if on a stable dose for ≥4 weeks * Life expectancy ≥12 months * Adequate renal, liver, and bone marrow function with the following acceptable initial laboratory values: * Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) must be ≤ 2.5 x the upper limit of normal (ULN). * Total bilirubin must be ≤ 1.5 x ULN. * Estimated creatinine clearance using the Cockcroft-Gault formula must be \> 40 mL/minute (See section 12.2 for formula) * Absolute neutrophil count (ANC) must be ≥ 1500/μL * Platelet count must be ≥ 100,000/μL * Willing and able to provide written informed consent and HIPAA authorization for the release of personal health information. NOTE: HIPAA authorization may be either included in the informed consent or obtained separately. * Karnofsky Performance status/ECOG Performance Status ≥70/2 (Appendix A: Performance Status Criteria) * Male patients must use condoms at all times, even after a vasectomy, during sexual intercourse with female partners of reproductive potential during treatment with vismodegib and for 2 months after the last dose to avoid exposing a pregnant partner and unborn fetus to vismodegib.
Exclusion criteria
* Current use of systemic corticosteroids (\>5 mg prednisone) * Known brain metastases, or untreated meningeal/dural disease * Receiving any other investigational agents or receipt of another investigational agent within 4 weeks of study entry * Patients taking anticoagulants or with a history of a bleeding diathesis (due to need for visceral biopsy) * Use of any prohibited concomitant medications (washout period of 1 week) * Insufficient time from last prior regimen or radiation exposure (washout period of 4 weeks) * Grade \> 2 treatment-related toxicity from prior therapy * Any other condition which, in the opinion of the Investigator, would preclude participation in this trial
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| The Proportion of mCRPC Patients Treated With Vismodegib Who Achieve a Pharmacodynamic (PD) Response in Tumor Biopsies | Up to 1 year | The primary endpoint is the proportion of mCRPC patients treated with vismodegib who achieve a pharmacodynamic (PD) response in tumor biopsies, defined as both a decrease in GLI1 mRNA greater than 1.2 times the standard deviation (SD) of the baseline values and a ≥50% (≥2-fold) reduction in GLI1 messenger ribonucleic acid (mRNA) expression in metastatic tumor biopsies after 4 weeks of treatment when comparing post-treatment biopsy to pre-treatment biopsy in the same patient. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| GLI1 Expression | Up to 1 Year | Suppression by vismodegib in tumor tissue of Hh-regulated transcripts and proteins was defined as the change from baseline in expression levels of GLI1 in situ tissue expression by mRNA in situ hybridization. |
| Progression-free Survival (PFS) | Up to 1 Year | Progression-free survival (PFS) is defined by the Prostate Cancer Working Group 2 (PCWG2) criteria using RECIST 1.1 criteria for each patient. PFS is defined as the time of first dose (a) until prostate specific antigen (PSA) progression (by 25% increase in PSA from nadir) or death and (b) until any evidence of progression (by 25% increase in PSA from nadir, a new lesion on bone or CT scan, or physical examination) or death. PFS will be assigned to the earliest observed time. |
| AKT1 Expression in Tumor Biopsies | Up to 1 Year | The tumor biopsies were evaluated for changes to Hh-regulated transcript, AKT1, between pre-treatment and post-treatment |
| The Effect of Vismodegib on PSA Responses | Up to 1 Year | The effect of vismodegib on PSA responses will be assessed as the number of patients with participants with ≥50% PSA reductions at any time point during study |
Countries
United States
Participant flow
Recruitment details
A total of 9 patients were enrolled on the study
Participants by arm
| Arm | Count |
|---|---|
| Vismodegib Vismodegib Treatment arm will receive Vismodegib by mouth 150 mg daily up to 1 year.
Vismodegib | 9 |
| Total | 9 |
Baseline characteristics
| Characteristic | Vismodegib |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 9 Participants |
| Age, Continuous | 65 years |
| Region of Enrollment United States | 9 participants |
| Sex: Female, Male Female | 0 Participants |
| Sex: Female, Male Male | 9 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | — / — |
| other Total, other adverse events | 9 / 9 |
| serious Total, serious adverse events | 5 / 9 |
Outcome results
The Proportion of mCRPC Patients Treated With Vismodegib Who Achieve a Pharmacodynamic (PD) Response in Tumor Biopsies
The primary endpoint is the proportion of mCRPC patients treated with vismodegib who achieve a pharmacodynamic (PD) response in tumor biopsies, defined as both a decrease in GLI1 mRNA greater than 1.2 times the standard deviation (SD) of the baseline values and a ≥50% (≥2-fold) reduction in GLI1 messenger ribonucleic acid (mRNA) expression in metastatic tumor biopsies after 4 weeks of treatment when comparing post-treatment biopsy to pre-treatment biopsy in the same patient.
Time frame: Up to 1 year
Population: The design had 90% power to detect a true 65% PD response rate across patients, with a false-positive rate of 3.3% under the null hypothesis that vismodegib has no effect in downregulating Gli1 expression.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Vismodegib | The Proportion of mCRPC Patients Treated With Vismodegib Who Achieve a Pharmacodynamic (PD) Response in Tumor Biopsies | 7 Participants |
AKT1 Expression in Tumor Biopsies
The tumor biopsies were evaluated for changes to Hh-regulated transcript, AKT1, between pre-treatment and post-treatment
Time frame: Up to 1 Year
Population: One patient did not receive a post-treatment biopsy, and another patient had insufficient tissue for evaluation from the repeat biopsy
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Vismodegib | AKT1 Expression in Tumor Biopsies | -1.15 expression fold change |
GLI1 Expression
Suppression by vismodegib in tumor tissue of Hh-regulated transcripts and proteins was defined as the change from baseline in expression levels of GLI1 in situ tissue expression by mRNA in situ hybridization.
Time frame: Up to 1 Year
Population: One patient did not receive a post-treatment biopsy, and another patient had insufficient tissue for evaluation from the repeat biopsy
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Vismodegib | GLI1 Expression | -9.8 expression fold change |
Progression-free Survival (PFS)
Progression-free survival (PFS) is defined by the Prostate Cancer Working Group 2 (PCWG2) criteria using RECIST 1.1 criteria for each patient. PFS is defined as the time of first dose (a) until prostate specific antigen (PSA) progression (by 25% increase in PSA from nadir) or death and (b) until any evidence of progression (by 25% increase in PSA from nadir, a new lesion on bone or CT scan, or physical examination) or death. PFS will be assigned to the earliest observed time.
Time frame: Up to 1 Year
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Vismodegib | Progression-free Survival (PFS) | 1.9 months |
The Effect of Vismodegib on PSA Responses
The effect of vismodegib on PSA responses will be assessed as the number of patients with participants with ≥50% PSA reductions at any time point during study
Time frame: Up to 1 Year
Population: Seven patients were evaluable for PSA response. One participant had no measurable PSA production at enrollment, and PSA remained \<0.01 throughout the study. A second patient had disease progression prior to the first on-study PSA evaluation.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Vismodegib | The Effect of Vismodegib on PSA Responses | 1 participants |