Conditions: Prostate Cancer
Keywords: Vismodegib Metastatic Castration-Resistant Prostate Cancer Accessible Metastatic Lesions for Tumor Biopsy
Allocation: NA | Intervention model: SINGLE_GROUP
Enrollment: 9
Healthy volunteers: no

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).

Arms:
arm 1: Vismodegib Treatment arm will receive Vismodegib by mouth 150 mg daily up to 1 year.

Interventions: intervention 1: Vismodegib
Intervention descriptions: intervention 1: None

Protocol document: