This Investigator-initiated, Treatment of High-Risk Prostate Cancer Guided by Novel Diagnostic Radio- and Molecular Tracers (THUNDER) study will be conducted in subjects with high-risk localized or locally advanced prostate cancer (PCa). The study contains both a randomized Phase 3 treatment intensification study, as well as a treatment de-intensification non-randomized Phase 2 study. The aim of the THUNDER study is to improve the outcome of high-risk PCa by improved risk stratification. Novel radiotracers and a genomic classifier (Decipher) will be used to guide treatment decisions, instead of standard imaging which is limited by lower sensitivity and specificity.
The hypothesis for the study is that treatment intensification based on a positive PSMA PET/ CT scan or Decipher high score (\> 0.85) improves time to new metastases detected on PSMA PET/ CT in high-risk PCa. In patients who are PSMA PET/ CT negative with a low/ intermediate Decipher score (≤ 0.85), it is hypothesized that treatment de-intensification will improve patient quality of life while maintaining a good oncological outcome.
The study will be conducted at multiple centers across Europe. Participation in the study will comprise a screening period, where the screening assessments must be completed before subjects are enrolled and randomized (only for Phase 3 subjects). Eligible, consenting subjects will then undergo treatment according to their assigned study phase and treatment group, to occur over up to 96 weeks (24 months) with a post-treatment follow-up period to monitor safety and efficacy. The study will be closed when 96 events have been registered for the primary endpoint, which is expected to be at 7-8 years from the time of randomization of the first subject.
Histopathology-proven PCa
High-risk locally advanced disease is defined as any of the following factors: PSA > 20 ng/mL OR T-stage 3 or 4 OR Gleason score 8-10 OR cN1.
An Eastern Cooperative Oncology Group (ECOG) Performance Status grade of 0 or 1.
Willingness to undergo a PSMA PET/ CT with or without contrast.
Definitive radiologic evidence of metastatic disease outside of the pelvic nodes (M1a, M1b or M1c) on conventional imaging (i.e., bone scan, CT scan, MRI)
PCa with predominant non-adenocarcinoma features (sarcomatoid or spindle or neuroendocrine small cell or squamous cell components or other non-adenocarcinoma)
Prior pelvic radiotherapy
Contraindications for pelvic radiotherapy