A Phase II Study of SB939 in Patients With Recurrent or Metastatic Castration Resistant Prostate Cancer
- To determine the efficacy, as measured by PSA response and progression-free survival,
of HDAC inhibitor SB939 in patients with recurrent or metastatic castration-resistant
- To determine the objective response and response duration in patients with measurable
disease at baseline.
- To determine the tolerability and toxicity of this drug in these patients.
- To determine the number of circulating tumor cells at baseline and after 6 weeks (and
12 weeks if patient is still on study treatment).
- To explore potential molecular factors predictive of response by assessment of archival
prostate tumor tissue.
- To explore ERG and PTEN expression on circulating tumor cells as a potential prognostic
and predictive marker for response to this drug.
- To determine time to PSA and time to objective progression in these patients.
OUTLINE: This is a multicenter study.
Patients receive oral HDAC Inhibitor SB939 once daily on days 1, 3, 5, 8, 10, 12, 15, 17,
and 19. Treatment repeats every 4 weeks for up to 12 courses in the absence of disease
progression or unacceptable toxicity.
Blood samples are collected periodically for correlative studies. Blood samples and Archival
tumor tissue are analyzed for TMPRSS2-ERG fusion and PTEN deletion status by FISH;
TMPRSS2-ERG fusion by RT-PCR; and for the number of circulating tumor cells.
After completion of study therapy, patients are followed up at 4 weeks and then every 3
Allocation: Non-Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment
Each patient will have PSA response calculated. Required at the end of every cycle.
Kim N. Chi, MD
British Columbia Cancer Agency
Canada: Health Canada