California-based Astex Pharmaceuticals has announced the initiation of a Phase I/II clinical trial of another heat shock protein 90 (HSP90) inhibitor (AT13387) in the treatment of men with metastatic, castration-resistant prostate cancer (mCRPC) who have progressed after treatment with abiraterone acetate + prednisone (or a similar steroid).
According to the company’s media release, issued earlier today, this is a two-part study:
- One group of about 50 patients will initially be enrolled into the Phase I component to investigate the safety and the clinical and biological activity of various doses of AT13387 in combination with abiraterone acetate (by monitoring depletion of androgen receptors in tumor and circulating tumor cells (CTCs).
- Assuming there are any signs of activity (with appropriate safety) in the Phase I component of the trial, a second group of just over 100 patients will be enrolled into the Phase II component, and randomized to treatment with either the best combination of AT13387 in combination with abiraterone acetate identified in Phase I or to AT13387 alone.
Also according to the Astex media release, “AT13387 is a small molecule inhibitor of HSP90 … believed to be responsible for supporting many tumor cells becoming cancerous. HSP90 acts as a “molecular chaperone” stabilizing and preventing the breakdown of key oncogenic proteins.” AT13387 is also being studied in other refractory tumor types.
As yet we can find no information about this specific trial on the ClinicalTrials.gov web site, nor have we been able to find any information about specific clinical sites at which patients are being enrolled into this trial. However, for those US-based patients who may be interested, you can contact the company by phone at 925.560-0100. Patients based in Europe can try calling the company’s European offices in Cambridge, England at +44 (0) 1223 226201. It is not clear from the media release whether there are study sites set up yet in either the USA or Europe.