As we reported last year, a new radiopharmaceutical has entered the pack. 131I-MIP-1095, a powerful beta-particle emitter attached to a PSMA-targeted ligand, will enter a multicenter, randomized, Phase II clinical trial. Progenics, the manufacturer, put out a press release, which can be read here.
They will be testing a combination of 131I-MIP-1095 with enzalutamide (Xtandi) in patients who are metastatic, castration resistant, have not yet had chemotherapy, and who have become resistant to abiraterone acetate (Zytiga). It is hoped that Xtandi will radiosensitize the cancer to the radiopharmaceutical with a resultant PSA decrease.
The goal is to recruit 120 evaluable patients. Half will get treated with the radiopharmaceutical + Xtandi; half will get Xtandi alone. All patients will be screened using DCFPyL PET/CT to assure that their metastases are PSMA-avid. The primary endpoint data — the percent who have greater than 50 percent PSA reduction — will be collected for a year. Secondary endpoint data — radiographic response, progression-free survival, and overall survival — will be reported at the end of two years.
The other two major radiopharmaceuticals in clinical trials are 177Lu-PSMA-617 and 225Ac-PSMA-617. 177Lu-PSMA-617 has entered a randomized, Phase III clinical trial in the US, with about 30 test sites expected. So far, recruiting has begun at community sites in Omaha, NE; Albuquerque, NM; Kettering, OH; and Houston, TX; and at four academic medical centers — the University of California, Los Angeles (UCLA), Tulane University, the Mayo Clinic, and Indiana University. There are also various Phase I and II clinical trials of this product in the US and internationally.
We recently reported information about the very promising outcomes of 225Ac-PSMA-617 in Germany. Some patients report that they are combining 225Ac-PSMA-617 and 177Lu-PSMA-617 to get the advantages of each. Weill Cornell Medical Center in New York City is investigating 225Ac-J591 in a Phase I clinical trial.
Editorial note: This commentary was written by Allen Edel for The “New” Prostate Cancer InfoLink.
Filed under: Drugs in development, Living with Prostate Cancer, Management, Treatment | Tagged: castration-resistant, injectable, Iodine-131-MIP-1095, metastatic, radiation, systenic, therapy |
THE "NEW" PROSTATE CANCER INFOLINK 
Sitemaster,
I was wondering why the exclusion of people previously treated with chemotherapy?
Dear Charles:
Probably for the very simple reason that the drug developer was trying to select for a very specific and definable group of men in whom I-131-MIP-195 was most likely to have a positive outcome. If it works in men who have not had chemotherapy. they can always also do a trial in men who have had chemotherapy later.
Thanks