Initial experience with 225Ac-PSMA-617 in patients with advanced-stage prostate cancer

Objectives: To date, targeted α-therapy with 225Ac-PSMA-617 although still preliminary, has demonstrated strong potential to significantly benefit advanced-stage prostate cancer patients. Here we report our initial experience with 225Ac-PSMA-617 in a developing country, as one of the first groups to provide this therapy. Methods: Eligible patients with confirmed advanced-stage prostate cancer were recruited and treated with standardized activities of 8 MBq 225Ac-PSMA-617 in two month intervals. In case of favorable responses activities were decreased to 6 MBq or 4 MBq in subsequent cycles to minimize toxicity. Baseline imaging and follow-up were performed with 68Ga-PSMA-11 PET/CT prior to the next treatment cycle. Interim treatment response evaluation was based on the radiologic response, tumor marker and functional results. Results: Twenty-five patients with a mean age of 66 years were treated. A treatment activity of 8 MBq exhibited moderate toxicity with grade I-II of xerostomia in 28% of patients and induced significant antitumor response in these high-tumor-burden patients. Remarkable antitumor activity by means of objective radiologic response or tumor marker decline was observed in 85% evaluable patients. Our short-term results also demonstrate a favourable hematological and renal toxicity profile and quality of life improvements. Conclusion: Standard treatment with 8 MBq 225Ac-PSMA617 every two months seems to be clinically safe with biochemical response and imaging response in around 85% of patients along with xerostomia in 28% of patients as the notable side effect. A larger multicenter trial is needed to confirm our preliminary results which are currently limited by short follow-up and small sample size.

SATHEKGE Mike;  KNOESEN Otto;  BRUCHERTSEIFER Frank;  REYNEKE F;  KRATOCHWIL Clemens;  LENGANA T;  GIESEL Frederik;  LAWAL I;  BOSHOMANE T;  VORSTER Mariza;  MORGENSTERN Alfred; 

2018-07-17

SOC NUCLEAR MEDICINE INC

JRC110544

0161-5505,