[Retrospective practice-related care research study on therapy of mCPRC with radium-223 dichloride]. / Retrospektive Versorgungsstudie von d-uo zur Therapie des mCRPC mit Radium-223-dichlorid.

During phase III study ERA-223, patients under combination therapy with radium-223 and abiraterone showed an increased risk of bone fractures and a possible higher risk of death. This observation led to a change in the German therapeutic guidelines in 2018. Radium-223 is now only allowed as a third-line monotherapy (besides ADT) in patients with metastatic castration resistant prostate cancer (mCRPC) with symptomatic bone lesions without known visceral metastases or for patients with mCRPC, for whom no other available systematic therapy is suitable. Since almost no data on practice-related care research on the use of radium-223 exist, we consulted members of d-uo (German Uro-Oncologists) over their therapy algorithms. This study analysed data of patients treated with radium-223 between 2014 and 2019. It could be shown that 50% of mCRPC-patients had received radium-223 in the past as third-line therapy. Half of these were treated in combination with new androgen receptor targeted therapies (ARTA) and no increase in bone fractures was observed. This was most likely due to the additional use of bone protecting agents. Despite the late cancer stage, treatment response was seen in almost half of the patients.

LHRH sparing therapy in patients with chemotherapy-naïve, mCRPC treated with abiraterone acetate plus prednisone: results of the randomized phase II SPARE trial.

BACKGROUND: Although the benefit of androgen deprivation therapy (ADT) continuation in metastatic castration-resistant prostate cancer (mCRPC) remains controversial, clinical evidence is lacking. Recent results indicated that treatment with abiraterone acetate (AA) plus prednisone (P) further suppresses serum testosterone levels over ADT alone, suggesting that continuation of ADT in the treatment of mCRPC may not be necessary. METHODS: In this exploratory phase 2 study, mCRPC patients were randomized with a 1:1 ratio to receive either continued ADT plus AA + P (Arm A) or AA + P alone (Arm B). The primary endpoint was the rate of radiographic progression-free survival (rPFS) at month 12. Secondary endpoints included PSA-response rate, objective response, time to PSA progression and safety. RESULTS: A total of 68 patients were equally randomized between the two study arms. Median testosterone-levels remained below castrate-levels throughout treatment in all patients. According to the intention-to-treat analysis the rPFS rate was 0.84 in Arm A and 0.89 in Arm B. Moderate and severe treatment-emergent adverse events were reported for 72% of the patients in Arm A and for 85% of the patients in Arm B. CONCLUSIONS: AA + P treatment without ADT may be effective in mCRPC patients and ADT may not be necessary in patients receiving AA + P.