Effectiveness of abiraterone acetate plus prednisone in chemotherapy-naïve patients with metastatic castration-resistant prostate cancer in a large prospective real-world cohort: the ABItude study

Abstract

Background: Real-world data on chemotherapy-naïve patients with metastatic castration-resistant prostate cancer (mCRPC) treated with abiraterone plus prednisone are limited, largely deriving from small retrospective studies. Methods: ABitude is an Italian, observational, prospective, multicenter study of mCRPC patients receiving abiraterone plus prednisone in clinical practice. Chemotherapy-naïve mCRPC patients were consecutively enrolled at abiraterone start (February 2016 to June 2017) and are being followed for 3 years, with evaluation approximately every 6 months. Several clinical and patients reported outcomes were examined. Results: In this second interim analysis, among 481 enrolled patients, 453 were evaluable for analyses. At baseline, the median age was 77 years and ~69% of patients had comorbidities (mainly cardiovascular diseases). Metastases were located mainly at bones and lymph nodes; 8.4% of patients had visceral metastases. During a median follow-up of 18 months, 1- and 2-year probability of radiographic progression-free survival were 73.9% and 56.2%, respectively; the corresponding rates for overall survival were 87.3% and 70.4%. In multivariable analyses, the number of bone metastases significantly affected radiographic progression-free survival and overall survival. During abiraterone plus prednisone treatment, 65% of patients had a ⩾50% prostate-specific antigen decline, and quality of life remained appreciably high. Among symptomatic patients according to the Brief Pain Inventory) (32%), scores significantly declined after 6 months of treatment. Overall, eight patients (1.7%) had serious adverse reactions to abiraterone. Conclusions: Abiraterone plus prednisone is effective and safe for chemotherapy-naïve mCRPC patients in clinical practice.

Real-world experience of abiraterone acetate plus prednisone in chemotherapy-naive patients with metastatic castration-resistant prostate cancer: long-term results of the prospective ABItude study

“…Using an unselected cohort of patients from several oncology, urology, and radiotherapy sites across Italy, the final analysis of the ABItude study over a 36-month study period showed the real-world effectiveness and safety of abiraterone for the treatment mCRPC patients naive to chemotherapy, confirming results from the interim analysis. 16 …”

“…Collecting prospectively hard oncologic endpoints and relevant patient-reported outcomes (PROs) on a large cohort of unselected patients, it represents a unique opportunity to evaluate the effectiveness and safety of abiraterone in the treatment of chemotherapy-naive mCRPC patients in routine clinical practice. Results from interim analyses at 18 months 16 of median follow-up showed favorable patient outcomes and no safety-related concerns. Herein, we have reported the final 36-month results of the ABItude study.…”

“…ABItude is an Italian, multicentric, observational, prospective study of mCRPC patients progressing after standard hormonal therapy with ADT, starting a first-line treatment with abiraterone as for clinical practice. 16 Enrollment took place between February 2016 and June 2017 in 49 participating Italian sites (urological, radiotherapy, and oncological units). Main selection criteria were as follows: men aged ≥18 years with histologically confirmed metastatic adenocarcinoma of the prostate, naive to chemotherapy, asymptomatic or mildly symptomatic according to clinical judgment, surgically or medically castrated, who had progressed on ADT, and in whom chemotherapy was not clinically indicated.…”

First-line treatment of metastatic castration-resistant prostate cancer: the real-world Italian cohort of the Prostate Cancer Registry

“…18 In particular, the present results are in agreement with those from a large prospective Italian cohort of first-line mCRPC patients followed 3 years, in which abiraterone acetate plus prednisone showed good clinical (and patients' reported) outcomes. 19 Our results on docetaxel are broadly comparable to those observed in a trial comparing the drug given as firstline treatment for mCRPC against cabazitaxel, which estimated a median OS of 24.3 months and a median PFS of 5.3 months in the docetaxel arm; 20 any comparison with the two 2004 landmark trials 5,7 is likely to be misleading, because of the limited available treatment options for mCRPC and the different patients' characteristics and disease management at the time of trials conduction.…”

“… 18 In particular, the present results are in agreement with those from a large prospective Italian cohort of first-line mCRPC patients followed 3 years, in which abiraterone acetate plus prednisone showed good clinical (and patients’ reported) outcomes. 19 …”