Patient-reported outcomes following abiraterone acetate plus prednisone added to androgen deprivation therapy in patients with newly diagnosed metastatic castration-naive prostate cancer (LATITUDE): an international, randomised phase 3 trial

Background In the LATITUDE trial, addition of abiraterone acetate plus prednisone to androgen deprivation therapy (ADT) improved overall survival compared with placebos plus ADT in patients with newly diagnosed, high-risk, metastatic castration-naive prostate cancer. Understanding the effects of treatments on patient-reported outcomes (PROs) and health-related quality of life (HRQOL) is important for treatment decisions; therefore we aimed to analyse the effects of ADT plus abiraterone acetate and prednisone versus ADT plus placebos on PROs and HRQOL in patients in the LATITUDE study. Methods In the multicentre, international, randomised, phase 3 LATITUDE trial, eligible patients were aged 18 years or older, had newly diagnosed, high-risk, metastatic castration-naive prostate cancer confirmed by bone scan (bone metastases) or by CT or MRI (visceral, soft tissue, or nodal metastases), and an Eastern Cooperative Oncology Group (ECOG) performance status score of 2 or less. Patients from 235 clinical sites in 34 countries were randomly assigned (1:1) following a country-by-country scheme done by permuted block randomisation (with two blocks) and stratified by the presence of visceral metastasis and ECOG performance status to receive ADT plus 1000 mg oral abiraterone acetate and 5 mg oral prednisone once daily or ADT plus placebos. Selection of ADT, chemical or surgical, was at the investigator's discretion. The co-primary endpoints of the trial, overall survival and radiographic progression-free survival, have been published. PRO data were collected directly on electronic tablet devices at the clinical sites during screening and before any other visit procedure on day 1 of cycles 1–3, monthly during cycles 4–13, and then every 2 months until the end of treatment, by use of the Brief Pain Inventory—Short Form (BPI-SF), Brief Fatigue Inventory (BFI), Functional Assessment of Cancer Therapy Prostate scale (FACT-P), and the EuroQol (EQ-5D-5L) questionnaires. PRO analyses were an exploratory endpoint. Analyses were by intention-to-treat. Results from the first pre-planned interim analysis (Oct 31, 2016), are presented here. This ongoing study is registered with Clinicaltrials.gov, number NCT01715285. Findings Between Feb 12, 2013, and Dec 11, 2014, 1199 patients were randomly assigned: 597 to ADT plus abiraterone acetate and prednisone and 602 to ADT plus placebos. Median follow-up was 30·9 months (IQR 21·2–33·2) in the ADT plus abiraterone acetate and prednisone group versus 29·7 months (1·4–43·5; 16·1–31·3) in the ADT plus placebos group. Median time to worst pain intensity progression assessed by the BPI-SF score was not reached in either group (ADT plus abiraterone acetate and prednisone, not reached [95% CI not reached to not reached]; 25th percentile 11·07 months [95% CI 9·23–18·43]; ADT plus placebos group, not reached [95% CI not reached to not reached]; 25th percentile 5·62 [95% CI 4·63–7·39]; hazard ratio [HR] 0·63 [95% CI 0·52–0·77]; p<0·0001). Median time to worst fatigue intensity was not reached in either the ADT plus abiraterone acetate and prednisone group (not reached [95% CI not reached to not reached]; 25th percentile 18·4 months [95% CI 12·9–27·7]) or the ADT plus placebos group (not reached [95% CI not reached to not reached]; 25th percentile 6·5 months [95% CI 5·6–9·2]; HR 0·65 [95% CI 0·53–0·81], p=0·0001). Median time to deterioration of functional status assessed by the FACT-P total score scale was 12·9 months (95% CI 9·0–16·6) in the ADT plus abiraterone acetate and prednisone group versus 8·3 months (7·4–11·1) in the ADT plus placebos group (HR 0·85 [95% CI 0·74–0·99]; p=0·032). Interpretation The addition of abiraterone acetate plus prednisone to ADT in patients with newly diagnosed, high-risk metastatic castration-naive prostate cancer improved overall PROs by consistently showing a clinical benefit in the progression of pain, prostate cancer symptoms, fatigue, functional decline, and overall HRQOL. Funding Janssen Research & Development.