PracticeUpdate: Haematology & Oncology

EUROPEAN SOCIETY OF MEDICAL ONCOLOGY 2016 CONGRESS 28

Dr Brian Lewis discusses his top abstracts on advanced prostate cancer from ESMO 2016 Dr Lewis is Assistant Professor of Clinical Medicine in the Department of Hematology and Medical Oncology, Tulane University School of Medicine in New Orleans, and Associate Editor of the PracticeUpdate Advanced Prostate Cancer Center of Excellence.

Abstract 720PD Long term efficacy and QOL data of chemohormonal therapy (C-HT) in low and high volume hormone naïve metastatic prostate cancer (PrCa): E3805 CHAARTED trial. C Sweeney, Y Chen, G Liu, et al • In this study, 790 men with hormone-naive metastatic prostate cancer were randomised to receive ADT alone or ADT plus docetaxel and stratified by low- or high-volume disease to evaluate long-term efficacy and quality of life.After a median follow-up of 53.7months, 299 of 513 high-volume patients and 100 of 277 low-volume patients had died. Median OS was significantly longer in patients receiving ADT plus docetaxel comparedwithADT alone (57.6 vs 47.2months; P= 0.0018). There was no difference in OS in low-volume patients receiving either treatment; however, high-volume patients receivingADT plus docetaxel demonstrated significantly increased OS (P < 0.0001). Quality of life was assessed by FACT-P score, revealing lower baseline quality of life in high-volume patients; the lowest quality-of-life score at 12 months was reported in high-volume patients receiving ADT alone. • Patients with a higher burden of metastatic prostate cancer exhibit significant clinical benefit with ADT plus docetaxel. Abstract 725PD Pembrolizumab for patients with advanced prostate adenocarcinoma: Preliminary results from the KEYNOTE-028 study. A Hansen, C Massard, PA Ott, et al • This phase IB study included 23 patients with advanced PD- L1-positive prostate adenocarcinoma to evaluate the safety and efficacy of pembrolizumab; 74% of patients had received at least two prior therapies. Pembrolizumab was dosed at 10 mg/kg every 2 weeks. After a median follow-up of 33 weeks, 14 patients had treatment-related adverse effects, including nausea, grade 3 fatigue, grade 3 peripheral neuropathy, grade 3 asthenia, and grade 4 lipase

increase, none of which resulted in treatment discontinuation or death. The overall response rate was 13%, with 3 partial responses and a 59-week median duration of response. The 6-month PFS and stable disease rates were 39%, and the median OS was 8 months. Exploratory analysis showed that a better clinical outcome was associated with the putative T-cell inflamed signature, which correlates with previous pembrolizumab data. • The study results demonstrated durable responses and tolerability of pembrolizumab in patients with advanced PD-L1-positive prostate adenocarcinoma. Abstract 748P Switch from abiraterone + prednisone to abiraterone + dexamethasone after PSA progression under abiraterone + prednisone in asymptomatic metastatic castration-resistant prostate cancer (mCRPC) patients. C Fenioux, C Louvet, D Prapotnich, et al • Of 120 patients with asymptomatic mCRPC enrolled in this study, 48 progressed biologically on abiraterone acetate (AA) + prednisone 10 mg daily. They were switched toAA + dexamethasone 0.5 mg daily at the time of PSA increase to evaluate outcomes and to determine predictive factors of switch efficiency. After a median follow-up of 14 months from switch, PFS rates were 14.5 and 23.1 months for patients receiving AA + dexamethasone and AA + prednisone then + dexamethasone, respectively. PSA decreased in 45.8% of patients following the switch. Significant predictive factors of switch efficiency included hormone sensitivity >5 years, low PSA level at switch, and <6 months to PSA progression on AA + prednisone. • Switching from prednisone to dexamethasone to reverse biological AA + prednisone resistance was successful in approximately half of patients with mCRPC in this study, warranting further randomised trials. Abstract 750P Radium-223 with concomitant bone-targeting agents in metastatic castration-resistant prostate cancer (CRPC) patients treated in an international early access program (EAP). F Saad, A Heidenreich, D Heinrich, et al • This single-arm phase 3B study included 696 patients with CRPC with bone metastases from 14 countries who received radium-223 50 kBq/kg. Of these patients, 127 received denosumab, 125 received bisphosphonates, and 435 received no bone-targeting agents. Patients receiving radium-223 and denosumab had a longer median OS and median time to first symptomatic skeletal event compared with patients not receiving bone-targeting agents. Patients receiving bisphosphonates exhibited prolonged time to first symptomatic skeletal event compared with patients who did not receive bone-targeting agents. • This study demonstrated that patients receiving radium-223 and bone- targeting agents had a longer time to first symptomatic skeletal event compared with patients who did not receive bone-targeting agents; however, OS was only improved in patients receiving denosumab.

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