Clinical perspectives: practical insights from clinical experience with cabazitaxel in Australia

Prostate cancer, and in particular the management options for patients with metastatic castration-resistant prostate cancer (mCRPC), remains an important health issue. The approval of cabazitaxel provides a new treatment option for patients who have progressed despite docetaxel therapy. Clinical use of cabazitaxel in mCRPC is based on the results of the TROPIC study, which demonstrated an approximately 30% reduction in the risk of death compared with mitoxantrone. In this paper, we draw on accumulating clinical experience with cabazitaxel in Australia to discuss important questions such as how to select the right patient for treatment and how to proactively prevent and manage toxicities associated with this therapy. Recognizing the need for a multidisciplinary approach to patient care, opinion and insight has been sought from medical oncologists, nurses and pharmacists. While lack of trial data means that a number of questions remain unanswered, local clinical experience has helped to guide treatment decisions and refine management protocols. Appropriate patient selection, careful ongoing monitoring and proactive management of adverse events will ensure optimal treatment of patients. Nurses in particular play an important role in educating patients and identifying patients at increased risk of developing adverse events with cabazitaxel. The oncology team must work together to educate patients; taking a proactive approach to issues such as adverse events will help maximize the clinical outcome of cabazitaxel treatment and impact positively on the patient's quality of life.

Evolution of the treatment paradigm for patients with metastatic castration-resistant prostate cancer

As recently as 2004, treatment options for men with metastatic castration-resistant prostate cancer (mCRPC) were limited, with docetaxel the only approved agent conferring a survival benefit. The therapeutic landscape is now very different, with several agents demonstrating prolonged survival since 2010. New agents for the treatment of mCRPC include sipuleucel-T, cabazitaxel, abiraterone acetate, enzalutamide and radium-223. All are now approved for use in this patient group, although the specific licensing terms vary between agents. In addition, denosumab may have utility in patients with bone metastases. A number of novel agents are also in development with promising initial results. However, because these treatment options have proliferated rapidly, there is currently a paucity of clinical evidence regarding their optimal sequencing. Selection of an appropriate treatment option should take into consideration disease characteristics, drug availability and patient choice. In summary, we discuss several new treatment options available for mCRPC and their integration into the current treatment paradigm.

Second-line treatment options in metastatic castration-resistant prostate cancer: a comparison of key trials with recently approved agents

Standard first-line treatment for metastatic castration-resistant prostate cancer (mCRPC) is docetaxel plus prednisone; however, patients will usually experience disease progression during or after docetaxel treatment due to inherent or acquired resistance. Before 2010, second-line options for mCRPC were limited. However, cabazitaxel, abiraterone acetate and enzalutamide have since been approved for patients with mCRPC whose disease has progressed during or after receiving docetaxel, based on the Phase III trials TROPIC, COU-AA-301 and AFFIRM. In all three trials, an overall survival benefit (primary endpoint) was seen in the experimental arm compared with the control arm: 15.1 vs. 12.7months for cabazitaxel plus prednisone compared with mitoxantrone plus prednisone in TROPIC (hazard ratio [HR] 0.70; P<0.0001); 14.8 vs. 10.9months for abiraterone acetateplus prednisone compared with placebo plus prednisone in COU-AA-301 (HR 0.65; P<0.001); and 18.4 vs. 13.6months for enzalutamide compared with placebo alone in AFFIRM (0.63; P<0.001). However, differences in patient populations, comparators, and selection and/or definition of secondary endpoints make it difficult to draw direct cross-trial comparisons. Radium-223 dichloride has also been approved for patients with mCRPC with metastases to bone but not other organs. To date, no comparative trials or sequencing studies with newer agents have been performed. Without such data, treatment decisions must be based on evaluation of the existing evidence. This commentary compares and contrasts study designs and key data from each of these Phase III trials, and also discusses recent and ongoing clinical trials with new agents in the first- and second-line settings in mCRPC.