medwireNews: Men with nonmetastatic, castration-resistant prostate cancer (CRPC) receiving enzalutamide maintain their low baseline pain levels and prostate cancer symptom burden and report high health-related quality of life (HRQoL), indicates a patient-reported outcomes analysis of the phase III PROSPER study.
In the randomized, double-blind trial, enzalutamide 160 mg/day was found to significantly improve metastasis-free survival over placebo. Now, this analysis of patient-reported outcomes from the same study, published in The Lancet Oncology, suggests that this survival benefit does not come at the cost of worsening pain control and HRQoL.
“Because patients with non-metastatic, castration-resistant prostate cancer generally have low levels of pre-treatment pain and favourable HRQOL compared with patients with advanced disease, treatments should aim to improve clinical outcomes while maintaining pain control and HRQOL,” write Bertrand Tombal (Université Catholique de Louvain, Brussels, Belgium) and co-researchers.
And the current findings, they say, suggest that “in addition to reducing the risk of metastasis […] enzalutamide also increases time to pain progression, symptom worsening, and HRQOL deterioration when compared with placebo.”
The researchers found that changes from baseline to week 97 with enzalutamide were similar to those with placebo for most patient-reported outcome scores, while some measures were improved.
For example, the time to clinically meaningful pain progression, as assessed using the Brief Pain Inventory Short Form, was significantly longer with enzalutamide than placebo, at a median of 36.8 versus not reached in the placebo group, giving a hazard ratio (HR) of 0.75.
Similarly, the time to clinically meaningful worsening of urinary and bowel symptoms on the EORTC Quality of Life Questionnaire-PR25 was significantly longer with enzalutamide than placebo, at a median of 36.9 versus 25.9 months (HR=0.58) and 33.2 versus 25.9 months (HR=0.72), respectively.
Furthermore, the Functional Assessment of Cancer therapy–Prostate (FACT-P) scale showed that active treatment, compared with placebo, was associated with a longer time to deterioration in emotional wellbeing (36.7 vs 29.5 months; HR=0.69), prostate cancer subscale scores (18.4 vs 14.7 months; HR=0.79), and FACT-P total scores (22.1 vs 18.4 months; HR=0.83).
Enzalutamide was associated with an increase in hormone therapy-related symptoms, but the researchers note that the difference compared with placebo was not clinically significant.
The authors conclude: “The efficacy, tolerability, and HRQOL profile shown in this study suggest that enzalutamide represents a treatment option for patients with non-metastatic, castration-resistant prostate cancer.”
Writing in an accompanying comment, Gillian Duchesne (University of Melbourne, Victoria, Australia) said: “The crucial question now is at which stage and in what sequence this drug, and others in its class […] should be used most appropriately.”
By Catherine Booth
medwireNews is an independent medical news service provided by Springer Healthcare. © 2019 Springer Healthcare part of the Springer Nature group
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