Pain evaluation in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC) treated with radium-223 (Ra-223) in the PARABO observation study

Ziel/Aim Ra-223 demonstrated a significant overall survival benefit and favorable safety profile in mCRPC in the ALSYMPCA study. PARABO is an ongoing, prospective, observational, non-interventional, single-arm study whose primary objective is to evaluate pain response in mCRPC pts treated with Ra-223 in a real-world setting.

Methodik/Methods The aim of this interim analysis was to assess the impact of Ra-223 on pain response, with and without the use of opioids. Pain response was determined by the worst pain item on the Brief Pain Inventory-Short Form (BPI-SF) questionnaire. A clinically meaningful pain response was defined as an improvement of ≥2 points; a 95 % exact confidence interval was reported.

Ergebnisse/Results Of the 346 pts enrolled, 311 were included in the interim safety analysis set; 49 % of whom used opioids at any time in the study. At baseline (BL), 185/311 (59.5 %) had an ECOG performance status of 1 and 222/304 (73.0 %) had ≥6 metastatic lesions. Lumbar vertebrae, pelvis and thigh were amongst the most frequently reported areas of most pain at BL. During the observation period after Ra-223 treatment, 126/211 (59.7 %) pts had a clinically meaningful pain response. Of the pts who used opioids vs those who did not, 62/113 (54.9 %) vs 64/98 (65.3 %) had a clinically meaningful pain response, and 28/110 (25.5 %) vs 19/127 (15.0 %) achieved almost complete pain relief after the third dose of Ra-223, respectively.

Schlussfolgerungen/Conclusions In this study, the majority (73.0 %) of pts had multiple lesions at BL and almost half (49 %) used opioids. Over half (59.7 %) of pts reported a decrease in worst pain after Ra-223 treatment, irrespective of opioid use. Of pts who used vs did not use opioids, 54.9 % vs 65.3 % achieved a clinically meaningful pain response. Overall, a fifth (19.8 %) of pts achieved almost complete pain relief after the third dose of Ra-223.

Publication History

Article published online:
08 April 2021