5331 - Pain evaluation in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC) treated with radium-223 (Ra-223) in the PARABO observation study

Background

Ra-223 demonstrated a significant overall survival benefit and favourable safety profile in mCRPC in the ALSYMPCA study (Parker C et al. N Engl J Med 2013; 369:213–223). PARABO (NCT02398526) is an ongoing, prospective, observational, non-interventional, single-arm study with a primary objective to evaluate pain response in mCRPC pts treated with Ra-223 in a real-world setting.

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 (Clopper–Pearson) confidence interval was reported.

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 (but not a superscan). 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 relief after the third dose of Ra-223, respectively.Table:

860P

QoL-Set-Pain-Response (n = 211);

QoL-Set-BPI-SF (n = 269); ^†This time point was chosen due to limited study numbers at later doses;

According to patients’ answer to the question “In the last 24 hours, how much relief have pain treatments or medications provided?” in the BPI-SF questionnaire.

Conclusions

In this study, reflective of real clinical practice, 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 relief after the third dose of Ra-223.

Clinical trial identification

NCT02398526.

Editorial acknowledgement

Jenny Feehan of OPEN Health Medical Communications (London, UK), with financial support from Bayer.

Legal entity responsible for the study

Bayer Pharma AG.

Funding

Bayer Pharma AG.

Disclosure

H. Palmedo: Honoraria (self), Travel / Accommodation / Expenses: Bayer Pharmaceuticals. S. Eschmann: Honoraria (self), Travel / Accommodation / Expenses: Bayer Pharmaceuticals. A. Werner: Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Bayer Pharmaceuticals; Advisory / Consultancy: Novartis. I. Selinski: Honoraria (self), Travel / Accommodation / Expenses: Bayer Pharmaceuticals. M. Möllers: Honoraria (self), Travel / Accommodation / Expenses: Bayer Pharmaceuticals. J. Kalinovsky: Full / Part-time employment: Bayer Pharmaceuticals. A. Benson: Full / Part-time employment: Bayer Pharmaceuticals. All other authors have declared no conflicts of interest.