Patient-reported outcomes in castration-resistant prostate cancer with bone metastases treated with radium-223 with or without olaparib.

BACKGROUND

The combination of olaparib plus radium-223 improved progression-free survival in patients with metastatic castration-resistant prostate cancer with bone metastases (BM) in the multicenter, randomized, phase 2 COMRADE trial (NCT03317391). Here, the patient-reported outcome (PRO) analysis of this trial is reported.

METHODS

Patients were randomized 1:1 to olaparib plus radium-223 (arm A) or radium-223 alone (arm B). PROs were assessed via the Functional Assessment of Cancer Therapy-Prostate (FACT-P) and Brief Pain Inventory (BPI) at baseline and every 12 weeks. Clinically meaningful changes were defined as a ≥10-point change in FACT-P total score and a ≥30% or ≥2-point change in BPI score. Mixed-effects analysis-of-covariance models assessed PRO changes with adjustment for baseline characteristics among patients with baseline and ≥1 postbaseline assessment within 24 weeks.

RESULTS

Of 114 treated patients, 74 (65%) were evaluable (arm A, n = 40; arm B, n = 34). Baseline characteristics were balanced, with a median age of 70-72 years and Eastern Cooperative Oncology Group performance status of 1 in 60%-62%, prior docetaxel in 50%-55%, >20 BM in 45%-47%, and pain medication use in 60%-72% of patients. No significant differences in FACT-P total score change was observed at Week 12 (-4.87; 95% CI, -13.4 to 3.62) or Week 24 (1.79; 95% CI, -8.28 to 11.9). BPI pain severity did not differ at Week 12 (0.44; 95% CI, -0.44 to 1.33) or Week 24 (-0.20; 95% CI, -1.32 to 0.93). Arm B showed greater improvement in BPI pain interference at Week 12 (1.09; 95% CI, 0.14 to 2.05), which was not sustained at Week 24.

CONCLUSIONS

The addition of olaparib to radium-223 was not associated with significant detriment to PROs or pain, which supports the tolerability of this combination.