Effects of six-cycle completion and earlier use of radium-223 therapy on prognosis for metastatic castration-resistant prostate cancer: A real-world multicenter retrospective study

Metastatic castration resistant prostate cancer patients' experience with Radium-223 treatment in Japan

Aim: We aimed to determine Japanese metastatic castration resistant prostate cancer (CRPC) patients' Ra-223 treatment experience. Patients & methods: Patients answered the Cancer Therapy Satisfaction Questionnaire (CTSQ domains: Satisfaction with Therapy [SWT], Expectations of Therapy [ET], Feelings about Side Effects [FSE]), the Memorial Anxiety Scale for Prostate Cancer (MAX-PC) and the FACT-Bone Pain (FACT-BP) Questionnaire at baseline, during (vists 3 and 5) and after treatment (end of observation; EOO). Results: Data from 72 patients were included. Baseline median CTSQ scores SWT: 66.1 (IQR19.7), ET: 75.0 (IQR45), and FSE 68.8 (IQR 34.4) were unchanged during vists 3 and 5, but the SWT (-3.57 [IQR17.9]) and ET (-5.0 [IQR30]) decreased while FSE was unchanged (0.0 [IQR31.25]) at EOO. The median MAX-PC (18.0 [IQR 49]) score was unchanged (0.0, IQR 6) while the median FACT BP (54.0 [IQR13]) score decreased by -1.0 (IQR 8) at EOO. Conclusion: Japanese metastatic castration resistant prostate cancer patients' experience is stable during Ra-223 treatment.

Trends in the use of local intervention for metastatic hormone-naïve prostate cancer: A multicenter retrospective study

OBJECTIVE

To evaluated the trends of local intervention and their impact on oncological outcomes in metastatic hormone-naïve prostate cancer (mHNPC) in real-world practice.

METHODS

This retrospective multicenter study included 760 patients treated with either androgen deprivation therapy (ADT) without local treatment (no castration-resistant prostate cancer [CRPC] progression within 12 months, control group) or ADT plus local intervention (intervention group) between January 2005 and March 2022. We evaluated the trends in the use of local intervention in patients with mHNPC and factors associated with CRPC-free survival in the intervention group.

RESULTS

The use of local intervention gradually increased in combination with upfront combination treatment (docetaxel or androgen receptor axis-targeted agents) for the duration of our study. The number of patients with local intervention combined with upfront treatment was significantly higher in patients with high tumor burden disease than in those with low tumor burden disease. Of the 108 patients who received local intervention, a duration of ≤7 months of initial therapy before local intervention and a level of prostate-specific antigen ≥0.20 ng/mL at the time of local intervention were significantly associated with poor CRPC-free survival.

CONCLUSIONS

The use of local intervention in combination with upfront therapy to treat mHNPC increased for the duration of our study regardless of the tumor burden. Local intervention in addition to the standard of care for mHNPC may be a feasible treatment option for selected patients, taking into consideration the duration of and response to initial treatment.

Bone-modifying agents are protective for symptomatic skeletal events in Radium-223 treatment

INTRODUCTION

Radium-223 (Ra-223) dichloride therapy increases overall survival and delays time to the first symptomatic skeletal event (SSE) in patients with castration-resistant prostate cancer (CRPC) and bone metastases. Bone-modifying agents (BMA) reduce SSE in patients with bone metastasis, but there is little information on their use with Ra-223. This study aimed to investigate the effect of BMA on SSE in patients with bone metastatic CRPC treated with Ra-223 in real-world practice.

METHODS

We included 73 patients treated with Ra-223 from 10 institutions in Japan. Time to the first SSE was estimated using the Kaplan-Meier method and compared between groups using the log-rank test. We used univariate analysis to ascertain the association between variables and SSE.

RESULTS

During a median follow-up of 12.7 months (interquartile range, 7-21.7), 12 (16.4%) patients presented SSE. Age and BMA use were different between men with and without SSE. The 1-year SSE-free survival rate from Ra-223 treatment initiation was 82.4% (95% CI, 69.4%-90.2%). BMA use was associated with favorable SSE-free survival (hazard risk, 0.23; 95% confidence interval, 0.061-0.85; p = 0.027). Two (4.7%) and seven (23.3%) patients presented symptomatic pathological bone fracture in groups with and without BMA use, respectively (p = 0.017).

CONCLUSION

This study stresses the importance of BMA use in patients with CRPC and bone metastases in Ra-223 treatment.

Impact of timing of radium‑223 administration on the survival of patients with bone metastatic castration‑resistant prostate cancer

The present study aimed to evaluate the optimal timing of radium-223 chloride (Ra-223) administration among patients with bone metastasis from castration-resistant prostate cancer (BmCRPC). Patients, who were diagnosed with BmCRPC and treated with Ra-223 therapy between October, 2016 and January, 2022, were reviewed. The survival time was calculated from the initiation of Ra-223 administration. The time from the diagnosis of BmCRPC to the initiation of Ra-223 administration was identified as a potential prognostic factor. A total of 51 patients were examined in the present study. Ra-223 was administered as the first- and second-line therapy (earlier Ra-223 administration) in 32 patients and as the third- to fifth-line therapy (later Ra-223 administration) in 19 patients. In the multivariate analysis, which considered the potential prognosis, the difference in survival times between patients who received early and late Ra-223 administration was not significant [hazard ratio (HR), 2.67; 95% confidence interval (CI), 0.79-9.07; P=0.11]. By contrast, an incomplete Ra-223 administration (HR, 128.03; 95% CI, 10.59-1548.42; P<0.01) and higher levels of prostate-specific antigen prior to Ra-223 administration (HR, 7.86; 95% CI, 2.7-27.24; P<0.01) were independent factors, significantly associated with a poorer prognosis. The timing of Ra-223 administration did not significantly affect the survival of patients from the initiation of treatment. Further studies are thus required to determine the optimal timing for Ra-223 administration.

Treatment outcomes with radium-223 in docetaxel-naïve versus docetaxel-treated metastatic castration-resistant prostate cancer patients: Real-world evidence from Taiwan

While radium (Ra)-223 is among the multiple, known life-prolonging treatments in bone-predominant metastatic castration-resistant prostate cancer (mCRPC), optimal treatment sequencing has not been determined, particularly in the Asia-Pacific context. Hence, we aimed to compare treatment outcomes of docetaxel-naïve and post-docetaxel mCRPC patients undergoing Ra-223 therapy in Taiwan. Using a single-center retrospective cohort design, we reviewed records of adult patients receiving Ra-223 for bone-metastatic mCRPC from 2018 to 2021. Patients were categorized into docetaxel-naïve or post-docetaxel groups based on history of docetaxel use preceding Ra-223. We compared the 2 groups in terms of all-cause death, 6-cycle treatment completion, and the following secondary outcomes: pain control, change in biochemical parameters (prostate-specific antigen, lactate dehydrogenase, alkaline phosphatase), biochemical response, and treatment-emergent adverse events. We performed total population sampling and a complete case analysis. We included 48 patients (25 docetaxel-naïve, 23 post-docetaxel) in the study. The mean follow-up duration was 12.4 months for the entire cohort. The docetaxel-naïve group exhibited a significantly lower all-cause mortality rate versus the post-docetaxel group (40.0% vs 78.3%, P = .02), as well as a significantly higher treatment completion rate (72.0% vs 26.1%, P < .01). We did not find significant differences in pain control, change in biochemical parameters, biochemical response, or hematologic treatment-emergent adverse events between the 2 groups. However, the docetaxel-naïve group had a numerically higher pain control rate, numerically greater improvements in alkaline phosphatase and prostate-specific antigen, and numerically lower rates of grade ≥ 3 neutropenia and grade ≥ 3 thrombocytopenia than the post-docetaxel group. Use of Ra-223 in docetaxel-naïve patients with mCRPC led to lower mortality and higher treatment completion than post-docetaxel use. Our study adds preliminary real-world evidence that Ra-223 may be used safely and effectively in earlier lines of treatment for bone-predominant mCRPC. Further large-scale, longer-term, and controlled studies are recommended.

Effectiveness and safety of radium-223 dichloride in patients with castration-resistant prostate cancer and bone metastases in real-world practice: A multi-institutional study

OBJECTIVE

Radium-223 (Ra-223) dichloride is the bone-targeted radioligand therapy that prolongs overall survival (OS) in patients with bone-metastatic castration-resistant prostate cancer (CRPC). We aimed to evaluate the safety and effectiveness of this treatment in real-world practice.

METHODS

We included Japanese men treated with Ra-223 for bone-metastatic CRPC from 10 institutions, retrospectively. Primary endpoint was OS. Secondary endpoint was maximum decline of alkaline phosphatase (ALP), lactate dehydrogenase, and prostate-specific antigen values, the rate of adverse events, and time to pathological fracture after Ra-223 treatment. Exploratory endpoint was the associations between clinical parameters and OS.

RESULTS

In total, 73 men with bone metastatic CRPC treated with Ra-223 were enrolled. The median OS was 20.9 months. ALP levels decreased significantly from pre-treatment (p = 0.03). Anemia occurred in three (4.1%) patients. Grade ≥ 3 non-pathological fractures occurred in four (5.5%) men. Nine (12.3%) patients presented pathological fracture; 7/30 (23.3%) were in men without concomitant use of a bone-modifying agent (BMA) while 2/43 (4.7%) were in patients with concomitant BMA (p = 0.03). The median OS in patients with ≥3 cycles treatment (27.2 months, p < 0.001) or hemoglobin ≥12 g/dl (27.2 months, p = 0.001) or absence of bone pain (36.3 months, p = 0.004) was significantly longer compared to those who with ≤2 cycles or hemoglobin<12 g/dl or presence of bone paint, respectively.

CONCLUSIONS

This study has shown the outcomes of Ra-223 treatment in real-world practice, where the number of treatment cycles, baseline anemia and bone pain may be useful to predict OS in Ra-223 treatment.

Prognostic Value of the BIO-Ra Score in Metastatic Castration-Resistant Prostate Cancer Patients Treated with Radium-223 after the European Medicines Agency Restricted Use: Secondary Investigations of the Multicentric BIO-Ra Study

The multicentric retrospective BIO-Ra study combined inflammatory indices from peripheral blood and clinical factors in a composite prognostic score for metastatic castration-resistant prostate cancer patients receiving Radium-223 (Ra-223). In the present study, we evaluated (i) the prognostic power of the BIO-Ra score in the framework of the restricted use of Ra-223 promoted by the European Medicines Agency in 2018; (ii) the treatment completion prediction of the BIO-Ra score. Four hundred ninety-four patients from the BIO-Ra cohort were divided into three risk classes according to the BIO-Ra score to predict the treatment completion rate (p < 0.001 among all the three groups). Patients receiving Ra-223 after restriction (89/494) were at later stages of the disease compared with the pre-restriction cohort (405/494), as a higher percentage of BIO-Ra high-risk classes (46.1% vs. 34.6%) and lower median Overall survival (12.4 vs. 23.7 months, p < 0.001) was observed. Despite this clinically relevant difference, BIO-Ra classes still predicted divergent treatment completion rates in the post-restriction subgroup (72%, 52.2%, and 46.3% of patients belonging to low-, intermediate-, and high-risk classes, respectively). Although the restricted use has increased patients at higher risk with unfavourable outcome after Ra-223 treatment, the BIO-Ra score maintains its prognostic value.