Safety and effectiveness of the radium-223-taxane treatment sequence in patients with metastatic castration-resistant prostate cancer in a global observational study (REASSURE).

BACKGROUND: Radium-223 and taxane chemotherapy each improve survival of patients with metastatic castration-resistant prostate cancer (mCRPC). Whether the radium-223-taxane sequence could extend survival without cumulative toxicity was explored. METHODS: The global, prospective, observational REASSURE study (NCT02141438) assessed real-world safety and effectiveness of radium-223 in patients with mCRPC. Using data from the prespecified second interim analysis (data cutoff, March 20, 2019), hematologic events and overall survival (OS) were evaluated in patients who were chemotherapy-naive at radium-223 initiation and subsequently received taxane chemotherapy starting ≤90 days ("immediate") or >90 days ("delayed") after the last radium-223 dose. RESULTS: Following radium-223 therapy, 182 patients received docetaxel (172 [95%]) and/or cabazitaxel (44 [24%]); 34 patients (19%) received both. Seventy-three patients (40%) received immediate chemotherapy and 109 patients (60%) received delayed chemotherapy. Median time from last radium-223 dose to first taxane cycle was 3.6 months (range, 0.3-28.4). Median duration of first taxane was 3.7 months (range, 0-22.0). Fourteen patients (10 in the immediate and four in the delayed subgroup) had grade 3/4 hematologic events during taxane chemotherapy, including neutropenia in two patients in the delayed subgroup and thrombocytopenia in one patient in each subgroup. Median OS was 24.3 months from radium-223 initiation and 11.8 months from start of taxane therapy. CONCLUSIONS: In real-world clinical practice settings, a heterogeneous population of patients who received sequential radium-223-taxane therapy had a low incidence of hematologic events, with a median survival of 1 year from taxane initiation. Thus, taxane chemotherapy is a feasible option for those who progress after radium-223. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT02141438. PLAIN LANGUAGE SUMMARY: Radium-223 and chemotherapy are treatment options for metastatic prostate cancer, which increase survival but may affect production of blood cells as a side effect. We wanted to know what would happen if patients received chemotherapy after radium-223. Among the 182 men treated with radium-223 who went on to receive chemotherapy, only two men had severe side effects affecting white blood cell production (neutropenia) during chemotherapy. On average, the 182 men lived for 2 years after starting radium-223 and 1 year after starting chemotherapy. In conclusion, patients may benefit from chemotherapy after radium-223 treatment without increasing the risk of side effects.

Radium-223 in women with hormone receptor-positive bone-metastatic breast cancer receiving endocrine therapy: pooled analysis of two international, phase 2, randomized, double-blind, placebo-controlled trials.

BACKGROUND: Most women with advanced breast cancer have skeletal metastases. Radium-223 is an alpha-emitting radionuclide that selectively targets areas of bone metastases. METHODS: Two double-blind, placebo-controlled studies of radium-223 were conducted in women with hormone receptor-positive (HR+), bone-predominant metastatic breast cancer. All patients received endocrine therapy (ET), as a single agent of the investigator's choice (Study A) or exemestane + everolimus (Study B). Patients were randomized to receive radium-223 (55 kBq/kg) or placebo intravenously every 4 weeks for six doses. Accrual was halted following unblinded interim analyses per protocol amendments, and both studies were terminated. We report pooled analyses of symptomatic skeletal event-free survival (SSE-FS; primary endpoint), radiologic progression-free survival (rPFS) and overall survival (OS; secondary), and time to bone alkaline phosphatase (ALP) progression (exploratory). RESULTS: In total, 382 patients were enrolled, and 196 SSE-FS events (70% planned total) were recorded. Hazard ratios (95% confidence intervals) and nominal p values for radium-223 + ET versus placebo + ET were: SSE-FS 0.809 (0.610-1.072), p = 0.1389; rPFS 0.956 (0.759-1.205), p = 0.7039; OS 0.889 (0.660-1.199), p = 0.4410; and time to bone ALP progression 0.593 (0.379-0.926), p = 0.0195. Radium-223- or placebo-related treatment-emergent adverse events were reported in 50.3% versus 35.1% of patients (grade 3/4: 25.7% vs. 8.5%), with fractures/bone-associated events in 23.5% versus 23.9%. CONCLUSIONS: In patients with HR+ bone-metastatic breast cancer, numeric differences favoring radium-223 + ET over placebo + ET for the primary SSE-FS endpoint were suggestive of efficacy, in line with the primary outcome measure used in the underlying phase 2 studies. No similar evidence of efficacy was observed for secondary progression or survival endpoints. Adverse events were more frequent with radium-223 + ET versus placebo + ET, but the safety profile of the combination was consistent with the safety profiles of the component drugs. Clinical trial registration numbers Study A: NCT02258464, registered October 7, 2014. Study B: NCT02258451, registered October 7, 2014.

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.

What is this study about? We wanted to know the treatment experience with Radium-223 (Ra-223) among Japanese prostate cancer patients. Ra-223 is a radioactive molecule used for the treatment of metastatic castration resistant prostate cancer. We asked patients to answer different questionnaires on treatment satisfaction, anxiety and quality of life before, during, and after treatment with Ra-223. What were the results? Based on the patients' answers to our questionnaires, treatment satisfaction, anxiety and quality of life remain stable while the patients undergo treatment with Ra-223, but in some aspects may decline after treatment. What do the results mean? The results mean that patients' experience during Ra-223 treatment is stable but patients should share any concerns they have about their treatment with their doctors.

Integrating radium-223 therapy into the management of metastatic prostate cancer care: a plain language summary.

WHAT IS THIS SUMMARY ABOUT?: Few life-prolonging treatment options are available for patients with metastatic castration-resistant prostate cancer (mCRPC). This article provides an overview of the current systemic treatments available for mCRPC and reviews studies that investigate the optimal timing for the use of radium-223. The aim is to illustrate possible systemic treatment sequences to maximize benefit from radium-223 therapy. WHAT IS METASTATIC CASTRATION-RESISTANT PROSTATE CANCER & HOW IS IT TREATED?: Prostate cancer is called mCRPC when it spreads to organs outside of the prostate (such as the lymph nodes, bones, liver, or lungs) and no longer responds to hormonal therapy. There are several treatment options available for mCRPC, such as abiraterone, enzalutamide, radium-223, docetaxel, cabazitaxel, olaparib, rucaparib, sipuleucel-T, and 177Lu-PSMA. It is important to understand the risks and benefits associated with each treatment and whether current use may have an impact on future treatment options, including eligibility in certain clinical trials. Maintaining bone health is also an important part of prostate cancer care. WHAT IS RADIUM-223?: Radium-223 is a radioactive molecule that releases strong radiation within a very small range around itself. It mainly travels to the bone where the prostate cancer has spread and kills the cancer cells in that area. Results from a clinical study named ALSYMPCA showed that men who received radium-223 lived longer in addition to having less bone pain. The most common side effects of radium-223 are nausea, vomiting, and diarrhea. Radium-223 minimally suppresses the bone marrow, which means that it slightly reduces the levels of red and white blood cells.

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.

A single arm phase II study of bone-targeted Sn-117 m-DTPA in symptomatic castration-resistant prostate cancer with skeletal metastases.

BACKGROUND: Several bone-seeking radionuclides have been developed for palliation of metastatic bone pain since 1956, however, so far radium-223 dichloride is the first and only Food and Drug Administration (FDA) approved targeted alpha therapy for metastatic castration-resistant prostate cancer (mCRPC) based on ALSYMPCA phase 3 study. While radium-223 does improve pain and overall survival outcomes, the improvement can come at the expense of side effects such as bone marrow toxicity. The development of new and better treatment with long-standing pain relief is clearly an unmet medical need. METHODS: The study is a non-randomized phase II study. The study population consists of 25 patients with CRPC who had progressed on any lines of prior therapies and whose serum testosterone level is less than 50 ng/dl and have metastatic lesions to at least two bone sites, with at least one site that has clinically meaningful pain at baseline (≥ 4 on an 11-point intensity scale). Eligible patients will be given two cycles of Sn-117 m-DTPA every 8 weeks or 56 days. Treatment will be administered by slow IV injection over 5-10 min. Retreatment after two cycles is allowed if patients meet the following retreatment criteria. The primary objective is to evaluate the efficacy of Sn-117 m-DTPA on sustained pain response in patients with CRPC metastatic to at least two bone sites and at least one with clinically meaningful pain at baseline (≥ 4 on an 11-point pain intensity scale). Sustained pain response is defined as: 1) achieving pain index ≤ 3 within a 12-week period and 2) maintaining pain index ≤ 3 over a 16-week period. The secondary objectives are: safety and tolerability, measurement of Sn-117 m-DTPA activity by gamma-camera dosimetry scans, therapeutic efficacy, time to the first symptomatic skeletal event, duration of pain response, changes in PSA and ALP levels, patient-reported outcomes and progression free survival and overall survival. DISCUSSION: Sn-117 m-DTPA is a unique bone-targeting theranostic radiopharmaceutical agent that selectively binds most heavily to bone metastases sites. This study will be the first prospective phase II trial to assess the pain efficacy and anti-tumor activity of Sn-117 m-DTPA in mCRPC with at least one clinically meaningful pain at baseline. TRIAL REGISTRATION: ClincialTrials.gov Identifier: NCT04616547.

Radium-223 in the Treatment of Metastatic Castrate-Resistant Prostate Cancer.

Background Radium 223 (Ra-223) has been successfully utilised for the treatment of men with metastatic castrate resistant prostate cancer (mCRPC). To date, no real world outcomes from its use in the Irish population have been described. Methods All men referred to our institution for Ra-223 from September 2016 to March 2019 were included. Patient demographics, treatments received, toxicities and outcomes were recorded. Overall survival (OS) and progression free survival (PFS) were analysed using the Kaplan-Meier method. Results Complete data was available for 54 men. Median age was 75 years (range 61-86 years). The median number of prior systemic treatments for mCRPC was 2 (range 0-4). Median ECOG performance status was 1 at the start of treatment and 2 at completion. The median number of Ra-223 cycles received was 4 with 37%(n=20) completing all 6 planned cycles. The most common treatment-related toxicity was fatigue seen in 52% of patients ( n=28). Improved pain scores were documented in 76% of men requiring opioid analgesia at the start of treatment. The median OS was 7 months. A good ECOG performance status, fewer than 6 bone metastases, normal alkaline phosphatase level at start of treatment and chemotherapy naivety were associated with improved OS. Conclusions Ra-223 is a moderately well tolerated palliative treatment amongst Irish men with mCRPC.

RADTHYR: an open-label, single-arm, prospective multicenter phase II trial of Radium-223 for the treatment of bone metastases from radioactive iodine refractory differentiated thyroid cancer.

PURPOSE: This is the first prospective trial evaluating the efficacy of alpha emitter Radium-223 in patients with bone metastases from radioactive iodine (RAI) refractory (RAIR) differentiated thyroid cancer. METHODS: RADTHYR is a multicenter, single-arm prospective Simon two-stage phase II trial (NCT02390934). The primary objective was to establish the efficacy of three administrations of 55 kBq/kg of Radium-223 by 18F-FDG PET/CT according to PERCIST criteria. Secondary objectives were to establish the efficacy of six administrations of Radium-223 by 18F-FDG PET/CT, 99mTc-HMDP bone scan and 18FNa PET/CT, clinical benefits, changes in serum bone markers, thyroglobulin levels, and safety. RESULTS: Ten patients were enrolled between July 2015 and December 2017 (4 M; median age 74 years). Prior to Radium-223 administration, patients received a median RAI cumulative activity of 15 GBq (7.4-35.6), external radiation therapy (n = 9), bone surgery (n = 8), cimentoplasty (n = 5), and cryoablation (n = 2). 18F-FDG PET/CT showed stable disease (SD) in 4/10 and progressive disease (PD) in 6/10 cases after three administrations and SD in 4/10, PD in 5/10 cases, and 1/10 non-evaluable (NE) case after six administrations. After six injections, 99mTc-HMDP bone scan showed SD in 9 cases and was NE in 1 case; 18FNa PET/CT showed SD in 8 cases, partial response (PR) in 1 case, and was NE in 1 case. No significant clinical benefits were reported during the study. A skeletal event occurred in 6 patients (median time without skeletal event of 12.1 months). Seventy-seven adverse events were reported during treatment (7 of grade 3-4). Three patients developed an acute myeloid, a promyelocytic, and a chronic myeloid leukemia after the last Radium-223 administration considered as drug-related. CONCLUSION: The trial was stopped after interim analysis for lack of response of bone metastases from RAIR thyroid cancer to Radium-223. Severe hematological toxicity was observed in patients heavily pretreated with RAI and external radiation. TRIAL REGISTRATION NUMBER: NCT02390934. Registration date 18.03.2015.

A randomised phase II trial of three dosing regimens of radium-223 in patients with bone metastatic castration-resistant prostate cancer.

BACKGROUND: Radium-223 prolongs overall survival and delays symptomatic skeletal events (SSEs) in patients with metastatic castration-resistant prostate cancer (mCRPC) and bone metastases. The approved radium-223 regimen is 55 kBq/kg every 4 weeks (q4w) for six cycles (standard dose). We investigated different radium-223 regimens in patients with mCRPC. PATIENTS AND METHODS: Patients were randomised 1 : 1 : 1 to radium-223 standard-dose, high-dose (88 kBq/kg q4w for six cycles) or extended-schedule arms (55 kBq/kg q4w for 12 cycles). The primary end point, SSE-free survival (SSE-FS), was compared in patients treated with a high- versus standard-dose regimen, or with a standard dose in an extended (>6 to 12 cycles) versus standard schedule (six cycles). RESULTS: A total of 391 patients were randomised; baseline characteristics were balanced between arms. On-treatment SSEs developed in 37/130 (28%), 42/130 (32%) and 48/131 (37%) patients in the standard-dose, high-dose and extended-schedule arms, respectively. There was no statistically significant difference in SSE-FS in the high- versus standard-dose arms [median 12.9 months versus 12.3 months; hazard ratio (HR) 1.06, 80% confidence interval (CI) 0.88-1.27, P = 0.70], and in the extended- versus standard-schedule arms (median 10.8 months versus 13.2 months; HR 1.26, 80% CI 0.94-1.69, P = 0.31). Overall survival in the three treatment arms was similar. As many as 370 (95%) patients received treatment (median of six cycles) in each arm. Grade ≥3 treatment-emergent adverse events (TEAEs) affected 34% of patients in the standard-dose, 48% in the high-dose and 53% in the extended-schedule arm, causing permanent discontinuation in 9%, 16% and 17% of patients, respectively. CONCLUSION: Radium-223 high-dose or extended-schedule regimens resulted in no change in SSE-FS or other efficacy end points and were associated with more grade ≥3 TEAEs. The extended-schedule regimen (beyond six doses) could not be implemented in a large proportion of patients due to disease progression. Therefore, the standard-dose schedule remains one of the standard therapies for patients with symptomatic mCRPC. TRIAL REGISTRATION: ClinicalTrials.govNCT02023697.

Fracture risk and survival outcomes in metastatic castration-resistant prostate cancer patients sequentially treated with abiraterone acetate and RADIUM-223.

PURPOSE: To evaluate the fracture risk and survival outcomes in patients with metastatic castration-resistant prostate cancer (mCRPC) who received sequentially abiraterone acetate (AA) and radium 223 [223Ra]RaCl2 in the daily clinical practice. MATERIALS: We retrospectively reviewed the records of mCRPC patients who received [223Ra]RaCl2 immediately after progressing during an AA treatment line in everyday clinical practice. RESULTS: We reviewed data of a consecutive series of 94 mCRPC patients. Most of the patients (85.1%) received [223Ra]RaCl2 as second- or third-line treatment. [223Ra]RaCl2 treatment was well-tolerated; there were only four cases of grade 3 anaemia, two cases of grade 3 leukopenia and one case of grade 3 neutropenia. The overall fracture rate is 2.1%; one fracture was recorded during the course of [223Ra]RaCl2 treatment, and one was recorded 1 month after its end. The fractures both occurred at metastatic sites. Median OS from [223Ra]RaCl2 start was more than 14 months regardless of the treatment line when [223Ra]RaCl2 was administered. CONCLUSION: The findings of this study show that the treatment with [223Ra]RaCl2 immediately after AA was active and safe with a very low risk of a fracture. Thus, the present observational report makes a valuable contribution to the current debate concerning the risks and benefits of including [223Ra]RaCl2 in the therapeutic algorithm.

A phase II randomized trial of RAdium-223 dichloride and SABR Versus SABR for oligomEtastatic prostate caNcerS (RAVENS).

BACKGROUND: Metastasis directed therapy (MDT) for patients with oligometastatic disease is associated with improvements in progression free survival (PFS) and overall survival (OS) compared to systemic therapy alone. Additionally, within a prostate-cancer-specific cohort, MDT is able to forestall initiation of androgen deprivation therapy (ADT) in men with hormone-sensitive, oligometastatic prostate cancer (HSOPCa) compared to observation. While MDT appears to be safe and effective in HSOPCa, a large percentage of men will eventually have disease recurrence. Patterns of failure in HSOPCa demonstrate patients tend to have recurrence in the bone following MDT, raising the question of sub-clinically-apparent osseous disease. Radium-223 dichloride is a radiopharmaceutical with structural similarity to calcium, allowing it to be taken up by bone where it emits alpha particles, and therefore might have utility in the treatment of micrometastatic osseous disease. Therefore, the primary goal of the phase II RAVENS trial is to evaluate the efficacy of MDT + radium-223 dichloride in prolonging progression free survival in men with HSOPCa. METHODS: Patients with HSOPCa and 3 or less metastases with at least 1 bone metastasis will be randomized 1:1 to stereotactic ablative radiation (SABR, also known as stereotactic body radiation therapy (SBRT)) alone vs SABR + radium-223 dichloride with a minimization algorithm to balance assignment by institution, primary intervention, prior hormonal therapy, and PSA doubling time. SABR is delivered in one to five fractions and patients in the SABR + radium-223 dichloride arm will receive six infusions of radium-223 dichloride at four-week intervals. The primary end point is progression free survival. The secondary clinical endpoints include toxicity and quality of life assessments, local control at 12 months, locoregional progression, time to distant progression, time to new metastasis, and duration of response. DISCUSSION: The RAVENS trial will be the first described phase II, non-blinded, randomized study to compare SABR +/- radium-223 dichloride in patients with HSOPCa and 3 or less metastases with at least one bone metastasis. The primary hypothesis is that SABR + radium-223 dichloride will increase median progression-free survival from 10 months in the SABR arm to 20 months in the SABR + radium-223 dichloride arm. TRIAL REGISTRATIONS: Clinicaltrials.gov. Identifier: NCT04037358. Date of Registration: July 30, 2019. Date of First Participant Enrolled: August 9, 2019. Date of Last Approved Amendment: October 16, 2019. Protocol Version: Version 5.

Addition of radium-223 to abiraterone acetate and prednisone or prednisolone in patients with castration-resistant prostate cancer and bone metastases (ERA 223): a randomised, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: Abiraterone acetate plus prednisone or prednisolone improves progression-free survival and overall survival in patients with metastatic castration-resistant prostate cancer. Radium-223 improves overall survival and delays the onset of symptomatic skeletal events in patients with castration-resistant prostate cancer and bone metastases. We assessed concurrent treatment with abiraterone acetate plus prednisone or prednisolone and radium-223 in such patients. METHODS: We did a randomised, double-blind, placebo-controlled, phase 3 trial at 165 oncology and urology centres in 19 countries. Eligible patients were aged 18 years or older, and had histologically confirmed, progressive, chemotherapy-naive, asymptomatic or mildly symptomatic castration-resistant prostate cancer and bone metastases, Eastern Cooperative Oncology Group performance status of 0 or 1, life expectancy of at least 6 months, and adequate haematological, renal, and liver function. Participants were randomly assigned (1:1) according to a permuted block design (block size 4) via interactive response technology to receive up to six intravenous injections of radium-223 (55 kBq/kg) or matching placebo once every 4 weeks. All patients were also scheduled to receive oral abiraterone acetate 1000 mg once daily plus oral prednisone or prednisolone 5 mg twice daily during and after radium-223 or placebo treatment. The primary endpoint was symptomatic skeletal event-free survival, which was assessed in the intention-to-treat population. Safety analyses were done in all patients who received at least one dose of any study drug. This trial is registered with ClinicalTrials.gov, number NCT02043678. Enrolment has been completed, and follow-up is ongoing. FINDINGS: Between March 30, 2014, and Aug 12, 2016, 806 patients were randomly assigned to receive radium-223 (n=401) or placebo (n=405) in addition to abiraterone acetate plus prednisone or prednisolone. The study was unblinded prematurely, on Nov 17, 2017, after more fractures and deaths were noted in the radium-223 group than in the placebo group (in an unplanned ad-hoc analysis), but all patients had completed radium-223 or placebo before this date. At the primary analysis (data cutoff Feb 15, 2018), 196 (49%) of 401 patients in radium-223 group had had at least one symptomatic skeletal event or died, compared with 190 (47%) of 405 patients in the placebo group (median follow-up 21·2 months [IQR 17·0-25·8]). Median symptomatic skeletal event-free survival was 22·3 months (95% CI 20·4-24·8) in the radium-223 group and 26·0 months (21·8-28·3) in the placebo group (hazard ratio 1·122 [95% CI 0·917-1·374]; p=0·2636). Fractures (any grade) occurred in 112 (29%) of 392 patients in the radium-223 group and 45 (11%) of 394 patients in the placebo group. The most common grade 3-4 treatment-emergent adverse events were hypertension (43 [11%] patients in the radium-223 group vs 52 [13%] patients in the placebo group), fractures (36 [9%] vs 12 [3%]) and increased alanine aminotransferase concentrations (34 [9%] vs 28 [7%]). Serious treatment-emergent adverse events occurred in 160 (41%) patients in the radium-223 group and 155 (39%) in the placebo group. Treatment-related deaths occurred in two (1%) patients in the radium-223 group (acute myocardial infarction and interstitial lung disease) and one (<1%) in the placebo group (arrhythmia). INTERPRETATION: The addition of radium-223 to abiraterone acetate plus prednisone or prednisolone did not improve symptomatic skeletal event-free survival in patients with castration-resistant prostate cancer and bone metastases, and was associated with an increased frequency of bone fractures compared with placebo. Thus, we do not recommend use of this combination. FUNDING: Bayer.

Re-treatment with radium-223: 2-year follow-up from an international, open-label, phase 1/2 study in patients with castration-resistant prostate cancer and bone metastases.

BACKGROUND: Radium-223 dichloride (radium-223) is approved for patients with castration-resistant prostate cancer (CRPC), symptomatic bone metastases, and no visceral disease using a dosing regimen of 6 injections (55 kBq/kg intravenously; 1 injection every 4 weeks). Early results from international, open-label, phase 1/2 study NCT01934790 showed that re-treatment with radium-223 was well tolerated with favorable effects on disease progression. Here we report safety and efficacy findings from 2-year follow-up of the radium-223 re-treatment study. METHODS: Patients with CRPC and bone metastases who completed 6 initial radium-223 injections with no disease progression in bone and later progressed were eligible for radium-223 re-treatment (up to 6 additional radium-223 injections), provided that hematologic parameters were adequate and chemotherapy had not been administered after the initial course of radium-223. Concomitant cytotoxic agents were not allowed during re-treatment but were allowed at the investigator's discretion during follow-up; other concomitant agents for prostate cancer (including abiraterone acetate or enzalutamide) were allowed at investigator's discretion. The primary objective was safety. Exploratory objectives included time to radiographic bone progression, radiographic progression-free survival (rPFS), time to total alkaline phosphatase (tALP), and prostate-specific antigen (PSA) progression, overall survival (OS), time to first symptomatic skeletal event (SSE), and SSE-free survival, all calculated from re-treatment start. Evaluation of safety and exploratory efficacy objectives included active 2-year follow-up. Safety results from active follow-up and updated efficacy are reported. RESULTS: Overall, 44 patients were re-treated with radium-223; 29 (66%) completed all 6 injections, and 34 (77%) entered 2-year active follow-up, during which no new safety concerns and no serious drug-related adverse events were noted. rPFS events (progression or death) occurred in 19 (43%) of 44 patients; median rPFS was 9.9 months. Radiographic bone progression occurred in 5 (11%) of 44 patients. Median OS was 24.4 months. Median times to first SSE and SSE-free survival were 16.7 and 12.8 months, respectively. Median time to tALP progression was not reached; median time to PSA progression was 2.2 months. CONCLUSIONS: Re-treatment with radium-223 in this selected patient population was well tolerated, led to minimal hematologic toxicity, and provided continued disease control in bone at 2-year follow-up.

Radium-223 in combination with paclitaxel in cancer patients with bone metastases: safety results from an open-label, multicenter phase Ib study.

PURPOSE: Concomitant treatment with radium-223 and paclitaxel is a potential option for cancer patients with bone metastases; however, myelosuppression risk during coadministration is unknown. This phase Ib study in cancer patients with bone metastases evaluated the safety of radium-223 and paclitaxel. METHODS: Eligible patients had solid tumor malignancies with ≥2 bone metastases and were candidates for paclitaxel. Treatment included seven paclitaxel cycles (90 mg/m2 per week intravenously per local standard of care; 3 weeks on/1 week off) plus six radium-223 cycles (55 kBq/kg intravenously; one injection every 4 weeks, starting at paclitaxel cycle 2). The primary end point was percentage of patients with grade 3/4 neutropenia or thrombocytopenia during coadministration of radium-223 and paclitaxel (cycles 2, 3) versus paclitaxel alone (cycle 1). RESULTS: Of 22 enrolled patients, 15 were treated (safety population), with 7 completing all six radium-223 cycles. Treated patients had primary cancers of breast (n = 7), prostate (n = 4), bladder (n = 1), non-small cell lung (n = 1), myxofibrosarcoma (n = 1), and neuroendocrine (n = 1). No patients discontinued treatment from toxicity of the combination. In the 13 patients who completed cycle 3, the rates of grade 3 neutropenia in cycles 2 and 3 were 31% and 8%, respectively, versus 23% in cycle 1; there were no cases of grade 4 neutropenia or grade 3/4 thrombocytopenia. Breast cancer subgroup safety results were similar to the overall safety population. CONCLUSION: Radium-223 was tolerated when combined with weekly paclitaxel, with no clinically relevant additive toxicities. This combination should be explored further in patients with bone metastases.

Interim analysis of the REASSURE (Radium-223 alpha Emitter Agent in non-intervention Safety Study in mCRPC popUlation for long-teRm Evaluation) study: patient characteristics and safety according to prior use of chemotherapy in routine clinical practice.

PURPOSE: REASSURE is a global, prospective, non-interventional study to assess long-term safety of radium-223 in patients with bone metastatic castration-resistant prostate cancer. Here we report an interim analysis of patients according to previous use of chemotherapy. METHODS: Radium-223 was administered in routine clinical practice. Interim safety analysis was planned after enrolment of the first 600 patients. Patient characteristics and safety data by previous administration of chemotherapy (docetaxel and/or cabazitaxel) were investigated. RESULTS: This interim analysis included 583 patients. Median duration of observation was 7 months (range, 0-20). Nineteen patients treated with concomitant chemotherapy were excluded, 564 (97%) were eligible for exploratory analysis according to prior use of chemotherapy; 190 (34%) had previously received and completed chemotherapy, and 374 (66%) had not. In the prior versus no prior chemotherapy group, a higher proportion of patients had an Eastern Cooperative Oncology Group performance status of ≥2 (22% vs 11%) and > 20 metastatic lesions (26% vs 15%), median alkaline phosphatase (162.0 vs 115.0 U/L) and prostate-specific antigen (132.0 vs 40.2 ng/mL) levels were higher, and a lower proportion completed 6 radium-223 injections (45% vs 63%). Drug-related treatment-emergent adverse events (TEAEs) occurred in 63 and 48%, and haematological drug-related TEAEs in 21 and 9% of patients who had or had not previously received chemotherapy. Four drug-related deaths were reported, all in the prior chemotherapy group. CONCLUSIONS: The short-term safety profile of radium-223 in routine clinical practice was comparable to other clinical studies, irrespective of prior chemotherapy use. Haematological TEAEs occurred more frequently in the prior chemotherapy group, presumably due to decreased bone marrow function as a consequence of more advanced disease and prior exposure to cytotoxic therapy. Patients who had not previously received chemotherapy appeared to have a lower burden of disease at baseline, and a lower proportion discontinued radium-223 treatment.

Radium-223 in asymptomatic patients with castration-resistant prostate cancer and bone metastases treated in an international early access program.

BACKGROUND: Radium-223, a targeted alpha therapy, is used to treat symptomatic patients with castration-resistant prostate cancer (CRPC) and bone metastases. Data for radium-223 in asymptomatic CRPC patients with bone metastases are lacking. METHODS: This was a prospective, single-arm phase 3b study. Patients with metastatic CRPC (malignant lymphadenopathy not exceeding 6 cm was allowed, visceral disease was excluded) received radium-223, 55 kBq/kg intravenously, every 4 weeks for up to 6 cycles. Co-primary endpoints were safety and overall survival. Post hoc analyses were performed according to baseline asymptomatic or symptomatic disease status. Asymptomatic status was defined as no pain and no opioid use at baseline. RESULTS: Seven hundred eight patients received ≥1 radium-223 injection: 548 (77%) were symptomatic to various degrees, and 135 (19%) were asymptomatic. Asymptomatic patients had more favorable baseline disease characteristics than symptomatic. A lower proportion of asymptomatic versus symptomatic patients had received prior abiraterone (25% vs 35%) and prior docetaxel (52% vs 62%). A higher proportion of asymptomatic (71%) versus symptomatic (55%) patients completed radium-223 treatment. Overall survival (hazard ratio [HR] 0.486), time to disease progression (HR 0.722) and time to first symptomatic skeletal event (HR 0.328) were better in asymptomatic than symptomatic patients. Alkaline phosphatase (ALP) response rates were similar (46% vs 47%), and ALP normalization (44% vs 25%) and prostate-specific antigen response rates (21% vs 13%) were higher in asymptomatic than symptomatic patients. A lower proportion of asymptomatic patients reported treatment-emergent adverse events (TEAEs, 61% vs 79%), grade 3-4 TEAEs (29% vs 40%) and drug-related TEAEs (28% vs 44%). There were two treatment-related deaths, both in patients with baseline symptomatic disease. CONCLUSIONS: Using radium-223 earlier in the disease course, when patients are asymptomatic or minimally symptomatic, may enable patients to complete treatment and optimize treatment outcome compared to symptomatic patients, and therefore may allow sequencing with other life-prolonging therapies. TRIAL REGISTRATION: The study was registered with ClinicalTrials.gov , number NCT01618370 on June 13, 2012 and the European Union Clinical Trials Register, EudraCT number 2012-000075-16 on April 4, 2012.

The changing role of radium-223 in metastatic castrate-resistant prostate cancer: has the EMA missed the mark with revising the label?

Radium-223 (223Ra) is a life-prolonging treatment in symptomatic men with metastatic castrate-resistant prostate cancer (mCRPC) and bone metastases, but no visceral disease, regardless of prior treatment with docetaxel. Together with four other drugs (i.e. abiraterone, cabazitaxel, docetaxel, enzalutamide), it has been available for clinical use since 2013 and has been shown to also provide benefits in quality-of-life and societal benefits. However, in 2018 the European Medicines Agency ruled to restrict the use of radium-223 to a more advanced disease setting after at least two lines of one or the other life-prolonging agent. This decision was triggered by the results of a safety interim analysis of ERA-223, a trial investigating the combination of 223Ra and abiraterone versus abiraterone alone in patients without prior chemotherapy (with the exception of adjuvant treatment) with asymptomatic bone predominant mCRPC. That safety analysis showed an early increased risk of fracture and deaths with the combination treatment. This review critically appraises the available and emerging data with 223Ra treatment in an attempt to assess the appropriateness of the revised label of radium-223.

Three-year follow-up of a phase II study of radium-223 dichloride in Japanese patients with symptomatic castration-resistant prostate cancer and bone metastases.

BACKGROUND: Radium-223 is a first-in-class targeted alpha therapy to prolong overall survival (OS) in castration-resistant prostate cancer with bone metastases (mCRPC). The aim of the present analysis was to assess the long-term safety with radium-223 in Japanese patients with mCRPC. METHODS: Patients with symptomatic mCRPC, ≥ 2 bone metastases and no known visceral metastases received up to 6 injections of radium-223 (55 kBq/kg), one every 4 weeks. Adverse events (AEs) considered to be related to radium-223 were reported until 3 years after the first injection. Pre-specified conditions, such as acute myelogenous leukemia, myelodysplastic syndrome, aplastic anemia, primary bone cancer, or other primary malignancies, were reported regardless of causality. RESULTS: Of the 49 patients enrolled in the study, 44 (89.8%) entered the survival follow-up period and 33 (67.3%) died. Throughout the entire study, there were no reports of second primary malignancy or other pre-specified conditions. Eight patients (16.3%) experienced post-treatment drug-related AEs, which were all hematological (anemia and decreased lymphocyte, platelet, and white blood cell counts). No serious post-treatment drug-related AEs were reported. Updated median OS was 19.3 months (95% CI: 14.2, 28.5). CONCLUSIONS: In Japanese patients with symptomatic mCRPC and bone metastases, radium-223 had a favorable long-term safety profile with no second primary malignancies reported. Taken together with median OS, which was comparable to that in the pivotal phase III ALSYMPCA study, these results support continued benefit from radium-223 in Japanese patients with mCRPC.

Radium-223 international early access program: results from the Spanish subset.

AIM: To report results from the Spanish subset included in the radium-223 international early access program (iEAP). PATIENTS & METHODS: Ninety patients with castration-resistant prostate cancer and bone metastases received radium-223 55 kBq/kg every 4 weeks for six cycles. RESULTS: The median time to disease progression was 8 months and to prostate-specific antigen progression was 4 months. The percentage of patients with ≥50% confirmed declines in prostate-specific antigen was 9%. The median overall survival was 14 months. Grade 3 or 4 treatment emergent adverse events (TEAEs) occurred in 34% of patients (serious TEAEs 28%, TEAEs leading to discontinuation 27%). CONCLUSION: Outcomes of the Spanish subset are consistent with the iEAP. Radium-223 was generally well tolerated with no safety concerns.

Phase II study of radium-223 dichloride in Japanese patients with symptomatic castration-resistant prostate cancer.

BACKGROUND: Radium-223 dichloride (radium-223) is the first targeted alpha therapy approved for the treatment of castration-resistant prostate cancer (CRPC) with bone metastases. This study investigated the efficacy and safety of radium-223 in Japanese patients with symptomatic CRPC and bone metastases. METHODS: In this open-label, multicenter, phase II study, patients with progressive, symptomatic CRPC and bone metastases were treated with radium-223 (55 kBq/kg, intravenously) in a 4-week cycle for six cycles. The primary endpoint was the percent change in total alkaline phosphatase (ALP) from baseline at 12 weeks. Secondary endpoints included the percent ALP change from baseline to end of treatment (EOT), ALP response rates, percent change in prostate-specific antigen (PSA) from baseline to 12 weeks and EOT, PSA response rates, overall survival (OS), and time to symptomatic skeletal events (SSEs). Adverse events were monitored throughout the study period. RESULTS: Of the 49 Japanese patients (median age 74 years), 28 completed all infusions. Mean percent change in total ALP and PSA from baseline to 12 weeks was -19.3 and +97.4%, respectively. One-year OS and SSE-free rate at the end of active follow-up were 78 and 89%, respectively. The ALP response rate was 31%, while the PSA response rate was 6%. Grade 3/4 treatment-emergent adverse events observed in ≥10% of patients included decreased lymphocyte count (14%), anemia (14%), anorexia (10%), and bone pain (10%). CONCLUSIONS: Radium-223 is effective and well tolerated in Japanese patients with CRPC and bone metastases. Results were comparable with the Alpharadin in Symptomatic Prostate Cancer Patients (ALSYMPCA) trial. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT01929655.