Safety and efficacy of abiraterone acetate plus prednisolone in patients with castration-resistant prostate cancer: a prospective, observational, post-marketing surveillance study.

BACKGROUND: Abiraterone acetate plus prednisolone is approved to treat patients with castration-resistant prostate cancer. This study evaluated the safety and efficacy of abiraterone acetate plus prednisolone in castration-resistant prostate cancer patients with or without previous chemotherapy in a real-world setting in Japan. METHODS: This study was an observational, prospective, post-marketing surveillance. Castration-resistant prostate cancer patients, who initiated abiraterone acetate after its approval in Japan, were enrolled. Data were collected during an observation period of 12 months and a follow-up period of another 12 months. Adverse events and adverse drug reactions were evaluated for safety. Prostate-specific antigen levels and overall survival were evaluated for efficacy. RESULTS: From 141 participating institutions, 497 patients were registered: 492 patients including 180 chemotherapy-naïve, 311 chemotherapy-experienced and one off-label-use patient received abiraterone and were evaluated for safety. Adverse events were observed in 225/492 patients (45.7%), adverse drug reactions in 131/492 patients (26.6%) and serious adverse drug reactions in 61/492 patients (12.4%). The most commonly observed adverse drug reaction was abnormal hepatic function (6.5%), followed by hypokalemia (3.0%) and decreased appetite (2.0%). At week 12, 110/432 patients (25.5%) achieved ≥50% decrease from baseline in prostate-specific antigen, and the proportion was higher in chemotherapy-naïve patients (56/161 patients; 34.8%) compared with chemotherapy-experienced patients (54/271 patients; 19.9%, P < 0.001). Survival rates at 24 months were 68.3% (295/432 patients), 73.9% (119/161 chemotherapy-naïve patients) and 64.9% (176/271 chemotherapy-experienced patients). CONCLUSIONS: This large-scale, real-world, post-marketing surveillance study confirmed the safety and efficacy of abiraterone acetate plus prednisolone in Japanese castration-resistant prostate cancer patients with or without previous chemotherapy.

Correction to: Skin rash following Administration of Apalutamide in Japanese patients with Advanced Prostate Cancer: an integrated analysis of the phase 3 SPARTAN and TITAN studies and a phase 1 open-label study.

An amendment to this paper has been published and can be accessed via the original article.

Skin rash following Administration of Apalutamide in Japanese patients with Advanced Prostate Cancer: an integrated analysis of the phase 3 SPARTAN and TITAN studies and a phase 1 open-label study.

BACKGROUND: A higher incidence of apalutamide-related skin rash has been observed in Japanese patients with prostate cancer (PC). METHODS: This integrated analysis of data of Japanese patients from 2 global Phase 3 studies, SPARTAN ( NCT01946204 ; patients with non-metastatic castration-resistant PC [nmCRPC]) and TITAN ( NCT02489318 ; patients with metastatic castration-sensitive PC [mCSPC]), and the Phase 1 study 56021927PCR1008 ( NCT02162836 ; patients with metastatic CRPC [mCRPC]), assessed clinical risk factors of apalutamide-related skin rash as well as the potential correlation with plasma exposure to apalutamide. Kaplan-Meier method was used for time-to-event analyses. Clinical risk factors for skin rash were assessed using odds ratio. RESULTS: Data from 68 patients (SPARTAN: n = 34, TITAN: n = 28, 56021927PCR1008: n = 6) receiving apalutamide 240 mg orally once-daily were analyzed. Rash (13 [19.1%]) and maculo-papular rash (11 [16.2%]) were the most frequently reported skin rash. All Grade and Grade 3 skin rash occurred in 35 (51.5%) and 10 (14.7%) patients, respectively. Most (85.7%) skin rash occurred within 4 months of apalutamide initiation and resolved in a median time of 1 month following the use of antihistamines, topical or systemic corticosteroids, with/without apalutamide dose interruptions/reductions. Median time-to-remission of first incidence of rash and maximum grade incidence of rash were 1.0 month (IQR: 0.36-1.81) and 1.0 month (IQR: 0.30-2.43), respectively. No significant clinical risk factors for the incidence of skin rash were observed. Areas under the curve (0-24 h) (AUC0-24, ss) at steady-state of plasma apalutamide concentration were numerically slightly higher in patients with skin rash than those without. CONCLUSIONS: No clinical risk factors for rash could be detected. There is a potential correlation between incidence of skin rash and plasma exposure to apalutamide. In general, apalutamide-related skin rash is easily managed, with appropriate treatment with or without dose adjustment. TRIAL REGISTRATION: Retrospective pooled analysis of NCT01946204 , NCT02489318 , and NCT02162836 .

Efficacy and safety of apalutamide in Japanese patients with nonmetastatic castration-resistant prostate cancer: a subgroup analysis of a randomized, double-blind, placebo-controlled, Phase-3 study.

BACKGROUND: In the global Phase-3 Selective Prostate Androgen Receptor Targeting with ARN-509 study, apalutamide plus ongoing androgen deprivation therapy (ADT) significantly increased metastasis-free survival (MFS) and improved other clinical outcomes in men with nonmetastatic castration-resistant prostate cancer (nm-CRPC) who were at high risk of developing metastases. In this subpopulation analysis of Selective Prostate Androgen Receptor Targeting with ARN-509 study, the efficacy and safety of apalutamide plus ADT were evaluated in Japanese patients with nm-CRPC. METHODS: The primary efficacy end point was MFS. Secondary efficacy end points were time to metastasis, progression-free survival, symptomatic progression, initiation of cytotoxic chemotherapy, and overall survival. Safety and pharmacokinetic parameters were also assessed. RESULTS: Fifty-five Japanese patients with ongoing ADT were randomized (apalutamide: n = 34, placebo: n = 21). Median treatment duration was 5.7 months in the apalutamide group and 11.0 months in the placebo group. Median MFS was not reached in the apalutamide group (95% confidence interval: 10.97, not estimable) and was 18.23 months (95% confidence interval: 11.04, 18.50) in the placebo group. Secondary end points were improved in the apalutamide group. The safety profile of apalutamide with ADT was comparable with the global population, and no new safety signals were identified in this Japanese subpopulation. Although, apalutamide exposure tended to be higher in the Japanese subpopulation compared with the non-Japanese population, this was likely to be explained by body weight and considered not clinically meaningful. CONCLUSION: In the Japanese subpopulation, treatment with apalutamide with ADT resulted in favorable efficacy outcomes with comparable benefit-risk profile to the global population with nm-CRPC who are at high-risk of developing metastases.

An open-label, phase 1 study of androgen receptor antagonist, apalutamide in Japanese patients with metastatic castration-resistant prostate cancer.

BACKGROUND: Apalutamide, a nonsteroidal potent androgen receptor antagonist, was safe and effective in patients with non-metastatic castration-resistant prostate cancer (nmCRPC) and metastatic-CRPC (mCRPC) in global studies. In this phase 1 study, safety, pharmacokinetics (PK), and efficacy of apalutamide were evaluated in Japanese patients with mCRPC. METHODS: In this open-label, multi-center study, patients received apalutamide 240 mg (once-daily, orally) for first 1 week (PK week) during which PK parameters were assessed. 1 week later (Cycle 1 Day1), after reassessing safety, continuous daily dosing (4 weeks/cycle; once-daily orally) was initiated. Endpoints evaluated were: safety, tolerability, PK and antitumour efficacy of apalutamide. Dose-limiting toxicities (DLTs) were evaluated during PK week and Cycle 1. RESULTS: All six patients received apalutamide. The most common treatment-emergent adverse events (TEAEs) were abdominal discomfort, nasopharyngitis, dysgeusia, rash, and hot flush [2/6 patients (33.3%) each]. No death or DLTs were reported. Grade 3 TEAEs were spinal-cord compression and renal disorder (1/6 patient each). In continuous daily dosing period, PK steady-state of apalutamide was reached approximately by week 4. A significant accumulation of apalutamide was observed (mean accumulation index 3.55), based on AUC0-24. Median (range) serum prostate-specific antigen level decreased from 54.42 (8.92-310.11) ng/mL at baseline to 11.70 (0.37-47.74) ng/mL at week 12 with ≥ 50% reduction in 4/6 (66.7%) patients and 90% reduction in 2/6 (33.3%) patients. CONCLUSION: Apalutamide had manageable safety profile, without any DLT or any new safety signals, and favourable efficacy in Japanese mCRPC patients. Thus, it was ascertained to be an adequate dosage regimen in Japanese mCRPC patients. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02162836.

Patient Preferences and Urologist Judgments on Prostate Cancer Therapy in Japan.

The purpose of the present study is to investigate the concordance of treatment preferences between patients and physicians in prostate cancer (PCa) in Japan. An internet-based discrete choice experiment was conducted. Patients and physicians were asked to select their preferred treatment from a pair of hypothetical treatments consisting of four attributes: quality of life (QOL), treatment effectiveness, side effects, and accessibility of treatment. The data were analyzed using a conditional logistic regression model to calculate coefficients and the relative importance (RI) of each attribute. A total of 103 PCa patients and 127 physicians responded. The study looked at 37 patients considered as advanced PCa and 66 who were non-advanced PCa. All of the physicians were urologists. Advanced PCa patients ranked the attributes as follows: treatment effectiveness (RI: 32%), accessibility of treatment (RI: 26%), QOL (RI: 23%), and side effects (RI: 19%). For physicians, the RI ranking was the same as for advanced PCa patients; treatment effectiveness (RI: 29%), accessibility of treatment (RI: 27%), QOL (RI: 26%), and side effects (RI: 18%). For non-advanced PCa patients, accessibility of treatment ranked the highest RI (27%) and treatment effectiveness ranked as the lowest RI (14%). Our study suggests that the ranking of the attributes was consistent between advanced PCa patients and physicians. The most influential attribute was treatment effectiveness. Treatment preferences also vary by disease stage.

Burden of illness of chemotherapy in castration-resistant prostate cancer patients in Japan: a retrospective database analysis.

OBJECTIVE: The objective was to assess the burden of chemotherapy for castration-resistant prostate cancer (CRPC) in Japan. METHODS: Utilizing a large administrative hospital database we compared a set of outcome measures 12 months before and after initiation of chemotherapy, namely total medical costs, number of outpatient visits, number of hospital admissions and number of days spent in hospital. RESULTS: A total of 598 CRPC patients were identified in the database. Total healthcare costs increased from 143,578 Japanese Yen (JPY) per patient per month (PPPM), before chemotherapy, to 333,628 JPY after start of chemotherapy. The number of hospital admissions increased by 280%, and the number of days spent in hospital by 380%. CONCLUSIONS: The overall costs of chemotherapy for patients diagnosed with castration-resistant prostate cancer in Japan are high. Our findings can serve as a basis for health economic evaluations.

Association of early PSA decline and time to PSA progression in abiraterone acetate-treated metastatic castration-resistant prostate cancer; a post-hoc analysis of Japanese phase 2 trials.

BACKGROUND: Previous studies have demonstrated an association between prostate-specific antigen (PSA) kinetics and predictive value for treatment outcomes. Abiraterone acetate (AA) is a newly approved cytochrome-P450C17 inhibitor for treatment of metastatic castration-resistant prostate cancer (mCRPC), and few studies have evaluated PSA kinetics using AA so far. Results of a study evaluating PSA kinetics in the beginning of AA and enzalutamide responded chemotherapy-treated patients suggested different trends between the drugs. PSA kinetics of AA-treated patients has been reported using large datasets; however, no studies which have fully evaluated PSA kinetics in the beginning treatment. The present study aimed to assess the PSA kinetics and relationship between the PSA kinetics and PSA progression in chemotherapy-naïve and chemotherapy-treated mCRPC patients receiving AA. METHODS: We used two Japanese phase II trial datasets: JPN-201, chemotherapy-naïve mCRPC (n = 48) and JPN-202, chemotherapy-treated mCRPC (n = 46). PSA kinetic parameters were calculated using actual PSA values measured every 4 weeks, and a subgroup analysis was performed to evaluate the influence of early PSA response on time to PSA progression (TTPP). In addition, we used a Cox proportional hazard model to investigate the influence of variables on TTPP. RESULTS: PSA declined from week 4 but took more time to achieve nadir. PSA kinetic parameters were different between the datasets, mean time to PSA nadir was 5.3 ± 5.6 and 2.0 ± 3.4 months, and TTPP was 9.5 ± 7.4 and 3.8 ± 4.8 months in JPN-201 and JPN-202, respectively. In the subgroup analysis of week 4 PSA decline status, Kaplan-Meier curves for TTPP were similar between early responders and non-progression patients in JPN-201 (median, 9.2 vs. 6.5 months, respectively) but separated in JPN-202 (median, 3.7 vs. 1.9 months, respectively). According to univariate Cox regression analysis, achievement of PSA response (≥50 %) at week 12 was associated with TTPP in the both trials, but the hazard ratio of PSA decline (≥30 %) at week 4 was not significant in JPN-201. CONCLUSIONS: Our results suggest that PSA kinetics were not comparable and early PSA response showed different association to TTPP according to prior history of chemotherapy. TRIAL REGISTRATION: The original trials are registered at ClinicalTrials.gov. The identifiers are; JNJ-212082-JPN-201 , registered 20 December 2012 and JNJ-212082-JPN-202 , registered 30January 2013.

Two placebo-controlled, randomized withdrawal studies to evaluate the fentanyl 1 day patch in opioid-naïve patients with chronic pain.

OBJECTIVE: To evaluate the efficacy and safety of fentanyl 1 day patch in opioid-naïve patients with non-cancer chronic pain insufficiently relieved by non-opioid analgesics. RESEARCH DESIGN AND METHODS: Two phase III placebo-controlled, double-blind, group-comparison, randomized withdrawal studies were conducted in patients with osteoarthritis and/or low back pain (N01 study) and post-herpetic neuralgia, complex regional pain syndrome, or chronic postoperative pain (N02) in Japan. Both studies consisted of period I (10-29 days of titration, fentanyl 12.5-50.0 µg/h) and period II (12 weeks double-blind). CLINICAL TRIAL REGISTRATION: N01, NCT01008618; N02, NCT01008553 MAIN OUTCOME MEASURES: The primary endpoint was the number of days until study discontinuation due to insufficient pain relief in period II, and secondary endpoints included pain scored on visual analog scale (VAS), subject's overall assessment, the number of rescue dose, brief pain inventory short form score, score on short-form 36-item health survey version 2.0, physician's overall assessment, and assessment of adverse events. RESULTS: Of the 218 (N01) and 258 (N02) subjects who entered period I, 150 and 163 subjects entered period II, respectively. In the N01 study, the between-group difference was significant in the VAS score (95% CI: 7.3 [1.1, 13.5] mm, P = 0.0215) but not in the primary endpoint (P = 0.0846, log-rank test). In the N02 study, both primary efficacy (P = 0.0003) and VAS (8.7 [2.4, 15.0] mm, P = 0.0071) results showed that fentanyl was more effective than placebo. The major adverse events were nervous system and gastrointestinal disorders typically associated with opioid analgesic use. The incidence of adverse events in the fentanyl group was 68.5% to 85.7%. CONCLUSIONS: Although the primary efficacy results showed significant effects of fentanyl in the N02 but not the N01 study, overall results showed that fentanyl 1 day patch is effective and well tolerated.

A phase 2 study of abiraterone acetate in Japanese men with metastatic castration-resistant prostate cancer who had received docetaxel-based chemotherapy.

OBJECTIVE: In this Phase 2 multicenter study the efficacy and safety of oral abiraterone acetate (1000 mg/once daily) plus prednisolone (5 mg/twice daily) was evaluated in metastatic castration-resistant prostate cancer patients from Japan who had previously received docetaxel-based chemotherapy. METHODS: Men (aged ≥20 years) with metastatic castration-resistant prostate cancer (prostate-specific antigen levels: ≥5 ng/ml), who had received 1 or 2 cytotoxic chemotherapies (with ≥1 regimen being docetaxel) for prostate cancer, were enrolled in this open-label, single-arm study. Primary efficacy endpoint was proportion of patients achieving a ≥50% prostate-specific antigen decline from baseline (prostate-specific antigen response rate) after 12-week treatment. Safety and pharmacokinetics were also assessed. RESULTS: Confirmed prostate-specific antigen response rate by Week 12 was 28.3% (90% confidence interval: 17.6%; 41.1%) or 13 out of 46 (full analysis set) treated patients. However, total prostate-specific antigen response rate including confirmed and unconfirmed responses was 34.8% (90% confidence interval: 23.2%; 47.9%). Secondary efficacy endpoints and outcomes were: improvement in Eastern Cooperative Oncology Group performance status score by ≥1 unit: 7/16 patients (43.8%); objective radiographic response: complete response, partial response and stable disease in 0, 1/22 (4.5%) and 9/22 (40.9%) patients, respectively; pain palliation response: 9/16 (56.3%) patients. The most common adverse events (>20% patients) were upper respiratory tract infection (13/47, 27.7% patients) and hepatic function abnormal (10/47, 21.3% patients, Grade 3: 8.5%). All mineralocorticoid-related toxicities were Grade 1/2. CONCLUSIONS: Abiraterone acetate plus prednisolone showed favorable efficacy in metastatic castration-resistant prostate cancer Japanese patients who had received chemotherapy. Abiraterone acetate plus prednisolone had an acceptable safety profile. CLINICAL TRIAL REGISTRATION NO: NCT01795703.

A phase 2 trial of abiraterone acetate in Japanese men with metastatic castration-resistant prostate cancer and without prior chemotherapy (JPN-201 study).

OBJECTIVE: Abiraterone acetate has been approved in >70 countries for chemotherapy-naïve metastatic castration-resistant prostate cancer patients. Efficacy and safety of abiraterone acetate (1000 mg/once daily) with prednisolone (5 mg/twice daily) in chemotherapy-naïve Japanese patients with metastatic castration-resistant prostate cancer was evaluated. METHODS: Men, ≥20 years, with prostate-specific antigen levels of ≥5 ng/ml and evidence of progression were enrolled in this Phase 2, multicenter, open-label study. Primary efficacy endpoint was proportion of patients achieving a prostate-specific antigen decline of ≥50% from baseline (prostate-specific antigen response) after 12 week of treatment. Secondary efficacy endpoints and safety were assessed. RESULTS: A confirmed prostate-specific antigen response was observed in 29/48 (60.4%) patients by week 12; lower limit of two-sided 90% confidence interval was >35% (threshold response rate), demonstrating efficacy of abiraterone acetate. Secondary efficacy endpoints: prostate-specific antigen response rate during treatment period: 62.5%; objective radiographic response, partial response: 4/18 (22.2%) patients; complete response: none; stable disease: 11/18 (61.1%) patients; median percent change in prostate-specific antigen level from baseline at Week 12: -66.62%. Median prostate-specific antigen response duration and progression-free survival were not reached, and median radiographic progression-free survival was 253 days. Of 31/48 (64.6%) patients experienced adverse events of special interest; most common was hepatic function abnormality (37.5%, Grade 3: 10.4%). One Grade 3 hypertension was the only mineralocorticoid adverse event >Grade 1/2. CONCLUSIONS: Efficacy of abiraterone acetate plus prednisolone was demonstrated by decline in prostate-specific antigen levels with evidence of antitumor activity by radiography in Japanese patients with chemotherapy-naïve metastatic castration-resistant prostate cancer. Abiraterone acetate plus prednisolone had an acceptable safety profile. CLINICAL TRIAL REGISTRATION NO: NCT01756638.

Ready conversion of patients with well-controlled, moderate to severe, chronic malignant tumor-related pain on other opioids to tapentadol extended release.

BACKGROUND AND OBJECTIVES: The effectiveness and tolerability of tapentadol extended release (ER), a centrally acting analgesic with µ-opioid receptor agonist and norepinephrine (noradrenaline) reuptake inhibitor activities, have been demonstrated in patients with chronic pain, including those switching directly from prior opioid therapy. The objective of the current study was to evaluate the effectiveness and safety of conversion to oral tapentadol ER (50-250 mg twice daily) from previous around-the-clock strong opioid therapy in patients with moderate to severe, chronic malignant tumor-related cancer pain that was well-controlled. METHODS: This randomized, open-label, phase III study, which was conducted in Japan, included a 1- to 2-week screening period (on previous opioid) and an 8-week, open-label treatment period. Eligible patients, who were taking a strong opioid analgesic and had a mean pain intensity score <4 during the 3 days prior to randomization (adequate pain control on previous strong opioid), were randomized (1:1) to receive twice-daily treatment with tapentadol ER (100-500 mg/day) or morphine sustained release (SR; 20-140 mg/day; reference for assay sensitivity). Initial doses were estimated based on the conversion ratio of tapentadol ER:oxycodone:morphine:fentanyl = 10:2:3:0.03. The primary effectiveness endpoint was the proportion of patients who maintained pain control [change from baseline in mean pain intensity (11-point numerical rating scale) less than +1.5 for 3 consecutive days and no more than two doses of rescue medication per day for 3 consecutive days) during the first week of open-label treatment. RESULTS: In the tapentadol ER group (n = 50), 84.0 % of patients (42/50; 95 % CI, 70.89-92.83) maintained pain control during Week 1. On the Patient Global Impression of Change, 2.1 % (1/48), 2.1 % (1/48), 22.9 % (11/48), and 50.0 % (24/48) of patients in the tapentadol ER group reported that their overall condition was "very much improved," "much improved," "minimally improved," and "not changed," respectively, at Week 1 compared with 0 %, 10.7 % (3/28), 28.6 % (8/28), and 53.6 % (15/28) reporting these ratings at Week 8. The sensitivity of effectiveness analyses was validated based on results using morphine SR; 98.0 % (49/50; 95 % CI, 89.35-99.95) of patients in the morphine SR group maintained pain control after 1 week of treatment. The overall safety profile was similar to that demonstrated in previous studies; tapentadol ER was associated with a lower incidence of gastrointestinal treatment-emergent adverse events than morphine SR [38.0 % (19/50) vs. 54.0 % (27/50)], including constipation [12.0 % (6/50) vs. 20.0 % (10/50)] and vomiting [6.0 % (3/50) vs. 26.0 % (13/50)]. CONCLUSIONS: Overall, results indicate that conversion from previous strong opioids to tapentadol ER (50-250 mg twice daily) was successful and resulted in safe and effective pain control with improved gastrointestinal tolerability versus morphine SR in patients with moderate to severe cancer-related pain that was well-controlled on their previous opioid.

Efficacy and safety of oral tapentadol extended release in Japanese and Korean patients with moderate to severe, chronic malignant tumor-related pain.

OBJECTIVE: This phase 3 study evaluated the efficacy and safety of tapentadol extended release (ER) compared with oxycodone controlled release (CR) for the management of moderate to severe, chronic malignant tumor-related cancer pain. RESEARCH DESIGN AND METHODS: This randomized, double-blind, active-controlled study included Japanese and Korean patients with moderate to severe, chronic malignant tumor-related pain. Patients were randomized (1:1) to receive oral tapentadol ER (25-200 mg bid) or oral oxycodone HCl CR (5-40 mg bid) for 4 weeks of double-blind treatment. ClinicalTrials.gov identifier: NCT01165281. MAIN OUTCOME MEASURES: This study was designed to evaluate the non-inferiority of the efficacy provided by tapentadol ER versus oxycodone CR, based on the mean change in average pain intensity (11 point numerical rating scale) from baseline to the last 3 days of study drug administration. Treatment-emergent adverse events (TEAEs) were recorded throughout the study. RESULTS: Of the 374 patients who were screened, 343 were randomized and 236 completed treatment. The least-squares mean difference in the change in pain intensity from baseline to the last 3 days of study treatment between tapentadol ER and oxycodone CR was -0.06 (95% confidence interval [CI], -0.506 to 0.383). The upper limit of the 95% CI was <1 (the predefined threshold value for non-inferiority), indicating that tapentadol ER provided analgesic efficacy that was non-inferior to that of oxycodone CR. The percentage of patients reporting at least one TEAE was similar in the tapentadol ER (87.5% [147/168]) and oxycodone CR (90.1% [155/172]) treatment groups, but the incidence of gastrointestinal TEAEs was lower in the tapentadol ER group (55.4% [93/168]) than in the oxycodone CR group (67.4% [116/172]). CONCLUSIONS: Tapentadol ER (25-200 mg bid) provides analgesic efficacy that is non-inferior to that provided by oxycodone HCl CR (5-40 mg bid) for the management of moderate to severe, chronic malignant tumor-related pain, and is well tolerated overall, with a better gastrointestinal tolerability profile than oxycodone CR.