Real-world cabazitaxel safety: the Italian early-access program in metastatic castration-resistant prostate cancer

Feasibility of cabazitaxel in octogenarian prostate cancer patients

Background

To evaluate the effectiveness and safety of cabazitaxel in castration-resistant prostate cancer patients aged ≥80 years, we performed a retrospective study on a sample of patients from 11 Italian cancer centers.

Materials and methods

Fifty-seven patients aged ≥80 years were treated with cabazitaxel after previous failure with docetaxel; 39 completed a comprehensive geriatric assessment questionnaire (34 fit and 5 vulnerable) and 8 patients (14%) had an Eastern Cooperative Oncology Group performance status (PS) ≥2, while most had a PS of 0-1 (86%). Cabazitaxel was administered at a dose of 25 mg/m2 in 30 (52%) patients and 20 mg/m2 or adapted schedules in 27 (48%) patients. These schedules were adopted mainly in patients ≥85 years (75%), with a PS ≥2 (87.5%), and those classified as vulnerable (100%).

Results

The duration of treatment was 4.8 months and was comparable in all subgroups; disease control rate was reported in 36 patients (63%); prostate-specific antigen response was recorded in 18 patients (31.5%). Median overall survival was 13.1 months regardless of age (<85/≥85 years), but overall survival was reduced in vulnerable (7.2 months) and PS ≥ 2 patients (6.8 months). The most frequently documented grade 3-4 toxicities were neutropenia (14%) and diarrhea (10.5%). Six patients (10.5%) dropped out due to severe toxicity.

Conclusions

Octogenarian patients can be treated with cabazitaxel with reduced doses or alternative schedules that are associated with less toxicity and fewer treatment interruptions. Comprehensive geriatric assessment could facilitate more appropriate patient selection.

Generating Evidence from Expanded Access Use of Rare Disease Medicines: Challenges and Recommendations

Patients with rare diseases often have limited or no options for approved treatments or participation in clinical trials. In such cases, expanded access (or “compassionate use”) provides a potential means of accessing unapproved investigational medicines. It is also possible to capture and analyze clinical data from such use, but doing so is controversial. In this perspective, we offer examples of evidence derived from expanded access programs for rare diseases to illustrate its potential value to the decision-making of regulators and payers in the European Union and the United States. We discuss ethical and regulatory aspects to the use of expanded access data, with a focus on rare disease medicines. The heterogeneous approach to expanded access among countries within the European Union leaves uncertainties to what extent data can be collected and analyzed. We recommend the issuance of new guidance on data collection during expanded access, harmonization of European pathways, and an update of existing European compassionate use guidance. We hereby aim to clarify the supportive role of expanded access in evidence generation. Harmonization across Europe of expanded access regulations could reduce manufacturer burdens, improve patient access, and yield better data. These changes would better balance the need to generate quality evidence with the desire for pre-approval access to investigational medicine.

Hypersensitivity Reactions to Platinum Agents and Taxanes

Hypersensitivity reactions (HSRs) to chemotherapy agents can present a serious challenge to treating patients with preferred or first-line therapies. Allergic reactions through an immunologic mechanism have been established for platinum and taxane agents, which are used to treat a wide variety of cancers including gynecologic cancers. Platin HSRs typically occur after multiple cycles of chemotherapy, reflecting the development of drug IgE sensitization, while taxane HSRs often occur on first or second exposure. Despite observed differences between platin and taxane HSRs, drug desensitization has been an effective method to reintroduce both chemotherapeutic agents safely. Skin testing is the primary diagnostic tool used to risk-stratify patients after initial HSRs, with more widespread use for platinum agents than taxanes. Different practices exist around the use of skin testing, drug challenge, and choice of desensitization protocol. Here, we review the epidemiology, mechanism, and clinical presentation of HSRs to platinum and taxane agents, as well as key controversies in their evaluation and management.

Continuing cabazitaxel beyond 10 cycles for metastatic castrate-resistant prostate cancer: is there a benefit?

AIM

Cabazitaxel prolongs survival in patients with metastatic castration-resistant prostate cancer in the postdocetaxel setting. We investigate the benefit of continuing cabazitaxel beyond 10 cycles in patients who are clinically responding without significant toxicity.

METHODS

A comparison was made between patients who received cabazitaxel for >10 cycles and those who had ≤10 cycles. Overall survival (OS), prostate-specific antigen (PSA) response, alkaline phosphatase (ALP) changes and treatment-associated adverse events were evaluated.

RESULTS

The median OS was 9 months (range 0.75-59), with OS significantly higher in patients who received extended duration of treatment: 14 months (range 3-90) vs 7 months (range 1.3-21) in patients treated with 4-10 cycles (HR 0.28, 95% CI 0.1 to 0.74, p=0.01). PSA decline did not show a significant correlation with OS (PSA decline ≥50%, p=0.54). Furthermore, there was no significant difference in OS between patients who had a normal versus high ALP at baseline. There was no clear evidence of cumulative toxicity in those having >10 cycles.

CONCLUSION

A substantial proportion of patients with metastatic castration-resistant prostate cancer were able to receive more than 10 cycles of cabazitaxel without clinically relevant cumulative toxicity.

Balancing the stability and drug activation in adaptive nanoparticles potentiates chemotherapy in multidrug-resistant cancer

Rationale: Prodrug strategies that render the drug temporarily inactive through a cleavable linkage are able to modulate the physicochemical properties of drugs for adaptive nanoparticle (NP) formulation. Here we used cabazitaxel as a model compound to test the validity of our "balancing NP stability and specific drug activation" strategy. Methods: Cabazitaxel is conjugated to hydrophobic polylactide fragments with varying chain lengths via a self-immolation linkage, yielding polymeric prodrugs that can be reactivated by reductive agents in cells. Following a nanoprecipitation protocol, cabazitaxel prodrugs can be stably entrapped in amphiphilic polyethylene-block-polylactide matrices to form core-shell nanotherapies with augmented colloidal stability. Results: Upon cellular uptake followed by intracellular reduction, the NPs spontaneously release chemically unmodified cabazitaxel and exert high cytotoxicity. Studies with near-infrared dye-labeled NPs demonstrate that the nanodelivery of the prodrugs extends their systemic circulation, accompanied with increased drug concentrations at target tumor sites. In preclinical mouse xenograft models, including two paclitaxel-resistant xenograft models, the nanotherapy shows a remarkably higher efficacy in tumor suppression and an improved safety profile than free cabazitaxel. Conclusion: Collectively, our approach enables more effective and less toxic delivery of the cabazitaxel drug, which could be a new generalizable strategy for re-engineering other toxic and water-insoluble therapeutics.

Abiraterone vs. docetaxel for metastatic hormone-sensitive prostate cancer: A microsimulation model

INTRODUCTION

Our aim was to determine whether androgen deprivation therapy (ADT) with abiraterone acetate (AA) or ADT with docetaxel chemotherapy (DC) resulted in improved quality-adjusted life years (QALYs) among men with de novo metastatic castration-sensitive prostate cancer (mCSPC) and the cost effectiveness of the preferred strategy using decision analytic techniques.

METHODS

A microsimulation model with a lifetime time horizon was constructed. Our primary outcome was QALYs. Secondary outcomes included cost, incremental cost effectiveness ratio (ICER), unadjusted overall survival (OS), rates of second- and third-line therapy, and adverse events. A systematic literature review was used to generate probabilities and utilities to populate the model. The base case was a 65-year-old patient with de novo mCSPC.

RESULTS

A total of 100 000 microsimulations were generated. Initial AA resulted in a gain of 0.45 QALYs compared to DC (3.36 vs. 2.91 QALYs) with an ICER of $276 251.82 per QALY gained with initial AA therapy. Median crude OS was 51 months with AA and 48 months with DC. Overall, 46.6% and 42.6% of patients received second-line therapy and 8.7% and 7.9% patients received third-line therapy in the AA and DC groups, respectively. Grade 3/4 adverse events were experienced in 17.6% of patients receiving initial AA and 22.3% of patients receiving initial DC.

CONCLUSIONS

Although ADT with AA results in a gain in QALYs and crude OS compared to DC, AA therapy is not a cost-effective treatment strategy to apply uniformly to all patients. The availability of AA as a generic medication may help to close this gap. The ultimate choice should be based on patient and tumor factors.

Real-world efficacy and safety of two doses of cabazitaxel (20 or 25 mg/m2) in patients with castration-resistant prostate cancer: results of a Japanese post-marketing surveillance study

Background

The recommended starting dose of cabazitaxel for castration-resistant prostate cancer (CRPC) is 25 mg/m² in Japan and Europe. Although lower doses are established alternatives based on randomized controlled trials, the safety and efficacy of 25 and 20 mg/m² in real-world settings are not well established. Therefore, we investigated the safety and efficacy of cabazitaxel at the recommended starting dose or a lower dose (20 mg/m²) in real-world clinical practice.

Methods

We compared the safety and efficacy of cabazitaxel between patients who received cabazitaxel at starting doses of 25 and 20 mg/m² (C25 and C20, respectively) in a Japanese post-marketing surveillance study of 662 patients with docetaxel-refractory CRPC. Safety was assessed in terms of adverse drug reactions (ADRs). Prostate-specific antigen (PSA) response rate, overall survival (OS), and time-to-treatment failure (TTF) were compared between the C25 and C20 groups in unmatched patients and after applying propensity score matching.

Results

The C20 and C25 groups comprised 190 and 159 patients without matching and 112 patients per group after matching. In unmatched patients, any-grade (C25 vs C20: 89.3% vs 78.4%, Fisher’s p < 0.01) and grade ≥ 3 (81.1% vs 61.1%) ADRs were more frequent in the C25 group. Neutropenia (any grade: 61.6% vs 54.2%; grade ≥ 3: 55.3% vs 42.6%) and febrile neutropenia (grade ≥ 3: 30.2% vs 14.7%) were more frequent in the C25 group. In matched patients, the PSA response rate (reduction in PSA ≥30% from a baseline ≥5 ng/mL) was 26.4 and 32.0% in the C20 and C25 groups, respectively, median OS was 291 days (95% CI 230–not reached) versus not reached (hazard ratio 0.73, 95% CI 0.50–1.08), and TTF favored C25 (hazard ratio 0.75, 95% CI 0.57–0.99).

Conclusions

Clinicians should consider the patient’s risk of clinically significant ADRs and prophylactic granulocyte colony stimulating factor when selecting the starting dose of cabazitaxel for CRPC. Some patients at high risk of ADRs or unfit patients may benefit from a lower starting dose of 20 mg/m², whereas fit patients may be candidates for a starting dose of 25 mg/m².

Trial registration

Not applicable.

Effect of Baseline Characteristics on Cabazitaxel Treatment Duration in Patients with Metastatic Castration-Resistant Prostate Cancer: A Post Hoc Analysis of the Compassionate Use/Expanded Access Programs and CAPRISTANA Registry

We examined factors that may impact cabazitaxel treatment duration in a real-life setting in a compassionate use program, expanded access program, and prospective observational study in metastatic castration-resistant prostate cancer (mCRPC). Patients with mCRPC previously treated with docetaxel (N = 1,621) received cabazitaxel 25 mg/m² intravenously every 3 weeks until disease progression, death, unacceptable toxicity or physician/patient decision. The median number of cabazitaxel cycles was six (range, 1-49); 708 patients (43.7%) received >6 cycles. Patients receiving >6 cycles tended to have a better Eastern Cooperative Oncology Group performance status of 0-1 (p = 0.0017 for ≤6 vs. >6 cycles). Overall, 348 patients (21.5%) were ≥75 years of age; 139 (39.9%) received >6 cycles. The main reason for discontinuation was disease progression; however, in patients receiving 1-2 cycles, the main reason for discontinuation was adverse events. Only 52 patients (3.2%) progressed during cycles 1-2. Cabazitaxel was well tolerated in these studies, which included some elderly and frail patients, offering clinicians an important treatment option in the management of mCRPC. Proactive management of adverse events may allow patients to receive a higher number of cabazitaxel cycles and derive greater benefit.

Overall and progression-free survival with cabazitaxel in metastatic castration-resistant prostate cancer in routine clinical practice: the FUJI cohort

Background

Cabazitaxel is a treatment of metastatic castration-resistant prostate cancer (mCRPC) after docetaxel failure. The FUJI cohort aimed to confirm the real-life overall and progression-free survival (OS, PFS) and safety of cabazitaxel.

Methods

Multicentre, non-interventional cohort of French mCRPC patients initiating cabazitaxel between 2013 and 2015, followed 18 months.

Results

Four hundred one patients were recruited in 42 centres. At inclusion, median age was 70, main metastatic sites were bones (87%), lymph nodes (42%) and visceral (20%). 18% had cabazitaxel in 2nd-line treatment, 39% in 3rd-line and 43% in 4th-line or beyond. All had prior docetaxel, and 82% prior abiraterone, enzalutamide or both. Median duration of cabazitaxel treatment was 3.4 months. Median OS from cabazitaxel initiation was 11.9 months [95% CI: 10.1–12.9]. In multivariate analyses, grade ≥ 3 adverse events, visceral metastases, polymedication, and >5 bone metastases were associated with a shorter OS. Main grade ≥ 3 adverse events were haematological with 8% febrile neutropenia.

Conclusion

Real-life survival with cabazitaxel in FUJI was shorter than in TROPIC (pivotal trial, median OS 15.1 months) or PROSELICA (clinical trial 20 vs 25 mg/m², median OS, respectively, 13.4 and 14.5 months). There was no effect of treatment-line on survival. No unexpected adverse concerns were identified.

Study registration

It was registered with the European Medicines Agency EUPASS registry, available at www.encepp.eu, as EUPAS10391. It has been approved as an ENCEPP SEAL study.

Real-world experience with cabazitaxel in patients with metastatic castration-resistant prostate cancer: a final, pooled analysis of the compassionate use programme and early access programme

BACKGROUND

Cabazitaxel is a second-generation taxane approved for use in patients with metastatic castration-resistant prostate cancer (mCRPC) previously treated with docetaxel. Early access programmes were established to allow eligible patients with mCRPC access to cabazitaxel before regulatory approval.

MATERIALS AND METHODS

The primary objective was to allow access to cabazitaxel before commercial availability for patients with mCRPC whose disease had progressed during or after chemotherapy with docetaxel; the secondary objective was overall safety. Patients received cabazitaxel 25 mg/m² on Day 1 of a 21-day cycle, with daily oral 10 mg prednisone/prednisolone. G-CSF was administered per ASCO guidelines.

RESULTS

In total, 1432 patients received cabazitaxel across 41 countries between 2010 and 2014 (median 6.0 treatment cycles [range 1-49]). The most frequently occurring treatment-emergent adverse events (TEAEs) possibly related to treatment were diarrhoea (33.3%), fatigue (25.4%) and anaemia (23.7%); the most frequently occurring possibly related Grade 3/4 TEAEs were neutropenia (18.7%) and febrile neutropenia (6.9%). G-CSF was administered in ≥ 1 cycle in 64% of patients (10.1% therapeutic use; 57.8% prophylactic use; 9.7% both uses).

CONCLUSION

The safety profile of cabazitaxel in this pooled analysis of two cabazitaxel early access programmes was manageable and consistent with previous Phase III trials (TROPIC, PROSELICA).

Second-Line Cabazitaxel Treatment in Castration-Resistant Prostate Cancer Clinical Trials Compared to Standard of Care in CAPRI: Observational Study in the Netherlands

BACKGROUND

Cabazitaxel has been shown to improve overall survival (OS) in metastatic castration-resistant prostate cancer (mCRPC) patients after docetaxel in the TROPIC trial. However, trial populations may not reflect the real-world population. We compared patient characteristics and outcomes of cabazitaxel within and outside trials (standard of care, SOC).

PATIENTS AND METHODS

mCRPC patients treated with cabazitaxel directly after docetaxel therapy before 2017 were retrospectively identified and followed to 2018. Patients were grouped on the basis of treatment within a trial or SOC. Outcomes included OS and prostate-specific antigen (PSA) response.

RESULTS

From 3616 patients in the CAPRI registry, we identified 356 patients treated with cabazitaxel, with 173 patients treated in the second line. Trial patients had favorable prognostic factors: fewer symptoms, less visceral disease, lower lactate dehydrogenase, higher hemoglobin, more docetaxel cycles, and longer treatment-free interval since docetaxel therapy. PSA response (≥ 50% decline) was 28 versus 12%, respectively (P = .209). Median OS was 13.6 versus 9.6 months for trial and SOC subgroups, respectively (hazard ratio = 0.73, P = .067). After correction for prognostic factors, there was no difference in survival (hazard ratio = 1.00, P = .999). Longer duration of androgen deprivation therapy treatment, lower lactate dehydrogenase, and lower PSA were associated with longer OS; visceral disease had a trend for shorter OS.

CONCLUSION

Patients treated with cabazitaxel in trials were fitter and showed outcomes comparable to registration trials. Conversely, those treated in daily practice showed features of more aggressive disease and worse outcome. This underlines the importance of adequate estimation of trial eligibility and health status of mCRPC patients in daily practice to ensure optimal outcomes.

[Chemotherapy-induced peripheral neuropathy: Symptomatology and epidemiology]

Chemotherapy-induced peripheral neuropathy (CIPN) is common with specific semiological characteristics. When CIPN appears, there are many difficulties in guaranteeing sustained treatment, especially with optimal protocol. Moreover, CIPN have bad repercussions on quality of life after cancer disease. In this article, we have achieved a current state of CIPN and try to report details about semiological characteristics and topography. We have also produced some epidemiological data. Nonetheless, we have not voluntarily introduced treatment because it will be the topic of further work.

Treatment of Advanced Prostate Cancer-A Review of Current Therapies and Future Promise

Despite many recent advances in the therapy for metastatic castration-resistant prostate cancer (mCRPC), the disease remains incurable, although men suffering from this disease are living considerably longer. In this review, we discuss the current treatment options available for this disease, such as taxane-based chemotherapy, the novel hormone therapies abiraterone and enzalutamide, and treatments such as radium-223 and sipuleucel-T. We also highlight the need for ongoing research in this field, because, despite numerous recent advances, the prognosis for mCRPC remains poor. Furthermore, as a growing body of evidence shows the increasing heterogeneity of the disease, and highlights the ongoing need for disease molecular stratification and validation/qualification of predictive biomarkers, we explore this burgeoning research space that is likely to transform how we treat this disease. We describe putative predictive biomarkers, including androgen receptor splice variants, phosphatase and tensin homolog (PTEN) loss, homologous recombination repair defects, including BRCA2 loss, and mismatch repair defects. The development of next-generation sequencing techniques and the routine biopsy of metastatic disease have driven significant advances in our understanding of the genomics of cancer, and are now poised to transform our treatment of this disease.

Efficacy and safety of post-docetaxel therapies in metastatic castration-resistant prostate cancer: a systematic review of the literature

OBJECTIVE

Prostate cancer is a highly prevalent form of cancer in older men and is one of the leading causes of death from cancer in men across the globe. Many therapeutic agents have been approved for patients with metastatic castration-resistant prostate cancer (mCRPC), particularly as a post-docetaxel treatment strategy. The objective of this systematic literature review was to assess published efficacy and safety data for select mCRPC therapies - such as abiraterone, cabazitaxel, and enzalutamide - in the post-docetaxel setting.

METHODS

Database searches of MEDLINE, Embase, and Cochrane CENTRAL, in conjunction with hand searches of multiple congress abstracts, yielded 13 randomized studies and 107 non-randomized studies that met the inclusion criteria.

RESULTS

Randomized studies demonstrated significant improvements in median overall survival (OS) outcomes over placebo for abiraterone (15.8 vs. 11.2 months) and enzalutamide (18.4 vs. 13.6 months), and similar significant improvements were noted for cabazitaxel over mitoxantrone (15.1 vs. 12.7 months). Differences in progression-free survival (PFS) were similarly significant, although variance in the criteria for measuring PFS may limit the extent to which these outcomes can be compared between studies. Non-randomized evidence included multiple publications from several early access and compassionate use programs with a primary objective to report safety outcomes. Results from these studies largely reflected the findings in randomized trials.

CONCLUSIONS

Overall, there is a growing body of evidence for post-docetaxel treatment options available in patients with mCRPC. Further head-to-head trials or indirect treatment comparisons may be a valuable method to assess the comparative efficacy of these therapies.

New Generation Nanomedicines Constructed from Self-Assembling Small-Molecule Prodrugs Alleviate Cancer Drug Toxicity

The therapeutic index for chemotherapeutic drugs is determined in part by systemic toxicity, so strategies for dose intensification to improve efficacy must also address tolerability. In addressing this issue, we have investigated a novel combinatorial strategy of reconstructing a drug molecule and using sequential drug-induced nanoassembly to fabricate supramolecular nanomedicines (SNM). Using cabazitaxel as a target agent, we established that individual synthetic prodrugs tethered with polyunsaturated fatty acids were capable of recapitulating self-assembly behavior independent of exogenous excipients. The resulting SNM could be further refined by PEGylation with amphiphilic copolymers suitable for preclinical studies. Among these cabazitaxel derivatives, docosahexaenoic acid-derived compound 1 retained high antiproliferative activity. SNM assembled with compound 1 displayed an unexpected enhancement of tolerability in animals along with effective therapeutic efficacy in a mouse xenograft model of human cancer, compared with free drug administered in its clinical formulation. Overall, our studies showed how attaching flexible lipid chains to a hydrophobic and highly toxic anticancer drug can convert it to a systemic self-deliverable nanotherapy, preserving its pharmacologic efficacy while improving its safety profile. Cancer Res; 77(24); 6963-74. ©2017 AACR.

The Influence of Prednisone on the Efficacy of Cabazitaxel in Men with Metastatic Castration-Resistant Prostate Cancer

Background: Cabazitaxel is a second-generation taxane that is approved for use with concomitant low dose daily prednisone in metastatic castration resistant prostate cancer (mCRPC) after docetaxel failure. Since the role of daily corticosteroids in improving cabazitaxel efficacy or ameliorating its safety profile has not been adequately investigated so far, we compared outcomes of patients receiving cabazitaxel with or without daily corticosteroids in a retrospective single-Institution cohort of mCRPC patients.

Patients and methods: Medical records of deceased patients with documented mCRPC treated with cabazitaxel following prior docetaxel between January, 2011 and January, 2017 were reviewed at the single participating center. Patients who were receiving daily doses of systemic corticosteroids other than low dose daily prednisone or prednisolone (<= 10 mg a day) were excluded. The primary end point of this analysis was overall survival (OS). Secondary end-points were exposure to cabazitaxel as well as incidence of grade 3-4 adverse events. Univariable and multivariable Cox proportional hazards regression was used to evaluate prednisone use and other variables as potentially prognostic for overall survival.

Results: Overall, among 91 patients, 57 patients received cabazitaxel concurrently with low dose prednisone and 34 patients did not receive concurrent prednisone. The median overall survival of the population was 9.8 months (interquartile range, 9 to 14). Patients receiving prednisone had an overall survival of 9 months (interquartile range, 8 to 12) vs.14 months (interquartile range, 9.4 to 16.7) for patients not treated with prednisone. Approximately 45% of patients had a >30% PSA decline at 12 weeks. Prednisone use was not significantly prognostic for overall survival or PSA decline ≥30% rates on regression analyses. Importantly, a >30% PSA decline at 12, but not at 3, 6, 9 weeks, was prognostic for improved survival at multivariate analysis

Conclusions: The data presented here support the hypothesis that omitting daily corticosteroids in cabazitaxel-treated patients has no negative impact on either survival or safety profile. In the large prospective trial CABACARE, cabazitaxel-treated patients will be randomized to receive or not receive daily prednisone. The CABACARE (EudraCT n. 2016-003646-81) study is currently ongoing at University Federico II of Naples and at other multiple participating centers in Italy.

Cabazitaxel in patients with metastatic castration-resistant prostate cancer: safety and quality of life data from the Australian early access program

AIM

Cabazitaxel is a next generation taxane that has been shown to improve overall survival in patients with metastatic castration-resistant prostate cancer (mCRPC) whose disease progressed during or after docetaxel-based therapy. A worldwide early access program (EAP) study was established to provide access to cabazitaxel ahead of commercial availability and to evaluate its safety and tolerability. The Australian EAP included patient-reported outcomes to evaluate the impact of cabazitaxel on quality of life (QoL). The final safety and QoL results from the Australian EAP for cabazitaxel are reported.

METHODS

Australian patients with mCRPC previously treated with a docetaxel-containing regimen received cabazitaxel (25 mg/m² ) every 3 weeks plus prednisone/prednisolone (10 mg daily) until disease progression, death, unacceptable toxicity, physician's decision or patient's refusal of further treatment. QoL data was collected using the AQoL-8D questionnaire.

RESULTS

104 patients from 18 Australian sites (median age at baseline, 70) enrolled in the EAP and completed at least one AQoL-8D questionnaire. Patients received a median of 6 cycles of cabazitaxel. 67 patients (64.4%) experienced grade ≥3 treatment-emergent adverse events (TEAEs); the most frequent TEAEs were neutropenia, febrile neutropenia, diarrhoea, and vomiting. QoL scores remained stable with increasing treatment cycles.

CONCLUSION

The results suggest that the safety profile cabazitaxel is manageable in the Australian clinical practice setting and that QoL is maintained with little or no detrimental effect of cabazitaxel in patients continuing on treatment without disease progression.

Towards better dose individualisation: metabolic phenotyping to predict cabazitaxel pharmacokinetics in men with prostate cancer

BACKGROUND

Cabazitaxel is approved for treatment of castration-resistant metastatic prostate cancer. The current dosing strategy of cabazitaxel is based on body surface area (BSA). Body surface area is known as a poor predictor for total systemic exposure to drugs, since it does not take into account variability in activity of metabolising enzymes, necessary for clearance of drugs. As exposure to cabazitaxel is related to treatment response, it is essential to develop a better individualised dosing strategy.

METHODS

Ten patients with metastatic castration-resistant prostate cancer, who received cabazitaxel dosed on BSA as a part of routine palliative care, were enrolled in this study. Midazolam was administered as phenotyping probe for cytochrome P450 isoenzyme 3A (CYP3A). The relationship between midazolam and cabazitaxel clearance was investigated using non-linear mixed effects modelling.

RESULTS

The clearance of Midazolam highly correlated with cabazitaxel clearance (R=0.74). Midazolam clearance significantly (P<0.004) explained the majority (∼60%) of the inter-individual variability in cabazitaxel clearance in the studied population.

CONCLUSIONS

Metabolic phenotyping of CYP3A using midazolam is a promising strategy to individualise cabazitaxel dosing. Before clinical application, a randomised study is warranted.

Cardiovascular toxicities of systemic treatments of prostate cancer

Prostate cancer is the most common cancer in men, with an incidence that is expected to increase in the coming years. Prostate cancer is usually diagnosed in men >65 years of age, thus the concurrent presence of cardiovascular diseases might influence the treatment, owing to the increased risk of cardiovascular mortality. The introduction of new drugs, such as abiraterone and enzalutamide for the management of metastatic disease has created further interest in treatment-related cardiovascular toxicities, although limited data from trials specifically designed to identify cardiovascular toxicities of these agents are currently available. The only available data are derived from published phase II-III study reports, expanded access or compassionate use programmes and meta-analyses of the effects of systemic therapies that are already approved for use in clinical practice or are in the early phases of development. These data are conflicting, although they seem to suggest that certain drugs are associated with an increased risk of cardiovascular adverse events. Clinical trial methodology could be improved by the enrolment of greater numbers of patients >65 years of age, and the use of comprehensive cardiological evaluations. Moreover, closer collaboration between oncologists and cardiologists is essential for the identification and/or management of cardiovascular adverse events in patients with prostate cancer.

Metastatic castration-resistant prostate cancer in very elderly patients: challenges and solutions

The treatment of elderly patients with cancer is usually viewed by clinicians as a challenge, because of the age-related decline in normal organ function and the frequent concomitant administration of multiple drugs for comorbid conditions. Clinicians therefore tend not to prescribe antineoplastic agents (mainly in the case of chemotherapy) to elderly patients, with the fear of excess toxicity leading to an unfavorable cost:benefit ratio. The cutoff age defining a cancer patient as elderly is usually 70 years, but over the last 10 years clinicians have paid more attention to functional status, as evaluated by means of a comprehensive geriatric assessment and comorbidity burden, rather than chronological age. In the case of metastatic castration-resistant prostate cancer (mCRPC), depending on their age at the time of diagnosis of PC, many (if not most) of the patients are more than 70 years old, and a fair number are very elderly patients aged ≥80 years. The availability of various agents capable of significantly prolonging survival has dramatically changed the therapeutic landscape of mCRPC patients, but very elderly patients are usually underrepresented in pivotal trials. This narrative review considers the available data concerning elderly and very elderly mCRPC patients enrolled in pivotal trials and the information provided by reports of everyday clinical practice, in order to explore the challenges related to the clinical management of this special population.

Effects of Budesonide on Cabazitaxel Pharmacokinetics and Cabazitaxel-Induced Diarrhea: A Randomized, Open-Label Multicenter Phase II Study

Purpose: Forty-seven percent of patients in the pivotal trial of cabazitaxel reported diarrhea of any grade. Aiming to reduce the incidence of diarrhea, we studied the effects of budesonide on the grade of cabazitaxel-induced diarrhea during the first two treatment cycles.Experimental Design: Between December 2011 and October 2015, 246 metastatic castration-resistant prostate cancer patients were randomized to receive standard-of-care cabazitaxel 25 mg/m² every 3 weeks plus prednisone 10 mg/day (group CABA) or same dose/schedule of cabazitaxel with concomitant budesonide 9 mg daily during the first two treatment cycles (group BUD). The occurrence of diarrhea was reported by physicians and by patients in a diary. χ² tests were used to compare incidence numbers. An intention-to-treat principle was used.Results: In the phase II trial, 227 patients were evaluable. Grade 2-3 diarrhea occurred in 35 patients (15%) and grade 4 diarrhea was not reported. The incidence of grade 2-3 diarrhea was comparable in both treatment groups: 14 of 113 patients in group CABA (12%) versus 21 of 114 patients in group BUD (18%; P = 0.21). Seven patients were admitted to the hospital with diarrhea (n = 5 group CABA vs. n = 2 group BUD). PSA response was seen in 30% of patients and was not affected by budesonide coadministration (P = 0.29). Also, other toxicities were not affected by budesonide coadministration.Conclusions: The incidence of cabazitaxel-induced diarrhea was notably lower than reported in the TROPIC trial and appears manageable in routine clinical practice. Budesonide coadministration did not reduce the incidence or severity of cabazitaxel-induced diarrhea. Clin Cancer Res; 23(7); 1679-83. ©2016 AACR.

Efficacy, quality of life, and safety of cabazitaxel in Canadian metastatic castration-resistant prostate cancer patients treated or not with prior abiraterone

INTRODUCTION

In the TROPIC study, cabazitaxel improved overall survival in abiraterone-naïve metastatic castration-resistant prostate cancer (mCRPC) patients post-docetaxel. To evaluate cabazitaxel in routine clinical practice, an international, single-arm trial was conducted. Efficacy, safety, and quality of life (QoL) data were collected from Canadian patients enrolled. Overall survival and progression-free survival were not collected as part of this study. Importantly, prior abiraterone use was obtained and its impact on clinical parameters was examined.

METHODS

Sixty-one patients from nine Canadian centres were enrolled, with prior abiraterone use known for 60 patients. Prostate-specific antigen (PSA) response rate, safety, and impact on QoL life were analyzed as a function of prior abiraterone use.

RESULTS

Overall, 92% of patients were ECOG 0/1, 88% had bone metastases, and 25% visceral metastases. Patients treated without prior abiraterone (NoPriorAbi) (n=35, 58%) and with prior abiraterone (PriorAbi) (n=25, 42%) had similar baseline characteristics, except for age and prior cumulative docetaxel dose. Median number of cabazitaxel cycles received was similar between groups (NoPriorAbi=6, PriorAbi=7), as was PSA response rate (NoPriorAbi=36.4%, PriorAbi=45.0%, p=0.54). Almost one-third (31%) of patients received prophylactic granulocyte colony-stimulating factors. Most frequent Grade 3/4 toxicities were neutropenia (14.8%); anemia, febrile neutropenia, fatigue (each at 9.8%); and diarrhea (8.2%). No treatment-related adverse event leading to death was observed. QoL and pain were improved with no difference seen between groups. Treatment discontinuation was mainly due to disease progression (45.9%) and adverse events (32.8%).

CONCLUSIONS

In routine clinical practice, cabazitaxel's risk-benefit ratio in mCRPC patients previously treated with docetaxel seems to be maintained independent of prior abiraterone use.

Translating Clinical Evidence-Based Medicine into the Real World: Single-Center Experience with Cabazitaxel in Metastatic Prostate Cancer Patients

Background: We studied the efficacy and safety of cabazitaxel in unselected real-life patients. Patients and Methods: We retrospectively investigated all patients with metastatic prostate cancer (mPC) treated with cabazitaxel 25 mg/m2 i.v. every 3 weeks combined with oral prednisolone (10 mg once daily) after first-line docetaxel chemotherapy. Study issues were to report patient characteristics and cabazitaxel data in terms of tolerance and efficacy. Overall survival (OS) and progression-free survival (PFS) were evaluated using the Kaplan-Meier method. All data were compared with TROPIC results. Results: From 2011 to 2014, 41 patients received cabazitaxel; 15 patients (37%) had a performance status (PS) ≥2 versus 7% (p < 0.0001) in TROPIC, and 38 patients (93%) presented a Gleason score ≥7 at baseline (vs. 60%; p < 0.0001). All patients had metastatic disease at baseline. Previous therapies were radiotherapy in 17 patients (41 vs. 61%; p = 0.01) and surgery in 24 patients (59 vs. 52%; p = 0.4). The median number of cabazitaxel cycles was 5 (1-10) versus 6 (3-10) in TROPIC. Five patients completed 10 cycles of cabazitaxel (12%) versus 28% in TROPIC (p = 0.03). Toxicities were anemia (12 patients, 29%), diarrhea (9 patients, 22%), nausea (7 patients, 17%), pain (6 patients, 15%), sepsis (4 patients, 10%), neutropenia (3 patients, 7%) and urinary tract infection (1 patient, 2%). The tumor response rate was 19.5 versus 14.4% in TROPIC (nonsignificant). PFS was 4.5 months (95% CI 3.3-6.4) in our analysis and 2.8 months (95% CI 2.4-3.0) in TROPIC. OS was 12.1 months (95% CI 9.2 to not reached) and 15.1 months (95% CI 14.1-16.3), respectively. Conclusion: In our unselected mPC patients with poorer baseline clinical conditions and aggressive disease, cabazitaxel seems efficient and not more toxic than in the TROPIC study.

Lack of Cumulative Toxicity Associated With Cabazitaxel Use in Prostate Cancer

Cabazitaxel provided a survival advantage compared with mitoxantrone in patients with castration-resistant prostate cancer refractory to docetaxel. Grade 3 to 4 (G3-4) neutropenia and febrile neutropenia were relatively frequent in the registrative XRP6258 Plus Prednisone Compared to Mitoxantrone Plus Prednisone in Hormone Refractory Metastatic Prostate Cancer (TROPIC) trial, but their incidence was lower in the Expanded Access Program (EAP). Although cumulative doses of docetaxel are associated with neuropathy, the effect of cumulative doses of cabazitaxel is unknown. In this retrospective review of prospectively collected data, the authors assessed "per cycle" incidence and predictors of toxicity in the Italian cohort of the EAP, with a focus on the effect of cumulative doses of cabazitaxel.The study population consisted of 218 Italian patients enrolled in the cabazitaxel EAP. The influence of selected variables on the most relevant adverse events identified was assessed using a Generalized Estimating Equations model at univariate and multivariate analysis."Per cycle" incidence of G 3 to 4 neutropenia was 8.7%, whereas febrile neutropenia was reported in 0.9% of cycles. All events of febrile neutropenia occurred during the first 3 cycles. Multivariate logistic regression analysis showed that higher prior dose of cabazitaxel was associated with decreased odds of having G3 to 4 neutropenia (OR = 0.90; 95% CI: 0.86-0.93; P < 0.01), febrile neutropenia (OR = 0.52; 95% CI: 0.34-0.81; P < 0.01) and G3 to 4 anemia (OR = 0.93; 95% CI: 0.86-1; P = 0.07). Patients with a body surface area >2 m2 presented increased odds of having G 3 to 4 neutropenia (OR = 0.93; 95% CI: 0.86-1; P = 0.07), but decreased odds of having G3 to 4 anemia.Among the toxicities assessed, the authors did not identify any that appeared to be associated with a higher number of cabazitaxel cycles delivered. Prior cumulative dose was associated with reduced G3 to 4 neutropenia and anemia. The apparent protective effect associated with higher doses of cabazitaxel is likely to be affected by early dose reduction and early toxicity-related treatment discontinuation. Because this analysis is limited by its retrospective design, prospective trials are required to assess the optimal duration of cabazitaxel treatment.

Rapidly progressive disease in a castration-resistant prostate cancer patient after cabazitaxel discontinuation

We report the case of a 51-year-old patient with metastatic prostate cancer at diagnosis and primary refractoriness to both androgen ablation therapy and docetaxel. At the time of cabazitaxel initiation, the patient had only osseous metastases and was constrained to a wheelchair because of bone pain. Ten cycles of cabazitaxel were administered, and a remarkable response was achieved, with improvement in biochemical markers, performance status, and bone scan findings. Two months after suspension of treatment by choice, the patient developed jaundice because of massive hepatic metastases and died after a few days because of hepatic failure.

Tolerability of cabazitaxel in patients with metastatic castration-resistant prostate cancer progressing after docetaxel and abiraterone acetate: a single-institution experience

Both abiraterone acetate (AA) and cabazitaxel (Cbz) have been shown to prolong survival in patients with metastatic castration-resistant prostate cancer (mCRPC) progressing during or after docetaxel (D). Although no standard sequencing has been established as yet, Cbz has recently been proven to be active after AA. However, to date, few data are available on its safety in this setting. Therefore, the primary endpoint of this study was to investigate Cbz tolerability in mCRPC patients treated previously with D and AA. From April 2011 to the present, 43 mCRPC patients received AA after D at our institution. Of these, 22 patients were subsequently treated with Cbz and were evaluable for toxicity in the present retrospective study. Cbz was administered at a dose of 25 mg/m plus 10 mg oral prednisone every 3 weeks. Adverse events (AEs) were reported using the NCI CTCAE (National Cancer Institute Common Terminology Criteria for Adverse Events) version 3.0. Despite the advanced stage of disease and frailty of our study population, there were no unexpected side effects. The most common AEs were hematologic. Neutropenia was observed in nine (40.9%) patients and of grade≥3 in six (27.2%). No febrile neutropenia occurred. The most common nonhematologic AEs were diarrhea and asthenia, reported in eight (36.3%) and in five (22.7%) patients, respectively. In this setting, Cbz toxicity seems to be manageable and comparable with second-line Cbz. Therefore, our results seem to support the safety of Cbz as a third-line treatment for mCRPC patients.

[How to manage patients with CRPC?]

Despite castrate levels of androgens, the androgen receptor (AR) remains active and continues to drive prostate cancer progression. Since the approval of docetaxel, four additional agents that show a survival benefit have been registered on the basis of randomized phase 3 trials. These have included enzalutamide and abiraterone, two agents designed specifically to affect the androgen axis, sipuleucel-T, which stimulates the immune system and cabazitaxel, a chemotherapeutic agent. Denosumab was shown to significantly delay skeletal-related events. Clinicians are challenged with a multitude of treatment options and potential sequencing of these agents that, consequently, make clinical decision making more complex. The induction of constitutively-active AR splice variants (AR-Vs) driving clonal proliferation of AR-negative and AR-independent metastases may be one major potential mechanism of resistance to new hormone therapies.

Clinical perspectives: practical insights from clinical experience with cabazitaxel in Australia

Prostate cancer, and in particular the management options for patients with metastatic castration-resistant prostate cancer (mCRPC), remains an important health issue. The approval of cabazitaxel provides a new treatment option for patients who have progressed despite docetaxel therapy. Clinical use of cabazitaxel in mCRPC is based on the results of the TROPIC study, which demonstrated an approximately 30% reduction in the risk of death compared with mitoxantrone. In this paper, we draw on accumulating clinical experience with cabazitaxel in Australia to discuss important questions such as how to select the right patient for treatment and how to proactively prevent and manage toxicities associated with this therapy. Recognizing the need for a multidisciplinary approach to patient care, opinion and insight has been sought from medical oncologists, nurses and pharmacists. While lack of trial data means that a number of questions remain unanswered, local clinical experience has helped to guide treatment decisions and refine management protocols. Appropriate patient selection, careful ongoing monitoring and proactive management of adverse events will ensure optimal treatment of patients. Nurses in particular play an important role in educating patients and identifying patients at increased risk of developing adverse events with cabazitaxel. The oncology team must work together to educate patients; taking a proactive approach to issues such as adverse events will help maximize the clinical outcome of cabazitaxel treatment and impact positively on the patient's quality of life.

Analysis of Side Effect Profile of Alopecia, Nail Changes, Peripheral Neuropathy, and Dysgeusia in Prostate Cancer Patients Treated With Docetaxel and Cabazitaxel

INTRODUCTION

We hypothesized that the adverse event (AE) profile of cabazitaxel with regard to alopecia, nail changes, neuropathy, and dysgeusia differs from docetaxel.

MATERIALS AND METHODS

Prospectively collected data on treatment-emergent AEs (frequency and grade [G]) from clinical trial databases of docetaxel every 3 weeks (q3w) (in TAX327 and VENICE) and cabazitaxel q3w (in TROPIC) were analyzed.

RESULTS

The frequency of new or worsening AEs (all G and G3-4) for 1301 patients was significantly less for alopecia, nail changes, neuropathy, and dysgeusia for cabazitaxel compared with docetaxel.

CONCLUSION

Treatment with cabazitaxel might cause less alopecia, nail changes, neuropathy, and dysgeusia compared with docetaxel.