Biomarker Development Trial of Satraplatin in Patients with Metastatic Castration-Resistant Prostate Cancer.

BACKGROUND: In the phase III SPARC trial, satraplatin, an oral platinum analogue, demonstrated anticancer activity in men with metastatic castration-resistant prostate cancer (mCRPC). Repeat biopsies are uncommon in mCRPC, limiting the feasibility of tissue-based biomarkers. This phase II study sought to evaluate the feasibility and utility of blood-based biomarkers to identify platinum-sensitive mCRPC. METHODS: Patients with mCRPC who had progressed on docetaxel were enrolled at a single center from 2011 to 2013. Subjects received satraplatin 80 mg/m2 by mouth daily on days 1-5 and prednisone 5 mg PO twice daily, on a 35-day cycle. Serial peripheral blood samples were collected for biomarker assessment. RESULTS: Thirteen docetaxel-refractory mCRPC patients were enrolled, with a median age of 69 years (range 54-77 years) and median PSA of 71.7 ng/mL (range 0.04-3057). Four of 13 patients (31%) responded to satraplatin (defined as a PSA decline of ≥30%). Responders demonstrated improved time to disease progression (206 vs. 35 days, HR 0.26, 95% CI, 0.02-0.24, P = .003). A 6-gene peripheral blood RNA signature and serum tissue inhibitor of metalloproteinase-1 (TIMP-1) levels were assessed as biomarkers, but neither was significantly associated with response to satraplatin. CONCLUSION: In this small series, one-third of mCRPC patients responded to platinum-based chemotherapy. Peripheral blood biomarker measurement is feasible in mCRPC, though the biomarkers we investigated were not associated with platinum response. Other biomarkers, such as DNA damage repair mutations, should be evaluated.

First-line therapy for elderly patients with advanced renal cell carcinoma in the immuno-oncology era: a network meta-analysis.

BACKGROUND: Tyrosine kinase inhibitors (TKI) or immune checkpoint blockade (ICB), either alone or in combination, confers a significant overall survival (OS) benefit for metastatic RCC in the first-line setting. However, guidance for optimal treatment selection in elderly patients remains limited. METHODS: A database search was performed to identify eligible randomized controlled trials (RCTs) evaluating first-line regimens for patients with advanced RCC older than 65 years old. The primary outcomes were progression-free survival (PFS) and OS. Indirect comparisons of available regimens were estimated using a random-effects network meta-analysis. RESULTS: A total of 14 and five RCTs were eligible for PFS and OS analyses. Compared with sunitinib, pembrolizumab plus axitinib (HR 0.68, 95% CI 0.48-0.97) and pembrolizumab plus lenvatinib (HR 0.61, 95% CI 0.4-0.94) were associated with improved OS. Pembrolizumab plus lenvatinib, nivolumab plus cabozantinib, pembrolizumab plus axitinib, and cabozantinib alone each showed improved PFS over sunitinib. Among these, pembrolizumab plus lenvatinib showed better PFS than pembrolizumab plus axitinib (HR 0.58, 95% CI 0.37-0.91), but no PFS difference compared to nivolumab plus cabozantinib (HR 0.63, 95% CI 0.39-1.03) and cabozantinib alone (HR 0.84, 95% CI 0.40-1.77). Network ranking showed pembrolizumab plus lenvatinib provided the favored OS and PFS benefit for elderly patients. CONCLUSIONS: The combination of ICB with TKI such as pembrolizumab plus lenvatinib needs to be considered over monotherapy in the elderly population, but further validation using real-world data or prospective trials is necessary to confirm the efficacy and safety of first-line regimens for the geriatric population with advanced RCC.

Neuroimmunological adverse events associated with immune checkpoint inhibitor: a retrospective, pharmacovigilance study using FAERS database.

PURPOSE: To investigate the characteristics and risk factors for neurologic adverse events (AEs) induced by immune checkpoint inhibitors (ICIs). METHODS: An observational, retrospective, and pharmacovigilance study based on the FAERS database collected between January 2014 and December 2019 was conducted. ICI-related AEs were defined as adverse reactions in patients using anti-PD-1 (nivolumab and pembrolizumab), anti-PD-L1 (atezolizumab, avelumab, and durvalumab), and anti-CTLA-4 (ipilimumab and tremelimumab). Neurologic AEs previously reported to be associated with ICI were evaluated in the disproportionality analysis using the reporting odds ratio (ROR). RESULTS: Among 50,406 ICI-related reports, 3619 (7.2%) neurological case was found: 1985 with anti-PD-1, 372 with anti-PD-L1, 366 with anti-CTLA-4, and 896 with the combination of ICIs. In comparison to non-ICI drug use, ICI use demonstrated higher risk for neurologic complication, including hypophysitis/hypopituitarism, myasthenia gravis, encephalitis/myelitis, meningitis, Guillain-Barre syndrome, vasculitis, and neuropathy. The risk of neurologic AEs associated with ICI combination therapy was as high as or even higher than ICI monotherapy, most significantly in hypophysitis/hypopituitarism. The proportion of serious neurological events and death related to combination therapy has been decreasing in recent years. Older age, male and female sex, and metastasis were not significant risk factors for the incidence of neurologic ICI-related AEs. Patients at older age, with melanoma or non-small cell lung cancer, or on dual ICI therapy may be at higher risk of fatal neurologic AEs. CONCLUSION: ICI use is associated with a higher risk of neurological complications, with dual ICI therapy posing a higher risk, while older age, sex, or metastasis were not. Patients at older age, with certain cancer types, or on dual ICI therapy may be at higher risk of fatal neurologic AEs.

Management of Atypical Renal Cell Carcinomas.

OPINION STATEMENT: Non-clear cell renal cell carcinoma (RCC) encompasses a diverse group of diseases, with research yielding different histologic findings and genetic profiles with each distinct subgroup. Simply mirroring the management techniques of clear cell RCC and borrowing from its growing armamentarium of therapeutic agents, while somewhat productive at first, but will ultimately be limiting. Further investigation into the molecular pathogenesis of disease, similarities and differences between specific subtypes, and mechanisms of resistance to therapeutics will help identify new targets, stimulate development of novel agents, and improve clinical trial offerings for non-clear cell RCC (nccRCC). As nccRCC has been largely excluded from past trials, there will be a need for future trials to be designed either to evaluate nccRCC specifically, or to include nccRCC as a prespecified subgroup. Multi-center collaborative trials should be supported, as many of the nccRCC subtypes are rare and remain underrepresented even within the construct of trials that only enroll nccRCC. Given the absence of clear molecular targets at present, patients with metastatic nccRCC should be offered and encouraged enrollment on clinical studies whenever possible.

Phase II Trial of Abiraterone Acetate Plus Prednisone in Black Men With Metastatic Prostate Cancer.

LESSONS LEARNED: The safety and activity findings of abiraterone acetate plus prednisone treatment in black men with mCRPC were similar to results from previously conducted studies with largely white populations.Poor trial accrual continues to be a challenge in black men with mCRPC and further efforts are needed to address such underrepresentation. BACKGROUND: Self-identified black men have higher incidence and mortality from prostate cancer in the United States compared with white men but are dramatically underrepresented in clinical trials exploring novel therapies for metastatic castration-resistant prostate cancer (mCRPC). METHODS: Black men with mCRPC were treated with abiraterone acetate (AA), 1,000 mg daily, and prednisone (P), 5 mg twice daily. The primary objective was to determine antitumor activity (defined by a ≥30% decline in prostate-specific antigen [PSA] level) and to correlate germline polymorphisms in androgen metabolism genes with antitumor activity. Secondary objectives included determining safety, post-treatment changes in measurable disease, and time to disease progression. RESULTS: From April 2013 to March 2016, a total of 11 black men were enrolled and received AA plus P (AA+P); 7 of 10 evaluable patients were docetaxel naive. Post-treatment declines in PSA level of ≥30% were achieved in 90% of patients. The side effect profile was consistent with prior clinical trials exploring AA+P in mCRPC. Due to poor accrual, the study was closed prematurely with insufficient sample size for the planned pharmacogenetic analyses. CONCLUSION: In this small prospective study terminated for poor accrual, the safety and activity of AA+P in black men with mCRPC was similar to that reported in prior studies exploring AA in largely white populations. Further efforts are needed to address underrepresentation of black men in mCRPC trials.

Systemic therapy for the treatment of hormone-sensitive metastatic prostate cancer: from intermittent androgen deprivation therapy to chemotherapy.

Treatment of advanced prostate cancer has changed considerably in recent years, but the vast majority of advances have been made in patients with metastatic castration-resistant disease. There have been relatively fewer advances in the earlier, hormonally responsive stage of metastatic disease. Since the empiric establishment of androgen deprivation therapy as first-line therapy for metastatic prostate cancer decades ago, there have been multiple studies looking at variations of suppressing testosterone, but the overall paradigm has not been strongly challenged until more recently. In particular, the dramatic results reported by the CHAARTED trial not only bring chemotherapy to an arena historically dominated solely by hormonal therapy but also stimulate renewed efforts into improving upon our management of metastatic hormone-sensitive prostate cancer.

Performance Status and End-of-Life Outcomes in Patients With Metastatic Castration-resistant Prostate Cancer Treated With Androgen Receptor Targeted Therapy.

OBJECTIVES: Androgen receptor targeted therapies (ARTs) are widely preferred over taxane chemotherapy due to their good tolerability and similar efficacy. However, there is a paucity of data that support the use of ART therapy or describe end-of-life (EOL) outcomes in patients with metastatic castration-resistant prostate cancer (mCRPC) with reduced performance status (PS) (European Cooperative Oncology Group [ECOG] ≥2). METHODS: We performed a retrospective, single-institution study of 142 patients with mCRPC who received ART therapy between 2010 and 2021. We assessed each record for baseline demographic and clinical information, ART treatment course, and survival and EOL outcomes. Our primary aim was to compare overall survival (OS) between the two groups (ECOG ≥2 vs 0 to 1), and our secondary aim was to describe EOL outcomes. Fisher exact tests and Wilcoxon signed-rank tests were used to compare baseline characteristics. Cox regression was used to compare OS for patients with ECOG ≥2 at the start of treatment with those who had an ECOG of 0 or 1. Descriptive analyses were performed to assess EOL outcomes between the groups. RESULTS: Patients with mCRPC and decreased PS experienced shorter OS on ART compared with those with higher PS. Moreover, when examining EOL outcomes, a near majority of these patients died in the hospital, with a greater percentage among those with an ECOG ≥2. CONCLUSION: These findings highlight the need for continual assessment of PS, improved shared decision-making in ART treatment, and additional research exploring the association between PS and EOL outcomes.

Risk Factors for Early Treatment Discontinuation Due to Toxicity Among Patients With Metastatic Castration-resistant Prostate Cancer Receiving Androgen Receptor-targeted Therapy.

OBJECTIVES: Androgen receptor-targeted therapies (ARTs) improve survival outcomes in patients with metastatic castration-resistant prostate cancer (mCRPC); however, a significant portion of patients discontinue treatment for various reasons including treatment-related toxicity. We aim to describe reasons for ART treatment discontinuation and identify predictors associated with increased risk of treatment discontinuation due to toxicity. METHODS: We performed a single-institution retrospective review of patients with mCRPC receiving ART between 2010 and 2021. Our primary aim was to identify risk factors for treatment discontinuation due to toxicity. Our secondary aim was to describe ART discontinuation patterns among patients with mCRPC. RESULTS: One hundred thirty-three patients with mCRPC started and discontinued ARTs. Fourteen patients (10.5%) discontinued treatment due to toxicity. Common reasons for treatment discontinuation include Prostate Specific Antigen test progression, radiographic progression, toxicity, and death. Significant predictors of treatment discontinuation due to toxicity on bivariate analysis and multivariate analysis included patient-reported falls (odds ratio [OR]: 7.67, CI: [1.31-40.42]; P =0.016), rash (OR: 13.4, CI: [1.35-134.81]; P =0.026), and weakness (OR: 4.16, CI: [1.15-15.0]; P =0.019). CONCLUSIONS: Our work presents the first description of ART treatment discontinuation and its causes in the real-world setting, as well as patient-reported side effects. Most patients with mCRPC discontinued treatment due to the progression of disease and a minority of patients discontinued secondary to treatment toxicity. Initial multivariable analysis suggests that patient-reported weakness, falls, and rash were associated with a higher likelihood of treatment discontinuation due to toxicity. Early monitoring of this population can prolong the duration of treatment and prevent unnecessary treatment burden.

Extraction of Treatment Information From Electronic Health Records and Evaluation of Testosterone Recovery in Patients With Prostate Cancer.

PURPOSE: Data quality and standardization remain a challenge when analyzing real-world clinical data. We built a clinical research database, using machine learning and natural learning processing, and investigated factors influencing testosterone recovery (T-recovery) in patients with localized prostate cancer (LPC) after initial androgen deprivation therapy (ADT). METHODS: Medication and treatment-associated dates missing in structured tables were extracted from patient notes using ConceptMapper, an automated data extraction tool, standardized and curated in Sema4 clinical research database. ADT usage duration was evaluated, and T-recovery in patients with LPC was analyzed by the Kaplan-Meier method and multivariable Cox proportional hazards models. We assessed the prognostic value of post-ADT T-recovery with prostate-specific antigen progression-free survival and failure-free survival. RESULTS: In total, 4,125 of 30,832 (13.4%) patients with prostate cancer had medication exclusively from notes with high precision and recall, F1 score ≥ 0.95. Association of dates with medication usage had a F1 score of 0.76. ADT duration estimation had higher accuracy combining information from notes to tables from electronic medical record (70% v 45%). Baseline testosterone was the strongest predictor of T-recovery in these patients. Patients with a baseline testosterone ≥ 300 ng/dL recovered in 9.79 versus 38 months for patients with baseline testosterone < 300 ng/dL (P < .0001). Shorter prostate-specific antigen progression-free interval was observed for patients with T-recovery (≥ 300 ng/dL) at 6 months after ADT cessation compared with patients without T-recovery (< 300 ng/dL; 13.7 v 25.1 months; P = .055). CONCLUSION: We augmented structured electronic medical record data with data extracted from notes and improved the accuracy of medication information for patients. ADT exposure and T-recovery in patients with LPC produced results consistent with the literature and clinical experience and illustrates the power of applying machine learning methods to enhance the quality of real-world evidence in answering clinically relevant questions.

Management of de novo metastatic hormone-sensitive prostate cancer: A comprehensive report of a single-center experience.

BACKGROUND: Upfront docetaxel or novel hormonal agents (NHA) such as abiraterone and enzalutamide have become the standard of care for metastatic hormone sensitive prostate cancer (mHSPC). We evaluated real-world management of patients treated with these agents at a single center. PATIENTS AND METHODS: Patients with de novo mHSPC treated with upfront docetaxel or an NHA between January 2014 and April 2019 at Mount Sinai Health System were included. We evaluated time to next treatment (TTNT), PSA progression free survival (PFS) and overall survival (OS) after initial treatment with these drugs. Kaplan Meier method and multivariable Cox proportional hazards models were used for analysis. We additionally assessed the prognostic value of post-treatment PSA. RESULTS: We identified 94 de novo mHSPC patients; 52 and 42 treated with upfront docetaxel and NHAs, respectively. NHAs were associated with a median TTNT of 20.7 months compared to 10.1 months with docetaxel (log-rank p = 0.023). We also observed median PSA PFS of 19 months for NHAs and 13.2 months for docetaxel (p = 0.069). However, OS between the two treatment groups was unchanged. Among docetaxel treated patients, TTNT was shorter among those with high metastasis burden (9.63 vs 25.5 months, p = 0.026) which was not observed among NHA treated patients (25.1 vs 20.7 months, p = 0.79). Regardless of treatment, lower post-treatment PSA levels were associated with improved TTNT (58.95 vs. 11.57 vs. 9.4 months for PSA ≤0.2, 0.2-0.4, >0.4ng/ml, respectively; p<0.001). CONCLUSION: Real world data demonstrated a shorter duration of treatment with docetaxel than NHAs, reflecting the time-limited nature of docetaxel regimens compared to the treat-till-progression approach of NHAs. While TTNT was generally longer for NHAs than docetaxel, some docetaxel-treated patients achieved significant periods of time off treatment. In addition, the depth of PSA response following combination treatment may hold prognostic value for mHSPC outcomes.

The Impact of Androgen Deprivation Therapy on COVID-19 Illness in Men With Prostate Cancer.

BACKGROUND: TMPRSS2, a cell surface protease regulated by androgens and commonly upregulated in prostate cancer (PCa), is a necessary component for SARS-CoV-2 viral entry into respiratory epithelial cells. Previous reports suggested a lower risk of SARS-CoV-2 among PCa patients on androgen deprivation therapy (ADT). However, the impact of ADT on severe COVID-19 illness is poorly understood. METHODS: We performed a multicenter study across 7 US medical centers and evaluated patients with PCa and SARS-CoV-2 detected by polymerase-chain-reaction between March 1, 2020, and May 31, 2020. PCa patients were considered on ADT if they had received appropriate ADT treatment within 6 months of COVID-19 diagnosis. We used multivariable logistic and Cox proportional-hazard regression models for analysis. All statistical tests were 2-sided. RESULTS: We identified 465 PCa patients (median age = 71 years) with a median follow-up of 60 days. Age, body mass index, cardiovascular comorbidity, and PCa clinical disease state adjusted overall survival (hazard ratio [HR] = 1.16, 95% confidence interval [CI] = 0.68 to 1.98, P = .59), hospitalization status (HR = 0.96, 95% CI = 0.52 to 1.77, P = .90), supplemental oxygenation (HR 1.14, 95% CI = 0.66 to 1.99, P = .64), and use of mechanical ventilation (HR = 0.81, 95% CI = 0.25 to 2.66, P = .73) were similar between ADT and non-ADT cohorts. Similarly, the addition of androgen receptor-directed therapy within 30 days of COVID-19 diagnosis to ADT vs ADT alone did not statistically significantly affect overall survival (androgen receptor-directed therapy: HR = 1.27, 95% CI = 0.69 to 2.32, P = .44). CONCLUSIONS: In this retrospective cohort of PCa patients, the use of ADT was not demonstrated to influence severe COVID-19 outcomes, as defined by hospitalization, supplemental oxygen use, or death. Age 70 years and older was statistically significantly associated with a higher risk of developing severe COVID-19 disease.

Rare case of metastatic liposarcoma to the thyroid gland and a review of the literature of metastatic sarcomas to the thyroid.

BACKGROUND: Liposarcomas are the second most common type of soft tissue sarcomas. Typically, myxoid liposarcomas have a metastatic rate of 10%, usually involving the retroperitoneal space, abdomen, and spine. Metastasis to the thyroid is extremely rare. DESIGN/METHOD: A 62-year-old male with a history of metastatic myxoid liposarcoma in his right thigh presented to our clinic for evaluation of a thyroid nodule incidentally identified on a CT scan. A subsequent FNA biopsy was suggestive of a metastatic liposarcoma. RESULTS: The patient underwent a left thyroid lobectomy and final pathology confirmed a grade II/III metastatic myxoid liposarcoma that measured 3.3 cm. The patient tolerated the procedure well. CONCLUSIONS: Our case highlights the role of a patient's medical history when evaluating thyroid nodules to optimize accurate diagnosis, as liposarcomas do not typically metastasize to the thyroid. We also provide an updated review of the literature on all cases of metastatic sarcomas to the thyroid.

The role of ketoconazole in current prostate cancer care.

Ketoconazole is a nonselective steroid 17α-hydroxylase/17,20 lyase (CYP17A1) inhibitor that has been used, off-label, as a second-line therapy for castration-resistant prostate cancer (CRPC). The drug has shown clinical efficacy without survival benefit. Despite not improving survival, ketoconazole has beneficial characteristics, such as its low cost, a relatively favourable toxicity profile compared with chemotherapy, and its efficacy both before and after chemotherapy. The approval of several new, highly effective treatments, including abiraterone acetate, enzalutamide, and apalutamide, warrants re-evaluation of the role of ketoconazole and other classic agents in achieving the optimal timing and sequencing of available agents to prolong survival and maintain patients' quality of life. In the current CRPC treatment landscape, we believe that ketoconazole can be considered in patients with nonmetastatic CRPC and in those with metastatic CRPC who do not respond to, tolerate, or have access to chemotherapy and other standard therapeutic options.

Profile of apalutamide in the treatment of metastatic castration-resistant prostate cancer: evidence to date.

Advances in therapies have led to the approval of six therapeutic agents since 2004, each demonstrating overall survival benefit in randomized studies, and these have significantly improved the outlook for men facing metastatic castration-resistant prostate cancer (CRPC). More recently, efforts have been directed at trying to effect change at earlier phases of the disease. Apalutamide (ARN-509), a second-generation androgen receptor antagonist, recently received approval in the nonmetastatic (M0) CRPC space. Similar to enzalutamide, apalutamide inhibits the binding of androgen to androgen receptor (AR), nuclear translocation of the androgen-AR complex, and binding of AR transcription complex to DNA-binding sites and transcription elements. Phase I and II trial experience demonstrates the safety and tolerability of apalutamide, as well as its efficacy in effecting prostate-specific antigen response and radiographic-free survival in CRPC. US Food and Drug Administration approval in M0 CRPC was granted following positive results from the phase III SPARTAN study, where apalutamide demonstrated significant improvements in metastasis-free survival and time to symptomatic progression as compared to placebo.

Strategies to avoid treatment-induced lineage crisis in advanced prostate cancer.

The increasing potency of therapies that target the androgen receptor (AR) signalling axis has correlated with a rise in the proportion of patients with prostate cancer harbouring an adaptive phenotype, termed treatment-induced lineage crisis. This phenotype is characterized by features that include soft-tissue metastasis and/or resistance to standard anticancer therapies. Potent anticancer treatments might force cancer cells to evolve and develop alternative cell lineages that are resistant to primary therapies, a mechanism similar to the generation of multidrug- resistant microorganisms after continued antibiotic use. Herein, we assess the hypothesis that treatment-adapted phenotypes harbour reduced AR expression and/or activity, and acquire compensatory strategies for cell survival. We highlight the striking similarities between castration-resistant prostate cancer and triple-negative breast cancer, another poorly differentiated endocrine malignancy. Alternative treatment paradigms are needed to avoid therapy-induced resistance. Herein, we present a new clinical trial strategy designed to evaluate the potential of rapid drug cycling as an approach to delay the onset of resistance and treatment-induced lineage crisis in patients with metastatic castration-resistant prostate cancer.

Moving beyond vascular endothelial growth factor-targeted therapy in renal cell cancer: latest evidence and therapeutic implications.

Renal cell cancer (RCC) continues to be among the most lethal malignancies in the USA. Introduction of anti-vascular epidermal growth factor receptor tyrosine kinase inhibitors over a decade ago resulted in improvement in disease outcomes, but further development of new therapies largely stagnated for many years. More recently, a better understanding of disease biology and treatment-resistance patterns has led to a second renaissance in drug development, with the anti-programmed cell death protein 1 immune checkpoint inhibitor, nivolumab, paving the way for additional therapies entering clinical trial testing in the treatment of RCC.

Blood mRNA expression profiling predicts survival in patients treated with tremelimumab.

PURPOSE: Tremelimumab (ticilimumab, Pfizer), is a monoclonal antibody (mAb) targeting cytotoxic T lymphocyte-associated antigen-4 (CTLA-4). Ipilimumab (Yervoy, BMS), another anti-CTLA-4 antibody, is approved by the U.S. Federal Drug Administration (FDA). Biomarkers are needed to identify the subset of patients who will achieve tumor control with CTLA-4 blockade. EXPERIMENTAL DESIGN: Pretreatment peripheral blood samples from 218 patients with melanoma who were refractory to prior therapy and receiving tremelimumab in a multicenter phase II study were measured for 169 mRNA transcripts using reverse transcription polymerase chain reaction (RT-PCR). A two-class latent model yielded a risk score based on four genes that were highly predictive of survival (P < 0.001). This signature was validated in an independent population of 260 treatment-naïve patients with melanoma enrolled in a multicenter phase III study of tremelimumab. RESULTS: Median follow-up was 297 days for the training population and 386 days for the test population. Expression levels of the 169 genes were closely correlated across the two populations (r = 0.9939). A four-gene model, including cathepsin D (CTSD), phopholipase A2 group VII (PLA2G7), thioredoxin reductase 1 (TXNRD1), and interleukin 1 receptor-associated kinase 3 (IRAK3), predicted survival in the test population (P = 0.001 by log-rank test). This four-gene model added to the predictive value of clinical predictors (P < 0.0001). CONCLUSIONS: Expression levels of CTSD, PLA2G7, TXNRD1, and IRAK3 in peripheral blood are predictive of survival in patients with melanoma treated with tremelimumab. Blood mRNA signatures should be further explored to define patient subsets likely to benefit from immunotherapy.

Metabolic and toxicological considerations of newly approved prostate cancer drugs.

INTRODUCTION: Despite increasing early detection and treatment of prostate cancer, a subset of patients presents with or develops metastatic disease. Androgen deprivation therapy is effective but resistance eventually develops, resulting in a lethal phenotype known as castration-resistant prostate cancer (CRPC). Recently, several novel treatments, each with distinct mechanisms of actions, have been approved for the treatment of CRPC. Understanding of the metabolic and toxicological considerations of each treatment is crucial to the successful management of patients with this lethal disease. AREAS COVERED: The present review focuses on the metabolism and toxicology characteristics of recently approved therapies in the treatment of metastatic CRPC. Specifically, the authors review the mechanism of action of these therapies in addition to their, efficacy and usage recommendations for hepatic and renal impairment. The authors, furthermore, also consider their adverse effect profile. EXPERT OPINION: Despite the expanding armamentarium of effective treatments for CRPC, the exact choice, timing and sequence of various therapies remains an inexact science and requires further investigation. Variations in patient comorbidities, disease burden, organ functions and adverse events are all critical determinants in selection of treatment. Identification and validation of molecular pathways and specific targets that drives disease progression will be critical in the continued development of effective treatments in advanced prostate cancer.