Treatment of non-metastatic castration-resistant prostate cancer: focus on apalutamide

Treatment patterns and outcomes in patients with nonmetastatic castration-resistant prostate cancer in the United States

Aim: Androgen receptor pathway inhibitors (ARPIs) prolong metastasis-free survival and overall survival in patients with nonmetastatic castration-resistant prostate cancer (nmCRPC). This study aimed to evaluate real-world treatment patterns, utilization and survival outcomes in patients with nmCRPC.Patients & methods: This retrospective cohort study used Optum database electronic health records of patients with nmCRPC from 1 January 2007 to 31 December 2020 in the US.Results: Of 1955 patients, >80% received androgen-deprivation therapy (ADT) alone or ADT + first-generation nonsteroidal antiandrogen (NSAA) as first-line treatment, while only 8.24% received ADT + ARPI. ADT + ARPI remained underutilized even among those with high-risk nmCRPC. Further, ADT + NSAA had no survival benefit compared with ADT alone.Conclusion: Practice-improvement strategies are needed for treatment intensification with ARPIs for patients with nmCRPC.

Treatment patterns and healthcare resource utilization in patients with metastatic hormone-sensitive prostate cancer and nonmetastatic castration-resistant prostate cancer in China: a real-world observational study

AIM

This study assessed the treatment patterns, healthcare resource utilization (HRU), costs, and annual prevalence and incidence of metastatic hormone-sensitive prostate cancer (mHSPC) and nonmetastatic castration-resistant prostate cancer (nmCRPC) in China.

METHODS

A retrospective study was conducted using electronic medical records (EMR) of patients with prostate cancer from three tertiary-care hospitals in China between January 2014 and March 2021. Descriptive statistics were used to analyze study outcomes.

RESULTS

In total, 1086 patients with mHSPC and 679 patients with nmCRPC were included. From 2015 to 2020, the annual percentage of prevalent and incident cases of mHSPC decreased from 22.4% to 20.0% and 11.1% to 6.9%, respectively; for nmCRPC, these increased from 3.8% to 13.6% and 3.3% to 8.4%. Androgen-deprivation therapy and first-generation antiandrogens (bicalutamide or flutamide) were the most frequently prescribed prostate cancer-related medications at baseline and follow-up in patients with mHSPC. Bicalutamide was the most frequently prescribed prostate cancer-related medication during follow-up in patients with nmCRPC. For mHSPC, inpatient admission costs were the highest, with the median (interquartile range) costs per person-month being USD 403.00 (USD 85.50-1226.20), whereas outpatient visit costs were the highest for nmCRPC (USD 372.60 [USD 139.50-818.50]).

LIMITATIONS

EMR-based study design did not capture treatment patterns, HRU and associated costs, and healthcare encounters that occurred outside of participating hospitals, which could have led to underestimation of the true disease burden.

CONCLUSIONS

A contrasting trend of a decline in the prevalence and incidence of mHSPC and an increase in these for nmCRPC was observed between 2015 and 2020 in China. Androgen-deprivation therapy and first-generation antiandrogens were the most frequently prescribed prostate cancer-related medications. Healthcare resource utilization was driven by inpatient costs in mHSPC and outpatient costs in nmCRPC.

The crosstalk between ubiquitination and endocrine therapy

Endocrine therapy (ET), also known as hormone therapy, refers to the treatment of tumors by regulating and changing the endocrine environment and hormone levels. Its related mechanism is mainly through reducing hormone levels and blocking the binding of hormones to corresponding receptors, thus blocking the signal transduction pathway to stimulate tumor growth. However, with the application of ET, some patients show resistance to ET, which is attributed to abnormal accumulation of hormone receptors (HRs) and the production of multiple mutants of HRs. The targeted degradation of abnormal accumulation protein mediated by ubiquitination is an important approach that regulates the protein level and function of intracellular proteins in eukaryotes. Here, we provide a brief description of the traditional and novel drugs available for ET in this review. Then, we introduce the link between ubiquitination and ET. In the end, we elaborate the clinical application of ET combined with ubiquitination-related molecules. KEY MESSAGES: • A brief description of the traditional and novel drugs available for endocrine therapy (ET). • The link between ubiquitination and ET. • The clinical application of ET combined with ubiquitination-related molecules.

Addressing the Reciprocal Crosstalk between the AR and the PI3K/AKT/mTOR Signaling Pathways for Prostate Cancer Treatment

The reduction in androgen synthesis and the blockade of the androgen receptor (AR) function by chemical castration and AR signaling inhibitors represent the main treatment lines for the initial stages of prostate cancer. Unfortunately, resistance mechanisms ultimately develop due to alterations in the AR pathway, such as gene amplification or mutations, and also the emergence of alternative pathways that render the tumor less or, more rarely, completely independent of androgen activation. An essential oncogenic axis activated in prostate cancer is the phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway, as evidenced by the frequent alterations of the negative regulator phosphatase and tensin homolog (PTEN) and by the activating mutations in PI3K subunits. Additionally, crosstalk and reciprocal feedback loops between androgen signaling and the PI3K/AKT/mTOR signaling cascade that activate pro-survival signals and play an essential role in disease recurrence and progression have been evidenced. Inhibitors addressing different players of the PI3K/AKT/mTOR pathway have been evaluated in the clinic. Only a limited benefit has been reported in prostate cancer up to now due to the associated side effects, so novel combination approaches and biomarkers predictive of patient response are urgently needed. Here, we reviewed recent data on the crosstalk between AR signaling and the PI3K/AKT/mTOR pathway, the selective inhibitors identified, and the most advanced clinical studies, with a focus on combination treatments. A deeper understanding of the complex molecular mechanisms involved in disease progression and treatment resistance is essential to further guide therapeutic approaches with improved outcomes.

Treatment Patterns Among Patients With Advanced Prostate Cancer in Brazil: An Analysis of a Private Healthcare System Database

Background

With the ongoing expansion of life-prolonging therapies approved to treat advanced prostate cancer, there is currently an unmet need to better understand real-world treatment patterns and identify optimal treatment sequencing for men with metastatic castration-resistant prostate cancer (mCRPC).

Methods

In this retrospective, observational cohort analysis, patients with confirmed mCRPC were identified in the Auditron claims database and used to describe mCRPC treatment patterns and trends in the Brazilian private healthcare system from 2014 to 2019. Demographics and clinical characteristics, prostate cancer stage at diagnosis, and type and number of treatment lines were evaluated. The primary endpoint was identification of the drugs used in first-line therapies in mCRPC, and the secondary endpoint included a description of sequential lines of therapy (second and third lines) in mCRPC.

Results

A total of 168 electronic patient records were reviewed. Docetaxel was the most frequently used first-line treatment (35.7%), followed by abiraterone (33.3%) and enzalutamide (13.1%). Docetaxel, abiraterone, and enzalutamide also accounted for 34.6%, 28.0%, and 15.0%, respectively, of second-line therapies. In third-line therapies, cabazitaxel (26.1%), enzalutamide (23.9%), docetaxel (15.2%), and abiraterone (15.2%) were most commonly prescribed. Irrespective of stage at diagnosis, treatment patterns were similar once the disease progressed to the metastatic castration-resistance stage.

Conclusions

Docetaxel was the most frequently utilized therapy for mCRPC treatment, followed by abiraterone and enzalutamide. Although the current analyses provide real-world insights into treatment patterns for patients with mCRPC in Brazil, additional real-world data are needed to further validate and expand on these findings.

HOW TO OPTIMALLY SEQUENCE AVAILABLE THERAPY LINES IN ADVANCED PROSTATE CANCER

Optimal sequencing of available therapy lines in patients with advanced prostate cancer often poses quite a challenge. The guidelines are sometimes equivocal and clinical trial data are not always applicable to a particular patient. There is a difference in availability of therapy options throughout the world. In decision making, a patient as a whole should be taken into consideration, not just the stage and biology of the disease, but also patient's age, performance status, comorbidities, previous therapy lines, drug's safety profile and patient's preferences. This review article will show certain therapeutic options in the treatment of advanced hormone-sensitive prostate cancer and castration resistant prostate cancer: non- metastatic and metastatic. An attempt will be made to clarify the optimal sequencing.

Patterns of Care and Outcomes for Non-Metastatic Prostate Cancer in the United States: Results of the CancerMPact® Survey 2018

Purpose

We describe patterns of care and treatment outcomes for non-metastatic PCa (nmPCA), either hormone-sensitive or castration-resistant, in the United States of America (USA) in 2018.

Methods

A survey (CancerMPact^®) recruited physicians nationwide to answer an online questionnaire about how they treated patients with nmPCA. Questions covered aspects of treatment at all disease stages. Board-certified urologists and oncologists with at least five years of clinical practice and who treated at least 30 PCa patients monthly were included.

Results

The survey included responses from ninety-four physicians with an average of 17.5 years of clinical practice, who had treated a combined average of 4415 patients with nmPCA per month in 2018. Approximately 40% of patients in stage I were managed with either active surveillance or observation/no therapy, decreasing to 20%, 8% and 6% in stages II, III and IV(M0), respectively. Intensity-modulated radiotherapy was favored over other radiotherapy modalities, with rates of use ranging between 60% and 69% depending on disease stage. Leuprolide as monotherapy or in combination with enzalutamide, abiraterone or bicalutamide were the most common systemic treatment options for non-metastatic hormone-sensitive PCa (nmHSPC) patients with the first or second recurrence. Only 16.5% of non-metastatic castration-resistant PCa (nmCRPC) patients did not relapse within five years of initial therapy for nmCRPC.

Conclusion

While PCa treatment recommendations are rapidly changing due to advances in treatment, we observed great concordance between their most current versions and real-world data treatment patterns reported by US physicians.

Treating the patient and not just the cancer: therapeutic burden in prostate cancer

BACKGROUND

Prostate cancer (PC) is a leading cause of death in older men. Androgen deprivation therapy (ADT) is considered the standard-of-care for men with locally advanced disease. However, continuous androgen ablation is associated with acute and long-term adverse effects and most patients will eventually develop castration-resistant PC (CRPC). The recent approval of three, second-generation androgen receptor inhibitors (ARIs), apalutamide, enzalutamide, and darolutamide, has transformed the treatment landscape of PC. Treatment with these second-generation ARIs have produced positive trends in metastasis-free survival, progression-free survival, and overall survival. For patients with non-metastatic CRPC, who are mainly asymptomatic from their disease, maintaining quality of life is a major objective when prescribing therapy. Polypharmacy for age-related comorbidities also is common in this population and may increase the potential for drug-drug interactions (DDIs).

METHOD

This review summarizes the multiple factors that may contribute to the therapeutic burden of patients with CRPC, including the interplay between age, comorbidities, concomitant medications, the use of ARIs, and financial distress.

CONCLUSIONS

As the treatment landscape in PC continues to rapidly evolve, consideration must be given to the balance between therapeutic benefits and potential treatment-emergent adverse events that may be further complicated by DDIs with concomitant medications. Patient-centered communication is a crucial aspect of alleviating this burden, and healthcare professionals (HCPs) may benefit from training in effective patient communication. HCPs should closely and frequently monitor patient treatment responses, in order to better understand symptom onset and exacerbation. Patients also should be encouraged to participate in exercise programs, and health information and support groups, which may assist them in preventing or mitigating certain determinants of the therapeutic burden associated with PC and its management.

Niraparib with androgen receptor-axis-targeted therapy in patients with metastatic castration-resistant prostate cancer: safety and pharmacokinetic results from a phase 1b study (BEDIVERE)

PURPOSE

To assess the safety and pharmacokinetics and determine the recommended phase 2 dose (RP2D) of niraparib with apalutamide or abiraterone acetate plus prednisone (AAP) in patients with metastatic castration-resistant prostate cancer (mCRPC).

METHODS

BEDIVERE was a multicenter, open-label, phase 1b study of niraparib 200 or 300 mg/day with apalutamide 240 mg or AAP (abiraterone acetate 1000 mg; prednisone 10 mg). Patients with mCRPC were previously treated with ≥ 2 lines of systemic therapy, including ≥ 1 androgen receptor-axis-targeted therapy for prostate cancer.

RESULTS

Thirty-three patients were enrolled (niraparib-apalutamide, 6; niraparib-AAP, 27). No dose-limiting toxicities (DLTs) were reported when combinations included niraparib 200 mg; five patients receiving niraparib 300 mg experienced DLTs [niraparib-apalutamide, 2/3 patients (66.7%); niraparib-AAP, 3/8 patients (37.5%)]. Although data are limited, niraparib exposures were lower when given with apalutamide compared with historical niraparib monotherapy exposures in patients with solid tumors. Because of the higher incidence of DLTs, the niraparib-apalutamide combination and niraparib 300 mg combination with AAP were not further evaluated. Niraparib 200 mg was selected as the RP2D with AAP. Of 19 patients receiving niraparib 200 mg with AAP, 12 (63.2%) had grade 3/4 treatment-emergent adverse events, the most common being thrombocytopenia (26.3%) and hypertension (21.1%). Five patients (26.3%) had adverse events leading to treatment discontinuation.

CONCLUSIONS

These results support the choice of niraparib 200 mg as the RP2D with AAP. The niraparib-AAP combination was tolerable in patients with mCRPC, with no new safety signals. An ongoing phase 3 study is further assessing this combination in patients with mCRPC.

TRIAL REGISTRATION NO

NCT02924766 (ClinicalTrials.gov).