Search

Background Phosphatidylinositol-3-kinase (PI3K) and androgen receptor pathway activation is common in metastatic castration resistant prostate cancer (mCRPC). Buparlisib is an oral, pan-class I PI3 kinase inhibitor. Methods This was a multisite single arm phase II trial of buparlisib 100 mg ± enzalutamide daily in men with mCRPC whose disease progressed on or who were not candidates for docetaxel. The primary end-point was the rate of radiographic/clinical progression-free survival (PFS) at 6 months. Results Thirty men were accrued: 67% post-docetaxel; median prostate specific antigen (PSA) was 70 ng/dl, 83% had ≥4 prior therapies for mCRPC; 43% received concurrent enzalutamide. The final 6 month PFS rate was estimated to be 10% (95% confidence interval 2.5–23.6%). Median PFS was 1.9 months and was 3.5 months with concurrent enzalutamide. Median overall survival was 10.6 months. Concurrent enzalutamide led to a five-fold reduction in buparlisib concentrations. PSA declines were observed in 23%; no patients achieved a ≥50% decline, and no radiographic responses were observed. Severe adverse events occurred in four men including respiratory infection and multi-organ failure, urinary tract obstruction, confusion and one seizure in the setting of a new central nervous system (CNS) metastasis. Grade III adverse events were seen in 43% of patients; common toxicities included grade I–II weight loss, diarrhoea, nausea, fatigue, anorexia, rash, hyperglycemia and anxiety/mood disorders. Conclusions Buparlisib did not demonstrate significant activity in men with mCRPC, suggesting that PI3K inhibition is not sufficient to reverse resistant mCRPC progression. Future studies of PI3K pathway inhibitors with concurrent enzalutamide should develop optimal dosing and focus on selected patients more likely to benefit. [ABSTRACT FROM AUTHOR]

Background. The iterative sure independence screening (ISIS) is a popular method in selecting important variables while maintaining most of the informative variables relevant to the outcome in high throughput data. However, it not only is computationally intensive but also may cause high false discovery rate (FDR). We propose to use the FDR as a screening method to reduce the high dimension to a lower dimension as well as controlling the FDR with three popular variable selection methods: LASSO, SCAD, and MCP. Method. The three methods with the proposed screenings were applied to prostate cancer data with presence of metastasis as the outcome. Results. Simulations showed that the three variable selection methods with the proposed screenings controlled the predefined FDR and produced high area under the receiver operating characteristic curve (AUROC) scores. In applying these methods to the prostate cancer example, LASSO and MCP selected 12 and 8 genes and produced AUROC scores of 0.746 and 0.764, respectively. Conclusions. We demonstrated that the variable selection methods with the sequential use of FDR and ISIS not only controlled the predefined FDR in the final models but also had relatively high AUROC scores. [ABSTRACT FROM AUTHOR]

Objective The Brief Pain Inventory ( BPI) was designed to yield separate scores for pain intensity and interference. It has been proposed that the pain interference factor can be further broken down into unique factors of affective (e.g., mood) and activity (e.g., work) interference. The purpose of this analysis was to confirm this affective/activity interference dichotomy. Patients and Methods A retrospective confirmatory factor analysis was completed for a sample of 184 individuals diagnosed with castrate-resistant prostate cancer (age 40-86, mean = 65.46, 77% White non- Hispanic) who had been administered the BPI as part of Cancer and Leukemia Group B trial 9480. A one-factor model was compared against two-factor and three-factor models that were developed based on the design of the instrument. Results Root mean squared error of approximation (0.075), comparative fit index (0.971), and change in chi-square, given the corresponding change in degrees of freedom (13.33, P < 0.05) values for the three-factor model (i.e., pain intensity, activity interference, and affective interference), were statistically superior in comparison with the one- and two-factor models. This three-factor structure was found to be invariant across age, mean prostate-specific antigen, and hemoglobin levels. Conclusions These results confirm that the BPI can be used to quantify the degree to which pain separately interferes with affective and activity aspects of a patient's everyday life. These findings will provide clinical trialists, pharmaceutical sponsors, and regulators with confidence in the flexibility of the BPI as they consider the use of this instrument to assist with understanding the patient experience as it relates to treatment. [ABSTRACT FROM AUTHOR]

Background: Activation of the PI3K-Akt-mTOR signaling pathway is common in advanced castration resistant prostate cancer (CRPC), typically through PTEN loss. Preclinical studies suggest that Akt-driven CaP cells are genetically susceptible to mammalian target of rapamycin (mTOR, or TORC1) inhibition. Everolimus is a Food and Drug Administration-approved inhibitor of TORC1.Materials and Methods: We performed a phase II study of everolimus in patients with mCRPC, who were refractory to standard of care hormonal and chemotherapeutic agents. Patients received everolimus 10 mg daily until unacceptable adverse events or disease progression. The primary efficacy outcome was confirmed 50% or greater prostate-specific antigen (PSA) response, using a 2 stage design with futility rules. Paired biopsies were utilized to assess for treatment effect on downstream TORC1 targets as well as tumor cell proliferation and apoptosis.Results: Out of 35 men enrolled with heavily pretreated mCRPC, 32 were evaluable for clinical efficacy. No PSA responses were observed, the median progression-free survival time was 3.6 months (95% confidence interval = 2.9-4.8) and the median overall survival time was 10.4 months (95% confidence interval = 5.8-15.8). Several patients had declines in serum PSA upon cessation of everolimus. Thus, the study was closed due to clinical futility. The most common toxicities were mucositis, fatigue, anorexia, hypertriglyceridemia, and thrombocytopenia and were largely low grade. Pathologic evaluation of paired metastatic biopsies demonstrated consistent inhibition of pS6, a downstream mTOR pharmacodynamics biomarker, but the tumor proliferation marker Ki-67 increased with therapy.Conclusions: Everolimus demonstrated predictable toxicity in advanced and heavily pretreated patients with mCRPC. No clinical or clear pathologic effects despite downstream TORC1 target inhibition, suggesting that single agent everolimus has no clinical utility in men with mCRPC. [ABSTRACT FROM AUTHOR]

Innovations in treatments, imaging and molecular characterisation have improved outcomes for people with advanced prostate cancer; however, many aspects of clinical management are devoid of high-level evidence. At the Advanced Prostate Cancer Consensus Conference (APCCC) 2019, many of these topics were addressed, and consensus was not always reached. The results from clinical trials will most reliably plus the gaps. An invited panel of 57 experts voted on 123 multiple-choice questions on clinical management at APCCC 2019. No consensus was reached on 88 (71.5%) questions defined as <75% of panellists voting for the same answer option. We reviewed clinicaltrials.gov to identify relevant ongoing phase III trials in these areas of non-consensus. A number of ongoing phase III trials were identified that are relevant to these non-consensus issues. However, many non-consensus issues appear not to be addressed by current clinical trials. Of note, no phase III but only phase II trials were identified, investigating side effects of hormonal treatments and their management. Lack of consensus almost invariably indicates gaps in existing evidence. The high percentage of questions lacking consensus at APCCC 2019 highlights the complexity of advanced prostate cancer care and the need for robust, clinically relevant trials that can fill current gaps with high-level evidence. Our review of these areas of non-consensus and ongoing trials provides a useful summary, indicating areas in which future consensus may soon be reached. This review may facilitate academic investigators to identify and prioritise topics for future research. • APCCC (Advanced Prostate Cancer Consensus Conference) addresses knowledge gaps. • At APCCC 2019, many topics did not reach a consensus. • This article reviews ongoing trials and identifies outstanding gaps in knowledge. • The need for robust, clinically relevant trials that can fill gaps is highlighted. • This review may facilitate academic investigators to prioritise research topics. [ABSTRACT FROM AUTHOR]

Background: The international Intermediate Clinical Endpoints in Cancer of the Prostate working group has established metastasis-free survival as a surrogate for overall survival in localised prostate cancer based on the findings of 19 predominantly radiotherapy-based trials. We sought to comprehensively assess aggregate trial-level performance of commonly reported intermediate clinical endpoints across all randomised trials in localised prostate cancer.Methods: For this meta-analysis, we searched PubMed for all trials in localised or biochemically recurrent prostate cancer published between Jan 1, 1970, and Jan 15, 2020. Eligible trials had to be randomised, therapeutic, reporting overall survival and at least one intermediate clinical endpoint, and with a sample size of at least 70 participants. Trials of metastatic disease were excluded. Intermediate clinical endpoints included biochemical failure, local failure, distant metastases, biochemical failure-free survival, progression-free survival, and metastasis-free survival. Candidacy for surrogacy was assessed using the second condition of the meta-analytical approach (ie, correlation of the treatment effect of the intermediate clinical endpoint and overall survival), using R2 weighted by the inverse variance of the log intermediate clinical endpoint hazard ratio. The intermediate clinical endpoint was deemed to be a surrogate for overall survival if R2 was 0·7 or greater.Findings: 75 trials (53 631 patients) were included in our analysis. Median follow-up was 9·1 years (IQR 5·7-10·6). Biochemical failure (R2 0·38 [95% CI 0·11-0·64]), biochemical failure-free survival (R2 0·12 [0·0030-0·33]), biochemical failure and clinical failure (R2 0·28 [0·0045-0·65]), and local failure (R2 0·085 [0·00-0·37]) correlated poorly with overall survival. Progression-free survival (R2 0·46 [95% CI 0·22-0·67]) showed moderate correlation with overall survival, and metastasis-free survival (R2 0·78 [0·59-0·89]) correlated strongly.Interpretation: Intermediate clinical endpoints based on biochemical and local failure did not meet the second condition of the meta-analytical approach and are not surrogate endpoints for overall survival in localised prostate cancer. Our findings validate metastasis-free survival as the only identified surrogate endpoint for overall survival to date.Funding: Prostate Cancer Foundation and National Institutes of Health. [ABSTRACT FROM AUTHOR]

New systemic therapies have prolonged the lives of men with metastatic castration-resistant prostate cancer (mCRPC). Use of these therapies in the adjuvant setting when the disease may be micrometastatic and potentially more sensitive to therapies may decrease mortality from prostate cancer. However, the conduct of adjuvant prostate cancer clinical trials is hampered by taking longer than a decade to reach the meaningful endpoint of overall survival (OS) and the fact that many men never die from prostate cancer, even if they relapse. A validated intermediate clinical endpoint (ICE) in prostate cancer that is a robust surrogate for OS has yet to be defined. This paper details the plans, process, and progress of the international Intermediate Clinical Endpoints in Cancer of the Prostate (ICECaP) working group to pool individual patient data from all available clinical trials of radiation or prostatectomy for localized disease and conduct the requisite analyses to determine whether an ICE can be identified. This paper further details the challenges and the a priori statistical analytical plans and strategies to define an ICE for adjuvant prostate cancer clinical trials. In addition, a brief review of the health economic analyses to model the benefits to patients, society and manufacturers is detailed. If successful, the results from this work will provide a robust surrogate for OS that will expedite the design and conduct of future adjuvant therapy trials using new agents that have proven activity in mCRPC. Moreover, it will also define the health economic benefits to patients and societies. [ABSTRACT FROM AUTHOR]