Factors Associated With Use of Sipuleucel-T to Treat Patients With Advanced Prostate Cancer

Racial disparity in prostate cancer: an outlook in genetic and molecular landscape

Prostate cancer (PCa) incidence, morbidity, and mortality rates are significantly impacted by racial disparities. Despite innovative therapeutic approaches and advancements in prevention, men of African American (AA) ancestry are at a higher risk of developing PCa and have a more aggressive and metastatic form of the disease at the time of initial PCa diagnosis than other races. Research on PCa has underlined the biological and molecular basis of racial disparity and emphasized the genetic aspect as the fundamental component of racial inequality. Furthermore, the lower enrollment rate, limited access to national-level cancer facilities, and deferred treatment of AA men and other minorities are hurdles in improving the outcomes of PCa patients. This review provides the most up-to-date information on various biological and molecular contributing factors, such as the single nucleotide polymorphisms (SNPs), mutational spectrum, altered chromosomal loci, differential gene expression, transcriptome analysis, epigenetic factors, tumor microenvironment (TME), and immune modulation of PCa racial disparities. This review also highlights future research avenues to explore the underlying biological factors contributing to PCa disparities, particularly in men of African ancestry.

Library Screening and Preliminary Characterization of Synthetic Cannabinoids Against Prostate and Pancreatic Cancer Cell Lines

Background: Our previous screening efforts with colorectal cancer cell lines suggested potential cannabinoid therapeutic leads for other solid cancers. Objectives: The aim of this study was to identify cannabinoid lead compounds that have cytostatic and cytocidal activities against prostate and pancreatic cancer cell lines and profile cellular responses and molecular pathways of select leads. Materials and Methods: A library of 369 synthetic cannabinoids was screened against 4 prostate and 2 pancreatic cancer cell lines with 48 h of exposure at 10 μM in medium with 10% fetal bovine serum using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) viability assay. Concentration titration of the top 6 hits was carried out to identify their concentration-response patterns and calculate IC50 values. Three select leads were examined for cell cycle, apoptosis, and autophagy responses. The role of cannabinoid receptors (CB1 and CB2) and noncanonical receptors in apoptosis signaling was examined with selective antagonists. Results: Two independent screening experiments in each cell line detected growth inhibitory activities against all six or a majority of cancer cell lines for HU-331 (a known cannabinoid topoisomerase II inhibitor), (±)5-epi-CP55,940, and PTI-2, each previously identified in our colorectal cancer study. 5-Fluoro NPB-22, FUB-NPB-22, and LY2183240 were novel hits. Morphologically and biochemically, (±)5-epi-CP55,940 elicited caspase-mediated apoptosis of PC-3-luc2 (a PC-3 subline with luciferase) prostate cancer and Panc-1 pancreatic cancer cell lines, each the most aggressive of the respective organ site. The apoptosis induced by (±)5-epi-CP55,940 was abolished by the CB2 antagonist, SR144528, but not modulated by the CB1 antagonist, rimonabant, and GPR55 antagonist, ML-193, nor TRPV1 antagonist, SB-705498. In contrast, 5-fluoro NPB-22 and FUB-NPB-22 did not cause substantial apoptosis in either cell line, but resulted in cytosolic vacuoles and increased LC3-II formation (suggestive of autophagy) and S and G2/M cell cycle arrests. Combining each fluoro compound with an autophagy inhibitor, hydroxychloroquine, enhanced the apoptosis. Conclusions: 5-Fluoro NPB-22, FUB-NPB-22, and LY2183240 represent new leads against prostate and pancreatic cancer cells in addition to the previously reported compounds, HU-331, (±)5-epi-CP55,940, and PTI-2. Mechanistically, the two fluoro compounds and (±)5-epi-CP55,940 differed regarding their structures, CB receptor involvement, and death/fate responses and signaling. Safety and antitumor efficacy studies in animal models are warranted to guide further R&D.

Racial disparity in the utilization of immunotherapy for advanced prostate cancer

PURPOSE

To identify whether there was a disparity in the utilization of immunotherapy in the treatment of black patients with metastatic castration resistant prostate cancer (mCRPC).

METHODS

Using the National Cancer Database, we identified patients between 2010- 2015 with likely minimally/asymptomatic mCRPC. We analyzed annual trends for chemotherapy and immunotherapy use and compared utilization by demographic and clinical features. Multivariable analysis was performed to determine predictors of receiving immunotherapy vs chemotherapy.

RESULTS

We identified 1301 patients with likely mCRPC. The majority were non Hispanic White (NHW - 63 %) and 23 % were non-Hispanic Black (NHB). Overall, there was increased utilization of immunotherapy in mCRPC from 2010 onwards, with the peak occurring in 2014 (4.6 %). Chemotherapy use increased significantly, peaking in 2014 to 26.1 %. However, the increased utilization of immunotherapy in the mCRPC was mainly seen in White patients: from 50 % to 74.2 % of the cohort. Conversely, there was a decrease in utilization of immunotherapy among Black mCPRC patients: from 50 % to 25.8 %. On multivariable analysis, there was no statistically significant difference between treatment types by race.

CONCLUSION

FDA approval of Sipuleucel-T for mCRPC led to increased utilization of immunotherapy shortly thereafter, but this was mainly noted in white patients. Black patients comparatively did not exhibit increased utilization of this novel agent after 2010. Further studies are necessary to help understand barriers to access to new treatment in mCRPC and eliminate the burden of disease in minority populations."

Cancer Cell Membrane Nanodiscs for Antitumor Vaccination

Cell membrane-based nanovaccines have demonstrated attractive features due to their inherently multiantigenic nature and ability to be formulated with adjuvants. Here, we report on cellular nanodiscs fabricated from cancer cell membranes and incorporated with a lipid-based adjuvant for antitumor vaccination. The cellular nanodiscs, with their small size and discoidal shape, are readily taken up by antigen-presenting cells and drain efficiently to the lymph nodes. Due to its highly immunostimulatory properties, the nanodisc vaccine effectively stimulates the immune system and promotes tumor-specific immunity. Using a murine colorectal cancer model, strong control of tumor growth is achieved in both prophylactic and therapeutic settings, particularly in combination with checkpoint blockades. Considerable therapeutic efficacy is also observed in treating a weakly immunogenic metastatic melanoma model. This work presents a new paradigm for the design of multiantigenic nanovaccines that can effectively activate antitumor immune responses and may be applicable to a wide range of cancers.

An inverse probability weighted regression method that accounts for right-censoring for causal inference with multiple treatments and a binary outcome

Comparative effectiveness research often involves evaluating the differences in the risks of an event of interest between two or more treatments using observational data. Often, the post-treatment outcome of interest is whether the event happens within a pre-specified time window, which leads to a binary outcome. One source of bias for estimating the causal treatment effect is the presence of confounders, which are usually controlled using propensity score-based methods. An additional source of bias is right-censoring, which occurs when the information on the outcome of interest is not completely available due to dropout, study termination, or treatment switch before the event of interest. We propose an inverse probability weighted regression-based estimator that can simultaneously handle both confounding and right-censoring, calling the method CIPWR, with the letter C highlighting the censoring component. CIPWR estimates the average treatment effects by averaging the predicted outcomes obtained from a logistic regression model that is fitted using a weighted score function. The CIPWR estimator has a double robustness property such that estimation consistency can be achieved when either the model for the outcome or the models for both treatment and censoring are correctly specified. We establish the asymptotic properties of the CIPWR estimator for conducting inference, and compare its finite sample performance with that of several alternatives through simulation studies. The methods under comparison are applied to a cohort of prostate cancer patients from an insurance claims database for comparing the adverse effects of four candidate drugs for advanced stage prostate cancer.

Vertical integration of oncologists and cancer outcomes and costs in metastatic castration-resistant prostate cancer

BACKGROUND

The share of oncology practices owned by hospitals (ie, vertically integrated) nearly doubled from 2007 to 2017. We examined how integration between hospitals and oncologists affected care quality, outcomes, and spending among metastatic castration-resistant prostate cancer (mCRPC) patients.

METHODS

Using Surveillance, Epidemiology, and End Results-Medicare linked data and the Medicare Data on Provider Practice and Specialty, we identified Medicare beneficiaries who initiated systemic therapy for mCRPC between 2008 and 2017 (n = 9172). Primary outcomes included 1) bone-modifying agents (BMA) use, 2) time on systemic therapy, 3) survival, and 4) Medicare spending for the first 3 months following therapy initiation. We used a differences-in-differences approach to estimate the impact of vertical integration on outcomes, adjusting for patient and provider characteristics.

RESULTS

The proportion of patients treated by integrated oncologists increased from 28% to 55% from 2008 to 2017. Vertical integration was associated with an 11.7 percentage point (95% confidence interval [CI] = 4.2 to 19.1) increased likelihood of BMA use. There were no satistically significant changes in time on systemic therapy, survival, or total per-patient Medicare spending. Further decomposition showed an increase in outpatient payment ($5190, 95% CI = $1451 to $8930) and decrease in professional service payment (-$4757, 95% CI = -$7644 to -$1870) but no statistically significant changes for other service types (eg, inpatient and prescription drugs).

CONCLUSIONS

Vertical integration was associated with statistically significant increased BMA use but not with other cancer outcomes among mCRPC patients. For oncologists who switched service billing from physician offices to outpatient departments, there was no statistically significant change in overall Medicare spending in the first 3 months of therapy initiation. Future studies should extend the investigation to other cancer types and patient outcomes.

Immunotherapy for Prostate Cancer: A Current Systematic Review and Patient Centric Perspectives

Prostate cancer is the most commonly diagnosed cancer in men worldwide, making up 21% of all cancer cases. With 345,000 deaths per year owing to the disease, there is an urgent need to optimize prostate cancer care. This systematic review collated and synthesized findings of completed Phase III clinical trials administering immunotherapy; a current clinical trial index (2022) of all ongoing Phase I-III clinical trial records was also formulated. A total of four Phase III clinical trials with 3588 participants were included administering DCVAC, ipilimumab, personalized peptide vaccine, and the PROSTVAC vaccine. In this original research article, promising results were seen for ipilimumab intervention, with improved overall survival trends. A total of 68 ongoing trial records pooling in 7923 participants were included, spanning completion until June 2028. Immunotherapy is an emerging option for patients with prostate cancer, with immune checkpoint inhibitors and adjuvant therapies forming a large part of the emerging landscape. With various ongoing trials, the characteristics and premises of the prospective findings will be key in improving outcomes in the future.

Advances in cancer vaccines for immunotherapy of prostate cancer

Prostate cancer is currently one of the most common malignancies that endanger the lives and health of elderly men. In recent years, immunotherapy, which exploits the activation of anti-cancer host immune cells to accomplish tumor-killing effects, has emerged as a new study avenue in the treatment of prostate cancer. As an important component of immunotherapy, cancer vaccines have a unique position in the precision treatment of malignant tumors. Monocyte cell vaccines, dendritic cell vaccines, viral vaccines, peptide vaccines, and DNA/mRNA vaccines are the most often used prostate cancer vaccines. Among them, Sipuleucel-T, as a monocyte cell-based cancer vaccine, is the only FDA-approved therapeutic vaccine for prostate cancer, and has a unique position and role in advancing the development of immunotherapy for prostate cancer. However, due to its own limitations, Sipuleucel-T has not been widely adopted. Meanwhile, owing to the complexity of immunotherapy and the specificity of prostate cancer, the remaining prostate cancer vaccines have not shown good clinical benefit in large randomized phase II and phase III trials, and further in-depth studies are still needed.

AR and PI3K/AKT in Prostate Cancer: A Tale of Two Interconnected Pathways

Prostate cancer (PCa) is the most common cancer in men. The androgen receptor (AR) has a pivotal role in the pathogenesis and progression of PCa. Many therapies targeting AR signaling have been developed over the years. AR signaling inhibitors (ARSIs), including androgen synthesis inhibitors and AR antagonists, have proven to be effective in castration-sensitive PCa (CSPC) and improve survival, but men with castration-resistant PCa (CRPC) continue to have a poor prognosis. Despite a good initial response, drug resistance develops in almost all patients with metastatic CRPC, and ARSIs are no longer effective. Several mechanisms confer resistance to ARSI and include AR mutations but also hyperactivation of other pathways, such as PI3K/AKT/mTOR. This pathway controls key cellular processes, including proliferation and tumor progression, and it is the most frequently deregulated pathway in human cancers. A significant interaction between AR and the PI3K/AKT/mTOR signaling pathway has been shown in PCa. This review centers on the current scene of different AR and PI3K signaling pathway inhibitors, either as monotherapy or in combination treatments in PCa, and the treatment outcomes involved in both preclinical and clinical trials. A PubMed-based literature search was conducted up to November 2022. The most relevant and recent articles were selected to provide essential information and current evidence on the crosstalk between AR and the PI3K signaling pathways. The ClinicalTrials.gov registry was used to report information about clinical studies and their results using the Advanced research tool, filtering for disease and target.

Seleno-aspirin compound AS-10 promotes histone acetylation ahead of suppressing androgen receptor transcription, G1 arrest, and apoptosis of prostate cancer cells

BACKGROUND

The novel selenium-aspirin compound AS-10 was recently reported by us with a cancer cell killing potency three orders of magnitude greater than aspirin in pancreatic cancer cell lines with caspase-mediated apoptosis and a reasonable selectivity against malignant cells. Although we also observed its cytocidal activity against PC-3 and DU145 androgen receptor (AR)-negative and P53-null/mutant aggressive human prostate cancer (PCa) cell lines in NCI-60 screen, the potential involvement and targeting of AR and P53 pathways that are intact in early-stage prostate carcinogenesis has not been examined, nor its primary molecular signaling after exposure.

METHODS

Human LNCaP PCa cells with functional AR and intact P53 were used to examine their cell cycle and cell fate responses to AS-10 exposure and upstream molecular signaling events including histone acetylation as a known aspirin effect. The AR-positive 22Rv1 human PCa cells were used to validate key findings.

RESULTS

In addition to confirming AS-10's superior cytocidal potency than aspirin against all four PCa cell lines, we report a rapid (within 5 min) promotion of histone acetylation several hours ahead of the suppression of AR and prostate-specific antigen (PSA, coded by KLK3 gene) in LNCaP and 22Rv1 cells. AS-10 decreased AR and KLK3 mRNA levels without impacting pre-existing AR protein degradation or nuclear translocation in LNCaP cells. Sustained exposure to AS-10 arrested cells predominantly in G1 , and induced caspase-mediated apoptosis without necrosis. The death induced by AS-10 in LNCaP cells was attenuated by nontranscriptional activation of P53 protein or Jun N-terminal Kinase cellular stress signaling and was mitigated modestly by glutathione-boosting antioxidant N-acetylcysteine. AS-10 synergized with histone deacetylase inhibitor SAHA to suppress AR/PSA abundance and kill LNCaP cells. RNA-seq confirmed AR suppression at the transcriptional level and suggested multiple oncogene, cyclin, and CDK/CKI transcriptional actions to contribute to the cellular consequences.

CONCLUSIONS

AS-10 promotes histone acetylation as its probable primary mechanism of action to induce PCa cell-cycle arrest and apoptosis, regardless of AR and P53 status. Nevertheless, the inhibition of AR signaling through mechanisms distinct from canonical AR antagonists may hold promise for combinatorial use with androgen deprivation therapy regimens or AR-axis targeting drugs.

Recent progress in cancer immunotherapy: Overview of current status and challenges

Cancer treatment is presently one of the most important challenges in medical science. Surgery, chemotherapy, radiotherapy, or combining these methods is used to eliminate the tumor. Hormone therapy, bone marrow transplantation, stem cell therapy as well as immunotherapy are other well-known therapeutic modalities. Immunotherapy, as the most important complementary method, uses the immune system for treating cancer followed by surgery, chemotherapy, and radiotherapy. This method is systematically used to prevent malignancies development mainly via potentiating antitumor immune cells activation and conversely compromising their exhaustion with the lowest negative effects on healthy cells. Active immunotherapy can be employed for cancer immunotherapy by directly using the ingredients of the immune system and activating immune responses. On the other hand, inactive immunotherapy is utilized by indirect induction and using immune cell-based products consisting of monoclonal antibodies. It has strongly been proved that combination therapy with immunotherapies and other therapeutic means, such as anti-angiogenic agents, could be a rational plan to treat cancer. Herein, we have focused on recent findings concerning the therapeutic merits of cancer therapy using immune checkpoint inhibitors (ICIs), adoptive cell transfer (ACT) and cancer vaccine alone or in combination with other approaches. Also, we offer a glimpse into the current challenges in this context.

Peptide Modification Diminishes HLA Class II-restricted CD4+ T Cell Recognition of Prostate Cancer Cells

Prostate cancer poses an ongoing problem in the western world accounting for significant morbidity and mortality in the male population. Current therapy options are effective in treating most prostate cancer patients, but a significant number of patients progress beyond a manageable disease. For these patients, immunotherapy has emerged as a real option in the treatment of the late-stage metastatic disease. Unfortunately, even the most successful immunotherapy strategies have only led to a four-month increase in survival. One issue responsible for the shortcomings in cancer immunotherapy is the inability to stimulate helper CD4⁺ T cells via the HLA class II pathway to generate a potent antitumor response. Obstacles to proper HLA class II stimulation in prostate cancer vaccine design include the lack of detectable class II proteins in prostate tumors and the absence of defined class II specific prostate tumor antigens. Here, for the first time, we show that the insertion of a lysosomal thiol reductase (GILT) into prostate cancer cells directly enhances HLA class II antigen processing and results in increased CD4⁺ T cell activation by prostate cancer cells. We also show that GILT insertion does not alter the expression of prostate-specific membrane antigen (PSMA), an important target in prostate cancer vaccine strategies. Our study suggests that GILT expression enhances the presentation of the immunodominant PSMA₄₅₉ epitope via the HLA class II pathway. Biochemical analysis showed that the PSMA₄₅₉ peptide was cysteinylated under a normal physiologic concentration of cystine, and this cysteinylated form of PSMA₄₅₉ inhibited T cell activation. Taken together, these results suggest that GILT has the potential to increase HLA class II Ag presentation and CD4⁺ T cell recognition of prostate cancer cells, and GILT-expressing prostate cancer cells could be used in designing cell therapy and/or vaccines against prostate cancer.

The Value of Phenotypic Precision Medicine in Prostate Cancer

Prostate cancer is the most common cancer among men and the second leading cause of cancer-related death. For patients who develop metastatic disease, tissue-based and circulating-tumor-based molecular and genomic biomarkers have emerged as a means of improving outcomes through the application of precision medicine. However, the benefit is limited to a minority of patients. An additional approach to further characterize the biology of advanced prostate cancer is through the use of phenotypic precision medicine, or the identification and targeting of phenotypic features of an individual patient's cancer. In this review article, we will discuss the background, potential clinical benefits, and limitations of genomic and phenotypic precision medicine in prostate cancer. We will also highlight how the emergence of image-based phenotypic medicine may lead to greater characterization of advanced prostate cancer disease burden and more individualized treatment approaches in patients.

F-18 Fluciclovine PET-CT Findings and Pseudoprogression on Immunotherapy

Immunotherapy plays a vital role in the treatment of several types of malignancies. While the molecular targets of immunotherapy differ, the desired goal is to increase the host immune response against neoplastic tissue. This upregulated immune state results in infiltration of the tumor with activated immune cells and may be misinterpreted as disease progression in anatomical and metabolic imaging studies, known as pseudoprogression. We present a case of pseudoprogression demonstrated on a fluoride-18 (F-18) fluciclovine positron emission tomography-computed tomography (PET-CT) scan of an 85-year-old male with metastatic castrate-resistant prostate cancer who underwent treatment with sipuleucel-T. An understanding of the pseudoprogression phenomenon and its manifestations is critical for both treating physicians and imaging specialists to facilitate decision-making regarding treatment.

A novel prognostic model predicting overall survival in patients with metastatic castration-resistant prostate cancer receiving standard chemotherapy: A multi-trial cohort analysis

PURPOSE

Generalizable, updated, and easy-to-use prognostic models for patients with metastatic castration-resistant prostate cancer (mCRPC) are lacking. We developed a nomogram predicting the overall survival (OS) of mCRPC patients receiving standard chemotherapy using data from five randomized clinical trials (RCTs).

METHODS

Patients enrolled in the control arm of five RCTs (ASCENT 2, VENICE, CELGENE/MAINSAIL, ENTHUSE 14, and ENTHUSE 33) were randomly split between training (n = 1636, 70%) and validation cohorts (n = 700, 30%). In the training cohort, Cox regression tested the prognostic significance of all available variables as a predictor of OS. Independent predictors of OS on multivariable analysis were used to construct a novel multivariable model (nomogram). The accuracy of this model was tested in the validation cohort using time-dependent area under the curve (tAUC) and calibration curves.

RESULTS

Most of the patients were aged 65-74 years (44.5%) and the median (interquartile range) follow-up time was 13.9 (8.9-20.2) months. At multivariable analysis, the following were independent predictors of OS in mCRPC patients: sites of metastasis (visceral vs. bone metastasis, hazard ratio [HR]: 1.24), prostate-specific antigen (HR: 1.00), aspartate transaminase (HR: 1.01), alkaline phosphatase (HR: 1.00), body mass index (HR: 0.97), and hemoglobin (≥13 g/dl vs. <11 g/dl, HR: 0.41; all p < 0.05). A nomogram based on these variables was developed and showed favorable discrimination (tAUC at 12 and 24 months: 73% and 72%, respectively) and calibration characteristics on external validation.

CONCLUSION

A new prognostic model to predict OS of patients with mCRPC undergoing first line chemotherapy was developed. This can help urologists/oncologists in counseling patients and might be useful to better stratify patients for future clinical trials.

Identification of prostate cancer subtypes based on immune signature scores in bulk and single-cell transcriptomes

Prostate cancer (PC) is heterogeneous in the tumor immune microenvironment (TIME). Subtyping of PC based on the TIME could provide new insights into intratumor heterogeneity and its correlates of clinical features. Based on the enrichment scores of 28 immune cell types in the TIME, we performed unsupervised clustering to identify immune-specific subtypes of PC. The clustering analysis was performed in ten different bulk tumor transcriptomic datasets and in a single-cell RNA-Seq (scRNA-seq) dataset, respectively. We identified two PC subtypes: PC immunity high (PC-ImH) and PC immunity low (PC-ImL), consistently in these datasets. Compared to PC-ImL, PC-ImH displayed stronger immune signatures, worse clinical outcomes, higher epithelial-mesenchymal transition (EMT) signature, tumor stemness, intratumor heterogeneity (ITH) and genomic instability, and lower incidence of TMPRSS2-ERG fusion. Tumor mutation burden (TMB) showed no significant difference between PC-ImH and PC-ImL, while copy number alteration (CNA) was more significant in PC-ImL than in PC-ImH. PC-ImH could be further divided into two subgroups, which had significantly different immune infiltration levels and clinical features. In conclusion, "hot" PCs have stronger anti-tumor immune response, while worse clinical outcomes versus "cold" PCs. CNA instead of TMB plays a crucial role in the regulation of TIME in PC. TMPRSS2-ERG fusion correlates with decreased anti-tumor immune response while better disease-free survival in PC. The identification of immune-specific subtypes has potential clinical implications for PC immunotherapy.

Immune mechanisms behind prostate cancer in men of African ancestry: A review

BACKGROUND

Men of African ancestry (AA) with prostate cancer suffer from worse outcomes. However, a recent analysis of patients treated with the dendritic cell vaccine sipuleucel-T for prostate cancer suggested that AA patients could have improved outcomes relative to whites.

METHODS

We conducted a focused literature review of Medline-indexed articles and clinical trials listed on clinicaltrials.gov.

RESULTS

We identify several studies pointing to enrichment of inflammatory cellular infiltrates and cytokine signaling among AA patients with prostate cancer. We outline potential genomic and transcriptomic alterations that may contribute to immunogenicity. Last, we investigate differences in host immunity and vaccine responsiveness that may be enhanced in AA patients.

CONCLUSIONS

AA patients with prostate cancer may be enriched for an immunogenic phenotype. Dedicated studies are needed to better understand the immune mechanisms that contribute to existing cancer disparities and test immune-based therapies in this population.

Harnessing the Immune System with Cancer Vaccines: From Prevention to Therapeutics

Prophylactic vaccination against infectious diseases is one of the most successful public health measures of our lifetime. More recently, therapeutic vaccination against established diseases such as cancer has proven to be more challenging. In the host, cancer cells evade immunologic regulation by multiple means, including altering the antigens expressed on their cell surface or recruiting inflammatory cells that repress immune surveillance. Nevertheless, recent clinical data suggest that two classes of antigens show efficacy for the development of anticancer vaccines: tumor-associated antigens and neoantigens. In addition, many different vaccines derived from antigens based on cellular, peptide/protein, and genomic components are in development to establish their efficacy in cancer therapy. Some vaccines have shown promising results, which may lead to favorable outcomes when combined with standard therapeutic approaches. This review provides an overview of the innate and adaptive immune systems, their interactions with cancer cells, and the development of various different vaccines for use in anticancer therapeutics.

Development of a Novel Immune Subtyping System Expanded with Immune Landscape and an 11-Gene Signature for Predicting Prostate Cancer Survival

Background

Nearly half of patients with prostate cancer will develop metastasis. Immunotherapy is currently a promising strategy for treating metastatic prostate cancer. This study aimed to construct an immune subtyping system and provide a more comprehensive understanding of tumor microenvironment.

Methods

Data were downloaded from TCGA database and cBioPortal database. Consensus clustering was used to identify immune subtypes. Immune features were scored by ESTIMATE and CIBERSORT. Efficacy of different subtypes in immunotherapy was predicted by TIDE tool. Immune landscape was delineated through “monocle.” Coexpressed gene modules were identified by weighted correlation network analysis. Univariate Cox regression analysis and LASSO analysis were applied to construct a prognostic model.

Results

Four immune subtypes (IS1 to IS4) were identified. Prognosis, mutation patterns, expression of immune genes, immune biomarkers, immunohistochemical biomarkers, and prediction efficacy of immunotherapy were significantly different among four immune subtypes. Five coexpressed gene modules were identified and an 11-gene prognostic model was constructed based on the modules.

Conclusions

The study developed a novel immune subtyping system and an 11-gene prognostic model of prostate cancer, which could guide personalized treatment and immunotherapy for patients with prostate cancer.

Outcomes in men with metastatic castration-resistant prostate cancer who received sipuleucel-T and no immediate subsequent therapy: experience at Dana Farber and in the PROCEED Registry

BACKGROUND

Sipuleucel-T has demonstrated survival benefit in phase 3 trials but is utilized in few men with metastatic castration-resistant prostate cancer (mCRPC) in part due to low rates of PSA and objective response. Given the requirement to develop immune-mediated antitumor activity as vaccine-based therapy, sipuleucel-T may have delayed clinical activity. We explored this in a cohort of men from PROCEED (NCT01306890), an FDA-requested outcomes registry, and in a separate institutional cohort of mCRPC patients treated with sipuleucel-T at Dana-Farber Cancer Institute (DFCI).

METHODS

Men with mCRPC who received 3 infusions of sipuleucel-T and did not initiate a new mCRPC directed therapy for ≥6 months after completion of sipuleucel-T were included. All patients had rising PSA before starting sipuleucel-T and available post-treatment PSA measurements. Clinical outcomes of interest included: PSA₅₀ response rate, time to subsequent mCRPC directed therapy, and overall survival (OS).

RESULTS

Of 1902 men with mCRPC treated in PROCEED and 255 patients treated consecutively with sipuleucel-T between 4/2010 and 4/2017 at DFCI, 171 and 28 patients were included, respectively. In the PROCEED sample, PSA₅₀ response was observed in 34 (19.9%) of patients at a median of 5.5 months (IQR: 3.9-9.5) since the last sipuleucel-T infusion; median time to subsequent mCRPC directed therapy was 10 months (95% CI: 9-11); and median OS was 49 months (95% CI: 43-NR). In the DFCI cohort, PSA₅₀ response was observed in 4 (14.3%) of patients at a median of 6.3 months (IQR: 4.7-7.0); median time to subsequent mCRPC directed therapy was 9 months (95% CI: 9-11); and median OS was 60 months (95% CI: 51-74).

CONCLUSIONS

In this analysis of mCRPC patients treated with sipuleucel-T who did not immediately initiate subsequent therapy using two datasets, delayed PSA response was observed in a subset of patients indicating delayed clinical activity.

Implementing Community-Based Prostate Cancer Education in Rural South Carolina: a Collaborative Approach Through a Statewide Cancer Alliance

The purpose of this study was to evaluate the impact of implementing community-based prostate health education programs in rural communities. Prostate cancer (PrCA) remains one of the most common cancers among men, and a growing body of literature demonstrates that large interracial differences in PrCA incidence and mortality rates consistently disfavor African Americans in comparison to European Americans. It also is evident, despite the overall decrease in cancer death rates in the USA in recent decades, rural areas are experiencing a reduction in death rates much more slowly. In this study, education session content focused on PrCA risk factors, symptoms, screening, healthy diet and exercise, treatment options, and provider communication strategies. Forty individuals participated and completed pre/post-education program surveys to assess changes in PrCA knowledge and cancer decision-making. Participants showed improvements in education and awareness following the session, and overall impressions of the program were consistently positive as exhibited by participants' answers on a satisfaction survey. The findings demonstrate the real need both in terms of research to understand the underlying problem and to provide practical solutions that can be implemented to reverse the current situation. The results obtained support community-based education programs as an effective means of delivering PrCA prevention, screening, and treatment information to rural communities.

Cancer immunotherapy in adult patients with HIV

The availability of antiretroviral therapy (ART) has increased the life expectancy of people with HIV (PWH) and reduced the incidence of AIDS-associated malignancies, yet PWH have a significantly increased incidence of malignancy and less favorable outcomes of cancer treatment compared with the general population.Immunotherapy has revolutionized cancer therapy, becoming the standard of care for various malignancy treatments. However, PWH are an underserved population with limited access to clinical trials and cancer treatment.This review of the available evidence on different classes of cancer immunotherapy in PWH is mostly based on case reports, case series, but few prospective studies and clinical trials due to the exclusion of PWH from most oncologic clinical trials. The results of the available evidence support the safety of immunotherapy in PWH. Immunotherapy has similar effectiveness in PWH, an acceptable toxicity profile, and has no clinically significant impact on HIV viral load and CD4-T cell count. In addition, there is no reported change in the incidence of opportunistic infections and other complications for PWH with well-controlled viremia.This review aims to briefly summarize the current state of immunotherapy in cancer, guide clinicians in the management of immunotherapy in cancer PWH, and encourage the inclusion of PWH in clinical trials of cancer immunotherapy.

Immunotherapy for Hepatocellular Carcinoma: Current Status and Future Prospects

Hepatocellular carcinoma (HCC) is the most prevalent primary liver cancer with poor prognosis. Surgery, chemotherapy, and radiofrequency ablation are three conventional therapeutic options that will help only a limited percentage of HCC patients. Cancer immunotherapy has achieved dramatic advances in recent years and provides new opportunities to treat HCC. However, HCC has various etiologies and can evade the immune system through multiple mechanisms. With the rapid development of genetic engineering and synthetic biology, a variety of novel immunotherapies have been employed to treat advanced HCC, including immune checkpoint inhibitors, adoptive cell therapy, engineered cytokines, and therapeutic cancer vaccines. In this review, we summarize the current landscape and research progress of different immunotherapy strategies in the treatment of HCC. The challenges and opportunities of this research field are also discussed.

Development and Verification of a Prostate Cancer Prognostic Signature Based on an Immunogenomic Landscape Analysis

Purpose

Prostate cancer (PCa) has a high incidence among older men. Until now, there are no immunological markers available to predict PCa patients’ survival. Therefore, it is necessary to explore the immunological characteristics of PCa.

Methods

First, we retrieved RNA-seq and clinical data of 499 PCa and 52 normal prostate tissue samples from the Cancer Genome Atlas (TCGA). We identified 193 differentially expressed immune-related genes (IRGs) between PCa and normal prostate tissues. Functional enrichment analyses showed that the immune system can participate in PCa initiation. Then, we constructed a correlation network between transcription factors (TFs) and IRGs. We performed univariate and multivariate Cox regression analyses and identified five key prognostic IRGs (S100A2, NOX1, IGHV7-81, AMH, and AGTR1). Finally, a predictive nomogram was established and verified by the C-index.

Results

We successfully constructed and validated an immune-related PCa prediction model. The signature could independently predict PCa patients’ survival. Results showed that high-immune-risk patients were correlated with advanced stage. We also validated the S100A2 expression in vitro using PCa and normal prostate tissues. We found that higher S100A2 expressions were related to lower biochemical recurrences. Additionally, higher AMH expressions were related to higher Gleason score, lymph node metastasis and positive rate, and tumor stages, and higher ATGR1 expressions were related to lower PSA value.

Conclusion

Overall, we detected five IRGs (S100A2, NOX1, IGHV7-81, AMH, and AGTR1) that can be used as independent PCa prognostic factors.

Factors influencing treatment of veterans with advanced prostate cancer

BACKGROUND

Treatments for metastatic castration-resistant prostate cancer (CRPC) differ in toxicity, administration, and evidence. In this study, clinical and nonclinical factors associated with the first-line treatment for CRPC in a national delivery system were evaluated.

METHODS

National electronic laboratory and clinical data from the Veterans Health Administration were used to identify patients with CRPC (ie, rising prostate-specific antigen [PSA] on androgen deprivation) who received abiraterone, enzalutamide, docetaxel, or ketoconazole from 2010 through 2017. It was determined whether clinical (eg, PSA) and nonclinical factors (eg, race, facility) were associated with the first-line treatment selection using multilevel, multinomial logistic regression. The average marginal effects (AMEs) were calculated of patient, disease, and facility characteristics on ketoconazole versus more appropriate CRPC therapy.

RESULTS

There were 4998 patients identified with CRPC who received first-line ketoconazole, docetaxel, abiraterone, or enzalutamide. After adjustment, increasing age was associated with receipt of abiraterone (adjusted odds ratio [aOR], 1.07; 95% credible interval [CrI], 1.06-1.09) or enzalutamide (aOR, 1.10; 95% CrI, 1.08-1.11) versus docetaxel. Greater preexisting comorbidity was associated with enzalutamide versus abiraterone (aOR, 1.53; 95% CrI, 1.23-1.91). Patients with higher PSA values at the start of treatment were more likely to receive docetaxel than oral agents and less likely to receive ketoconazole than other oral agents. African American men were more likely to receive ketoconazole than abiraterone, enzalutamide, or docetaxel (AME, 2.8%; 95% CI, 0.7%-4.9%). This effect was attenuated when adjusting for facility characteristics (AME, 1.9%; 95% CI, -0.4% to 4.1%).

CONCLUSIONS

Clinical factors had an expected effect on the first-line treatment selection. Race may be associated with the receipt of a guideline-discordant first-line treatment.

The value of new drugs for advanced prostate cancer

BACKGROUND

The US Food and Drug Administration has recently approved a number of new cancer drugs. The clinical trials that serve as the basis for new cancer drug approvals may not reflect how the drugs will perform in routine practice and do not measure the impact of the drugs on spending. The authors sought to evaluate the real-world effectiveness and value of drugs recently approved for advanced prostate cancer.

METHODS

Using Surveillance, Epidemiology, and End Results-Medicare data, the authors identified fee-for-service Medicare beneficiaries aged 65 years or older who began treatment with a drug approved for metastatic castration-resistant prostate cancer in 2007-2009, when only 1 drug was approved for metastatic castration-resistant prostate cancer, and in 2014-2016, when 5 additional drugs were approved. They calculated life expectancy and lifetime medical costs (ie, Medicare reimbursements) for each group.

RESULTS

Between 2007-2009 and 2014-2016, life expectancy increased by 12.6 months. Lifetime medical costs increased by $87,000. The incremental cost per life-year gained was $83,000.

CONCLUSION

The release of 5 new drugs coincided with increases in survival rates and spending. This study's estimates indicate that the new drugs collectively were cost-effective.

Changing the History of Prostate Cancer with New Targeted Therapies

The therapeutic landscape of metastatic castration-resistant prostate cancer (mCRPC) is changing due to the emergence of new targeted therapies for the treatment of different molecular subtypes. Some biomarkers are described as potential molecular targets different from classic androgen receptors (AR). Approximately 20–25% of mCRPCs have somatic or germline alterations in DNA repair genes involved in homologous recombination. These subtypes are usually associated with more aggressive disease. Inhibitors of the enzyme poly ADP ribose polymerase (PARPi) have demonstrated an important benefit in the treatment of these subtypes of tumors. However, tumors that resistant to PARPi and wildtype BRCA tumors do not benefit from these therapies. Recent studies are exploring drug combinations with phosphatidylinositol-3-kinase (PI3K) or protein kinase B (AKT) inhibitors, as mechanisms to overcome resistance or to induce BRCAness and synthetic lethality. This article reviews various different novel strategies to improve outcomes in patients with prostate cancer.

Identification of patients with metastatic castration-sensitive or metastatic castration-resistant prostate cancer using administrative health claims and laboratory data

OBJECTIVE

To develop algorithms to identify metastatic castration-sensitive prostate cancer (mCSPC) patients and castration-resistant prostate cancer (mCRPC) patients, using health claims data and laboratory test results.

METHODS

A targeted literature review summarized mCSPC and mCRPC patient selection criteria previously used in real-world retrospective studies. Novel algorithms to identify mCSPC and mCRPC were developed based on diagnosis codes indicating hormone sensitivity/resistance, prostate-specific antigen (PSA) test results, and claims for castration and mCRPC-specific treatments. These algorithms were applied to claims data from Optum Clinformatics Extended DataMart (Date of Death) Databases (commercial insurance/Medicare Advantage [COM/MA]; 01 January 2014-31 July 2019) and Medicare Fee-for-Service (Medicare-FFS; 01 January 2014-31 December 2017).

RESULTS

Previous real-world studies identified mCSPC primarily based on metastasis diagnosis codes, and mCRPC based on mCRPC-specific drugs. Using the current study's algorithms, 7034 COM/MA and 19,981 Medicare-FFS patients were identified as having mCSPC, and 2578 COM/MA and 11,554 Medicare-FFS as having mCRPC. Most mCSPC patients were identified based on evidence of being hormone/castration-naive. Patients were identified as having mCRPC most commonly based on rising PSA (COM/MA), or at the metastasis diagnosis date if it occurred after castration (Medicare-FFS). Among patients with mCSPC, 14-17% had evidence of progression to castration resistance during a median 1-year follow-up period, mostly based on use of mCRPC-specific drugs.

CONCLUSIONS

Comprehensive algorithms based on claims and laboratory data were developed to identify and distinguish patients with mCSPC and mCRPC. This will facilitate appropriate identification of mCSPC and mCRPC patients based on health claims data and better understanding of patient unmet needs in real-world settings.

A comparison of parametric propensity score-based methods for causal inference with multiple treatments and a binary outcome

We consider comparative effectiveness research (CER) from observational data with two or more treatments. In observational studies, the estimation of causal effects is prone to bias due to confounders related to both treatment and outcome. Methods based on propensity scores are routinely used to correct for such confounding biases. A large fraction of propensity score methods in the current literature consider the case of either two treatments or continuous outcome. There has been extensive literature with multiple treatment and binary outcome, but interest often lies in the intersection, for which the literature is still evolving. The contribution of this article is to focus on this intersection and compare across methods, some of which are fairly recent. We describe propensity-based methods when more than two treatments are being compared, and the outcome is binary. We assess the relative performance of these methods through a set of simulation studies. The methods are applied to assess the effect of four common therapies for castration-resistant advanced-stage prostate cancer. The data consist of medical and pharmacy claims from a large national private health insurance network, with the adverse outcome being admission to the emergency room within a short time window of treatment initiation.

Veridical Causal Inference using Propensity Score Methods for Comparative Effectiveness Research with Medical Claims

Medical insurance claims are becoming increasingly common data sources to answer a variety of questions in biomedical research. Although comprehensive in terms of longitudinal characterization of disease development and progression for a potentially large number of patients, population-based inference using these datasets require thoughtful modifications to sample selection and analytic strategies relative to other types of studies. Along with complex selection bias and missing data issues, claims-based studies are purely observational, which limits effective understanding and characterization of the treatment differences between groups being compared. All these issues contribute to a crisis in reproducibility and replication of comparative findings using medical claims. This paper offers practical guidance to the analytical process, demonstrates methods for estimating causal treatment effects with propensity score methods for several types of outcomes common to such studies, such as binary, count, time to event and longitudinally-varying measures, and also aims to increase transparency and reproducibility of reporting of results from these investigations. We provide an online version of the paper with readily implementable code for the entire analysis pipeline to serve as a guided tutorial for practitioners. The online version can be accessed at https://rydaro.github.io/. The analytic pipeline is illustrated using a sub-cohort of patients with advanced prostate cancer from the large Clinformatics TM Data Mart Database (OptumInsight, Eden Prairie, Minnesota), consisting of 73 million distinct private payer insurees from 2001-2016.

Treatment Combinations with DNA Vaccines for the Treatment of Metastatic Castration-Resistant Prostate Cancer (mCRPC)

Simple Summary

The only vaccine approved by FDA as a treatment for cancer is sipuleucel-T, a therapy for patients with metastatic castration-resistant prostate cancer (mCRPC). Most investigators studying anti-tumor vaccines believe they will be most effective as parts of combination therapies, rather than used alone. Unfortunately, the cost and complexity of sipuleucel-T makes it difficult to feasibly be used in combination with many other agents. In this review article we discuss the use of DNA vaccines as a simpler vaccine approach that has demonstrated efficacy in several animal species. We discuss the use of DNA vaccines in combination with traditional treatments for mCRPC, and other immune-modulating treatments, in preclinical and early clinical trials for patients with mCRPC.

Abstract

Metastatic castration-resistant prostate cancer (mCRPC) is a challenging disease to treat, with poor outcomes for patients. One antitumor vaccine, sipuleucel-T, has been approved as a treatment for mCRPC. DNA vaccines are another form of immunotherapy under investigation. DNA immunizations elicit antigen-specific T cells that cause tumor cell lysis, which should translate to meaningful clinical responses. They are easily amenable to design alterations, scalable for large-scale manufacturing, and thermo-stable for easy transport and distribution. Hence, they offer advantages over other vaccine formulations. However, clinical trials with DNA vaccines as a monotherapy have shown only modest clinical effects against tumors. Standard therapies for CRPC including androgen-targeted therapies, radiation therapy and chemotherapy all have immunomodulatory effects, which combined with immunotherapies such as DNA vaccines, could potentially improve treatment. In addition, many investigational drugs are being developed which can augment antitumor immunity, and together with DNA vaccines can further enhance antitumor responses in preclinical models. We reviewed the literature available prior to July 2020 exploring the use of DNA vaccines in the treatment of prostate cancer. We also examined various approved and experimental therapies that could be combined with DNA vaccines to potentially improve their antitumor efficacy as treatments for mCRPC.

Is There a Role for Immunotherapy in Prostate Cancer?

In the last decade, immunotherapy has revolutionized the treatment landscape of several hematological and solid malignancies, reporting unprecedented response rates. Unfortunately, this is not the case for metastatic castration-resistant prostate cancer (mCRPC), as several phase I and II trials assessing programmed death receptor 1 (PD-1) and cytotoxic T-lymphocyte antigen-4 (CTLA-4) inhibitors have shown limited benefits. Moreover, despite sipuleucel-T representing the only cancer vaccine approved by the Food and Drug Administration (FDA) for mCRPC following the results of the IMPACT trial, the use of this agent is relatively limited in everyday clinical practice. The identification of specific histological and molecular biomarkers that could predict response to immunotherapy represents one of the current challenges, with an aim to detect subgroups of mCRPC patients who may benefit from immune checkpoint monoclonal antibodies as monotherapy or in combination with other anticancer agents. Several unanswered questions remain, including the following: is there-or will there ever be-a role for immunotherapy in prostate cancer? In this review, we aim at underlining the failures and promises of immunotherapy in prostate cancer, summarizing the current state of art regarding cancer vaccines and immune checkpoint monoclonal antibodies, and discussing future research directions in this immunologically "cold" malignancy.

Cancer immunotherapy: dawn of the death of cancer?

Cancer is one of the proficient evaders of the immune system which claims millions of lives every year. Developing therapeutics against cancer is extremely challenging as cancer involves aberrations in self, most of which are not detected by the immune system. Conventional therapeutics like chemotherapy, radiotherapy are not only toxic but they significantly lower the quality of life. Immunotherapy, which gained momentum in the 20th century, is emerging as one of the alternatives to the conventional therapies and is relatively less harmful but more costly. This review explores the modern advances in an array of such therapies and try to compare them along with a limited analysis of concerns associated with them.

Pharmacotherapeutic strategies for castrate-resistant prostate cancer

INTRODUCTION

Metastatic castration-resistant prostate cancer (CRPC) is a potentially symptomatic disease with an eventual lethal outcome. Novel pharmaceutical agents are continuously studied with encouraging results in CRPC.

AREAS COVERED

In this perspective, the authors present established and promising pharmacotherapeutic strategies for the management of CRPC; both with and without metastases. Apart from the different treatment strategies, the authors present the relevant sequence of treatment through disease progression.

EXPERT OPINION

Usually, docetaxel should be considered the first line treatment in mCRPC. Abiraterone acetate (AA) plus prednisone or enzalutamide (ENZ) could be alternative treatments in chemotherapy naïve patients. Sipuleucel-T has been approved for the treatment of asymptomatic or minimally symptomatic mCRPC. Ra-223 has been approved for patients with mCRPC with symptomatic bone metastases (not visceral metastases). Cabazitaxel has been approved as the second line treatment to docetaxel in mCRPC. No differences in the overall survival has been observed between sequences starting with docetaxel versus AA/ENZ. Between AA-to-ENZ and ENZ-to-AA sequence, the AA-to-ENZ sequence appeared to be more favorable than the ENZ-to-AA regarding progression-free survival but not overall survival. Carbazitaxel seemed to retain its activity regardless of the treatment sequence. Of note, ENZ and apalutamide have been approved in non-metastatic CRPC.

Geographic disparities in access to glioblastoma treatment based on Hispanic ethnicity in the United States: Insights from a national database

BACKGROUND

Access to treatment for glioblastoma (GBM) can be impacted by multiple demographic parameters. Barriers specific to the Hispanic population of the United States (US) are not fully understood. Therefore, the aim of this study was to elucidate geographic disparities for access to GBM treatment in the US Hispanic population.

METHODS

All GBM patients with known Hispanic ethnicity status (and Caucasian race) in the US National Cancer Database (NCDB) between the years 2005-2016 were retrospectively reviewed. Treatment statuses of surgical resection, chemotherapy, radiation therapy and triple therapy (resection, chemotherapy and radiation) were summarized, and analyzed by comparison and regression analyses over US Census regions.

RESULTS

A total cohort size of 40,232 Caucasian GBM patients were included, with 3,111 (8%) identifying as Hispanic. The odds of treatment by chemotherapy (OR 0.78, P < 0.01), radiation therapy (OR 0.82, P < 0.01) and triple therapy (OR 0.84, P < 0.01) were all significantly lower in the Hispanic group versus non-Hispanic group. The odds of being treated in the Hispanic group were significantly lower in multiple Census regions with respect to surgical resection (New England, OR 0.51; Mountain, OR 0.68), chemotherapy (East North Central, OR 0.77; Middle Atlantic, OR 0.71; Pacific, OR 0.77), radiation therapy (Middle Atlantic, OR 0.77) and triple therapy (New England, OR 0.49; Middle Atlantic, OR 0.87; Pacific, OR 0.84). Significant barriers to triple therapy in the Hispanic group within these regions were older age (OR 0.97; P < 0.01), treatment in a community facility (OR 0.85, P = 0.03), lack of insurance (OR 0.71, P = 0.03), yearly income < $40,227 (OR 0.69, P < 0.01), low education levels (OR 0.75, P = 0.03) and presence of co-morbidity (OR 0.82; P < 0.01).

CONCLUSIONS

Currently in the US, there exists heterogenous geographic disparities for Hispanic GBM patients to access different treatments compared to non-Hispanic patients. Multiple circumstances can influence access to treatment within the Hispanic community of these regions, and greater investigation with more granularity required to reveal mechanisms in which these disparities may be addressed in the future.

CHALLENGES IN MANIPULATING IMMUNE SYSTEM TO TREAT PROSTATE CANCER

First cancer vaccine that was approved for routine therapy was sipuleucel-T for treatment of patients with metastatic castration resistant prostate cancer. However, other immunotherapy drugs evaluated in prostate cancer, particularly immune checkpoint inhibitors, have failed to show therapeutic effect. There are several potential explanations for lack of response of prostate cancer to these drugs. These explanations, which are related to specific genetic (e.g. low mutational burden) and immunological (e.g. immunosuppressive tumor immune microenvironment) background of prostate cancer are discussed in this review. Also, new therapeutic strategies to overcome prostate cancer immunotherapy resistance and to select subgroups of patients that could benefit from immunotherapy are outlined.

Investigating the Multi-Target Pharmacological Mechanism of Hedyotis diffusa Willd Acting on Prostate Cancer: A Network Pharmacology Approach

Hedyotis diffusa Willd (HDW) is one of the most well-known herbs used in the treatment of prostate cancer. However, the potential mechanisms of its anti-tumor effects have not been fully explored. Here, we applied a network pharmacology approach to explore the potential mechanisms of HDW against prostate cancer (PCa). We obtained 14 active compounds from HDW and 295 potential PCa related targets in total to construct a network, which indicated that quercetin and ursolic acid served as the main ingredients in HDW. Mitogen-activated Protein Kinase 8 (MAPK8), Interleukin 6 (IL6), Vascular Endothelial Growth Factor A (VEGFA), Signal Transducer and Activator of Transcription 3 (STAT3), Jun Proto-Oncogene (JUN), C-X-C Motif Chemokine Ligand 8 (CXCL8), Interleukin-1 Beta (IL1B), Matrix Metalloproteinase-9 (MMP9), C-C Motif Chemokine Ligand 2 (CCL2), RELA Proto-Oncogene (RELA), and CAMP Responsive Element Binding Protein 1 (CREB1) were identified as key targets of HDW in the treatment of PCa. The protein-protein interaction (PPI) cluster demonstrated that CREB1 was the seed in this cluster, indicating that CREB1 plays an important role in connecting other nodes in the PPI network. This enrichment demonstrated that HDW was highly related to translesion synthesis, unfolded protein binding, regulation of mitotic recombination, phosphatidylinositol and its kinase-mediated signaling, nucleotide excision repair, regulation of DNA recombination, and DNA topological change. The enrichment results also showed that the underlying mechanism of HDW against PCa may be due to its coordinated regulation of several cancer-related pathways, such as angiogenesis, cell differentiation, migration, apoptosis, invasion, and proliferation.

Immunotherapy in Metastatic Castration-Resistant Prostate Cancer: Past and Future Strategies for Optimization

PURPOSE OF REVIEW

To date, prostate cancer has been poorly responsive to immunotherapy. In the current review, we summarize and discuss the current literature on the use of vaccine therapy and checkpoint inhibitor immunotherapy in metastatic castration-resistant prostate cancer (mCRPC).

RECENT FINDINGS

Sipuleucel-T currently remains the only FDA-approved immunotherapeutic agent for prostate cancer. Single-agent phase 3 vaccine trials with GVAX and PROSTVAC have failed to demonstrate survival benefit to date. Clinical trials using combination approaches, including combination PROSTVAC along with a neoantigen vaccine and checkpoint inhibitor immunotherapy, are ongoing. Checkpoint inhibitor monotherapy clinical trials have demonstrated limited efficacy in advanced prostate cancer, and combination approaches and molecular patient selection are currently under investigation. The optimal use of vaccine therapy and checkpoint inhibitor immunotherapy in metastatic castration-resistant prostate cancer remains to be determined. Ongoing clinical trials will continue to inform future clinical practice.

Adoption of Abiraterone and Enzalutamide by Urologists

OBJECTIVE

To investigate the adoption of abiraterone and enzalutamide by urologists. Abiraterone and enzalutamide are oral therapies approved for the treatment of metastatic castration-resistant prostate cancer, a disease most commonly treated by medical oncologists.

METHODS

Using the Medicare Part D Public Use Files from 2013 to 2016, we identified total abiraterone and enzalutamide prescriptions 2013-2016 and urologists who prescribed moderate to high volumes of these drugs. We then characterized the urologist practices of those urologists according to practice context (eg, single-specialty group) using data from the Centers for Medicare and Medicaid Services, and the geographic distribution of those providers.

RESULTS

We found abiraterone prescriptions increased from 71,423 in 2013 to a peak of 100,371 in 2015 and enzalutamide prescriptions continued to increase from 29,572 in 2013 to 100,980 in 2016. Prescriptions by urologists increased between 2013 and 2016 while prescriptions by other specialties plateaued. The number of moderate-high prescribing urologists increased from 98 (abiraterone) and 22 (enzalutamide) in 2013, to 301 (abiraterone) and 671 (enzalutamide) by 2016 with 1063 unique urologists prescribing moderate-high volumes of either drug between 2013 and 2016. Among urologists who prescribe androgen deprivation therapy, 5% were moderate-high prescribers of abiraterone and 12% of enzalutamide in 2016. The majority of moderate-high prescribing urologists were in single-specialty groups (70%).

CONCLUSION

Urologists are increasingly prescribing oral therapies for metastatic castration-resistant prostate cancer. Understanding the distribution of urologists specializing in castration-resistant prostate cancer therapeutics will help guide future interventions to optimize the care for this important patient population.

Adverse Events Associated With the Use of Sipuleucel-T Reported to the US Food and Drug Administration's Adverse Event Reporting System, 2010-2017

IMPORTANCE

Sipuleucel-T was the first therapeutic cancer vaccine approved by the US Food and Drug Administration (FDA) in 2010. Although almost a decade has passed since its approval for the treatment of asymptomatic or minimally symptomatic castration-resistant prostate cancer (CRPC), there remains a paucity of literature describing safety data in the postmarketing period.

OBJECTIVE

To describe the postmarketing safety experience for sipuleucel-T.

DESIGN, SETTING, AND PARTICIPANTS

In this case series study, US reports for sipuleucel-T submitted to the FDA's Adverse Event Reporting System were searched and reviewed between April 29, 2010, and December 31, 2017. This system is a spontaneous safety surveillance database for drug and therapeutic biologic products. The analysis of 3216 reports and select case reviews were undertaken between February and November 2018.

MAIN OUTCOMES AND MEASURES

Descriptive statistics were used to assess adverse event reports for sipuleucel-T. Empirical Bayes Geometric Means (EBGM) and their 90% confidence intervals (CIs) were computed to identify disproportionate (ie, at least twice the expected) reporting of sipuleucel-T-event pairs. Selected adverse events and death reports were individually reviewed.

RESULTS

In total, 3216 reports were identified for sipuleucel-T, of which 2014 (62.6%) were serious. For all included reports, the patients' median (interquartile range) age was 73 (67-79) years, and 3149 were specified to be males. Chills (n = 318), malaise (n = 196), pyrexia (n = 189), culture positive (n = 184), fatigue (n = 180), and nausea (n = 173) were among the most commonly reported adverse events. Infusion-related reactions (EBGM, 12.1; 90% CI, 9.4-15.3), infections, vascular events, and transient ischemic attacks (EBGM, 2.9; 90% CI, 2.2-3.9) were reported disproportionately. Among 249 deaths for which relevant dates were available, 128 (51.4%) were reported within 30 days of a sipuleucel-T infusion, of which 81.2% included a specified cause of death; of these 104 deaths, there were 37 neoplasms (35.6%), 25 cardiac disorders (24.0%), 18 nervous system disorders (17.3%), and 9 infections (8.7%).

CONCLUSIONS AND RELEVANCE

Reported adverse events were generally consistent with the safety experience observed in prelicensure studies and described in the sipuleucel-T package insert. Off-label use among overtly symptomatic men with CRPC, reporting bias, or lack of product effectiveness may have influenced the reporting of deaths within 30 days of treatment initiation. With this overview of sipuleucel-T experience, the present study serves as a resource for health care professionals and patients as they weigh the risks and benefits of treatment in the context of all available therapeutic options for CRPC.