Randomized, Double-Blind, Placebo-Controlled Phase III Study of Tasquinimod in Men With Metastatic Castration-Resistant Prostate Cancer

Efficacy of tasquinimod in men with metastatic castration-resistant prostate cancer: A meta-analysis of randomized controlled trials

BACKGROUND

Tasquinimod is an oral quinoline-3-carboxamide derivative for the treatment of metastatic castration-resistant prostate cancer (mCRPC). Tasquinimod has antiangiogenic, immunomodulatory, and antimetastatic properties, but it is also associated with toxicities, including skeletal pain, digestive disorders, fatigue, insomnia, and mental disorders. We aimed to perform a meta-analysis to evaluate the efficacy, safety, and long-term survival for tasquinimod in patients with mCRPC.

METHODS

Searches were carried out in PubMed, Embase, and the Cochrane Library. Eligible articles included randomized clinical trials (RCTs) comparing systemic or combination therapy (excluding primary or secondary androgen deprivation therapy, bone protective agents, or radionuclides) with placebo in men with mCRPC.

RESULTS

Three RCTs were selected for final evaluation. The pooled results from the 3 studies indicated that tasquinimod was associated with good radiologic progression-free survival (rPFS) in mCRPC. For adverse effects (AEs), the results of meta-analysis indicated that patients with mCRPC who received tasquinimod had obvious anemia (risk ratio (RR) 1.35, 95% confidence interval (CI) 1.06-1.73, P = .02), back pain (RR: 1.57, 95% CI: 1.01-2.47, P = .05), pain in the extremities (RR: 1.90, 95% CI: 1.14-3.17, P = .01), insomnia (RR: 1.50, 95% CI: 1.03-2.17, P = .03), vomiting (RR: 1.52, 95% CI: 1.04-2.21, P = .03), and peripheral edema (RR: 1.52, 95% CI: 1.03-2.23, P = .03).

CONCLUSIONS

Tasquinimod is associated with better rPFS in mCRPC. The toxicity of tasquinimod requires further investigation, it is not recommended for routine clinical use.

Consensus on management of castration-resistant prostate cancer on behalf of the Urological Tumours Working Group (URONCOR) of the Spanish Society of Radiation Oncology

BACKGROUND

The knowledge in the field of castration-resistant prostate cancer (CRPC) is developing rapidly, with emerging new therapies and advances in imaging. Nonetheless, in multiple areas there is still a lack of or very limited evidence, and clear guidance from clinicians regarding optimal strategy is required.

METHODS

A modified Delphi method, with 116 relevant questions divided into 7 different CRPC management topics, was used to develop a consensus statement by the URONCOR group.

RESULTS

A strong consensus or unanimity was reached on 93% of the proposed questions. The seven topics addressed were: CRPC definition, symptomatic patients, diagnosis of metastasis, CRPC progression, M0 management, M1 management and sequencing therapy, and treatment monitoring.

CONCLUSIONS

The recommendations based on the radiation oncology experts' opinions are intended to provide cancer specialists with expert guidance and to standardise CRPC patient management in Spain, facilitating decision-making in different clinically relevant issues regarding CRPC patients.

Systematic Review and Network Meta-Analysis of Treatments for Chemotherapy-Naive Patients with Asymptomatic/Mildly Symptomatic Metastatic Castration-Resistant Prostate Cancer

OBJECTIVES

To estimate the relative effectiveness of enzalutamide in chemotherapy-naive metastatic castration-resistant prostate cancer by conducting a systematic literature review and a network meta-analysis (NMA).

METHODS

A systematic literature review identified randomized controlled trials comparing enzalutamide, abiraterone/prednisone, radium-223, sipuleucel-T, or docetaxel with each other or placebo in chemotherapy-naive or mixed populations (with and without prior chemotherapy) with asymptomatic/mildly symptomatic metastatic castration-resistant prostate cancer. Feasibility assessment evaluated the trials' suitability for NMA inclusion. The main outcomes were hazard ratios (HRs) for overall survival (OS) and radiographic progression-free survival (rPFS).

RESULTS

Searches of relevant bibliographic databases, trial registers, Web sites, and conference abstracts conducted in October 2014 identified 25,712 records. Ten randomized controlled trials were eligible for the NMA. Enzalutamide was superior to placebo for OS and rPFS (fixed-effects model). NMA results (fixed-effects model) showed no evidence of a difference between enzalutamide and abiraterone/prednisone (HR 0.95 [95% CrI 0.77-1.16]), sipuleucel-T (HR 1.07 [95% CrI 0.84-1.37]), or radium-223 (HR 1.10 [95% CrI 0.87-1.37]) for OS. HRs were similar for the random-effects model. Nevertheless, results (fixed-effects model) suggested that enzalutamide was superior to abiraterone/prednisone (HR 0.59 [95% CrI 0.48-0.72]) and sipuleucel-T (HR 0.32 [95% CrI 0.25-0.42]) for rPFS. Results also suggested superiority of enzalutamide versus placebo, abiraterone/prednisone, or sipuleucel-T for time to chemotherapy.

CONCLUSIONS

For rPFS, the NMA suggests that enzalutamide is superior to abiraterone/prednisone and sipuleucel-T. There is no evidence of a statistically significant difference in OS between enzalutamide and abiraterone/prednisone, sipuleucel-T, or radium-223. Given the limitations in network construction and underlying assumptions made to complete these analyses, results should be interpreted with caution.

Systematic bias between blinded independent central review and local assessment: literature review and analyses of 76 phase III randomised controlled trials in 45 688 patients with advanced solid tumour

OBJECTIVE

Unbiased assessment of tumour response is crucial in randomised controlled trials (RCTs). Blinded independent central review is usually used as a supplemental or monitor to local assessment but is costly. The aim of this study is to investigate whether systematic bias existed in RCTs by comparing the treatment effects of efficacy endpoints between central and local assessments.

DESIGN

Literature review, pooling analysis and correlation analysis.

DATA SOURCES

PubMed, from 1 January 2010 to 30 June 2017.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Eligible articles are phase III RCTs comparing anticancer agents for advanced solid tumours. Additionally, the articles should report objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS) or time to progression (TTP); the treatment effect of these endpoints, OR or HR, should be based on central and local assessments.

RESULTS

Of 76 included trials involving 45 688 patients, 17 (22%) trials reported their endpoints with statistically inconsistent inferences (p value lower/higher than the probability of type I error) between central and local assessments; among them, 9 (53%) trials had statistically significant inference based on central assessment. Pooling analysis presented no systematic bias when comparing treatment effects of both assessments (ORR: OR=1.02 (95% CI 0.97 to 1.07), p=0.42, I2=0%; DCR: OR=0.97 (95% CI 0.92 to 1.03), p=0.32, I2=0%); PFS: HR=1.01 (95% CI 0.99 to 1.02), p=0.32, I2=0%; TTP: HR=1.04 (95% CI 0.95 to 1.14), p=0.37, I2=0%), regardless of funding source, mask, region, tumour type, study design, number of enrolled patients, response assessment criteria, primary endpoint and trials with statistically consistent/inconsistent inferences. Correlation analysis also presented no sign of systematic bias between central and local assessments (ORR, DCR, PFS: r>0.90, p<0.01; TTP: r=0.90, p=0.29).

CONCLUSIONS

No systematic bias could be found between local and central assessments in phase III RCTs on solid tumours. However, statistically inconsistent inferences could be made in many trials between both assessments.

Effectiveness and tolerability of targeted drugs for the treatment of metastatic castration-resistant prostate cancer: a network meta-analysis of randomized controlled trials

PURPOSE

Castration-resistant prostate cancer (CRPC) refers to prostate cancer that has progressed after initial androgen deprivation therapy (ADT). Over the years, treatment strategies for metastatic CRPC (mCRPC) have undergone considerable changes. We performed a network meta-analysis to assess the effectiveness and tolerability of targeted agents for mCRPC.

METHODS

We search databases including MEDLINE, EMBASE, and the Cochrane Library through Sep 5, 2017. The major effectiveness outcomes were progression-free survival (PFS) and overall survival (OS). The tolerability outcome was severe adverse events (AEs) of grade ≥ 3.

RESULTS

Twenty-six articles assessing a total of 20,314 patients were included in this study. A random-effect analysis showed that targeted agents could significant prolong PFS in mCRPC patients (I2 = 94.3%; hazard ratio (HR): 0.74; 95% confidence interval (CI): 0.65-0.84; p < 0.001). In addition, the surface under the cumulative ranking curve (SUCRA) ranking from the network analysis showed that enzalutamide was the most effective in improving the PFS of mCRPC patients (100%), followed by abiraterone (90.1%) and tasquinimod (84.2%). Additionally, targeted agents could clearly prolong OS in mCRPC patients (I2 = 71.6%; HR: 0.91; 95% CI: 0.85-0.97; p < 0.001). Furthermore, based on SUCRA ranking, enzalutamide was the most effective in improving the OS of mCRPC patients (97.2%), followed by abiraterone (91.1%) and zibotentan (65.8%). Intetumumab was associated with the lowest incidence of severe AEs (94.9%), followed by atrasentan (85.1%) and placebo (79.3%).

CONCLUSION

In patients with mCRPC, enzalutamide, abiraterone and tasquinimod can prolong PFS, and enzalutamide and abiraterone can prolong OS. Additionally, enzalutamide and abiraterone can improve both PFS and OS with a low risk of causing severe AEs.

Can RECIST response predict success in phase 3 trials in men with metastatic castration-resistant prostate cancer?

BACKGROUND

Intermediate endpoints are needed in early phase studies of men with metastatic castration-resistant prostate cancer (mCRPC) that can reliably predict success in phase 3 trials. Among men with measurable disease, objective response may provide information as to whether a treatment is likely to be successful.

METHODS

We conducted a systematic review of systemic agents that have proceeded to phase 3 trials in men with mCRPC and examined the relationship between improvements in measurable disease response in phase 2 trials and successful phase 3 trials leading to regulatory approval. Only trials that included men with radiographically measurable disease were included.

RESULTS

We examined 31 eligible mCRPC phase 3 trials between 1992 and 2017 and 29 of the preceding phase 2 trials for RECIST responses. Measurable tumor responses in phase 2 trials were higher for successful therapies in phase 3 trials in chemotherapy-naive men with mCRPC, but were less correlated with success in trials investigating docetaxel combination regimens or the post chemotherapy mCRPC setting. Many failed agents did not produce higher than expected response rates over control arms; however, several agents such as anti-angiogenic therapies or orteronel produced higher than expected responses without survival benefit.

CONCLUSIONS

Objective responses in men with mCRPC may be associated with prolonged survival, but this association is mechanism dependent and inconsistent across trials or disease states. These data support considering RECIST response as a supportive but not sole endpoint in phase 2 trials to support launching phase 3 trials.

Antigen-Specific CD8 Lytic Phenotype Induced by Sipuleucel-T in Hormone-Sensitive or Castration-Resistant Prostate Cancer and Association with Overall Survival

Purpose: Sipuleucel-T is FDA approved for the treatment of metastatic castration-resistant prostate cancer (mCRPC) based on the IMPACT trial showing a 4.1-month benefit in median overall survival (OS) for patients receiving sipuleucel-T versus control. Although efficacy of sipuleucel-T is well established, its mechanism remains incompletely understood.Patients and Methods: Patient samples from three sipuleucel-T trials were assessed for peripheral cellular immune responses to the immunogen PA2024 and the target antigen prostatic acid phosphatase (PAP). PAP- and PA2024-specific proliferative and cytolytic responses were characterized to delineate sipuleucel-T-induced immune responses. To quantify potential cytotoxic T lymphocyte (CTL) activity, cell-surface CD107a expression on PAP- or PA2024-specific CD8⁺ T cells was measured in sipuleucel-T-treated patient and healthy volunteer samples.Results: Increased PA2024-specific CD4⁺ (P = 0.030) and CD8⁺ (P = 0.052) T-cell proliferation from baseline to week 6 was observed (N = 14) post-sipuleucel-T, with greater magnitude of PA2024-specific responses compared with PAP. PAP- and PA2024-CTL activity (CD107a positivity) significantly increased at weeks 6 and 26 after sipuleucel-T treatment (P < 0.0001; N = 22). At 26 weeks post-sipuleucel-T, OS correlated with the magnitude of PAP (Pearson R, 0.52; P = 0.013) or PA2024 (Pearson R, 0.67; P = 0.0006) CTL activity. Higher PA2024-CTL activity at week 26 was significantly associated with longer OS using tertile analysis (P = 0.0005; N = 22), with PA2024 responses correlating with PAP responses at week 26 (R = 0.90; P = 1.53E^-08).Conclusions: This study is the first to report PAP-specific CD8⁺ T-cell responses elicited by sipuleucel-T treatment. Increased and persistent potential PA2024-specific CTL activity correlated with PAP-specific CTL activity and associated with improved OS following sipuleucel-T treatment. Clin Cancer Res; 24(19); 4662-71. ©2018 AACR.

Neutrophil elastase in the tumor microenvironment

Myeloid cell production within the bone marrow is accelerated in the setting of cancer, and the numbers of circulating and infiltrating neutrophils and granulocytic myeloid derived suppressor cells (MDSCs) correlate with tumor progression and patient survival. Cancer is therefore able to hijack the normally host-protective immune system and use it to further fuel growth and metastasis. Myeloid cells secrete neutrophil elastase and neutrophil extracellular traps (NETs) in response to cues within the tumor microenvironment, thereby leading to enhanced activity in a variety of cancer types. Neutrophil elastase may indeed be a driver of tumorigenesis, since genetic deletion and pharmacological inhibition markedly reduces tumor burden and metastatic potential in numerous preclinical studies. In this review, we examine the current evidence for neutrophil elastase as a stimulatory factor in cancer, focusing on precise mechanisms by which it facilitates primary tumor growth and secondary organ metastasis. We conclude with a brief overview of neutrophil elastase inhibitors and discuss their potential use in cancer therapy.

Assessing angiogenic responses induced by primary human prostate stromal cells in a three-dimensional fibrin matrix assay

Accurate modeling of angiogenesis in vitro is essential for guiding the preclinical development of novel anti-angiogenic agents and treatment strategies. The formation of new blood vessels is a multifactorial and multi-stage process dependent upon paracrine factors produced by stromal cells in the local microenvironment. Mesenchymal stem cells (MSCs) are multipotent cells in adults that can be recruited to sites of inflammation and tissue damage where they aid in wound healing through regenerative, trophic, and immunomodulatory properties. Primary stromal cultures derived from human bone marrow, normal prostate, or prostate cancer tissue are highly enriched in MSCs and stromal progenitors. Using conditioned media from these primary cultures, a robust pro-angiogenic response was observed in a physiologically-relevant three-dimensional fibrin matrix assay. To evaluate the utility of this assay, the allosteric HDAC4 inhibitor tasquinimod and the anti-VEGF monoclonal antibody bevacizumab were used as model compounds with distinct mechanisms of action. While both agents had a profound inhibitory effect on endothelial sprouting, only bevacizumab induced significant regression of established vessels. Additionally, the pro-angiogenic properties of MSCs derived from prostate cancer patients provides further evidence that selective targeting of this population may be of therapeutic benefit.

Validation of the Association of RECIST Changes With Survival in Men With Metastatic Castration-Resistant Prostate Cancer Treated on SWOG Study S0421

BACKGROUND

Phase 2 trials evaluating new agents for metastatic castration-resistant prostate cancer (mCRPC) have relied on bone scan and prostate-specific antigen changes to assess activity. Given the increasing detection of measurable disease, Response Evaluation Criteria in Solid Tumors (RECIST) changes warrant consideration to evaluate activity. We validated the association of RECIST 1.0 changes with survival in men with mCRPC receiving docetaxel.

PATIENTS AND METHODS

Data for men with measurable disease from the Southwest Oncology Group (SWOG) S0421, a phase 3 trial in men with mCRPC receiving docetaxel and prednisone plus placebo or atrasentan, were used. Cox proportional hazards regression was used to evaluate the association of RECIST 1.0 outcomes within 120 days, ie, unconfirmed partial response (uPR), stable disease, and progressive disease (PD), with overall survival (OS) from day 120, adjusted for prognostic factors.

RESULTS

Overall, 326 men were evaluable for landmark analysis, of whom 23 had PD, 230 stable disease, and 73 uPR. OS beyond day 120 was significantly different (P = .004) among these subgroups, with median (95% confidence interval) OS of 7.1 (3.5-8.8), 13.4 (11.4-15.6), and 16.3 (10.0-19.6) months for those with PD, stable disease, and uPR, respectively. In a multivariable model, the hazard ratio (95% confidence interval) for patients with PD was 2.47 (1.42-4.29) compared to patients with an uPR (P = .002).

CONCLUSION

The association of RECIST 1.0 changes with OS in men with mCRPC receiving docetaxel was validated. Given limitations of bone scan and prostate-specific antigen alterations, improvements in objective RECIST 1.0 changes should be reported in phase 2 trials before launching phase 3 trials.

A randomized, double-blind, placebo-controlled phase II study of maintenance therapy with tasquinimod in patients with metastatic castration-resistant prostate cancer responsive to or stabilized during first-line docetaxel chemotherapy

BACKGROUND

This phase II study was conducted to assess clinical efficacy of tasquinimod maintenance therapy in patients with metastatic castrate-resistant prostate cancer not progressing during first-line docetaxel-based therapy.

PATIENTS AND METHODS

Patients were randomly assigned (1 : 1) to receive tasquinimod (0.25-1.0 mg/day orally) or placebo. The primary end point was radiologic progression-free survival (rPFS); secondary efficacy end points included: overall survival (OS); PFS on next-line therapy (PFS 2) and symptomatic PFS, assessed using the Brief Pain Inventory (BPI) questionnaire and analgesic use. Quality of life was measured by the Functional Assessment of Cancer Therapy-Prostate (FACT-P) questionnaire and by the EuroQol-5 Dimension Quality of Life Instrument (EQ-5D). Adverse events were recorded.

RESULTS

A total of 219 patients were screened and 144 patients randomized. The median duration of treatment was 18.7 weeks (range 0.6-102.7 weeks) for the tasquinimod arm and 19.2 weeks (range 0.4-80.0 weeks) for the placebo arm. Median (90% CI) rPFS was 31.7 (24.3-53.7) and 22.7 (16.1-25.9) weeks in the tasquinimod and placebo arms, respectively [HR (90% CI) 0.6 (0.4-0.9), P = 0.0162]. The median OS was not reached because only 14 deaths occurred by the cut-off date. No statistically significant differences between treatment arms were noted for symptomatic PFS, PFS 2, BPI score, FACT-P score, or EQ-5D. The incidence of any treatment emergent adverse event (TEAE) was similar in the tasquinimod and placebo arms (97.2% versus 94.3%, respectively), whereas severe TEAEs (NCI-CTC Grade 3-5) incidence was higher in the tasquinimod group (50.7% versus 27.1%).

CONCLUSIONS

Randomized trials testing new drugs as maintenance can be successfully conducted after chemotherapy in castrate-resistant prostate cancer. Maintenance tasquinimod therapy significantly reduced the risk of rPFS by 40%.

CLINICALTRIALS

gov identifier NCT01732549.

A Phase II Multicentre, Open-Label, Proof-of-Concept Study of Tasquinimod in Hepatocellular, Ovarian, Renal Cell, and Gastric Cancers

BACKGROUND

Tasquinimod is a small molecule with immunomodulatory, anti-angiogenic, and anti-metastatic properties that targets the tumor microenvironment. This study aimed to obtain a clinical proof of concept that tasquinimod was active and tolerable in patients with advanced solid tumors.

PATIENTS AND METHODS

This early stopping design, open-label, proof-of-concept clinical trial evaluated the clinical activity of tasquinimod in four independent cohorts of patients with advanced hepatocellular (n = 53), ovarian (n = 55), renal cell (n = 38), and gastric (n = 21) cancers. Tasquinimod was given orally every day (0.5 mg/day for at least 2 weeks, with dose increase to 1 mg/day) until radiological progression according to Response Evaluation Criteria in Solid Tumor (RECIST) 1.1 criteria, intolerable toxicity, or patient withdrawal. The primary efficacy endpoint was progression-free survival (PFS) rate according to RECIST 1.1 by central assessment.

RESULTS

Interim futility analyses at 8 weeks (6 weeks for the gastric cancer cohort) found adequate clinical activity of tasquinimod only in the hepatocellular cohort and recruitment to the other three cohorts was stopped. PFS rates were 26.9% at 16 weeks, 7.3% at 24 weeks, 13.2% at 16 weeks, and 9.5% at 12 weeks, respectively, in hepatocellular, ovarian, renal cell, and gastric cancer cohorts. The pre-defined PFS threshold was not reached in the hepatocellular cancer cohort at the second stage of the trial. The most common treatment-related adverse events were fatigue (48.5%), nausea (34.1%), decreased appetite (31.7%), and vomiting (24.6%).

CONCLUSIONS

This study failed to demonstrate clinical activity of tasquinimod in heavily pre-treated patients with advanced hepatocellular, ovarian, renal cell, and gastric cancer.

TRIAL REGISTRATION

NCT01743469.

Extracellular S100A9 Protein in Bone Marrow Supports Multiple Myeloma Survival by Stimulating Angiogenesis and Cytokine Secretion

Dysregulated expression of S100 protein family members is associated with cancer proliferation, invasion, angiogenesis, and inflammation. S100A9 induces myeloid-derived suppressor cell (MDSC) accumulation and activity. MDSCs, immunosuppressive cells that contribute to tumor immune escape, are the main producers of S100A9. In this study, we evaluated the role of extracellular S100A9 and the therapeutic relevance of S100A9 inhibition in multiple myeloma (MM), using the immunocompetent murine 5T33MM model. We demonstrated the presence of S100A9 and its receptor TLR4 in both monocytic and granulocytic MDSCs in human and mouse samples. We showed that S100A9 acted as a chemoattractant for MM cells and induced MDSCs to express and secrete inflammatory and pro-myeloma cytokines, including TNFα, IL6, and IL10. Blocking S100A9 interactions in vivo with the small molecule ABR-238901 did not directly affect MDSC accumulation but did reduce IL6 and IL10 cytokine expression by MDSC. ABR-238901 treatment in vivo reduced angiogenesis but had only minor effects on tumor load as single agent (6% reduction). However, ABR-238901 treatment in combination with bortezomib resulted in an increased reduction in tumor load compared with single treatments (50% relative reduction compared with bortezomib alone). Our data suggest that extracellular S100A9 promotes MM and that inhibition of S100A9 may have therapeutic benefit. Cancer Immunol Res; 5(10); 839-46. ©2017 AACR.

Myeloid-derived cells in prostate cancer progression: phenotype and prospective therapies

Prostate cancer is the second most common cause of cancer mortality in men in the United States. As is the case for other tumor types, accumulating evidence suggests an important role for myeloid-derived cells in the promotion and progression of prostate cancer. Here, we briefly describe myeloid-derived cells that interact with tumor cells and what is known about their immune suppressive function. We next discuss new evidence for tumor cell-mediated myeloid infiltration via the PI3K/PTEN/AKT signaling pathway and an alternative mechanism for immune evasion that may be regulated by an endoplasmic reticulum stress response. Finally, we discuss several interventions that target myeloid-derived cells to treat prostate cancer.

Clinical development of immunotherapy for prostate cancer

Prostate cancer is the most common cancer in men, and the second leading cause of cancer-related death in Western countries. Prostate cancer-related death occurs in patients with metastatic castration-resistant prostate cancer. Although several new drugs for castration-resistant prostate cancer have been approved, each of these has prolonged survival by just a few months. Consequently, new therapies are sorely needed. Recently, it has been recognized that immunotherapy is an effective treatment for prostate cancer patients. Several strategies, such as cancer vaccines and immune checkpoint inhibitors, have been investigated in clinical studies for prostate cancer patients. In the present review, the results of the most recent clinical studies investigating immunotherapy in prostate cancer patients are reported, and the future clinical development of immunotherapy for prostate cancer is discussed.

Prevalence of Measurable Disease in Metastatic Castration-resistant Prostate Cancer

BACKGROUND

Because of the low historical prevalence of measurable disease in metastatic castration-resistant prostate cancer (mCRPC), phase II trials have used prostate-specific antigen (PSA) and bone scan changes as primary end points. Frequent whole-body imaging and improved computed tomography technology currently identify measurable disease more frequently, warranting consideration of objective response as a major end point.

PATIENTS AND METHODS

Data from reported phase III trials of mCRPC were analyzed. The proportion of patients with measurable disease, setting (pre-docetaxel [D], D-based, post-D), year of starting accrual, PSA, and the requirement for symptoms were collected. The χ² test was used to evaluate the association of variables with measurable disease rate.

RESULTS

Twenty phase III trials totaling 19,276 men with mCRPC were evaluable. Three trials (n = 1289) started accruing before 2000 and 17 trials (n = 17,987) accrued after 2000. The proportion of measurable disease rate for all trials was 47.5%. The measurable disease rate was significantly higher (P < .001) in trials that accrued after 2000 versus before 2000 (48.7% vs. 31.1%; P < .001), D-based (51.8%) or post-D patients (48.9%) compared with pre-D patients (38.6%) and in trials allowing symptomatic versus asymptomatic/minimally symptomatic patients (50.1% vs. 40.0%).

CONCLUSION

The proportion of men with measurable disease was significantly higher in phase III trials of mCRPC that accrued after 2000, in D-based or post-D patients and in trials that allowed symptomatic patients. Because of the association of objective measurable changes with survival, Response Evaluation Criteria in Solid Tumors changes might warrant consideration as a major end point in phase II trials to obtain a firm signal of efficacy before launching phase III trials.

Recent advances in genitourinary tumors: A review focused on biology and systemic treatment

Updated information published up to 2016 regarding major advances in renal cancer, bladder cancer, and prostate cancer is here presented. Based on an ever better understanding of the genetic and molecular alterations that govern the initial pathogenic mechanisms of tumor oncogenesis, an improvement in the characterization and treatment of urologic tumors has been achieved in the past year. According to the Cancer Genome Atlas (ATLAS) project, alterations in the MET pathway are characteristics of type 1 papillary renal cell carcinomas, and activation of NRF2-ARE pathway is associated with the biologically distinct type 2. While sunitinib and pazopanib continue to be the standard first-line treatment in metastatic renal cell carcinoma of clear cell histology, nivolumab and cabozantinib are now the agents of choice in the second-line setting. In relation to urothelial bladder carcinoma, new potential molecular targets such as FGFR3, PI3K/AKT, RTK/RAS, CDKN2A, ARIDIA, ERBB2 have been identified. Response to adjuvant cisplatin-based chemotherapy appears to be related to basal, luminal, and p53-like intrinsic subtypes. A phase II study with eribulin and a maintenance phase II trial with vinflunine have shown promising results. Similarly, the use of the check point inhibitors in advanced disease is likely to revolutionize the management of patients who have progressed after cisplatin-based chemotherapy. In prostate cancer, seven mutually exclusive molecular subtypes have been identified by the TCGA project. Chemotherapy has been consolidated as a key treatment for castration-sensitive metastatic prostate cancer, and abiraterone, enzalutamide, cabazitaxel, and radium-223 remain standard therapeutic options for men with metastatic castration-resistant prostate cancer. All this progress will undoubtedly contribute to the development of new treatments and therapeutic strategies that will improve the survival and quality of life of our patients.

A comprehensive review of immunotherapies in prostate cancer

Prostate cancer is the second most common malignant neoplasm in men worldwide and the fifth cause of cancer-related death. Although multiple new agents have been approved for metastatic castration resistant prostate cancer over the last decade, it is still an incurable disease. New strategies to improve cancer control are needed and agents targeting the immune system have shown encouraging results in many tumor types. Despite being attractive for immunotherapies due to the expression of various tumor associated antigens, the microenvironment in prostate cancer is relatively immunosuppressive and may be responsible for the failures of various agents targeting the immune system in this disease. To date, sipuleucel-T is the only immunotherapy that has shown significant clinical efficacy in this setting, although the high cost and potential trial flaws have precluded its widespread incorporation into clinical practice. Issues with patient selection and trial design may have contributed to the multiple failures of immunotherapy in prostate cancer and provides an opportunity to tailor future studies to evaluate these agents more accurately. We have reviewed all the completed immune therapy trials in prostate cancer and highlight important considerations for the next generation of clinical trials.

Phase Ib Trial of Cabazitaxel and Tasquinimod in Men With Heavily Pretreated Metastatic Castration Resistant Prostate Cancer (mCRPC): The CATCH Trial

BACKGROUND

Tasquinimod is an immunomodulating and anti-antiangiogenic oral agent with anti-prostate cancer activity in preclinical studies and in clinical trials of men with metastatic castration resistant prostate cancer (mCRPC), including single agent activity and in combination with taxanes. We sought to identify the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D) of tasquinimod in combination with cabazitaxel and prednisone in men with chemorefractory mCRPC.

METHODS

Men with mCRPC who had failed prior docetaxel chemotherapy received cabazitaxel 25 mg/m² every 3 weeks with oral tasquinimod at 1 of 3 escalating dose levels (0.25, 0.5, and 1.0 mg once daily) with prednisone and PEG-filgastrim support, using a 3 + 3 dose escalation design. Treatment continued until progressive disease or unacceptable toxicity.

RESULTS

We enrolled 25 men with chemorefractory mCRPC. The RP2D was 0.5 mg tasquinimod based on excess DLTs (two of three men) observed at dose level 3 (1.0 mg) including grade 3 sensory neuropathy and grade 3 atrial fibrillation. Dose level 2 was expanded to 14 men, where 3 DLTs were observed: grade 3 fatigue, grade 4 febrile neutropenia, and grade 3 liver function abnormalities. The proportion of men with a ≥30% PSA decline was 63% and the median composite progression-free survival (PFS) was 8.5 months (95% CI 4.2-16.4 months) based on 12 PFS events. The median number of cycles of cabazitaxel was 6 (range 1-13), with six men receiving >10 cycles. Best overall RECIST responses (CR + PR) were observed in three men (12%), with stable disease in 12 (48%). No pharmacokinetic interactions were observed.

CONCLUSIONS

We determined the RP2D of tasquinimod combined with cabazitaxel to be 0.5 mg daily following a 3 week lead-in of tasquinimod 0.25 mg with growth factor support. No unexpected toxicities occurred. Prostate 77: 385-395, 2017. © 2016 Wiley Periodicals, Inc.

Epigenetics in cancer: Fundamentals and Beyond

Activation of oncogenes or the deactivation of tumor suppressor genes has long been established as the fundamental mechanism leading towards carcinogenesis. Although this age old axiom is vastly accurate, thorough study over the last 15years has given us unprecedented information on the involvement of epigenetic in cancer. Various biochemical pathways that are essential towards tumorigenesis are regulated by the epigenetic phenomenons like remodeling of nucleosome by histone modifications, DNA methylation and miRNA mediated targeting of various genes. Moreover the presence of mutations in the genes controlling the epigenetic players has further strengthened the association of epigenetics in cancer. This merger has opened up newer avenues for targeted anti-cancer drug therapy with numerous pharmaceutical industries focusing on expanding their research and development pipeline with epigenetic drugs. The information provided here elaborates the elementary phenomena of the various epigenetic regulators and discusses their alteration associated with the development of cancer. We also highlight the recent developments in epigenetic drugs combining preclinical and clinical data to signify this evolving field in cancer research.

Targeting cancer-related inflammation in the era of immunotherapy

Recent advances in cancer immunotherapy, particularly immune checkpoint blockade therapy have dramatically changed the therapeutic strategy against advanced malignancies. Still, only a subset of patients shows a good response to any single therapy. Moreover, it remains largely unsolved how we can maintain durable clinical responses, or how we can successfully treat a broader range of cancers by immunotherapy. Growing evidence suggests that the major barrier to more successful cancer immunotherapy is the tumour microenvironment (TME), where chronic inflammation has a predominant role in tumour survival and proliferation, angiogenesis and immunosuppression. Over the past decades, our understanding of cancer-related inflammation has significantly evolved, and now we have various therapeutic options tailored to the TME. These therapeutic strategies include inhibiting inflammatory mediators or their downstream signalling molecules, blocking the recruitment of myeloid cells, modulating immunosuppressive functions in myeloid cells and re-educating the TME. In this review, we discuss the role of cancer-related inflammation as a potential target in the era of immunotherapy.

The Society for Immunotherapy of Cancer consensus statement on immunotherapy for the treatment of prostate carcinoma

Prostate cancer is the most commonly diagnosed malignancy and second leading cause of cancer death among men in the United States. In recent years, several new agents, including cancer immunotherapies, have been approved or are currently being investigated in late-stage clinical trials for the management of advanced prostate cancer. Therefore, the Society for Immunotherapy of Cancer (SITC) convened a multidisciplinary panel, including physicians, nurses, and patient advocates, to develop consensus recommendations for the clinical application of immunotherapy for prostate cancer patients. To do so, a systematic literature search was performed to identify high-impact papers from 2006 until 2014 and was further supplemented with literature provided by the panel. Results from the consensus panel voting and discussion as well as the literature review were used to rate supporting evidence and generate recommendations for the use of immunotherapy in prostate cancer patients. Sipuleucel-T, an autologous dendritic cell vaccine, is the first and currently only immunotherapeutic agent approved for the clinical management of metastatic castrate resistant prostate cancer (mCRPC). The consensus panel utilized this model to discuss immunotherapy in the treatment of prostate cancer, issues related to patient selection, monitoring of patients during and post treatment, and sequence/combination with other anti-cancer treatments. Potential immunotherapies emerging from late-stage clinical trials are also discussed. As immunotherapy evolves as a therapeutic option for the treatment of prostate cancer, these recommendations will be updated accordingly.

Adjunct Strategies for Tuberculosis Vaccines: Modulating Key Immune Cell Regulatory Mechanisms to Potentiate Vaccination

Tuberculosis (TB) remains a global health threat of alarming proportions, resulting in 1.5 million deaths worldwide. The only available licensed vaccine, Bacillus Calmette–Guérin, does not confer lifelong protection against active TB. To date, development of an effective vaccine against TB has proven to be elusive, and devising newer approaches for improved vaccination outcomes is an essential goal. Insights gained over the last several years have revealed multiple mechanisms of immune manipulation by Mycobacterium tuberculosis (Mtb) in infected macrophages and dendritic cells that support disease progression and block development of protective immunity. This review provides an assessment of the known immunoregulatory mechanisms altered by Mtb, and how new interventions may reverse these effects. Examples include blocking of inhibitory immune cell coreceptor checkpoints (e.g., programed death-1). Conversely, immune mechanisms that strengthen immune cell effector functions may be enhanced by interventions, including stimulatory immune cell coreceptors (e.g., OX40). Modification of the activity of key cell “immunometabolism” signaling pathway molecules, including mechanistic target of rapamycin, glycogen synthase kinase-3β, wnt/β-catenin, adenosine monophosophate-activated protein kinase, and sirtuins, related epigenetic changes, and preventing induction of immune regulatory cells (e.g., regulatory T cells, myeloid-derived suppressor cells) are powerful new approaches to improve vaccine responses. Interventions to favorably modulate these components have been studied primarily in oncology to induce efficient antitumor immune responses, often by potentiation of cancer vaccines. These agents include antibodies and a rapidly increasing number of small molecule drug classes that have contributed to the dramatic immune-based advances in treatment of cancer and other diseases. Because immune responses to malignancies and to Mtb share many similar mechanisms, studies to improve TB vaccine responses using interventions based on “immuno-oncology” are needed to guide possible repurposing. Understanding the regulation of immune cell functions appropriated by Mtb to promote the imbalance between protective and pathogenic immune responses may guide the development of innovative drug-based adjunct approaches to substantially enhance the clinical efficacy of TB vaccines.

Immunotherapy for prostate cancer: False promises or true hope?

Prostate cancer is the most commonly diagnosed cancer, and the second leading cause of cancer-related death for men in the United States. Despite the approval of several new agents for advanced disease, each of these has prolonged survival by only a few months. Consequently, new therapies are sorely needed. For other cancer types, immunotherapy has demonstrated dramatic and durable treatment responses, causing many to hope that immunotherapies might provide an ideal treatment approach for patients with advanced prostate cancer. However, apart from sipuleucel-T, prostate cancer has been conspicuously absent from the list of malignancies for which immunotherapies have received recent approval from the US Food and Drug Administration. This has left some wondering whether immunotherapy will "work" for this disease. In this review, the authors describe current developments in immunotherapy, including approaches to engage tumor-targeting T cells, disrupt immune regulation, and alter the immunosuppressive tumor microenvironment. The authors then describe the recent application of these approaches to the treatment of prostate cancer. Given the Food and Drug Administration approval of 1 agent, and the finding that several others are in advanced stages of clinical testing, the authors believe that immunotherapies offer real hope to improve patient outcomes for men with prostate cancer, especially as investigators begin to explore rational combinations of immunotherapies and combine these therapies with other conventional therapies. Cancer 2016;122:3598-607. © 2016 American Cancer Society.