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

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

Genomic differences between black and white patients implicate a distinct immune response to papillary renal cell carcinoma

Significant disparities in survival, incidence and possibly response to current therapies exist between black and white patients with renal cell carcinoma (RCC). Recent genomic evidence to account for these disparities has been reported for clear cell RCC. However, racial disparities at the genomic level for papillary RCC (pRCC) which is a genetically distinct and less responsive histologic subtype of RCC have not been reported. Using The Cancer Genome Atlas (TCGA) data, the present study assessed gene-level expression, somatic mutation and pathway differences between 58 black and 58 white patients with pRCC propensity matched on age, gender and pathologic T stage. Distinct tumor biology with differential expression patterns were observed in black vs. white patients with pRCC. Specifically, significance analysis of microarrays was applied to TCGA gene expression data and identified 163 genes and 120 genes overexpressed in black and white patients, respectively (FDR q<0.05). Gene Set Enrichment Analysis identified 62 gene sets enriched (p<0.10) in blacks. Enrichment of immune immune system pathways were noted in black patients. These included the B cell receptor signaling pathway, the NOD-like receptor signaling pathway and genes involved in defensins. The VEGF pathway was also more significant in black patients. CRYBB2, a gene associated with the WNT pathway was overexpressed in Black patients. While our data requires validation, these findings suggest that race may have implications for distinct immune responses to cancer and that the use of immunotherapies, and VEGFR inhibitors to target these pathways may improve survival in black patients with advanced pRCC.

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

Lessons Learned

The safety and activity findings of abiraterone acetate plus prednisone treatment in black men with mCRPC were similar to results from previously conducted studies with largely white populations.

Poor trial accrual continues to be a challenge in black men with mCRPC and further efforts are needed to address such underrepresentation.

Background.

Self-identified black men have higher incidence and mortality from prostate cancer in the United States compared with white men but are dramatically underrepresented in clinical trials exploring novel therapies for metastatic castration-resistant prostate cancer (mCRPC).

Methods.

Black men with mCRPC were treated with abiraterone acetate (AA), 1,000 mg daily, and prednisone (P), 5 mg twice daily. The primary objective was to determine antitumor activity (defined by a ≥30% decline in prostate-specific antigen [PSA] level) and to correlate germline polymorphisms in androgen metabolism genes with antitumor activity. Secondary objectives included determining safety, post-treatment changes in measurable disease, and time to disease progression.

Results.

From April 2013 to March 2016, a total of 11 black men were enrolled and received AA plus P (AA+P); 7 of 10 evaluable patients were docetaxel naive. Post-treatment declines in PSA level of ≥30% were achieved in 90% of patients. The side effect profile was consistent with prior clinical trials exploring AA+P in mCRPC. Due to poor accrual, the study was closed prematurely with insufficient sample size for the planned pharmacogenetic analyses.

Conclusion.

In this small prospective study terminated for poor accrual, the safety and activity of AA+P in black men with mCRPC was similar to that reported in prior studies exploring AA in largely white populations. Further efforts are needed to address underrepresentation of black men in mCRPC trials.

Leiomyosarcoma of the Inferior Vena Cava With Kidney Invasion

Primary leiomyosarcomas of the inferior vena cava (IVC) are rare tumors associated with poor prognosis, and surgical resection with the goal of obtaining negative margins is the gold standard for initial treatment. Tumor characteristics of both extraluminal extension into renal parenchyma and intraluminal extension of the subdiaphragmatic IVC are even less common. The prognosis of vascular leiomyosarcomas is determined by the location and the size of the tumor, as these factors determine the risk of local recurrence and metastasis. We present a case of a 30-year old female incidentally found to have a 14 cm right renal mass and IVC thrombus.

Comparative Effectiveness of Treatment Strategies for Bladder Cancer With Clinical Evidence of Regional Lymph Node Involvement

PURPOSE

Patients with bladder cancer with clinical lymph node involvement (cN+) are at high risk for distant metastases, but are potentially curable. Such patients are excluded from neoadjuvant chemotherapy trials and pooled with patients with distant metastases in first-line chemotherapy trials not suited to define the role of combined-modality therapy. To address this evidence void, we performed a comparative effectiveness analysis.

METHODS

We included cTanyN1-3M0 bladder cancer patients from the National Cancer Data Base (2003-2012) treated with chemotherapy and/or cystectomy. We used multistate survival analysis, allowing for delayed entry, to assess overall survival (OS) according to various treatment strategies. Effectiveness was estimated with multivariable adjustment for tumor-, patient-, and facility-level characteristics.

RESULTS

Among 1,739 patients (cN1, 48%; cN2, 45%; cN3, 7%), 1,104 underwent cystectomy and 635 were treated with chemotherapy alone. Of the cystectomy patients, 363 received preoperative and 328 received adjuvant chemotherapy. The crude 5-year OS for chemotherapy alone, cystectomy alone, preoperative chemotherapy followed by cystectomy, and cystectomy followed by adjuvant chemotherapy was 14% (95% CI, 11% to 17%), 19% (95% CI, 15% to 24%), 31% (95% CI, 25% to 38%), and 26% (95% CI, 21% to 34%), respectively. Compared with cystectomy alone, preoperative chemotherapy was associated with a significant improvement in OS (hazard ratio, 0.80; 95% CI, 0.66 to 0.97). Adjuvant chemotherapy was also associated with a significant improvement in survival compared with cystectomy alone. The survival of patients treated with chemotherapy alone was worse than those treated with cystectomy alone.

CONCLUSION

A subset of patients with cN+ bladder cancer achieves long-term survival. Combined-modality therapy, with chemotherapy and cystectomy, is associated with the best outcomes.

Heart rate and suicide: findings from two cohorts of 533 000 Taiwanese and 75 000 Norwegian adults

OBJECTIVE

To investigate the association of resting heart rate with suicide in two large cohorts.

METHOD

The MJ cohort (Taiwan) included 532 932 adults from a health check-up programme (1994-2008). The HUNT cohort (Norway) included 74 977 adults in the Nord-Trøndelag County study (1984-1986), followed up to 2004. In both cohorts heart rate was measured at baseline, and suicide was ascertained through linkage to cause-of-death registers. Risk of suicide was estimated using Cox proportional hazards models.

RESULTS

There were 569 and 188 suicides (average follow-up period of 8.1 and 16.9 years) in the MJ and HUNT cohorts respectively. Sex- and age-adjusted hazard ratio for every 10 beat increase in heart rate per minute was 1.08 (95% Confidence Interval 1.00-1.16) and 1.24 (1.12-1.38) in the MJ and HUNT cohorts, respectively. In the MJ cohort this association was confined to individuals with a history of heart diseases vs. those without such a history (P for interaction = 0.008). In the HUNT cohort the association did not differ by history of heart diseases and was robust to adjustment for health-related life style, medication use, and symptoms of anxiety and depression.

CONCLUSION

Elevated resting heart rate may be a marker of increased suicide risk.

Effectiveness of Adjuvant Chemotherapy for Locally Advanced Bladder Cancer

PURPOSE

Given that randomized trials exploring adjuvant chemotherapy for bladder cancer have been underpowered and/or terminated prematurely, yielding inconsistent results and creating an evidence gap, we sought to compare the effectiveness of cystectomy versus cystectomy plus adjuvant chemotherapy in real-world patients.

PATIENTS AND METHODS

We conducted an observational study to compare the effectiveness of adjuvant chemotherapy versus observation postcystectomy in patients with pathologic T3-4 and/or pathologic node-positive bladder cancer using the National Cancer Data Base. We compared overall survival using propensity score (-adjusted, -stratified, -weighted, and -matched) analyses based on patient-, facility-, and tumor-level characteristics. A sensitivity analysis was performed to examine the impact of performance status.

RESULTS

A total of 5,653 patients met study inclusion criteria; 23% received adjuvant chemotherapy postcystectomy. Chemotherapy-treated patients were younger and more likely to have private insurance, live in areas with a higher median income and higher percentage of high school-educated residents, and have lymph node involvement and positive surgical margins (P < .05 for all comparisons). Stratified analyses adjusted for propensity score demonstrated an improvement in overall survival with adjuvant chemotherapy (hazard ratio, 0.70; 95% CI, 0.64 to 0.76), and similar results were achieved with propensity score matching and weighting. The association between adjuvant chemotherapy and improved survival was consistent in subset analyses and was robust to the effects of poor performance status.

CONCLUSION

In this observational study, adjuvant chemotherapy was associated with improved survival in patients with locally advanced bladder cancer. Although neoadjuvant chemotherapy remains the preferred approach based on level I evidence, these data lend further support for the use of adjuvant chemotherapy in patients with locally advanced bladder cancer postcystectomy who did not receive chemotherapy preoperatively.

Frequency and clinical implications of pathologic complete response (pCR) at cystectomy for muscle-invasive bladder cancer (MIBC) with or without neoadjuvant chemotherapy (NAC)

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Background: Subsets of patients (pts) with MIBC, with or without NAC, have no pathologic evidence of disease at cystectomy. The frequency and implications of pCR in “real world” pts has not been well characterized. Methods: Using the National Cancer Database, pts with cT2-4aN0M0 bladder cancer who underwent cystectomy alone (CYS) or with NAC from 2003-2011 were identified. pCR was defined as pT0N0M0. In the CYS and NAC cohorts, the association between pCR and overall survival was analyzed using Cox proportional hazard methods. Results: 12,245 pts met eligibility (CYS: 10,940; NAC: 1,305). The pCR rate with CYS was 4.8% (95% CI 4.4-5.3%) and with NAC was 21.6% (95% CI 19.4-24.0%). In both cohorts, logistic regression revealed lower cT stage and higher cystectomy volume were associated with increased pCR. pCR was associated with a significant improvement in survival in both cohorts (Table). Conclusions: The frequency of pCR in real world pts was substantially lower than reported in clinical trials; however, pCR was associated with markedly improved survival in both CYS and NAC groups. Molecular predictors of pCR in both groups warrant evaluation. Whether the survival benefit associated with pCR in the CYS cohort simply reflects the “smallest/best” tumors or whether there is a role, and mechanistic rationale, for surgical approaches to increase pCR (i.e., re-TURBT in MIBC) warrants study. Finally, our findings lend further support for use of pCR as an endpoint in NAC clinical trials. [Table: see text]

Front-line management patterns in the prospective metastatic renal cell cancer (MaRCC) registry

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Background: Over the past decade, seven agents were approved for metastatic renal cell carcinoma (mRCC) leading to a rapidly evolving clinical landscape. Clinical trials addressing treatment efficacy, sequencing, and other questions may continue to impact management decisions. Furthermore, our prior retrospective experience indicates a significant proportion of pts may not receive systemic therapy in the first year after diagnosis with metastatic disease. This analysis describes contemporary patterns of care in the first 109 real world pts enrolled in a multicenter, prospective, observational registry. Methods: MaRCC Registry will enroll 500 pts from up to 60 US academic (ACAD) and community (COMM) sites with ~2 years of recruitment and ≥ 3 years of follow-up. Key inclusion criteria are age ≥ 18 years and diagnosis of mRCC with no prior systemic therapy (STx) for mRCC at study entry. Pts currently not on STx but who are being observed are permitted. Key endpoints include descriptive characteristics of treatments (e.g. treatment agents, sequence, duration, reasons for therapy choice and discontinuation), treatment effectiveness (e.g. overall response rate, progression free survival, overall survival), quality of life (PROs), medication adherence, and health resource utilization. Results: At data cutoff, 105 pts have been accrued with known STx status; median age 64 (Q1-3 range, 56-70); 66% male; 75% ACAD; 87% clear cell histology; and 31% stage IV at diagnosis. Initial management strategies are shown in the table. The initial management decision after accrual was to defer systemic therapy (Def STx) in 40% (N=44). In ACAD and COMM sites, Def STx percentages were 38% and 48% respectively. Baseline demographics and clinical characteristics were not notably different between Def STx pts and those treated with STx. Conclusions: In our prospective registry, we have identified a large percentage of pts who initially received Def STx. In the context of contemporary pts undergoing investigational and standard of care STx, we will describe the management and outcomes of the Def STx population. [Table: see text]

A robust blood gene expression-based prognostic model for castration-resistant prostate cancer

BACKGROUND

Castration-resistant prostate cancer (CRPC) is associated with wide variations in survival. Recent studies of whole blood mRNA expression-based biomarkers strongly predicted survival but the genes used in these biomarker models were non-overlapping and their relationship was unknown. We developed a biomarker model for CRPC that is robust, but also captures underlying biological processes that drive prostate cancer lethality.

METHODS

Using three independent cohorts of CRPC patients, we developed an integrative genomic approach for understanding the biological processes underlying genes associated with cancer progression, constructed a novel four-gene model that captured these changes, and compared the performance of the new model with existing gene models and other clinical parameters.

RESULTS

Our analysis revealed striking patterns of myeloid- and lymphoid-specific distribution of genes that were differentially expressed in whole blood mRNA profiles: up-regulated genes in patients with worse survival were overexpressed in myeloid cells, whereas down-regulated genes were noted in lymphocytes. A resulting novel four-gene model showed significant prognostic power independent of known clinical predictors in two independent datasets totaling 90 patients with CRPC, and was superior to the two existing gene models.

CONCLUSIONS

Whole blood mRNA profiling provides clinically relevant information in patients with CRPC. Integrative genomic analysis revealed patterns of differential mRNA expression with changes in gene expression in immune cell components which robustly predicted the survival of CRPC patients. The next step would be validation in a cohort of suitable size to quantify the prognostic improvement by the gene score upon the standard set of clinical parameters.

Comparative effectiveness of adjuvant chemotherapy (AC) versus observation in patients with ≥ pT3 and/or pN+ bladder cancer (BCa)

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Background: Though Level I evidence supports the use of neoadjuvant chemotherapy (NAC) in BCa, the data supporting AC has been mixed. Experience suggests an adequately powered trial to definitively assess the role of AC is unlikely to be completed. Alternative approaches to evidence development are necessary. Methods: Patients who underwent cystectomy for ≥pT3 and/or pN+ M0 BCa were identified from the National Cancer Database. Patients who received NAC and/or diagnosed after 2006 (most recent year with survival data) were excluded. Logistic regression was used to calculate propensity scores representing the predicted probabilities of assignment to AC versus observation based on: age, demographics, year of diagnosis, pT stage, margin status, lymph node density, distance to hospital, hospital cystectomy volume, and hospital type and location. A propensity score-matched cohort of AC versus observation (1:2) patients was created. Stratified Cox proportional hazards regression was used to estimate the hazard ratio (HR) for overall survival for the matched sample while propensity score adjusted and inverse probability of treatment weighted proportional hazards models were used to estimate adjusted HR for the full sample. A sensitivity analysis examined the impact of comorbidities. Results: 3,294 patients undergoing cystectomy alone and 937 patients undergoing cystectomy plus AC met inclusion criteria.Patients receiving AC were significantly more likely to: be younger, have more lymph nodes examined and involved, have higher pT stage, have positive margins, reside in the Northeast and closer to the hospital, and have private insurance. AC was associated with improved overall survival (Table). The results were robust to sensitivity analysis for comorbidities. Conclusions: AC was associated with improved survival in patients with ≥pT3 and/or pN+ BCa in this large comparative effectiveness analysis. [Table: see text]

Influence of prostate cancer disease state and therapeutic selection on peripheral whole-blood RNA signature

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Background: Prostate cancer is a heterogeneous disease with differences in tumor stromal interactions contributing to variability in treatment response and outcome. Gene expression of peripheral blood cells is altered by interactions with neoplastic tissue. We previously developed a peripheral whole blood six-gene signature prognostic for survival in mCRPC. Here we evaluate how different clinical disease states and treatment with different therapeutic agents impact this signature. Methods: Whole blood was collected in PAXgene Blood RNA tubes in two cohorts of prostate cancer patients, one at Mount Sinai (n=135), the other in Munich (n=59), in the context of prospective clinical studies. Whole blood RNA was extracted and the six target genes were amplified using qPCR. Scores were derived using normalized cycle threshold (ΔCT) values of the six genes, according to the model: 2 x ABL2 + SEMA4D + ITGAL – C1QA – TIMP1 – CDKN1A. Patients were categorized by disease state in the Mount Sinai cohort, and by treatment received in the Munich cohort, for data analysis. Results: CRPC is the only disease state with a mean six-gene score (18.06) above the high-risk cutoff (17.9), and is significantly higher than localized or hormone sensitive advanced disease (16.07, 16.52, respectively; p=0.0002). Among patients with localized disease, there was no significant difference in the mean six-gene scores for patients with low-, intermediate-, and high-risk disease (16.07, 15.33, 16.66, respectively; p=0.27). In CRPC patients treated with docetaxel, there are significant changes to the six-gene score over the course of treatment (p=0.002), with a notable percentage decrease (-6.2%) at the 2-8 week timepoint that is not observed in patients treated with abiraterone or enzalutamide. Conclusions: Gene expression profiling of whole blood is influenced by the clinical state of prostate cancer as seen by differences to the six-gene score from localized to castrate resistant disease. Cytotoxic chemotherapy appears to modulate the six-gene score, something not seen with AR-directed therapies. Further investigation will be needed to understand the significance of these changes.

Muscle invasive bladder cancer: closing the gap between practice and evidence

Bladder cancer is the fourth most common cancer in the United States, and will lead to an estimated 15,580 deaths in 2014. Prompted by physical symptoms and signs, most patients will initially present with clinically localized disease. Once bladder cancer invades beyond the muscularis propria, the likelihood of development of metastatic disease increases substantially. Radical cystectomy is potentially curative for muscle-invasive bladder cancer though approximately 50% of patients will develop metastatic recurrence. Two large randomized studies have demonstrated that the use of neoadjuvant cisplatin-based chemotherapy prior to cystectomy improves survival. However, despite the existing level 1 evidence, this approach has been largely underutilized in practice. In this review, we will focus on this disconnect between efficacy and effectiveness and explore possible solutions in an effort to bridge this existing gap.

Phase Ib/II trial of gemcitabine, cisplatin, and lenalidomide as first-line therapy in patients with metastatic urothelial carcinoma

BACKGROUND

Outcomes with current chemotherapy in metastatic urothelial carcinoma (MUC) remain poor. Lenalidomide, an antiangiogenic and immunomodulatory agent, enhances the effects of chemotherapy in preclinical studies. In this phase Ib/II study, we sought to determine a tolerable dose of lenalidomide in combination with gemcitabine and cisplatin (GCL) in patients with MUC and to explore the safety and activity of this regimen.

METHODS

Patients with chemotherapy-naïve MUC received gemcitabine 1,000 mg/m(2) on days 1 and 8 and cisplatin 70 mg/m(2) on day 1 every 21 days. In phase Ib, there were four planned escalating dose levels of lenalidomide (10, 15, 20, and 25 mg) daily on days 1-14.

RESULTS

Seven patients received GCL in phase Ib. The dose of lenalidomide was not escalated beyond 10 mg because of cytopenias requiring repeated dose delays and reductions. Two additional patients were enrolled in phase II, but the study was ultimately terminated due to poor tolerability and slow accrual. The most frequent grade ≥ 3 adverse events were cytopenias and diarrhea. Three of the nine patients experienced an objective response (one complete response, two partial responses).

CONCLUSION

Chronic administration of the GCL regimen was poorly tolerated because of additive and cumulative myelosuppression.

Phase Ib study of dovitinib in combination with gemcitabine plus cisplatin or gemcitabine plus carboplatin in patients with advanced solid tumors

PURPOSE

Dovitinib is a small molecule kinase inhibitor with activity against the fibroblast growth factor and vascular endothelial growth factor receptor families. The purpose of this phase Ib study was to define the recommended phase 2 dose of the combinations of gemcitabine and cisplatin or gemcitabine and carboplatin plus dovitinib.

METHODS

Patients with advanced solid tumors were enrolled in two parallel dose escalation arms (cisplatin- or carboplatin-based regimens). Treatment was administered with gemcitabine (1,000 mg/m(2) on days 1 and 8), cisplatin (70 mg/m(2)), or carboplatin (AUC 5) on day 1, and dovitinib (orally on days 1-5, 8-12, and 15-19), every 21 days. The starting dose of dovitinib was 300 mg and was dose escalated in successive cohorts using 3 + 3 dose escalation rules.

RESULTS

Fourteen patients with advanced solid tumors were enrolled, five to the cisplatin arm and nine to the carboplatin arm. Patients enrolled in the cisplatin arm received a median of two cycles of treatment (range 1-5), and patients enrolled in the carboplatin arm received a median of one cycle of treatment (range 1-4). There were no protocol-defined dose-limiting toxicities in the cisplatin arm. However, the cohort was closed due to the need for frequent dose delays and/or reductions and two patients experiencing severe thromboembolic events. There were two dose-limiting toxicities in the carboplatin arm at the starting dose level of dovitinib (both prolonged neutropenia), and the dose of dovitinib was de-escalated to 200 mg. Two additional dose-limiting toxicities (prolonged neutropenia and febrile neutropenia) occurred in the lower dose cohort, and the study was closed. No patients achieved an objective response to treatment.

CONCLUSIONS

Dovitinib in combination with gemcitabine plus cisplatin or gemcitabine plus carboplatin was poorly tolerated due to myelosuppression.

The role of cabazitaxel in the treatment of metastatic castration-resistant prostate cancer

For decades, cytotoxic therapy was considered ineffective for the treatment of metastatic castration-resistant prostate cancer (mCRPC). Earlier therapies such as estramustine and mitoxantrone received regulatory approval based upon improvement in palliative endpoints. In 2004, docetaxel became the first treatment to demonstrate a significant survival benefit in patients with mCRPC based on two randomized phase III studies, TAX327 and SWOG 99-16. Cabazitaxel, a third-generation taxane, was chosen for clinical development based on its decreased affinity for the drug efflux pump, p-glycoprotein, which is a frequent cause of drug resistance in docetaxel-resistant preclinical models. In 2010, cabazitaxel was approved by the US Food and Drug Administration as the first therapy to show a survival benefit for the treatment of patients with docetaxel-refractory mCRPC. This review summarizes the existing literature on the use of cabazitaxel, focusing on its efficacy and safety in combination with prednisone in the treatment of mCRPC, as well as its role in an era of new therapeutic options.