Ian D. Davis

Pazopanib in Locally Advanced or Metastatic Renal Cell Carcinoma: Results of a Randomized Phase III Trial

PURPOSE Pazopanib is an oral angiogenesis inhibitor targeting vascular endothelial growth factor receptor, platelet-derived growth factor receptor, and c-Kit. This randomized, double-blind, placebo-controlled phase III study evaluated efficacy and safety of pazopanib monotherapy in treatment-naive and cytokine-pretreated patients with advanced renal cell carcinoma (RCC). PATIENTS AND METHODS Adult patients with measurable, locally advanced, and/or metastatic RCC were randomly assigned 2:1 to receive oral pazopanib or placebo. The primary end point was progression-free survival (PFS). Secondary end points included overall survival, tumor response rate (Response Evaluation Criteria in Solid Tumors), and safety. Radiographic assessments of tumors were independently reviewed. Results Of 435 patients enrolled, 233 were treatment naive (54%) and 202 were cytokine pretreated (46%). PFS was significantly prolonged with pazopanib compared with placebo in the overall study population (median, PFS 9.2 v 4.2 months; hazard ratio [HR], 0.46; 95% CI, 0.34 to 0.62; P < .0001), the treatment-naive subpopulation (median PFS 11.1 v 2.8 months; HR, 0.40; 95% CI, 0.27 to 0.60; P < .0001), and the cytokine-pretreated subpopulation (median PFS, 7.4 v 4.2 months; HR, 0.54; 95% CI, 0.35 to 0.84; P < .001). The objective response rate was 30% with pazopanib compared with 3% with placebo (P < .001). The median duration of response was longer than 1 year. The most common adverse events were diarrhea, hypertension, hair color changes, nausea, anorexia, and vomiting. There was no evidence of clinically important differences in quality of life for pazopanib versus placebo. CONCLUSION Pazopanib demonstrated significant improvement in PFS and tumor response compared with placebo in treatment-naive and cytokine-pretreated patients with advanced and/or metastatic RCC.

A randomised, double-blind phase III study of pazopanib in patients with advanced and/or metastatic renal cell carcinoma: Final overall survival results and safety update

BACKGROUND In this randomised phase III study (VEG105192; NCT00334282), pazopanib previously demonstrated statistically and clinically meaningful improvement of progression-free survival versus placebo in patients with advanced/metastatic renal cell carcinoma (mRCC). Final overall survival (OS) and updated safety results are now reported. METHODS Treatment-naive or cytokine-pretreated mRCC patients (n=435) stratified and randomised (2:1) to pazopanib 800 mg daily or placebo, were treated until disease progression, death or unacceptable toxicity. Upon progression, placebo patients could receive pazopanib through an open-label study. Final OS in the intent-to-treat population was analysed using a stratified log-rank test. Rank-preserving structural failure time (RPSFT) and inverse probability of censoring weighted (IPCW) analyses were performed post-hoc to adjust for crossover. FINDINGS The difference in final OS between pazopanib- and placebo-treated patients was not statistically significant (22.9 versus 20.5 months, respectively; hazard ratio [HR]=0.91; 95% confidence interval [CI], 0.71-1.16; one-sided P=.224). Early and frequent crossover from placebo to pazopanib and prolonged duration of crossover treatment confounded the OS analysis. In IPCW analyses, pazopanib decreased mortality (HR=0.504; 95% CI, 0.315-0.762; two-sided P=.002). Similar, albeit non-significant, results were obtained in RPSFT analyses (HR=0.43; 95% CI, 0.215-1.388; two-sided P=.172). Since the last cutoff, cumulative exposure to pazopanib increased by 30%. The pazopanib safety profile showed no new safety signals or changes in the type, frequency and severity of adverse events. INTERPRETATION Although no significant difference in OS was observed in this study, extensive crossover from placebo to pazopanib confounded final OS analysis. Post-hoc analyses adjusting for crossover suggest OS benefit with pazopanib treatment for mRCC patients.

Efficacy and Safety of Pazopanib in Patients With Metastatic Renal Cell Carcinoma

PURPOSE Inactivation of the von Hippel-Lindau gene in clear-cell renal cell carcinomas (RCC) leads to overexpression of hypoxia inducible factor, a transcription factor regulating vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) gene expression. Pazopanib, an angiogenesis inhibitor targeting VEGF receptor, PDGF receptor, and c-KIT, was evaluated in patients with RCC. PATIENTS AND METHODS This phase II study was designed as a randomized discontinuation study but was revised to an open-label study on the recommendation of the data monitoring committee (based on week 12 response rate [RR] of 38% in the first 60 patients). The primary end point was changed from progressive disease rate at 16 weeks postrandomization to RR. Pazopanib 800 mg was administered orally once daily. Pazopanib 800 mg was administered orally once daily. RESULTS The study enrolled 225 patients with metastatic RCC; 155 patients (69%) were treatment naïve, and 70 patients (31%) had received one prior cytokine- or bevacizumab-containing regimen. Overall RR was 35%; median duration of response was 68 weeks. Median progression-free survival (PFS) was 52 weeks. Eastern Cooperative Oncology Group performance status of 0 and time from diagnosis to treatment of more than 1 year were correlated with prolonged PFS. Pazopanib was generally well tolerated. The most common adverse events were diarrhea, fatigue, and hair depigmentation. The most common laboratory abnormalities were elevated AST and ALT. CONCLUSION Pazopanib demonstrated durable activity in patients with advanced RCC and was generally well tolerated in this population. These findings support the further development of pazopanib in advanced RCC.

CLINICAL ROLE OF F-18 FLUORODEOXYGLUCOSE POSITRON EMISSION TOMOGRAPHY FOR DETECTION AND MANAGEMENT OF RENAL CELL CARCINOMA

PURPOSE We evaluate the accuracy of F-18 fluorodeoxyglucose (FDG)-positron emission tomography (PET) for staging and management of renal cell carcinoma. MATERIALS AND METHODS FDG-PET was performed in 25 patients with known or suspected primary renal tumors and/or metastatic disease and compared with conventional imaging techniques, including computerized tomography (CT). Histopathological confirmation was obtained in 18 patients and confirmation of the disease was by followup in the remainder. The impact of FDG-PET on disease management was also assessed. RESULTS Of the 17 patients with known or suspected primary tumors FDG-PET was true positive in 15, true negative in 1 and false-negative in 1. Comparative CT was true positive in 16 patients and false-positive in 1. The accuracy of FDG-PET and CT was similar (94%). All patients would have undergone radical nephrectomy after conventional imaging findings but FDG-PET results altered treatment decisions for 6 (35%), of whom 3 underwent partial nephrectomy and 3 avoided surgery due to confirmation of benign pathology or detection of unsuspected metastatic disease. Of the 8 cases referred for evaluation of local recurrence and/or metastatic disease FDG-PET changed treatment decisions in 4 (50%), with disease up staged in 3 and recurrence excluded in 1. Compared with CT, FDG-PET was able to detect local recurrence and distant metastases more accurately and differentiated recurrence from radiation necrosis. CONCLUSIONS FDG-PET accurately detected local disease spread and metastatic disease in patients with renal cell carcinoma and altered treatment in 40%. FDG-PET may have a role in the diagnostic evaluation of patients with renal cell carcinoma preoperatively and staging of metastatic disease.

Management of patients with advanced prostate cancer: recommendations of the St Gallen Advanced Prostate Cancer Consensus Conference (APCCC) 2015

The first St Gallen Advanced Prostate Cancer Consensus Conference (APCCC) Expert Panel identified and reviewed available evidence for the ten most important areas of controversy in advanced prostate cancer management. Recommendations based on expert opinion are presented. Detailed decisions on treatment will involve clinical consideration of disease extent and location, prior treatments, host factors, patient preferences and logistical and economic constraints.

Rational approaches to human cancer immunotherapy.

Over most of the 20th century, immunotherapy for cancer was based on empiricism. Interesting phenomena were observed in the areas of cancer, infectious diseases, or transplantation. Inferences were made and extrapolated into new approaches for the treatment of cancer. If tumors regressed, the treatment approaches could be refined further. However, until the appropriate tools and reagents were available, investigators were unable to understand the biology underlying these observations. In the early 1990s, the first human tumor T cell antigens were defined and dendritic cells were discovered to play a pivotal role in antigen presentation. The current era of cancer immunotherapy is one of translational research based on known biology and rationally designed interventions and has led to a rapid expansion of the field. The beginning of the 21st century brings the possibility of a new era of effective cancer immunotherapy, combining rational, immunological treatments with conventional therapies to improve the outcome for patients with cancer.

Tumor Antigen Expression in Melanoma Varies According to Antigen and Stage

Purpose: Melanoma cells express antigens that can induce T-cell and antibody responses. Obtaining a detailed understanding of antigen expression in primary and metastatic melanoma is essential if these molecules are to be useful targets for immunotherapy of melanoma. Experimental Design: Malignant melanomas (n = 586) from 426 patients were typed for antigen expression. Multiple samples were available from 86 individuals, enabling analysis of antigen expression patterns over time. Paraffin-embedded samples were tested by immunohistochemistry for the presence of the differentiation antigens: gp100, Melan-A, tyrosinase, and the “cancer/testis” antigens MAGE-A1, MAGE-A4, and NY-ESO-1. Results: Samples were primary tumors (n = 251), lymph node metastases (n = 174), s.c. metastases (n = 71), and distant metastases (n = 90). The differentiation antigens were strongly expressed in 93% to 95% of tumors regardless of stage. In contrast, the frequency of cancer/testis antigen expression in primary tumors for MAGE-A1, MAGE-A4, and NY-ESO-1 was lower (20%, 9%, and 45%, respectively). MAGE-A1 and MAGE-A4 were acquired with advancing disease (to 51% and 44% in distant metastases, respectively) but not NY-ESO-1, which remained positive in 45%. MAGE-A1 expression was twice as prevalent in ulcerated primaries as in nonulcerated primaries (30% versus 15%; P = 0.006) and in thicker as opposed to thin melanomas (26% versus 10%; P = 0.1). Conclusions: This large series describes patterns of antigen expression in melanoma and their evolution over time. This will help inform decisions about selection of patients and target antigens for melanoma immunotherapy clinical trials.

Breast and prostate cancer: more similar than different

Breast cancer and prostate cancer are the two most common invasive cancers in women and men, respectively. Although these cancers arise in organs that are different in terms of anatomy and physiological function both organs require gonadal steroids for their development, and tumours that arise from them are typically hormone-dependent and have remarkable underlying biological similarities. Many of the recent advances in understanding the pathophysiology of breast and prostate cancers have paved the way for new treatment strategies. In this Opinion article we discuss some key issues common to breast and prostate cancer and how new insights into these cancers could improve patient outcomes.

Dovitinib versus sorafenib for third-line targeted treatment of patients with metastatic renal cell carcinoma: an open-label, randomised phase 3 trial

BACKGROUND An unmet medical need exists for patients with metastatic renal cell carcinoma who have progressed on VEGF-targeted and mTOR-inhibitor therapies. Fibroblast growth factor (FGF) pathway activation has been proposed as a mechanism of escape from VEGF-targeted therapies. Dovitinib is an oral tyrosine-kinase inhibitor that inhibits VEGF and FGF receptors. We therefore compared dovitinib with sorafenib as third-line targeted therapies in patients with metastatic renal cell carcinoma. METHODS In this multicentre phase 3 study, patients with clear cell metastatic renal cell carcinoma who received one previous VEGF-targeted therapy and one previous mTOR inhibitor were randomly assigned through an interactive voice and web response system to receive open-label dovitinib (500 mg orally according to a 5-days-on and 2-days-off schedule) or sorafenib (400 mg orally twice daily) in a 1:1 ratio. Randomisation was stratified by risk group and region. The primary endpoint was progression-free survival (PFS) assessed by masked central review. Efficacy was assessed in all patients who were randomly assigned and safety was assessed in patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov, number NCT01223027. FINDINGS 284 patients were randomly assigned to the dovitinib group and 286 to the sorafenib group. Median follow-up was 11·3 months (IQR 7·9-14·6). Median PFS was 3·7 months (95% CI 3·5-3·9) in the dovitinib group and 3·6 months (3·5-3·7) in the sorafenib group (hazard ratio 0·86, 95% CI 0·72-1·04; one-sided p=0·063). 280 patients in the dovitinib group and 284 in the sorafenib group received at least one dose of study drug. Common grade 3 or 4 adverse events included hypertriglyceridaemia (38 [14%]), fatigue (28 [10%]), hypertension (22 [8%]), and diarrhoea (20 [7%]) in the dovitinib group, and hypertension (47 [17%]), fatigue (24 [8%]), dyspnoea (21 [7%]), and palmar-plantar erythrodysaesthesia (18 [6%]) in the sorafenib group. The most common serious adverse event was dyspnoea (16 [6%] and 15 [5%] in the dovitinib and sorafenib groups, respectively). INTERPRETATION Dovitinib showed activity, but this was no better than that of sorafenib in patients with renal cell carcinoma who had progressed on previous VEGF-targeted therapies and mTOR inhibitors. This trial provides reference outcome data for future studies of targeted inhibitors in the third-line setting. FUNDING Novartis Pharmaceuticals Corporation.

The regulatory T cell-associated transcription factor FoxP3 is expressed by tumor cells.

FoxP3 is a member of the forkhead family of transcription factors critically involved in the development and function of CD25(+) regulatory T cells (Treg). Until recently, FoxP3 expression was thought to be restricted to the T-cell lineage. However, using immunohistochemistry and flow cytometric analysis of human melanoma tissue, we detected FoxP3 expression not only in the tumor infiltrating Treg but also in the melanoma cells themselves. FoxP3 is also widely expressed by established human melanoma cell lines (as determined by flow cytometry, PCR, and Western blot), as well as cell lines derived from other solid tumors. Normal B cells do not express FoxP3; however, expression could be induced after transformation with EBV in vitro and in vivo, suggesting that malignant transformation of healthy cells can induce FoxP3. In addition, a FOXP3 mRNA variant lacking exons 3 and 4 was identified in tumor cell lines but was absent from Treg. Interestingly, this alternative splicing event introduces a translation frame-shift that is predicted to encode a novel protein. Together, our results show that FoxP3, a key regulator of immune suppression, is not only expressed by Treg but also by melanoma cells, EBV-transformed B cells, and a wide variety of tumor cell lines.