A phase 2, single-arm study of ramucirumab in patients with metastatic renal cell carcinoma with disease progression on or intolerance to tyrosine kinase inhibitor therapy.

BACKGROUND: Multitargeted tyrosine kinase inhibitors (TKIs) have antitumor activity in metastatic renal cell carcinoma (mRCC). Resistance to these agents develops frequently, and their use is often limited by intolerance. Ramucirumab is a recombinant human monoclonal antibody directed against human vascular endothelial growth factor receptor-2. For this study, the authors investigated the clinical efficacy and safety of ramucirumab in patients with TKI-resistant/intolerant mRCC. METHODS: In this single-arm phase 2 trial, patients received ramucirumab 8 mg/kg every 2 weeks until they developed disease progression or intolerable toxicity. The primary endpoint was the best objective response rate (ORR); additional endpoints included the disease control rate (DCR), progression-free survival (PFS), the median duration of overall response, and safety. RESULTS: Thirty-nine patients with RCC received ramucirumab monotherapy. Prior TKI therapy included sunitinib (59% of patients), sunitinib and sorafenib (30.8% of patients), and sorafenib (10.3% of patients). The ORR was 5.1% (95% confidence interval [CI], 0.6%-17.3%). The 12-week DCR was 64.1% (95% CI, 47.2%-78.8%). The median PFS was 7.1 months (95% CI, 4.1-9.7 months), and the median overall survival was 24.8 months (95% CI, 18.9-32.6 months). Grade 3 or higher adverse events that occurred in ≥5% of patients included grade 3 hypertension (7.7%) and proteinuria (5.1%). There was 1 on-study death from multiorgan failure. CONCLUSIONS: Although the study did not meet its primary endpoint of ≥15% ORR, ramucirumab was associated with evidence of antitumor activity in patients with TKI-resistant/intolerant mRCC. Ramucirumab was safe and well tolerated.

A phase I study of temsirolimus and bryostatin-1 in patients with metastatic renal cell carcinoma and soft tissue sarcoma.

BACKGROUND: Temsirolimus, an inhibitor of mammalian target of rapamycin (mTOR) complex 1, is approved for the treatment of metastatic renal cell carcinoma (RCC). Bryostatin-1 inhibits protein kinase C, a downstream effector of mTOR complex 2. We observed antitumor effects with the combination of temsirolimus and bryostatin-1 in RCC cell lines. METHODS. Four cohorts of patients received weekly bryostatin-1 (20 µg/m²) with temsirolimus (10, 15, 25, or 37.5 mg) in 28-day cycles. RESULTS: Thirty patients received a total of 138 cycles across four dose levels. Twenty-five patients had RCC (17 clear cell, 7 papillary, and 1 unclassified). Two sarcoma patients with prior cytotoxic therapy experienced dose-limiting toxicity at 15 mg of temsirolimus (grade 3 neutropenia and grade 3 hypophosphatemia). Subsequently, patients with prior cytotoxic therapy were excluded. Two additional dose-limiting toxicities were noted with 37.5 mg of temsirolimus (grade 3 neutropenia and grade 3 creatinine elevation). Consequently, the maximum tolerated dose was defined as temsirolimus at 25 mg and bryostatin-1 at 20 µg/m² every 28 days. Of the 25 RCC patients, 3 patients had partial responses that lasted for 14 months, 28 months, and ≥ 80 months, respectively. Partial responses were seen in both clear cell and papillary histology. CONCLUSION: This combination of 37.5 mg of temsirolimus with 20 µg/m² of bryostatin-1 was reasonably safe and well tolerated. Durable responses were observed in 3 of 25 patients with RCC.

Serum amino acid levels as a biomarker for renal cell carcinoma.

PURPOSE: Prognosis in renal cell carcinoma is dependent on tumor stage at presentation, with significant differences in survival between early and late stage disease. Currently to our knowledge no screening tests or biomarkers have been identified for the early detection of kidney cancer. Therefore, we investigated whether serum amino acid profiles are a potentially useful biomarker in patients with renal cell carcinoma. MATERIALS AND METHODS: The concentrations of 26 amino acids were determined in serum taken preoperatively from 189 patients with renal cell carcinoma, and from 104 age and sex matched controls. RESULTS: Statistically significant changes were observed in patient levels of 15 amino acids, with 13 being decreased and 2 being increased. A logistic regression model using 8 amino acids including cysteine, ornithine, histidine, leucine, tyrosine, proline, valine and lysine was created to distinguish cases from controls. A receiver operator curve based on this model had an area under the curve of 0.81. This same model also had predictive value in terms of overall survival and tumor recurrence in patients with renal cell carcinoma. CONCLUSIONS: Our findings suggest that serum amino acid levels may be useful as a screening tool for the identification of individuals with renal cell carcinoma and the prediction of outcomes.

Selecting targeted therapies for patients with renal cell carcinoma.

Advanced renal cell carcinoma (RCC) is a heterogeneous disease with variable histology, biology, and response to treatment. In the past 5 years, 6 new agents have been approved for the treatment of RCC, and many more are in clinical development. With an ever-increasing number of treatment options, selecting among them for a particular patient can be a daunting task for clinicians. This article describes how treatment choice can be guided by the disease setting and histology, as well as patient characteristics, comorbidities, and preference within the context of available data. Results from clinical trials are combined with practical considerations to make recommendations for first-line and subsequent treatment of patients with clear cell and non-clear cell RCC. These recommendations should supplement the current NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for the treatment of advanced RCC.

NCCN Task Force report: optimizing treatment of advanced renal cell carcinoma with molecular targeted therapy.

The outcome of patients with metastatic renal cell carcinoma has been substantially improved with administration of the currently available molecularly targeted therapies. However, proper selection of therapy and management of toxicities remain challenging. NCCN convened a multidisciplinary task force panel to address the clinical issues associated with these therapies in attempt to help practicing oncologists optimize patient outcomes. This report summarizes the background data presented at the task force meeting and the ensuing discussion.

Combined classical cytogenetics and microarray-based genomic copy number analysis reveal frequent 3;5 rearrangements in clear cell renal cell carcinoma.

Karyotypic analysis and genomic copy number analysis with single nucleotide polymorphism (SNP)-based microarrays were compared with regard to the detection of recurrent genomic imbalances in 20 clear cell renal cell carcinomas (ccRCCs). Genomic imbalances were identified in 19 of 20 tumors by DNA copy number analysis and in 15 tumors by classical cytogenetics. A statistically significant correlation was observed between the number of genomic imbalances and tumor stage. The most common genomic imbalances were loss of 3p and gain of 5q. Other recurrent genomic imbalances seen in at least 15% of tumors included losses of 1p32.3-p33, 6q23.1-qter and 14q and gain of chromosome 7. The SNP-based arrays revealed losses of 3p in 16 of 20 tumors, with the highest frequency being at 3p21.31-p22.1 and 3p24.3-p25.3, the latter encompassing the VHL locus. One other tumor showed uniparental disomy of chromosome 3. Thus, altogether loss of 3p was identified in 17 of 20 (85%) cases. Fourteen tumors showed both overlapping losses of 3p and overlapping gains of 5q, and the karyotypic assessment performed in parallel revealed that these imbalances arose via unbalanced 3;5 translocations. Among the latter, there were common regions of loss at 3p21.3-pter and gain at 5q34-qter. These data suggest that DNA copy number analysis will supplant karyotypic analysis of tumor types such as ccRCC that are characterized by recurrent genomic imbalances, rather than balanced rearrangements. These findings also suggest that the 5q duplication/3p deficiency resulting from unbalanced 3;5 translocations conveys a proliferative advantage of particular importance in ccRCC tumorigenesis.

Phase II Trial of Eribulin in Patients With Metastatic Hormone Refractory Prostate Cancer: A Trial of the ECOG-ACRIN Cancer Research Group (E5805).

BACKGROUND: Eribulin mesylate, a synthetic analog of halichondrin B, is a novel tubulin-binding agent that inhibits cancer cell proliferation at low-nanomolar levels. METHODS: In a multicenter ECOG trial, patients with progressive metastatic CRPC, ECOG 0-2 were treated with eribulin 1.4 mg/m as an IV bolus over 5 minutes on days 1 and 8 of a 21-day cycle. This noncomparative study stratified points to either a chemonaive (CN), prior-taxane (Tax) only, or 2 prior cytotoxic (TCx) chemotherapy arm. The trial was powered to detect a 50% PSA reduction using Consensus Criteria in at least 40% versus 20% (90% power, one-sided α=0.10) for the CN stratum and 25% versus. 10% (power 87%, one-sided α=0.10) for the Tax and TCx strata. RESULTS: In total, 119 pts received treatment of which 116 were eligible for the primary response determination in this study. Median age 70 years (range, 45 to 88); median number of treatment cycles 4 (range, 1 to 20+); ECOG 0-1 90%. Confirmed PSA response rates (50% decline from baseline) were 29% (90% [18.2%, 41.2%]; P=0.20), 10% (90% [5.2%, 27.1%]; P=1.00), and 4% ([0.2%, 18.3%]; P=0.59) in the chemonaive stratum, the prior-taxane stratum, and the 2-prior-chemotherapy stratum, respectively. Median progression-free survival was 3.5 months (95% CI, 2.0, 5.9), 2.3 months (95% CI, 2.0, 2.9) and 3.7 months (95% CI, 2.1, 4.2) for the chemonaive stratum, the prior-taxane stratum and the 2-prior-chemotherapy stratum, respectively. Nonhematological toxicities of any grade (mainly grade 1 and 2) were fatigue (74%), neuropathy (40%), alopecia (39%), nausea (35%), and anorexia (34%). Common hematological toxicities were decreased leukocytes (75%), decreased neutrophils (72%), and decreased hemoglobin (66%). The most common grade ≥ 3 toxicities were decreased neutrophils (55%), decreased leukocytes (42%), sensory neuropathy (13%), and fatigue (11%). Overall, there was a 4% rate of febrile neutropenia. CONCLUSIONS: In summary, per the prespecified study endpoints, eribulin did not have adequate activity in chemotherapy naïve or chemotherapy pretreated patients with metastatic CRPC to support further study in this setting.

Axitinib treatment in patients with cytokine-refractory metastatic renal-cell cancer: a phase II study.

BACKGROUND: Axitinib (AG-013736) is an oral, potent, and selective inhibitor of vascular endothelial growth factor receptors 1, 2, and 3. We aimed to assess the activity and safety of axitinib in patients with metastatic renal-cell cancer who had failed on previous cytokine-based treatment. METHODS: Between Oct 3, 2003, and April 7, 2004, 52 patients were enrolled. All patients who had at least one measurable target lesion received axitinib orally (starting dose 5 mg twice daily). The primary endpoint was objective response (ie, percentage of patients with confirmed complete response or partial response by use of Response Evaluation Criteria In Solid Tumors [RECIST] criteria. Secondary endpoints were duration of response, time to progression, overall survival, safety, pharmacokinetics, and patient-reported health-related quality of life. This trial is registered on the clinical trials site of the US National Cancer Institute website http://www.clinicaltrials.gov/ct/show/NCT00076011. FINDINGS: In an intention-to-treat analysis, two complete and 21 partial responses were noted, for an objective response rate of 44.2% (95% CI 30.5-58.7). Median response duration was 23.0 months (20.9-not estimable; range 4.2-29.8). However, 12 of 23 initial responders progressed with response duration ranging from 4.2 months to 26.5 months. Additionally, 22 patients showed stable disease for longer than 8 weeks, including 13 patients with stable disease for 24 weeks or longer. Four patients had early disease progression. Three patients had missing response data. Median time to progression was 15.7 months (8.4-23.4, range 0.03-31.5) and median overall survival was 29.9 months (20.3-not estimable; range 2.4-35.8). Treatment-related adverse events included diarrhoea, hypertension, fatigue, nausea, and hoarseness. Treatment-related hypertension occurred in 30 patients and resolved with antihypertensive treatment in all but eight patients, of whom seven patients had a history of hypertension at baseline. INTERPRETATION: Axitinib shows clinical activity in patients with cytokine-refractory metastatic renal-cell cancer. Although 28 patients had grade 3 or grade 4 treatment-related adverse events, these adverse events were generally manageable and controlled by dose modification or supportive care, or both. Further studies are needed to confirm these findings.

Phase 2 Study of Weekly Paclitaxel Plus Estramustine in Metastatic Hormone-Refractory Prostate Carcinoma: ECOG-ACRIN Cancer Research Group (E1898) Trial.

INTRODUCTION: This multicenter phase 2 study assessed the combination of estramustine and weekly paclitaxel with metastatic castration-resistant prostate cancer (CRPC). PATIENTS AND METHODS: We enrolled 77 patients who had received no prior chemotherapy for CRPC between 1998 and 2000; a total of 74 subjects were eligible for the study. Each 8-week cycle included paclitaxel 90 mg/m2 provided intravenously weekly for 6 weeks, followed by 2 weeks off therapy and oral estramustine 280 mg twice daily for 3 days beginning 24 hours before the first dose of paclitaxel. The primary end point was rate of objective or prostate-specific antigen (PSA) response at 16 weeks. A 50% response rate was considered of further interest. RESULTS: Eligible patients received a median of 3 cycles (range, 1-10 cycles). The response rate among patients with measurable disease was 34% (95% confidence interval [CI], 19-52). The PSA response rate was 58% (95% CI, 47-70). Clinical benefit rate was 45% (95% CI, 33-57). The median progression-free survival was 5.9 months (95% CI, 4.4-6.7). The median overall survival was 17.6 months (95% CI, 14.6-20.8). The most common clinical grade 3/4 toxicities were fatigue (14%) and sensory neuropathy (7%). Grade 3/4 hematologic toxicities included lymphopenia (21%) and anemia (9%). There was one toxicity-related death. Quality-of-life scores improved by week 8, but the change was not statistically significant. CONCLUSION: The combination has activity defined by PSA declines in CRPC but did not meet the protocol-specified end point for efficacy as defined by objective response rate. Since this study was conducted, more effective, better-tolerated regimens have been developed.

Impact of zoledronic acid on renal function in patients with cancer: Clinical significance and development of a predictive model.

Zoledronic acid is a potent bisphosphonate licensed for the treatment of myeloma and bone metastases from solid tumors. Renal deterioration is the most significant toxicity associated with zoledronic acid. We attempted to define the incidence and clinical significance of renal deterioration in patients receiving zoledronic acid and to develop a risk-factor profile for this treatment sequela. This study is a retrospective analysis of all patients who received zoledronic acid at Fox Chase Cancer Center, Philadelphia, Pa, between 1/10/02 and 1/30/04. Data recorded included patient demographics, tumor characteristics, comorbid illnesses, concomitant medications, cancer therapy, number of zoledronic acid doses administered, and serial creatinine measurements. In total, 3,115 evaluable doses of zoledronic acid were administered to 446 patients (median, 4 doses; mean, 6.98 doses; range, 1-28 doses) at a dose of 4 mg over 15 minutes every 3-4 weeks. Of these 446 patients, 42 experienced renal deterioration (median rise in creatinine level, 1.0 mg/dL; range, 0.5-4.4 mg/dL), requiring discontinuation of zoledronic acid therapy in 8 cases. No patient required dialysis and no patient died as a result of zoledronic acid-induced renal dysfunction. On multivariable analysis, predictive factors for the development of renal deterioration were patient age, a diagnosis of myeloma or renal cell cancer, cumulative number of doses, concomitant therapy with a nonsteroidal anti-inflammatory drug, and current or prior therapy with cisplatin. Using these factors, we constructed a predictive model with an area under the receiver operating characteristic curve of 0.75. The incidence of clinically significant renal deterioration in patients treated with zoledronic acid is low.We present a predictive model for decision support when estimating this risk.

Sunitinib in patients with metastatic renal cell carcinoma.

CONTEXT: Current treatment options for metastatic renal cell carcinoma (RCC) are limited and there is a need to identify novel and effective therapies. Sunitinib malate is an oral multitargeted tyrosine kinase inhibitor, which has shown activity in an initial study of cytokine-refractory metastatic RCC patients. OBJECTIVE: To confirm the antitumor efficacy of sunitinib as second-line treatment in patients with metastatic clear-cell RCC, the predominant cell type of this malignancy. DESIGN, SETTING, AND PATIENTS: Open-label, single-arm, multicenter clinical trial. Patients were enrolled between February and November 2004, with follow-up continuing until disease progression, unacceptable toxicity, or withdrawal of consent. The reported data apply through August 2005. Patients (N = 106) had metastatic clear-cell RCC, which had progressed despite previous cytokine therapy. INTERVENTION: Repeated 6-week cycles of sunitinib, 50 mg per day given orally for 4 consecutive weeks followed by 2 weeks off per treatment cycle. MAIN OUTCOME MEASURES: Assessment of clinical response, degree of tumor regression on imaging studies using the Response Evaluation Criteria in Solid Tumors (RECIST) guidelines. Primary end point was overall objective response rate (complete plus partial). Secondary end points were progression-free survival and safety. Response was evaluated by independent third-party core imaging laboratory and by treating physicians (investigator assessment). RESULTS: All 106 patients received sunitinib and were included in the intent-to-treat population for safety analyses. Of these, 105 patients were evaluable for efficacy analyses. The objective response rate according to an independent third-party assessment resulted in 36 patients with partial response (34%; 95% confidence interval, 25%-44%), and a median progression-free survival of 8.3 months (95% confidence interval, 7.8-14.5 months). The most common adverse events experienced by patients were fatigue in 30 (28%) and diarrhea 21 (20%). Neutropenia, elevation of lipase, and anemia were the most common laboratory abnormalities observed in 45 (42%), 30 (28%), and 27 (26%) patients, respectively. CONCLUSION: The results of this trial demonstrate the efficacy and manageable adverse-event profile of sunitinib as a single agent in second-line therapy for patients with cytokine-refractory metastatic clear-cell RCC. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00077974.

Randomized phase II study of multiple dose levels of CCI-779, a novel mammalian target of rapamycin kinase inhibitor, in patients with advanced refractory renal cell carcinoma.

PURPOSE: To evaluate the efficacy, safety, and pharmacokinetics of multiple doses of CCI-779, a novel mammalian target of rapamycin kinase inhibitor, in patients with advanced refractory renal cell carcinoma (RCC). PATIENTS AND METHODS: Patients (n = 111) were randomly assigned to receive 25, 75, or 250 mg CCI-779 weekly as a 30-minute intravenous infusion. Patients were evaluated for tumor response, time to tumor progression, survival, and adverse events. Blood samples were collected to determine CCI-779 pharmacokinetics. RESULTS: CCI-779 produced an objective response rate of 7% (one complete response and seven partial responses) and minor responses in 26% of these advanced RCC patients. Median time to tumor progression was 5.8 months and median survival was 15.0 months. The most frequently occurring CCI-779-related adverse events of all grades were maculopapular rash (76%), mucositis (70%), asthenia (50%), and nausea (43%). The most frequently occurring grade 3 or 4 adverse events were hyperglycemia (17%), hypophosphatemia (13%), anemia (9%), and hypertriglyceridemia (6%). Neither toxicity nor efficacy was significantly influenced by CCI-779 dose level. Patients were retrospectively classified into good-, intermediate-, or poor-risk groups on the basis of criteria used by Motzer et al for a first-line metastatic RCC population treated with interferon alfa. Within each risk group, the median survivals of patients at each dose level were similar. CONCLUSION: In patients with advanced RCC, CCI-779 showed antitumor activity and encouraging survival and was generally well tolerated over the three dose levels tested.

Phase II and pharmacodynamic study of the farnesyltransferase inhibitor R115777 as initial therapy in patients with metastatic pancreatic adenocarcinoma.

PURPOSE: R115777 is a selective nonpeptidomimetic inhibitor of farnesyltransferase (FTase), one of several enzymes responsible for posttranslational modification that is required for the function of p21(ras) and other proteins. Given that RAS mutations are nearly universal in pancreatic cancer and R115777 demonstrated preclinical activity against pancreatic cell lines and xenografts, this phase II study was undertaken to determine its clinical activity and effect on target proteins in patients with measurable metastatic pancreatic adenocarcinoma. PATIENTS AND METHODS: Twenty patients who had not received prior therapy for metastatic disease were treated with 300 mg of R115777 orally every 12 hours for 21 of 28 days. Inhibition of FTase activity in peripheral-blood mononuclear cells was measured using a lamin B C-terminus peptide as substrate. Western blot analysis was performed to monitor farnesylation status of the chaperone protein HDJ-2. RESULTS: No objective responses were seen. Median time to progression was 4.9 weeks, and median survival time was 19.7 weeks. The estimated 6-month survival rate was 25%, with no patients progression-free at 6 months. Grade 3/4 toxicities were liver enzyme elevation, anemia, neutropenia, thrombocytopenia, fatigue, nausea/vomiting, rash, and anorexia. FTase activity (mean +/- SD) decreased by 49.8% +/- 9.8% 4 hours after treatment on day 1 and 36.1% +/- 24.8% before treatment on day 15. HDJ-2 farnesylation (mean +/- SD) decreased by 33.4% +/- 19.8% on day 15. CONCLUSION: Although treatment with R115777 resulted in partial inhibition of FTase activity in mononuclear cells, it did not exhibit single-agent antitumor activity in patients with previously untreated metastatic pancreatic cancer.

Patient characteristics compete with dose as predictors of acute treatment toxicity in early phase clinical trials.

PURPOSE: The purpose of this study was to identify patient characteristics that may be risk factors or markers of susceptibility to adverse treatment effects in cancer Phase I and II clinical trials. PATIENTS AND METHODS: A total of 459 patients enrolled in 23 therapeutic Phase I and II studies at the Fox Chase Cancer Center were included in the analysis. Patient-specific characteristics, medical and treatment history, doses of experimental agents, and graded toxicities were extracted from case report forms. We developed a novel summary measure, the toxicity index (TI), to better discriminate patients on the basis of their overall toxicity experiences. Mixed model ANOVA was used to model TI on the basis of data from all trials using a specific agent. Generalized estimating equations in the context of binary logistic regression were used to model dose-limiting toxicity. RESULTS: Seventeen pretreatment factors, including performance status, alkaline phosphatase, total bilirubin, serum creatinine, and tobacco use, emerged as significant predictors of toxicity as defined by dose-limiting toxicity or TI. Unexpectedly, dose was not always a predictor of toxicity. Even for values within the normal range, the TI identified serum bilirubin and alkaline phosphatase as predictors of toxicity after treatment with docetaxel and alkaline phosphatase as a predictor for toxicity after treatment with irinotecan. CONCLUSIONS: Independent of dose, certain pretreatment characteristics, including measures of organ function that are in the normal range, were found to be predictors of treatment toxicity. Because of its sensitivity to differences in overall toxicity, the TI should prove to be a useful tool for identifying predictors of chemotherapy-related toxicity.

Weekly bryostatin-1 in metastatic renal cell carcinoma: a phase II study.

PURPOSE: We conducted a Phase II trial of bryostatin-1, an inhibitor of protein kinase C, in advanced renal cell carcinoma to measure toxicity, response rate, time to progression, and induction of cytokines. EXPERIMENTAL DESIGN: A total of 32 patients (26 male and 6 female) received bryostatin-1 at 35-40 microg/m(2) i.v. over 1 h on days 1, 8, and 15 of each 4-week cycle. Plasma interleukin-6, tumor necrosis factor-alpha, and C-reactive protein levels were assayed pretreatment, 1 and 23 h after completion of bryostatin-1 infusion at weeks 1 and 5. RESULTS: Cycles (102) of bryostatin-1 were given (median 2, range 1-8). The most common grade 1 or 2 toxicities were myalgias (46.8%), fatigue (59.3%), and dyspnea (18.8%). Grade 3-4 toxicity included myalgias (40.6%), ataxia (9.3%), and dyspnea (15.6%). Four (12%) patients experienced cardiac events while on study (cardiac arrhythmias and congestive heart failure occurred in 2 patients, and 2 patients had fatal cardiac arrests). Of 32 patients evaluable for response, 2 (6.3%) had partial responses lasting 9 with 6 months. A total of 15 patients (46.8%) had stable disease, and 6 (18.8%) patients had stable disease for >or=6 months. Plasma interleukin-6 increased >or=2-fold over baseline measurements in 5 of 17 patients (29.4%) but did not correlate with response or toxicity. CONCLUSIONS: Although weekly bryostatin-1 at 35-40 microg/m(2) produced a low proportion of objective responses, prolonged (>6 months) stable disease or partial remission in 25% of patients suggests that this agent, or other inhibitors of protein kinase C, may have a role in the treatment of renal cell carcinoma, perhaps in combination with other agents.

Hydroxychloroquine Destabilizes Phospho-S6 in Human Renal Carcinoma Cells.

mTOR inhibitors are used to treat metastatic renal cell cancer (RCC), but most patients eventually become resistant. One possible mechanism for resistance is upregulation of autophagy, a pathway that helps recycle intracellular proteins and promotes cell survival. Hydroxychloroquine (HCQ), a potent autophagy inhibitor used to treat malaria and autoimmune disorders, is currently being studied in the context of cancer treatment. Here, we have investigated the effects of HCQ on three different renal carcinoma derived cell lines. We found that HCQ treatment inhibits RCC cell growth, promotes apoptosis, inhibits mitochondrial oxygen consumption, and increases rates of glycolysis. To understand the molecular mechanism behind these effects, we examined various nodes in the mTOR pathway and compared the effects of HCQ with the effects of the mTOR inhibitor RAD001. A key downstream readout of the pathway, phospho-S6 protein, was inhibited by both HCQ and RAD001. However, the upstream kinase, P70S6K was only inhibited by RAD001 and not HCQ, suggesting that the block by HCQ was downstream of P70S6K. Treatment with the proteasome inhibitor bortezomib restored phospho-S6 levels, suggesting that the reduction of phospho-S6 is caused by increased degradation of phospho-S6, but not total S6. Surprisingly, treatment with other autophagy inhibitors did not exhibit the same effects. Our findings suggest that HCQ causes the down-regulation of phospho-S6 in RCC cell lines via a novel mechanism that is not shared with other autophagy inhibitors.

Treatments for improving survival of patients with prostate cancer.

Prostate cancer is a heterogeneous disease characterised by a long natural history relative to other solid tumours. With the diagnosis of prostate cancer being made earlier, the emphasis of treatment has shifted from palliation of symptoms to altering disease-related morbidity and mortality and thus improving overall survival. Treatment of prostate cancer increasingly involves an approach that combines local therapies directed at the primary tumour together with systemic therapies to potentiate their effect and to control subclinical metastatic disease. Patients with localised tumours who are at high risk of relapsing with radiation therapy alone are surviving longer because of the addition of adjuvant hormonal therapy. Although a survival benefit in similar patients undergoing prostatectomy has not yet been established, preliminary results indicate that adjuvant hormonal therapy delays relapse. Chemotherapy is an effective palliative modality for patients with hormone- refractory metastatic disease, and recently completed phase III trials will determine if chemotherapy can prolong survival for this group. The role of chemotherapy in patients with locally advanced tumours is also being investigated in randomised clinical trials. Because bone is the dominant site of metastases for most patients with prostate cancer, the development of therapies that can slow tumour growth specifically within bone is a logical strategy. Bisphosphonates and bone-targeted radionuclides are two such approaches that have shown encouraging results even in the most advanced stages of the disease. Although one can now reasonably hypothesise that survival has improved because of recent therapeutic advances, it remains to be conclusively established that cytotoxic or other systemic therapy can extend survival of patients with prostate cancer. Only the results of ongoing randomised trials can definitely establish that more patients with locally advanced and metastatic prostate cancer are living longer.

PD-1 expression on peripheral blood cells increases with stage in renal cell carcinoma patients and is rapidly reduced after surgical tumor resection.

Programmed death-1 (PD-1) receptor is an inhibitory receptor on hematopoietic cells that can negatively regulate immune responses, particularly responses to tumors, which often upregulate PD-1 ligands. PD-1/PD-1 ligand blocking antibodies can reverse the inhibition and show significant therapeutic promise in treating renal cell carcinoma (RCC), lung cancer, and melanoma. While PD-1 expression on tumor-infiltrating lymphocytes has been associated with poor outcome in RCC, we sought to define immune cell biomarkers, including PD-1, on peripheral blood mononuclear cells (PBMC) that could predict disease progression of RCC patients before and after nephrectomy. We analyzed expression of numerous immune cell markers on fresh PBMCs from 90 RCC patients preoperatively and 25 age-matched healthy controls by 10-color flow cytometry. Postoperative blood samples were also analyzed from 23 members of the RCC patient cohort. The most striking phenotypic immune biomarker in RCC patients was a significant increase in PD-1 expression on certain PBMCs in a subset of patients. Increased PD-1 expression on CD14(bright) myelomonocytic cells, effector T cells, and natural killer (NK) cells correlated to disease stage, and expression was significantly reduced on all cell types soon after surgical resection of the primary tumor. The results indicate that PD-1 expression on fresh peripheral blood leukocytes may provide a useful indicator of RCC disease progression. Furthermore, measuring PD-1 levels in peripheral blood may assist in identifying patients likely to respond to PD-1 blocking antibodies, and these therapies may be most effective before and immediately after surgical resection of the primary tumor, when PD-1 expression is most prominent.