Jonathan E. Rosenberg

Atezolizumab in patients with locally advanced and metastatic urothelial carcinoma who have progressed following treatment with platinum-based chemotherapy: a single-arm, multicentre, phase 2 trial

BACKGROUND Patients with metastatic urothelial carcinoma have few treatment options after failure of platinum-based chemotherapy. In this trial, we assessed treatment with atezolizumab, an engineered humanised immunoglobulin G1 monoclonal antibody that binds selectively to programmed death ligand 1 (PD-L1), in this patient population. METHODS For this multicentre, single-arm, two-cohort, phase 2 trial, patients (aged ≥18 years) with inoperable locally advanced or metastatic urothelial carcinoma whose disease had progressed after previous platinum-based chemotherapy were enrolled from 70 major academic medical centres and community oncology practices in Europe and North America. Key inclusion criteria for enrolment were Eastern Cooperative Oncology Group performance status of 0 or 1, measurable disease defined by Response Evaluation Criteria In Solid Tumors version 1.1 (RECIST v1.1), adequate haematological and end-organ function, and no autoimmune disease or active infections. Formalin-fixed paraffin-embedded tumour specimens with sufficient viable tumour content were needed from all patients before enrolment. Patients received treatment with intravenous atezolizumab (1200 mg, given every 3 weeks). PD-L1 expression on tumour-infiltrating immune cells (ICs) was assessed prospectively by immunohistochemistry. The co-primary endpoints were the independent review facility-assessed objective response rate according to RECIST v1.1 and the investigator-assessed objective response rate according to immune-modified RECIST, analysed by intention to treat. A hierarchical testing procedure was used to assess whether the objective response rate was significantly higher than the historical control rate of 10% at an α level of 0·05. This study is registered with ClinicalTrials.gov, number NCT02108652. FINDINGS Between May 13, 2014, and Nov 19, 2014, 486 patients were screened and 315 patients were enrolled into the study. Of these patients, 310 received atezolizumab treatment (five enrolled patients later did not meet eligibility criteria and were not dosed with study drug). The PD-L1 expression status on infiltrating immune cells (ICs) in the tumour microenvironment was defined by the percentage of PD-L1-positive immune cells: IC0 (<1%), IC1 (≥1% but <5%), and IC2/3 (≥5%). The primary analysis (data cutoff May 5, 2015) showed that compared with a historical control overall response rate of 10%, treatment with atezolizumab resulted in a significantly improved RECIST v1.1 objective response rate for each prespecified immune cell group (IC2/3: 27% [95% CI 19-37], p<0·0001; IC1/2/3: 18% [13-24], p=0·0004) and in all patients (15% [11-20], p=0·0058). With longer follow-up (data cutoff Sept 14, 2015), by independent review, objective response rates were 26% (95% CI 18-36) in the IC2/3 group, 18% (13-24) in the IC1/2/3 group, and 15% (11-19) overall in all 310 patients. With a median follow-up of 11·7 months (95% CI 11·4-12·2), ongoing responses were recorded in 38 (84%) of 45 responders. Exploratory analyses showed The Cancer Genome Atlas (TCGA) subtypes and mutation load to be independently predictive for response to atezolizumab. Grade 3-4 treatment-related adverse events, of which fatigue was the most common (five patients [2%]), occurred in 50 (16%) of 310 treated patients. Grade 3-4 immune-mediated adverse events occurred in 15 (5%) of 310 treated patients, with pneumonitis, increased aspartate aminotransferase, increased alanine aminotransferase, rash, and dyspnoea being the most common. No treatment-related deaths occurred during the study. INTERPRETATION Atezolizumab showed durable activity and good tolerability in this patient population. Increased levels of PD-L1 expression on immune cells were associated with increased response. This report is the first to show the association of TCGA subtypes with response to immune checkpoint inhibition and to show the importance of mutation load as a biomarker of response to this class of agents in advanced urothelial carcinoma. FUNDING F Hoffmann-La Roche Ltd.

Bevacizumab Plus Interferon Alfa Compared With Interferon Alfa Monotherapy in Patients With Metastatic Renal Cell Carcinoma: CALGB 90206

PURPOSE Bevacizumab is an antibody that binds to vascular endothelial growth factor (VEGF) and has activity in metastatic renal cell carcinoma (RCC). Interferon alfa (IFN) is a historic standard first-line treatment for RCC. A prospective, randomized phase III trial of bevacizumab plus IFN versus IFN monotherapy was conducted. PATIENTS AND METHODS Patients with previously untreated, metastatic clear-cell RCC were randomly assigned to receive either bevacizumab (10 mg/kg intravenously every 2 weeks) plus IFN (9 million U subcutaneously three times weekly) or the same dose and schedule of IFN monotherapy in a multicenter phase III trial. The primary end point was overall survival (OS). Secondary end points were progression-free survival (PFS), objective response rate (ORR), and safety. RESULTS Between October 2003 and July 2005, 732 patients were enrolled. The prespecified stopping rule for OS has not yet been reached. The median PFS was 8.5 months in patients receiving bevacizumab plus IFN (95% CI, 7.5 to 9.7 months) versus 5.2 months (95% CI, 3.1 to 5.6 months) in patients receiving IFN monotherapy (log-rank P < .0001). The adjusted hazard ratio was 0.71 (95% CI, 0.61 to 0.83; P < .0001). Bevacizumab plus IFN had a higher ORR as compared with IFN (25.5% [95% CI, 20.9% to 30.6%] v 13.1% [95% CI, 9.5% to 17.3%]; P < .0001). Overall toxicity was greater for bevacizumab plus IFN, including significantly more grade 3 hypertension (9% v 0%), anorexia (17% v 8%), fatigue (35% v 28%), and proteinuria (13% v 0%). CONCLUSION Bevacizumab plus IFN produces a superior PFS and ORR in untreated patients with metastatic RCC as compared with IFN monotherapy. Toxicity is greater in the combination therapy arm.

Phase III Trial of Bevacizumab Plus Interferon Alfa Versus Interferon Alfa Monotherapy in Patients With Metastatic Renal Cell Carcinoma: Final Results of CALGB 90206

PURPOSE Bevacizumab is an antibody that binds vascular endothelial growth factor and has activity in metastatic renal cell carcinoma (RCC). Interferon alfa (IFN-alpha) is the historic standard initial treatment for RCC. A prospective, randomized, phase III trial of bevacizumab plus IFN-alpha versus IFN-alpha monotherapy was conducted. PATIENTS AND METHODS Patients with previously untreated, metastatic clear cell RCC were randomly assigned to receive either bevacizumab (10 mg/kg intravenously every 2 weeks) plus IFN-alpha (9 million units subcutaneously three times weekly) or the same dose and schedule of IFN-alpha monotherapy in a multicenter phase III trial. The primary end point was overall survival (OS). Secondary end points were progression-free survival (PFS), objective response rate, and safety. RESULTS Seven hundred thirty-two patients were enrolled. The median OS time was 18.3 months (95% CI, 16.5 to 22.5 months) for bevacizumab plus IFN-alpha and 17.4 months (95% CI, 14.4 to 20.0 months) for IFN-alpha monotherapy (unstratified log-rank P = .097). Adjusting on stratification factors, the hazard ratio was 0.86 (95% CI, 0.73 to 1.01; stratified log-rank P = .069) favoring bevacizumab plus IFN-alpha. There was significantly more grade 3 to 4 hypertension (HTN), anorexia, fatigue, and proteinuria for bevacizumab plus IFN-alpha. Patients who developed HTN on bevacizumab plus IFN-alpha had a significantly improved PFS and OS versus patients without HTN. CONCLUSION OS favored the bevacizumab plus IFN-alpha arm but did not meet the predefined criteria for significance. HTN may be a biomarker of outcome with bevacizumab plus IFN-alpha.

Antitumor Activity and Biomarker Analysis of Sunitinib in Patients With Bevacizumab-Refractory Metastatic Renal Cell Carcinoma

PURPOSE To assess the safety and efficacy of sunitinib in patients with bevacizumab-refractory metastatic renal cell carcinoma (mRCC) and explore biomarkers for sunitinib response. PATIENTS AND METHODS Patients with mRCC and disease progression after bevacizumab-based therapy received oral sunitinib 50 mg once daily in 6-week cycles on a 4/2 schedule (4 weeks with treatment followed by 2 weeks without treatment) in a phase II multicenter study. The primary end point was objective response rate (ORR). Secondary end points included progression-free survival (PFS), duration of response (DR), overall survival (OS), and safety. Plasma soluble proteins (vascular endothelial growth factor [VEGF]-A, VEGF-C, soluble VEGF receptor [sVEGFR]-3, and placental growth factor [PlGF]) levels were measured. RESULTS Sixty-one patients were enrolled. The ORR was 23.0% (95% CI, 13.2% to 35.5%), median PFS was 30.4 weeks (95% CI, 18.3 to 36.7 weeks), median DR was 44.1 weeks (95% CI, 25.0 to 102.7 weeks), and median OS was 47.1 weeks (95% CI, 36.9 to 79.4 weeks). Mean plasma VEGF-A and PlGF levels significantly increased whereas VEGF-C and sVEGFR-3 levels decreased with sunitinib treatment. Lower baseline levels of sVEGFR-3 and VEGF-C were associated with longer PFS and ORR. Most treatment-related adverse events were of mild-to-moderate intensity and included fatigue, hypertension, and hand-foot syndrome. CONCLUSION Sunitinib has substantial antitumor activity in patients with bevacizumab-refractory mRCC and modulates circulating VEGF pathway biomarkers. These data support the hypothesis that sunitinib inhibits signaling pathways involved in bevacizumab resistance. Baseline levels of sVEGFR-3 and VEGF-C may have potential utility as biomarkers of clinical efficacy in this setting.

Phase I Clinical Trial of the CYP17 Inhibitor Abiraterone Acetate Demonstrating Clinical Activity in Patients With Castration-Resistant Prostate Cancer Who Received Prior Ketoconazole Therapy

PURPOSE Abiraterone acetate is a prodrug of abiraterone, a selective inhibitor of CYP17, the enzyme catalyst for two essential steps in androgen biosynthesis. In castration-resistant prostate cancers (CRPCs), extragonadal androgen sources may sustain tumor growth despite a castrate environment. This phase I dose-escalation study of abiraterone acetate evaluated safety, pharmacokinetics, and effects on steroidogenesis and prostate-specific antigen (PSA) levels in men with CPRC with or without prior ketoconazole therapy. PATIENTS AND METHODS Thirty-three men with chemotherapy-naïve progressive CRPC were enrolled. Nineteen patients (58%) had previously received ketoconazole for CRPC. Bone metastases were present in 70% of patients, and visceral involvement was present in 18%. Three patients (9%) had locally advanced disease without distant metastases. Fasted or fed cohorts received abiraterone acetate doses of 250, 500, 750, or 1,000 mg daily. Single-dose pharmacokinetic analyses were performed before continuous daily dosing. RESULTS Adverse events were predominantly grade 1 or 2. No dose-limiting toxicities were observed. Hypertension (grade 3, 12%) and hypokalemia (grade 3, 6%; grade 4, 3%) were the most frequent serious toxicities and responded to medical management. Confirmed > or = 50% PSA declines at week 12 were seen in 18 (55%) of 33 patients, including nine (47%) of 19 patients with prior ketoconazole therapy and nine (64%) of 14 patients without prior ketoconazole therapy. Substantial declines in circulating androgens and increases in mineralocorticoids were seen with all doses. CONCLUSION Abiraterone acetate was well tolerated and demonstrated activity in CRPC, including in patients previously treated with ketoconazole. Continued clinical study is warranted.

Risk of Arterial Thromboembolic Events With Sunitinib and Sorafenib: A Systematic Review and Meta-Analysis of Clinical Trials

PURPOSE Sunitinib and sorafenib are oral vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitors (TKIs) used in a vast range of cancers. Arterial thromboembolic events (ATE) have been described with these agents, although the overall risk remains unclear. We did a systematic review and meta-analysis to determine the incidence and the relative risk (RR) associated with the use of sunitinib and sorafenib. PATIENTS AND METHODS PubMed databases were searched for articles published from January 1966 to July 2009, and abstracts presented at the American Society of Clinical Oncology (ASCO) and the European Society of Medical Oncology (ESMO) meetings held between 2004 and 2009 were searched for relevant clinical trials. Eligible studies included phase II and III trials and expanded access programs. Statistical analyses were conducted to calculate the summary incidence, RRs, and 95% CIs, using random-effects or fixed-effects models based on the heterogeneity of included studies. RESULTS A total of 10,255 patients were selected for this meta-analysis. The incidence for ATE was 1.4% (95% CI, 1.2% to 1.6%). The RR of ATEs associated with sorafenib and sunitinib was 3.03 (95% CI, 1.25 to 7.37; P = .015) compared with control patients. The analysis was also stratified for the underlying malignancy (renal cell cancer v non-renal cell cancer) and TKI (sunitinib v sorafenib), but no significant differences in incidence or RR were observed. CONCLUSION Treatment with VEGFR TKIs sunitinib and sorafenib is associated with a significant increase in the risk of ATEs.

Phase II and Biomarker Study of the Dual MET/VEGFR2 Inhibitor Foretinib in Patients With Papillary Renal Cell Carcinoma

PURPOSE Foretinib is an oral multikinase inhibitor targeting MET, VEGF, RON, AXL, and TIE-2 receptors. Activating mutations or amplifications in MET have been described in patients with papillary renal cell carcinoma (PRCC). We aimed to evaluate the efficacy and safety of foretinib in patients with PRCC. PATIENTS AND METHODS Patients were enrolled onto the study in two cohorts with different dosing schedules of foretinib: cohort A, 240 mg once per day on days 1 through 5 every 14 days (intermittent arm); cohort B, 80 mg daily (daily dosing arm). Patients were stratified on the basis of MET pathway activation (germline or somatic MET mutation, MET [7q31] amplification, or gain of chromosome 7). The primary end point was overall response rate (ORR). RESULTS Overall, 74 patients were enrolled, with 37 in each dosing cohort. ORR by Response Evaluation Criteria in Solid Tumors (RECIST) 1.0 was 13.5%, median progression-free survival was 9.3 months, and median overall survival was not reached. The presence of a germline MET mutation was highly predictive of a response (five of 10 v five of 57 patients with and without germline MET mutations, respectively). The most frequent adverse events of any grade associated with foretinib were fatigue, hypertension, gastrointestinal toxicities, and nonfatal pulmonary emboli. CONCLUSION Foretinib demonstrated activity in patients with advanced PRCC with a manageable toxicity profile and a high response rate in patients with germline MET mutations.

Potentiating Endogenous Antitumor Immunity to Prostate Cancer through Combination Immunotherapy with CTLA4 Blockade and GM-CSF

CTL-associated antigen 4 (CTLA4) is a costimulatory molecule expressed on activated T cells that delivers an inhibitory signal to these T cells. CTLA4 blockade with antibody treatment has been shown to augment antitumor immunity in animal models and is being developed as a treatment for cancer patients. As has been seen in preclinical models, combining CTLA4 blockade and granulocyte macrophage colony-stimulating factor (GM-CSF)-based immunotherapies can enhance the antitumor efficacy of this approach. We therefore examined whether CTLA4 blockade could be combined with GM-CSF administration. We treated 24 patients with metastatic, castration-resistant prostate cancer in a phase I trial where sequential cohorts were treated with increasing doses of ipilimumab, a fully human anti-CTLA4 antibody. Study subjects also received s.c. injections of GM-CSF at a fixed dose. Of the six patients treated at the highest dose level, three had confirmed PSA declines of >50%, including one patient that had a partial response in visceral metastases. Expansion of activated, circulating CD25(+) CD69(+) CD8(+) T cells occurred more frequently at higher doses of treatment and was greater in magnitude than was seen in patients who received the same doses of either ipilimumab or GM-CSF alone. By screening sera with protein arrays, we showed that our treatment can induce antibody responses to NY-ESO-1. These results show that this combination immunotherapy can induce the expansion not only of activated effector CD8 T cells in vivo but also of T cells that are specific for known tumor-associated antigens from the endogenous immune repertoire.

Congestive Heart Failure Risk in Patients With Breast Cancer Treated With Bevacizumab

PURPOSE Bevacizumab is a treatment option in patients with metastatic breast cancer. Congestive heart failure (CHF) has been reported, although the overall incidence and relative risk (RR) of this complication remains unclear. We performed an up-to-date, comprehensive meta-analysis to determine the risk of serious CHF in patients with breast cancer receiving bevacizumab. METHODS The databases of Medline were searched for articles from 1966 to March 2010. Abstracts presented at the American Society of Clinical Oncology and the San Antonio Breast Cancer Symposium meetings were also searched for relevant clinical trials. Eligible studies include randomized trials with bevacizumab in patients with breast cancer. Adequate reporting of safety profile data was required for inclusion. Statistical analyses were conducted to calculate the summary incidence, RR, and 95% CIs by using random-effects models. RESULTS A total of 3,784 patients were included. Overall incidence results for high-grade CHF in bevacizumab- and placebo-treated patients were 1.6% (95% CI, 1.0% to 2.6%) and 0.4% (95% CI, 0.2% to 1.0%), respectively. The RR of CHF in bevacizumab-treated patients was 4.74 (95% CI, 1.66 to 11.18; P = .001) compared with placebo-treated ones. In subgroup analyses, there were no significant differences in CHF incidence or risk between patients treated with low-dose (2.5 mg/kg) versus high-dose (5 mg/kg) bevacizumab or among patients treated with different chemotherapy regimens. No evidence of publication bias was observed. CONCLUSION This is the first comprehensive report to show that bevacizumab is associated with an increased risk of significant heart failure in patients with breast cancer.

Prognostic Factors in Patients With Advanced Transitional Cell Carcinoma of the Urothelial Tract Experiencing Treatment Failure With Platinum-Containing Regimens

PURPOSE The present study sought to identify pretreatment prognostic factors for overall survival (OS) in patients with metastatic transitional cell carcinoma of the urothelial tract (TCCU) who experienced treatment failure with the first-line, platinum-based regimen included in the phase III vinflunine trial. PATIENTS AND METHODS In total, 370 patients with platinum-refractory TCCU were included in this analysis. Potential prognostic factors were recorded prospectively. Univariate analysis was used to identify clinical and laboratory factors that significantly impact survival. Multivariate analysis was used to identify independent prognostic factors, and bootstrap analysis was performed for internal validation, forming a prognostic model. External validation was performed on the phase II vinflunine study CA183001. RESULTS Multivariate analysis and the internal validation identified Eastern Cooperative Oncology Group performance status (PS) more than 0, hemoglobin level less than 10 g/dL, and the presence of liver metastasis as the main adverse prognostic factors for OS. External validation confirmed these prognostic factors. Four subgroups were formed based on the presence of zero, one, two, or three prognostic factors; the median OS times for these groups were 14.2, 7.3, 3.8, and 1.7 months (P < .001), respectively. CONCLUSION We identified and both internally and externally validated three adverse risk factors (PS, hemoglobin level, and liver metastasis) that predict for OS and developed a scoring system that classifies patients with platinum-refractory disease on second-line chemotherapy into four risk groups with different outcome. Similar to the first-line setting, the presence of visceral metastases and poor PS predict a worse prognosis. These factors, together with low hemoglobin, can be used for prognostication and future patient stratification in clinical trials.