Efficacy and safety of pazopanib in patients with metastatic renal cell carcinoma

Combination of Anti-Angiogenics and Immunotherapies in Renal Cell Carcinoma Show Their Limits: Targeting Fibrosis to Break through the Glass Ceiling?

This review explores treating metastatic clear cell renal cell carcinoma (ccRCC) through current therapeutic modalities-anti-angiogenic therapies and immunotherapies. While these approaches represent the forefront, their limitations and variable patient responses highlight the need to comprehend underlying resistance mechanisms. We specifically investigate the role of fibrosis, prevalent in chronic kidney disease, influencing tumour growth and treatment resistance. Our focus extends to unravelling the intricate interplay between fibrosis, immunotherapy resistance, and the tumour microenvironment for effective therapy development. The analysis centres on connective tissue growth factor (CTGF), revealing its multifaceted role in ccRCC-promoting fibrosis, angiogenesis, and cancer progression. We discuss the potential of targeting CTGF to address the problem of fibrosis in ccRCC. Emphasising the crucial relationship between fibrosis and the immune system in ccRCC, we propose that targeting CTGF holds promise for overcoming obstacles to cancer treatment. However, we recognise that an in-depth understanding of the mechanisms and potential limitations is imperative and, therefore, advocate for further research. This is an essential prerequisite for the successful integration of CTGF-targeted therapies into the clinical landscape.

Fullerenols Mitigate Radiation-Induced Myocardial Injury

Radiation-induced heart disease is a serious side effect of radiation therapy that can lead to severe consequences. However, effective and safe methods for their prevention and treatment are presently lacking. This study reports the crucial function of fullerenols in protecting cardiomyocytes from radiation injury. First, fullerenols are synthesized using a simple base-catalyzed method. Next, the as-prepared fullerenols are applied as an effective free radical scavenger and broad-spectrum antioxidant to protect against X-ray-induced cardiomyocyte injury. Their ability to reduce apoptosis via the mitochondrial signaling pathway at the cellular level is then verified. Finally, it is observed in animal models that fullerenols accumulate in the heart and alleviate myocardial damage induced by X-rays. This study represents a timely and essential analysis of the prevention and treatment of radiological myocardial injury, providing new insights into the applications of fullerenols for therapeutic strategies.

Comparative safety of tyrosine kinase inhibitors in the treatment of metastatic renal cell carcinoma: a systematic review and network meta-analysis

Objective: This study aimed to compare the safety profile of tyrosine kinase inhibitors (TKIs) approved for use as monotherapy or combination therapy for the first-line treatment of adult patients with metastatic clear cell renal cell carcinoma (RCC). Methods: A systematic review with frequentist network meta-analysis (NMA) was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We included randomized controlled trials (RCTs) investigating the use of: cabozantinib, pazopanib, sorafenib, sunitinib, tivozanib, cabozantinib + nivolumab, lenvatinib + pembrolizumab, axitinib + avelumab, and axitinib + pembrolizumab in previously untreated adult patients with metastatic clear cell RCC. Eligible studies were identified by two reviewers in MEDLINE (via PubMed), EMBASE, and Cochrane Library. The risk of bias for RCTs was assessed using the Cochrane Collaboration tool. The P score was used to determine the treatment ranking. The mean probability of an event along with the relative measures of the NMA was considered with the treatment rankings. Results: A total of 13 RCTs were included in the systematic review and NMA. Sorafenib and tivozanib used as monotherapy were the best treatment options. Sorafenib achieved the highest P score for treatment discontinuation due to adverse events (AEs), fatigue, nausea, vomiting of any grade, and hypertension of any grade or grade ≥3. Tivozanib achieved the highest P score for AEs, grade ≥3 AEs, dose modifications due to AEs, and grade ≥3 diarrhea. Sunitinib was the best treatment option in terms of diarrhea and dysphonia of any grade, while cabozantinib, pazopanib, and axitinib + pembrolizumab-in terms of grade ≥3 fatigue, nausea, and vomiting. TKIs used in combination were shown to have a poorer safety profile than those used as monotherapy. Lenvatinib + pembrolizumab was considered the worst option in terms of any AEs, grade ≥3 AEs, treatment discontinuation due to AEs, dose modifications due to AEs, fatigue of any grade, nausea, vomiting, and grade ≥3 nausea. Axitinib + avelumab was the worst treatment option in terms of dysphonia, grade ≥3 diarrhea, and hypertension, while cabozantinib + nivolumab was the worst option in terms of grade ≥3 vomiting. Interestingly, among the other safety endpoints, cabozantinib monotherapy had the lowest P score for diarrhea and hypertension of any grade. Conclusion: The general safety profile, including common AEs, is better when TKIs are used as monotherapy vs. in combination with immunological agents. To confirm these findings, further research is needed, including large RCTs.

Adjuvant immunotherapy for locally advanced renal cell carcinoma

INTRODUCTION

Locally advanced renal cell carcinoma (RCC) presents a therapeutic challenge due to 20-40% relapse risk post-nephrectomy. There has been substantial interest in utilizing immunotherapy interrupting the PD-1/PD-L1 axis in the perioperative space, especially in the adjuvant setting, in order to minimize such risk.

AREAS COVERED

We conducted a PubMed search using the terms 'adjuvant' and 'RCC.' We begin by examining landmark studies in the postoperative space for locally advanced RCC, with special emphasis on immunotherapeutic biologics. Important considerations are outlined in an effort to explain the conflicting data on the benefit of adjuvant immunotherapy as well as to adequately assess the magnitude of potential benefit of the recently approved adjuvant pembrolizumab. Relevant contemporary challenges and opportunities as well as future directions of the field are also discussed.

EXPERT OPINION

Systemic immunotherapy with monoclonal antibodies targeting the PD-1/PD-L1 axis likely holds promise, either alone or potentially in combinations, in minimizing recurrence risk for locally advanced RCC. However, emphasis on post-protocol care, robust endpoint selection, and continued work and validation on predictive biomarkers are needed to confidently select those patients that may benefit the most and minimize biologic and financial toxicity.

Hepatotoxicity of Small Molecule Protein Kinase Inhibitors for Cancer

Small molecule protein kinase inhibitors (PKIs) have become an effective strategy for cancer patients. However, hepatotoxicity is a major safety concern of these drugs, since the majority are reported to increase transaminases, and few of them (Idelalisib, Lapatinib, Pazopanib, Pexidartinib, Ponatinib, Regorafenib, Sunitinib) have a boxed label warning. The exact rate of PKI-induced hepatoxicity is not well defined due to the fact that the majority of data arise from pre-registration or registration trials on fairly selected patients, and the post-marketing data are often based only on the most severe described cases, whereas most real practice studies do not include drug-related hepatotoxicity as an end point. Although these side effects are usually reversible by dose adjustment or therapy suspension, or by switching to an alternative PKI, and fatality is uncommon, all patients undergoing PKIs should be carefully pre-evaluated and monitored. The management of this complication requires an individually tailored reappraisal of the risk/benefit ratio, especially in patients who are responding to therapy. This review reports the currently available data on the risk and management of hepatotoxicity of all the approved PKIs.

To Investigate Growth Factor Receptor Targets and Generate Cancer Targeting Inhibitors

Receptor tyrosine kinase (RTK) regulates multiple pathways, including Mitogenactivated protein kinases (MAPKs), PI3/AKT, JAK/STAT pathway, etc. which has a significant role in the progression and metastasis of tumor. As RTK activation regulates numerous essential bodily processes, including cell proliferation and division, RTK dysregulation has been identified in many types of cancers. Targeting RTK is a significant challenge in cancer due to the abnormal upregulation and downregulation of RTK receptors subfamily EGFR, FGFR, PDGFR, VEGFR, and HGFR in the progression of cancer, which is governed by multiple RTK receptor signalling pathways and impacts treatment response and disease progression. In this review, an extensive focus has been carried out on the normal and abnormal signalling pathways of EGFR, FGFR, PDGFR, VEGFR, and HGFR and their association with cancer initiation and progression. These are explored as potential therapeutic cancer targets and therefore, the inhibitors were evaluated alone and merged with additional therapies in clinical trials aimed at combating global cancer.

Multifaceted Roles of Chemokine C-X-C Motif Ligand 7 in Inflammatory Diseases and Cancer

Over recent years, C-X-C motif ligand 7 (CXCL7) has received widespread attention as a chemokine involved in inflammatory responses. Abnormal production of the chemokine CXCL7 has been identified in different inflammatory diseases; nevertheless, the exact role of CXCL7 in the pathogenesis of inflammatory diseases is not fully understood. Persistent infection or chronic inflammation can induce tumorigenesis and progression. Previous studies have shown that the pro-inflammatory chemokine CXCL7 is also expressed by malignant tumor cells and that binding of CXCL7 to its cognate receptors C-X-C chemokine receptor 1 (CXCR1) and C-X-C chemokine receptor 2 (CXCR2) can influence tumor biological behavior (proliferation, invasion, metastasis, and tumor angiogenesis) in an autocrine and paracrine manner. CXCL7 and its receptor CXCR1/CXCR2, which are aberrantly expressed in tumors, may represent new targets for clinical tumor immunotherapy.

Predictive Biomarkers of Overall Survival in Patients with Metastatic Renal Cell Carcinoma Treated with IFNα ± Bevacizumab: Results from CALGB 90206 (Alliance)

PURPOSE

CALGB 90206 was a phase III trial of 732 patients with metastatic renal cell carcinoma (mRCC) comparing bevacizumab plus IFNα (BEV + IFN) with IFNα alone (IFN). No difference in overall survival (OS) was observed. Baseline samples were analyzed to identify predictive biomarkers for survival benefit.

PATIENTS AND METHODS

A total of 32 biomarkers were assessed in 498 consenting patients randomly assigned into training (n = 279) and testing (n = 219) sets. The proportional hazards model was used to test for treatment arm and biomarker interactions of OS. The estimated coefficients from the training set were used to compute a risk score for each patient and to classify patients by risk in the testing set. The resulting model was assessed for predictive accuracy using the time-dependent area under the ROC curve (tAUROC).

RESULTS

A statistically significant three-way interaction between IL6, hepatocyte growth factor (HGF), and bevacizumab treatment was observed in the training set and confirmed in the testing set (P < 0.0001). The model based on IL6, HGF, and bevacizumab treatment was predictive of OS (P < 0.001), with the high- and low-risk groups having a median OS of 10.2 [95% confidence interval (CI), 8.0-13.8] and 34.3 (95% CI, 28.5-40.5) months, respectively. The average tAUROC for the final model of OS based on 100 randomly split testing sets was 0.78 (first, third quartiles = 0.77, 0.79).

CONCLUSIONS

IL6 and HGF are potential predictive biomarkers of OS benefit from BEV + IFN in patients with mRCC. The model based on key biological and clinical factors demonstrated predictive efficacy for OS. These markers warrant further validation in future anti-VEGF and immunotherapy in mRCC trials. See related commentaries by Mishkin and Kohn, p. 2722 and George and Bertagnolli, p. 2725.

Intracellular Signaling Pathways Mediating Tyrosine Kinase Inhibitor Cardiotoxicity

Tyrosine kinase inhibitors (TKIs) are used to treat several cancers; however, a myriad of adverse cardiotoxic effects remain a primary concern. Although hypertension (HTN) is the most common adverse effect reported with TKI therapy, incidents of arrhythmias (eg, QT prolongation, atrial fibrillation) and heart failure are also prevalent. These complications warrant further research toward understanding the mechanisms of TKI-induced cardiotoxicity. Recent literature has given some insight into the intracellular signaling pathways that may mediate TKI-induced cardiac dysfunction. In this article, we discuss the cardiotoxic effects of TKIs on cardiomyocyte function, signaling, and possible treatments.

Pazopanib with 5-FU and oxaliplatin as first line therapy in advanced gastric cancer: A randomized phase-II study-The PaFLO trial. A study of the Arbeitsgemeinschaft Internistische Onkologie AIO-STO-0510

VEGF inhibition in gastric cancer has a proven benefit in the second line setting. Pazopanib, an oral tyrosine kinase inhibitor, selectively inhibits VEGFR-1, -2 and -3, c-kit and PDGF-R resulting in inhibition of angiogenesis. This open-label randomized phase II trial (2:1) investigated the efficacy of combining pazopanib with FLO (5-fluorouracil, oxaliplatin) vs FLO alone (internal control arm) as first-line treatment in patients with advanced adenocarcinoma of the stomach and gastroesophageal junction (GEJ). Eighty-seven patients were randomized and 78 patients were eligible and evaluable (PaFLO arm 51 patients, FLO arm 27 patients). The PFS rate at 6 months (primary endpoint) was 34% in the PaFLO arm vs 30% in the FLO arm. Comparing PaFLO with FLO median PFS was 4.66 months (95% confidence interval [CI] 2.87-6.46) vs 4.47 months (95% CI 1.79-7.14) (95% CI, hazard ratio [HR] 0.96 (0.60-1.55), P = .882 [exploratory]); median OS was 10.19 months (95% CI 5.46-14.92) vs 7.33 months (95% CI 4.93-9.73), (95% CI HR 1.01 [0.62-1.65], P = .953, exploratory), disease control rate was 72% vs 59%. PaFLO was well tolerable, toxicities were slightly higher in the PaFLO arm. Major adverse events were loss of appetite, nausea, fatigue, diarrhea, neutropenia and thrombocytopenia. Adding pazopanib to chemotherapy shows signs of efficacy but no major improvement in this randomized phase 2 trial. The PFS at 6 months in both arms was lower than expected from the literature. Biomarkers identifying subgroups who benefit and novel combinations are needed. ClinicalTrials.gov: NCT01503372.

Small Molecule Kinase Inhibitor Drugs (1995-2021): Medical Indication, Pharmacology, and Synthesis

The central role of dysregulated kinase activity in the etiology of progressive disorders, including cancer, has fostered incremental efforts on drug discovery programs over the past 40 years. As a result, kinase inhibitors are today one of the most important classes of drugs. The FDA approved 73 small molecule kinase inhibitor drugs until September 2021, and additional inhibitors were approved by other regulatory agencies during that time. To complement the published literature on clinical kinase inhibitors, we have prepared a review that recaps this large data set into an accessible format for the medicinal chemistry community. Along with the therapeutic and pharmacological properties of each kinase inhibitor approved across the world until 2020, we provide the synthesis routes originally used during the discovery phase, many of which were only available in patent applications. In the last section, we also provide an update on kinase inhibitor drugs approved in 2021.

Anti-angiogenic Agents: A Review on Vascular Endothelial Growth Factor Receptor-2 (VEGFR-2) Inhibitors

Tumor growth inhibition can be achieved by inhibiting angiogenesis, which has been a field of great concern in recent years. Important targets to inhibit angiogenesis include vascular endothelial growth factor receptor (VEGFR) and its homologous tyrosine kinase receptor. Anti-angiogenic therapy based on inhibition of VEGFR-2 is an effective clinical treatment strategy. The research progress of VEGFR-2 inhibitors is reviewed in this paper from the aspects of drug development and chemical synthesis.

Renal toxicity of targeted therapies for renal cell carcinoma in patients with normal and impaired kidney function

The introduction of novel targeted therapies during the last 2 decades has led to a significant improvement in patients' clinical outcomes with renal cell carcinoma. However, this improvement came at the price of a whole new spectrum of adverse events, including renal toxicity. Systemic treatment of patients with kidney neoplasms who often present with impairment of kidney function, even prior to treatment, poses an increasing diagnostic and therapeutic challenge for clinicians. Common lifestyle-related comorbidities, i.e., hypertension and diabetes, may contribute to further impairment of kidney function. The lack of official guidelines and the exclusion of patients with reduced kidney function from the clinical trials of recently approved drugs complicate the issue even further. Early detection and correct management of renal toxic effects are crucial to preserve kidney function and ensure the optimal administration of life-prolonging therapies. This review presents detailed information on the renal toxicities of three groups of drugs commonly used in renal cell carcinoma treatment: tyrosine kinase inhibitors, mammalian target of rapamycin inhibitors, and immune checkpoint inhibitors. We outline the incidence and underlying mechanisms of renal adverse effects with a focus on patients on renal replacement therapy, as well as present suggestions for their management.

A Phase I Trial of the MET/ALK/ROS1 Inhibitor Crizotinib Combined with the VEGF Inhibitor Pazopanib in Patients with Advanced Solid Malignancies

BACKGROUND

Crizotinib inhibits ALK, MET and ROS1 tyrosine kinases but the development of resistance to monotherapy is an issue. The anti-angiogenic properties of pazopanib could overcome crizotinib drug resistance. Additionally, the anti-angiogenic properties of crizotinib could augment the clinical efficacy of pazopanib.

METHODS

We evaluated the safety and responses in patients with advanced solid tumors treated with crizotinib and pazopanib.

RESULTS

Eighty-two patients (median age 53 years, range 18-78 years) were enrolled. The median number of prior systemic therapies was 3 (range, 0-8). We were able to dose escalate to dose level 8 (crizotinib 250 mg twice daily and pazopanib 800 mg daily) with no MTD identified. Grade 3 or 4 toxicities were seen in 32% of patients with the highest prevalence being fatigue (n=9, 11%), diarrhea (n=6, 7%), vomiting (n=3, 4%), anemia (n=2, 2%) and ALT increased (n=2, 2%). Of the 82 patients, 61 (74%) had measurable disease by RECISTv1.1 and reached first restaging (6 weeks). Partial response (PR) was observed in 6/61 (10%) patients, and stable disease (SD) lasting ≥6 months was observed in 10/61 patients (16%) (total = 16/61 (26%) of patients with SD ≥6 months/PR).

CONCLUSION

Dose level 6 (crizotinib 200 mg twice daily and pazopanib 600 mg daily) was the most tolerable dosing of the combination and can be used in future studies. We also observed moderate clinical activity in patients with advanced solid tumors that had received numerous prior therapies.

Clear-cell renal cell carcinoma - A comprehensive review of agents used in the contemporary management of advanced/metastatic disease

Renal cell carcinoma represents the most common malignancy of the kidney and the majority of cases are categorized as clear cell carcinomas. The elucidation of the specific alterations in key molecular and metabolic pathways responsible for cancer development and progression have prompted the rationalization of our classification of this disease and have provided specific targetable molecules implicated in carcinogenesis. Although immunotherapy has been an established option in the treatment of metastatic renal cell cancer for many years, its role has been renewed and upgraded with the implementation of anti-angiogenic agents and immune checkpoint inhibitors in our treatment armamentarium. The future holds promise, as newer agents become available and combination regimens of immunotherapy with anti-angiogenic agents have become the standard of care in the management of metastatic disease and are currently being evaluated in earlier settings. Proper patient selection and individualization of our treatment strategies are of utmost importance in order to provide optimal care to patients suffering from renal cell carcinoma.

Potentially life‑threatening severe cutaneous adverse reactions associated with tyrosine kinase inhibitors (Review)

Tyrosine kinase inhibitors (TKIs) have emerged as a new frontier of cancer therapy. These agents include inhibitors of epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), BRAF, mitogen‑activated protein kinase kinase (also referred to as MEK), bcr‑abl, c‑KIT, platelet‑derived growth factor (PDGFR), fibroblast growth factor receptor (FGFR), anaplastic lymphoma kinase (ALK) and vascular endothelial growth factor (VEGF). Along with the evolving applications of TKIs, there has been an increased recognition of the breadth of potential cutaneous toxicities to these agents. In this review, we provide an overview of potentially life‑threatening severe cutaneous adverse reactions (SCARs) that may occur during therapy with TKIs. These toxicities include Stevens‑Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN), drug reaction with eosinophilia and systemic symptoms (DRESS), and acute generalized exanthematous pustulosis (AGEP).

Panniculitis in a patient with metastatic renal cell carcinoma on a tyrosine kinase inhibitor

A 71-year-old female was diagnosed with localized renal cell carcinoma in July 2008 with subsequent metastasis in 2012 to the right adrenal gland, lungs, and brain. Due to disease progression, she was started on pazopanib 800 mg daily in October 2012. In November 2016, the patient developed an ill-defined, red, 10 × 15 cm indurated plaque on the left lateral upper thigh with a discrete 3 cm firm tender tumor without ulceration. An incisional biopsy was performed and showed panniculitis with features resembling sclerosing lipogranuloma. Alternative causes including rheumatologic disease and trauma were ruled out. We report the first case of pazopanib-induced panniculitis. Key clinical and histopathological features include tender subcutaneous nodules, exclusion of other causes, and fatty microcysts within a densely sclerotic background on pathology. As targeted therapies are becoming increasingly common in the field of oncology, prompt identification and reporting of adverse reactions is critical for proper management.

Multikinase inhibitor-induced liver injury in patients with cancer: A review for clinicians

BACKGROUND

Multikinase inhibitors (MKI) are targeted molecular agents that have revolutionized cancer management. However, there is a paucity of data concerning MKI-related liver injury risk and clinical guidelines for the management of liver toxicity in patients receiving MKI for cancer are scarce.

DESIGN

We conducted a PubMed search of articles in English published from January 2000 to December 2018 related to hepatotoxicity of the 29 FDA-approved MKIs at doses used in clinical practice. The search terms were the international non-proprietary name of each agent cross-referenced with «hepatotoxicity», «hepatitis», «hepatic adverse event», or «liver failure», and «phase II clinical trial», «phase III clinical trial», or «case report».

RESULTS

Following this search, 140 relevant studies and 99 case reports were considered. Although asymptomatic elevation of aminotransferase levels has been frequently observed in MKI clinical trials, clinically significant hepatotoxicity is a rare event. In most cases, the interval between treatment initiation and the onset of liver injury is between one week and two months. Liver toxicity is often hepatocellular and less frequently mixed. Life-threatening MKI-induced hepatic injury has been described, involving fulminant liver failure or death. Starting from existing data, a description of MKI-related liver events, grading of hepatotoxicity risk, and recommendations for management are also given for various MKI molecules.

CONCLUSION

All MKIs can potentially cause liver injury, which is sometimes irreversible. As there is still no strategy available to prevent MKI-related hepatotoxicity, early detection remains crucial. The surveillance of liver function during treatment may help in the early detection of hepatotoxicity. Furthermore, the exclusion of potential causes of hepatic injury is essential to avoid unnecessary MKI withdrawal.

Tumor response criteria for assessing pazopanib first-line therapy in patients with metastatic renal cell carcinoma (mRCC)

PURPOSE

To identify the optimum response criteria for first-line targeted pazopanib therapy in patients with mRCC using solid tumor response criteria and clinical risk factors.

METHODS

Pre- and post-treatment CTs of patients (n = 43) with mRCC treated with first-line pazopanib therapy were analyzed retrospectively. Treatment response was evaluated with Response Evaluation Criteria in Solid Tumors (RECIST) v1.1, Choi, modified Choi (mChoi), revised Choi (rChoi), MASS (Morphology, Attenuation, Size, and Structure), 10% threshold criteria, and subjective assessment. Memorial Sloan-Kettering Cancer Center and International Metastatic Renal Cell Carcinoma Database Consortium clinical risk factors were also used to define response groups. Response evaluations were correlated with overall survival (OS) and progression-free survival (PFS) using log-rank test.

RESULTS

Patients with partial response (PR) by mChoi and rChoi had longer OS than those with stable disease (SD) (P < 0.001). Responders by 10% threshold criteria also had better OS, without or combined with clinical criteria. Patients with PR by rChoi, mChoi, RECIST v1.1, MASS criteria, and by subjective assessment had longer PFS than those with SD. rChoi and mChoi criteria best delineated the difference in PFS for patients with PR versus SD, without or combined with clinical criteria.

CONCLUSION

For mRCC patients treated with pazopanib, OS and PFS for PR and SD groups were best predicted by rChoi and mChoi criteria, without or combined with clinical risk factors. 10% threshold criteria also predicted OS and PFS, whereas RECIST did so only in a limited number of patients.

Imatinib, sunitinib and pazopanib: From flat-fixed dosing towards a pharmacokinetically guided personalized dose

Tyrosine kinase inhibitors (TKIs) are anti‐cancer drugs that target tyrosine kinases, enzymes that are involved in multiple cellular processes. Currently, multiple oral TKIs have been introduced in the treatment of solid tumours, all administered in a fixed dose, although large interpatient pharmacokinetic (PK) variability is described. For imatinib, sunitinib and pazopanib exposure‐treatment outcome (efficacy and toxicity) relationships have been established and therapeutic windows have been defined, therefore dose optimization based on the measured blood concentration, called therapeutic drug monitoring (TDM), can be valuable in increasing efficacy and reducing the toxicity of these drugs.

In this review, an overview of the current knowledge on TDM guided individualized dosing of imatinib, sunitinib and pazopanib for the treatment of solid tumours is presented. We summarize preclinical and clinical data that have defined thresholds for efficacy and toxicity. Furthermore, PK models and factors that influence the PK of these drugs which partly explain the interpatient PK variability are summarized. Finally, pharmacological interventions that have been performed to optimize plasma concentrations are described. Based on current literature, we advise which methods should be used to optimize exposure to imatinib, sunitinib and pazopanib.

Real-World Effectiveness and Tolerability of Pazopanib as First Targeted Therapy in Metastatic Renal Cell Carcinoma: A Retrospective Chart Review in Latin America

INTRODUCTION

Pazopanib is approved in Latin America as first targeted therapy for patients with metastatic renal cell carcinoma (mRCC).

METHODS

A retrospective chart review of adult patients with mRCC who initiated pazopanib as first targeted therapy between January 2011 and March 2016 was conducted among oncology care centers in Argentina, Brazil, Chile, Colombia, and Mexico. Patient characteristics, treatment patterns, overall survival (OS), progression-free survival (PFS), and adverse events were summarized.

RESULTS

A total of 156 charts of patients with mRCC receiving first-line pazopanib were reviewed (29, 54, 27, 28, and 18 patients from Argentina, Brazil, Chile, Colombia, and Mexico, respectively). The mean age at initial mRCC diagnosis was 61.6 years, 73.7% were male, and 51.3% were Hispanic. The median dose of pazopanib was 800 mg and the median time from initial mRCC diagnosis to pazopanib start was 2.2 months. The median time on treatment was 10.0 months. At the time of data extraction, 16.7% of patients remained on pazopanib, with clinical progression listed as the main reason for discontinuation. Subsequent therapy was received by 25.6% of patients; the most common were everolimus (9.6%) and axitinib (5.8%). Overall, median PFS and OS were 10.8 and 16.9 months, respectively, and varied across countries. The most common all-grade adverse events were diarrhea (44.9%), asthenia/fatigue (43.6%), and nausea (28.8%).

CONCLUSIONS

Pazopanib was used for first-line mRCC treatment in a clinically diverse patient population across Latin America. Real-world PFS and tolerability were similar to clinical studies of pazopanib.

FUNDING

Novartis Pharmaceuticals Corporation, Inc.

Analysis of the characteristics of chemotherapy-resistant renal cell carcinomas based on global transcriptional analysis of their tissues and cell lines

Starvation-resistant renal cell carcinoma (RCC) cell lines are considered dormant-state cells that survive even under glucose starvation. The cellular biological and global transcriptional analysis using these cells identified potential markers of chemotherapy-resistant RCC and therapeutic agent candidates. Recently, we showed that ARL4C was a predictive biomarker for poor prognosis in patients with chemotherapy-resistant RCC by the global transcriptional analysis of patient primary tissues. The objective of this study was to identify the characteristics of chemotherapy-resistant RCC by the global transcriptional analysis of primary tissues of patients with RCC and RCC cell lines. The connective global transcriptional analysis showed that two starvation-resistant RCC cell lines, SW839 and KMRC-1, were strongly correlated to tissues of patients with chemotherapy-resistant RCC and showed high expressions of invasive- and proliferation-related genes. We found fibronectin (FN1) expression was a predictive biomarker in some patients with chemotherapy-resistant RCC, which especially correlated with two starvation-resistant RCC cell lines. These results indicate these cell lines emulate chemotherapy-resistant RCC and might be useful in the search for markers to predict poor prognosis and in the development of therapeutic agents and their index markers for chemotherapy-resistant RCCs.

The Efficacy and Safety of Tyrosine Kinase Inhibitors for Von Hippel-Lindau Disease: A Retrospective Study of 32 Patients

Background: Von Hippel-Lindau (VHL) disease is an autosomal-dominant hereditary cancer syndrome. Currently, studies on tyrosine kinase inhibitor (TKI) therapy for VHL disease are scarce. In this study, we retrospectively evaluated the efficacy and safety of four TKIs in patients with VHL disease. Methods: Patients diagnosed with VHL disease who were receiving TKIs were recruited. Patients were treated with sunitinib (n = 12), sorafenib (n = 11), axitinib (n = 6), or pazopanib (n = 3). The therapeutic response was evaluated according to the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. Results: From July 2009 to September 2018, 32 patients with VHL disease were eligible and included in this study. The median duration of TKI therapy was 22 months (IQR 8.5-44.75), and the median follow-up period was 31.5 months (IQR 13.5-63.5). According to the RECIST, 9 (28%) of 32 patients showed a partial response, 15 (47%) achieved stable disease, and eight exhibited continued disease progression. A partial response was observed in 11 (31%) of 36 renal cell carcinomas, 4 (27%) of 15 pancreatic lesions, and 1 (20%) of five central nervous system (CNS) hemangioblastomas. The average tumor size decreased significantly for renal cell carcinomas (P = 0.0001), renal cysts (P = 0.027), and pancreatic lesions (P = 0.003) after TKI therapy. Common side effects included hand-foot skin reactions, diarrhea, alopecia, thrombocytopenia, and fatigue. Conclusions: Partial alleviation of VHL disease-related tumors can be achieved by TKI therapies in some patients, providing an alternative treatment strategy, and the side effects of TKIs are acceptable. Larger prospective studies are warranted to further evaluate the efficacy and safety of TKIs in patients with VHL disease.

Targeted cancer therapies: Oral health care implications

BACKGROUND

Targeted treatments have been incorporated into oncology protocols, often with more traditional therapies, and are not totally free of adverse reactions, some of which affect the orofacial region.

METHODS

The authors searched PubMed, the Cochrane Library, and the US Food and Drug Administration Approved Drug Products database to identify reported adverse effects of targeted agents in the orofacial region as well as other implications in oral health care. Their principal focus was the relatively newer category of molecularly targeted drugs which are called small molecules (SMs).

RESULTS

The authors identified several categories of SMs and biological agents (for example, monoclonal antibodies) with adverse effects in the orofacial region. The oral and perioral regions are also fields for which there are therapeutic applications for targeted therapies, particularly to treat malignant neoplasms such as head and neck cancers.

CONCLUSIONS

SMs are the most rapidly growing group of targeted cancer treatments. Patients receiving SMs and other targeted antineoplastic agents may require oral medicine advice and special-care dentistry.

PRACTICAL IMPLICATIONS

In this narrative review, the authors focus mainly on the orofacial adverse effects of targeted cancer therapies and outline many of the agents that are in use so the dentally focused reader can familiarize themselves with these adverse effects and agents.

Impact of tivozanib on patient outcomes in treatment of advanced renal cell carcinoma

Renal cell carcinoma (RCC) is the most common type of kidney malignancy, and the clear-cell subtype represents the majority of RCCs. RCC is a heterogeneous disease in terms of genetic and histological features which determine the behavior of the disease. The von Hippel-Lindau (VHL) is a tumor suppressor gene and mutations of this gene are seen in 95% of clear-cell RCCs. Inactivation of VHL causes the accumulation of hypoxia-inducible factor-1 (HIF-1), and in turn, accumulation of HIF-1 induces overexpression of vascular endothelial growth factor (VEGF); the increase in VEGF expression makes RCC a highly vascularized tumor, and forms the rationale for antiVEGF treatment. In the past decade, improvement in the survival of RCC patients has been observed due to new effective therapies, such as antiVEGF and mammalian target of rapamycin (mTOR) targeting agents and immune checkpoint inhibitors. The majority of VEGF targeted agents are not just selective to VEGF receptors, but usually also have inhibitory effects on other kinases, such as c-KIT and FLT3. Tivozanib is an extremely potent and selective tyrosine kinase inhibitor (TKI) of VEGFR-1, 2, and 3, with a relatively long half-life, that is approved by the European Commission for the treatment of advanced/metastatic RCC. Tivozanib, at very low serum concentration can inhibit phosphorylation of VEGFR -1, -2, and -3 tyrosine kinase activity. This article summarizes the clinical data on tivozanib in the treatment of advanced/metastatic RCC.

The Effect of Using Pazopanib With Food vs. Fasted on Pharmacokinetics, Patient Safety, and Preference (DIET Study)

Pazopanib is taken fasted in a fixed oral daily dose of 800 mg. We hypothesized that ingesting pazopanib with food may improve patients' comfort and reduce gastrointestinal (GI) adverse events. Therefore, we investigated the bioequivalent dose of pazopanib when taken with food compared with 800 mg pazopanib taken fasted. In addition, we investigated the differences in GI toxicity, patient satisfaction, and patient's preference for either intake. The intake of 600 mg pazopanib with food resulted in a bioequivalent exposure and was preferred over a standard pazopanib dose without food. No differences were seen in GI toxicities under both intake regimens. Patients seem to be more positive about their feelings about side effects and satisfaction with their therapy when pazopanib was taken with food. Forty-one of the patients (68%) preferred the intake with a continental breakfast.

Prognostic or predictive value of circulating cytokines and angiogenic factors for initial treatment of multiple myeloma in the GIMEMA MM0305 randomized controlled trial

BACKGROUND

Several new drugs are approved for treatment of patients with multiple myeloma (MM), but no validated biomarkers are available for the prediction of a clinical outcome. We aimed to establish whether pretreatment blood and bone marrow plasma concentrations of major cytokines and angiogenic factors (CAFs) of patients from a phase 3 trial of a MM treatment could have a prognostic and predictive value in terms of response to therapy and progression-free and overall survival and whether these patients could be stratified for their prognosis.

METHODS

Blood and bone marrow plasma levels of Ang-2, FGF-2, HGF, VEGF, PDGF-β, IL-8, TNF-α, TIMP-1, and TIMP-2 were determined at diagnosis in MM patients enrolled in the GIMEMA MM0305 randomized controlled trial by an enzyme-linked immunosorbent assay (ELISA). These levels were correlated both reciprocally and with the type of therapy and patients' characteristics and with a group of non-MM patients as controls.

RESULTS

No significant differences were detected between the blood and bone marrow plasma levels of angiogenic cytokines. A cutoff for each CAF was established. The therapeutic response of patients with blood plasma levels of CAFs lower than the cutoff was better than the response of those with higher levels in terms of percentage of responding patients and quality of response.

CONCLUSION

FGF-2, HGF, VEGF, and PDGF-β plasma levels at diagnosis have predictive significance for response to treatment. The stratification of patients based on the levels of CAFs at diagnosis and their variations after therapy is useful to characterize different risk groups concerning outcome and response to therapy.

TRIAL REGISTRATION

Clinical trial information can be found at the following link: NCT01063179.

Pazopanib: Evidence review and clinical practice in the management of advanced renal cell carcinoma

Background

Pazopanib is indicated in the first-line treatment of metastatic renal cell cancer (mRCC). The aim of this study was to review the efficacy, safety, and pharmacokinetics of pazopanib and see how these aspects are linked to clinical practice.

Methods

A non-exhaustive systematic review was conducted according to the three topics. No publication restrictions were imposed and the selected languages were Spanish and English. After that, a summary of the main results and findings of the review was presented and discussed during three meetings (one for each topic) with 13 medical oncologists that usually treat mRCC. At these meetings, a questionnaire on the first-line use of pazopanib in clinical practice was also drawn up. After the meetings, the questionnaire was completed by 60 specialist medical oncologists in renal cancer.

Results

The efficacy and safety of pazopanib have been demonstrated in several clinical trials, and subsequently confirmed in studies in real-world clinical practice. In addition to its clinical benefit and good safety profile, quality of life results for pazopanib, which compare favorably to sunitinib, make it a good option in the first-line treatment of patients. Special populations have been included in studies conducted with pazopanib, and it is safe for use in elderly patients, poor functional status, kidney failure, and mild or moderate hepatic impairment, and in patients with concomitant cardiovascular disease. The results of the questionnaire have shown that pazopanib is perceived as an effective drug, in which quality of life (QoL) outcomes are valued above all.

Conclusions

This paper offers a comprehensive and critical summary of efficacy, tolerability, and pharmacokinetics of pazopanib in the treatment of mRCC. Pazopanib is an effective treatment with an acceptable safety profile. Its QoL and tolerability results offer certain advantages when compared with other therapeutic alternatives, and its use appears to be safe in different patient profiles.

Phototoxic Reaction Induced by Pazopanib

Multikinase inhibitors (MKIs) are a novel target therapy that offers promising long-term survival for patients with advanced-stage cancer. However, they cause a wide range of adverse reactions, skin and skin appendage being the most prevalent. Photosensitivity reactions are well-recognized effects from certain MKIs such as sunitinib and vandetanib. However, phototoxic reaction induced by pazopanib has never been reported. We present here the first case of pazopanib-induced phototoxic drug reaction in a patient with renal cell carcinoma.

Reversible Hypopigmentation with Pazopanib

Tablet Pazopanib known to cause Hypo pigmentation and Hyperpigmentation as per various literature reports. We report here a case of reversible hypopigmentation with Pazopanib in a patient treated for spindle cell sarcoma. Patient did not have any clinical symptoms except for cosmetic significance.

Pazopanib in patients with von Hippel-Lindau disease: a single-arm, single-centre, phase 2 trial

BACKGROUND

No approved systemic therapy exists for von Hippel-Lindau disease, an autosomal dominant disorder with pleiotropic organ manifestations that include clear cell renal cell carcinomas; retinal, cerebellar, and spinal haemangioblastomas; pheochromocytomas; pancreatic serous cystadenomas; and pancreatic neuroendocrine tumours. We aimed to assess the activity and safety of pazopanib in patients with von Hippel-Lindau disease.

METHODS

In this non-randomised, single-centre, open-label, phase 2 trial, adult patients with clinical manifestations of von Hippel-Lindau disease were recruited from the University of Texas MD Anderson Cancer Center (Houston, TX, USA) and were treated with pazopanib (800 mg orally daily) for 24 weeks, with an option to continue treatment if desired by the patient and treating physician. Primary endpoints were the proportion of patients who achieved an objective response and safety in the per-protocol population. The objective response was measured for each patient and each lesion type. Radiographic assessments were done at baseline and every 12 weeks throughout the study. Activity and safety were assessed with continuous monitoring and a Bayesian design. This study is registered with ClinicalTrials.gov, number NCT01436227, and is closed to accrual.

FINDINGS

Between Jan 18, 2012, and Aug 10, 2016, we screened 37 patients with genetically confirmed or clinical features consistent with von Hippel-Lindau disease, of whom 31 eligible patients were treated with pazopanib. The proportion of patients who achieved an objective response was 42% (13 of 31 patients). By lesion sites responses were observed in 31 (52%) of 59 renal cell carcinomas, nine (53%) of 17 pancreatic lesions, and two (4%) of 49 CNS haemangioblastomas. Seven (23%) of 31 patients chose to stay on the treatment after 24 weeks. Four (13%) of 31 patients withdrew from the study because of grade 3 or 4 transaminitis, and three (10%) discontinued study treatment because of treatment intolerance with multiple intercurrent grade 1-2 toxicities. Treatment-related serious adverse events included one case each of appendicitis and gastritis and one patient had a fatal CNS bleed.

INTERPRETATION

Pazopanib was associated with encouraging preliminary activity in von Hippel-Lindau disease, with a side-effect profile consistent with that seen in previous trials. Pazopanib could be considered as a treatment choice for patients with von Hippel-Lindau disease and growing lesions, or to reduce the size of unresectable lesions in these patients. The safety and activity of pazopanib in this setting warrants further investigation.

FUNDING

Novartis Inc and NIH National Cancer Institute core grant.

The Impact of Pazopanib on the Cardiovascular System

Pazopanib is an approved treatment for renal cell carcinoma and a second-line treatment for nonadipocytic soft-tissue sarcoma. However, its clinical efficacy is limited by its cardiovascular side effects. Pazopanib and other vascular endothelial growth factor receptor tyrosine kinase inhibitors have been associated with the development of hypertension, QT interval prolongation, and other cardiovascular events; however, these mechanisms are largely unknown. Gaining a deeper understanding of these mechanisms is essential for the development of appropriate surveillance strategies and possible diagnostic biomarkers to allow us to monitor patients and modulate therapy prior to significant cardiac insult. This approach will be vital in keeping patients on these life-saving therapies and may be applicable to other tyrosine kinase inhibitors as well. In this review, we provide a comprehensive overview of the preclinical and clinical side effects of pazopanib with a focus on the mechanisms responsible for its toxicity to the cardiovascular system.

Does Dose Modification Affect Efficacy of First-Line Pazopanib in Metastatic Renal Cell Carcinoma?

Background

Pazopanib is a standard treatment for metastatic renal cell carcinoma (mRCC), and 800 mg/daily is considered the optimal dose. However, some patients require dose modification because of toxicity. Whether a reduced dose of pazopanib is as effective as the standard dose in achieving clinical benefit remains unclear.

Objectives

Our objective was to conduct a retrospective analysis to investigate the clinical effect of different therapeutic doses of first-line pazopanib in patients with mRCC.

Methods

Consecutive patients with mRCC treated with first-line pazopanib between 2011 and 2016 at the Istituto Nazionale Tumori of Milan were retrospectively analysed for demographics, response, outcomes, and toxicity. Three patient groups were compared: group 1 received the standard dose of 800 mg/day; group 2 started with 800 mg/day and then reduced the dose to 400 or 600 mg/day because of toxicity; and group 3 received a reduced starting dose of 400 or 600 mg/day because they had an Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 2 and/or comorbidities.

Results

In total, 69 patients were evaluated: 34 in group 1, 19 in group 2, and 16 in group 3. After a median follow-up of 13.9 months (range 0.3–43.8), 27 (39.1%) patients had progressive disease (PD) and three (4.3%) patients had died. The incidence rate of PD or death per 100 person-months was 2.5 [95% confidence interval (CI) 0.6–4.4; hazard ratio (HR) 1] in group 1 and 3.9 (95% CI 0–14.3; HR 1.43) in the combined group (2 + 3). The discontinuation rate due to PD was 28% in group 1, 42% in group 2, and 44% in group 3. The objective response rate was 44, 11, and 19% in groups 1, 2, and 3, respectively.

Conclusions

Our results may suggest that patients with mRCC receiving a lower dose of first-line pazopanib might not have a meaningful progression-free survival advantage compared with those receiving a standard dose. These data highlight that proper management of treatment-related side effects may lead to optimal drug exposure.

Doxorubicin-resistant pleomorphic liposarcoma with PDGFRA gene amplification is targeted and regressed by pazopanib in a patient-derived orthotopic xenograft mouse model

Pleomorphic liposarcoma (PLPS) is a heterogeneous resistant group of tumors. Complete surgical resection is the only known way to treat PLPS. PLPS is reristant to both radiation and chemotherapy. Therefore, precise individualized therapy is needed to improve outcome of advanced PLPS patients. In this study, a patient-derived orthotopic xenograft (PDOX) model of a PDGFRA-amplified PLPS was established in the biceps femoris of nude mice by surgical orthotopic implantation (SOI) in order to match the patient. The PLPS PDOX was treated with pazopanib (PAZ) which targets PDGFRA, as well as with temozolomide (TEM) and first-line therapy doxorubicin (DOX). The PLPS PDOX was resistant to DOX and responded very well to PAZ as well as TEM. The tumor volume on treatment day-14 relative to day-1 was as follows: DOX (4.50 ± 2.6, p = 0.8087); PAZ (1.29 ± 0.9, p = 0.0008 compared to the control, p = 0.0167 compared to DOX); TEM (1.07 ± 0.8, p = 0.0079 compared to the control, p = 0.0079 compared to DOX). There was no significant difference in body weight between any treated group or control. The PAZ- and TEM-treated tumors showed extensive necrosis compared to the DOX-treated and untreated PDOX tumors. The present study showed that PDGFRA amplification could be effectively targeted by PAZ. The PLPS PDOX model also identified the efficacy of TEM which does not target PDGFRA, indicating that the PDOX model can identify effective targeted therapy as well as standard therapy and at the same time, identify ineffective drugs, even if they are first-line.

Adjuvant therapy for advanced renal cell carcinoma

INTRODUCTION

Locally advanced, non-metastatic renal cell carcinoma (RCC) is conventionally managed with surgery. However, patients are at a high risk of RCC recurrence and have poor survival outcomes. An effective adjuvant systemic treatment is needed to improve on these outcomes. Targeted molecular and immune-based therapies have been investigated, or are under investigation, but their role in this setting remains unclear. Areas covered: A comprehensive search of PubMed and ClinicalTrials.gov was performed for relevant literature. The following topics pertinent to adjuvant therapy in RCC were evaluated: strategies for patient selection, cytokine-based immunotherapy, vaccine therapy, VEGF and non-VEGF targeted molecular agents, and immune checkpoint inhibitors. Expert commentary: Strong evidence for the incorporation of adjuvant therapy in high-risk RCC is lacking. Multiple targeted molecular therapies have been examined with only one approved for use. Genetic and molecular-based prognostic models are needed to determine who may benefit from adjuvant therapy. Developing adjuvant therapy strategies in the future depends on the results of important ongoing trials with immunotherapy and targeted agents.

Repurposing anticancer drugs for targeting necroptosis

Necroptosis represents a form of programmed cell death that can be engaged by various upstream signals, for example by ligation of death receptors, by viral sensors or by pattern recognition receptors. It depends on several key signaling proteins, including the kinases Receptor-Interacting Protein (RIP)1 and RIP3 and the pseudokinase mixed-lineage kinase domain-like protein (MLKL). Necroptosis has been implicated in a number of physiological and pathophysiological conditions and is disturbed in many human diseases. Thus, targeted interference with necroptosis signaling may offer new opportunities for the treatment of human diseases. Besides structure-based drug design, in recent years drug repositioning has emerged as a promising alternative to develop drug-like compounds. There is accumulating evidence showing that multi-targeting kinase inhibitors, for example Dabrafenib, Vemurafenib, Sorafenib, Pazopanib and Ponatinib, used for the treatment of cancer also display anti-necroptotic activity. This review summarizes recent evidence indicating that some anticancer kinase inhibitors also negatively affect necroptosis signaling. This implies that some cancer therapeutics may be repurposed for other pathologies, e.g. ischemic or inflammatory diseases.

Prognostic and Predictive Factors for Renal Cell Carcinoma

Metastatic renal cell carcinoma (mRCC) is an incurable malignancy, characterized by its resistance to traditional chemotherapy, radiation, and hormonal therapy. Treatment perspectives and prognosis of patients with mRCC have been significantly improved by advances in the understanding of its molecular pathogenesis, which have led to the development of targeted therapeutics. Different molecular factors derived from the tumor or the host detected in both tissue or serum could be predictive of therapeutic benefit. Some of them suggest a rational selection of patients to be treated with certain therapies, though none have been validated for routine use. This article provides an overview of both clinical and molecular factors associated with predictive or prognostic value in mRCC and emphasizes that both should be considered in parallel to provide the most appropriate, individualized treatment and achieve the best outcomes in clinical practice.

Radiotherapy and Vascular Endothelial Growth Factor Receptor-Tyrosine Kinase Inhibitors in Renal Cancer

Treatment of metastatic renal cell carcinoma (mRCC) has seen substantial progress over the last decade. A number of targeted therapies have been shown to improve clinical outcome. Vascular endothelial growth factor receptor (VEGFR)-tyrosine kinase inhibitors (TKIs) are an effective option in treating mRCC. RCC is traditionally perceived to be a radioresistant malignancy with a limited role of radiotherapy (RT) in the management of localized disease. While RCC appears to be radioresistant using conventionally fractionated RT, preclinical data suggest increased radiosensitivity when an ablative, hypofractionated schedule is used. RT is a common treatment for metastases; therefore, it is important to understand how best to use the combination of RT with targeted therapies. Preclinical studies have suggested that the combination of anti-angiogenic drugs with RT enhances the therapeutic effect compared with ionizing radiation alone. However, clinical data gave rise to warnings due to an increased incidence of severe gastrointestinal side effects. This article reviews the literature behind the preclinical and clinical data of the combination of RT with VEGFR-TKIs currently approved for RCC (sunitinib, sorafenib, pazopanib, and axitinib), with a focus on dose schedules as well as efficacy and toxicity.

Variable response of CNS hemangioblastomas to Pazopanib in a single patient with von Hippel-Lindau disease: Case report

Von Hippel-Lindau (VHL) disease is a multisystem genetic disease, the cardinal manifestations of which include central nervous system hemangioblastomas (CNS HB), renal cell carcinomas (RCC), and pheochromocytoma. Tumorigenesis in VHL of both RCC and CNS HB occurs secondary to downstream effects of a mutated or absent VHL protein. Treatment of RCCs with tyrosine kinase inhibitors (TKIs) such as Pazopanib is now first line therapy, but their effect on VHL-associated CNS HBs remains unknown. We report the use of Pazopanib in a patient with VHL disease for treatment of RCC who also harbored multiple CNS HBs. Following initiation of treatment, a large cervical and a lumbar spinal HB regressed in size while the remaining CNS HBs exhibited stable or progressive disease. These findings highlight the multiplicity of factors contributing to hemangioblastoma development, even among tumors with a common germline mutation, and the potential limitations of TKIs, but additionally this report supports the conservative management of asymptomatic VHL patients with spinal HBs whereby tumor response to TKI treatment may alleviate or postpone the need for surgery.

Pazopanib-Induced Hepatotoxicity in an Experimental Rat Model

Pazopanib is an effective treatment for advanced renal cell carcinoma and soft tissue sarcoma. Besides classical adverse events of this drug class, hepatotoxicity has been described as a frequent side effect. The aim of the present study was to evaluate the effect of pazopanib on the liver in an experimental rat model. Sixteen Wistar albino rats were divided into 3 groups: experimental toxicity was induced with pazopanib (10 mg/kg) administered for 28 days (group 2) or 56 days (group 3) orally by gavage. Group 1 (control group) received only distilled water. Rats in groups 2 and 3 were sacrificed after the collection of blood and tissue samples on the 28th and 56th days, respectively. We found significant differences in bilirubin, alkaline phosphatase, lactate dehydrogenase, glucose, triglyceride, very-low-density lipoprotein, and iron values (p < 0.050 for all) but none in any other parameter (p > 0.050). All rats in the control group had normal histological features; however, none of the rats in groups 2 and 3 showed normal histology. In group 2, we observed mild sinusoidal dilatation, congestion, enlarged Kupffer cells, accumulation of yellow-brown-black pigment in the Kupffer cells and the accumulation of hemosiderin with Prussian blue reaction in the hepatocytes. In group 3, the findings mentioned above were more prominent, and besides these findings focal acinar transformation and macrovesicular steatosis were also observed. In group 3, mild inflammation within the portal areas was observed consisting of lymphocytes, neutrophils, and eosinophils. This study is the first that reports the biochemical and histopathological evaluation of pazopanib-related hepatic toxicity.

Pazopanib Exposure Relationship with Clinical Efficacy and Safety in the Adjuvant Treatment of Advanced Renal Cell Carcinoma

Purpose: PROTECT, a phase III, randomized, placebo-controlled study, evaluated pazopanib efficacy and safety in the adjuvant renal cell carcinoma setting. The relationship between pazopanib exposure (C_trough) and efficacy and safety was evaluated.Patients and Methods: Evaluable steady-state blood trough concentrations were collected from 311 patients at week 3 or 5 (early C_trough) and 250 patients at week 16 or 20 (late C_trough). Pazopanib pharmacokinetic (PK) data were analyzed via a population model approach. Relationship between C_trough or dose intensity and disease-free survival (DFS) was explored via Kaplan-Meier and multivariate analysis. Adverse events (AE) and AE-related treatment discontinuation proportions were summarized by C_trough quartiles.Results: Most (>90%) patients with early or late C_trough data started on 600 mg. Mean early and late C_trough overlapped across dose levels. Patients with higher early C_trough quartiles achieved longer DFS (adjusted HR, 0.58; 95% confidence interval, 0.42-0.82; P = 0.002). Patients achieving early or late C_trough >20.5 μg/mL had significantly longer DFS: not estimable (NE) versus 29.5 months, P = 0.006, and NE versus 29.9 months, P = 0.008, respectively. Dose intensity up to week 8 did not correlate with DFS, consistent with population PK model-based simulations showing overlapping pazopanib exposure with 600 and 800 mg doses. The proportion of AE-related treatment discontinuation and grade 3/4 AEs, with the exception of hypertension, was not correlated to C_troughConclusions: In the adjuvant setting, higher pazopanib C_trough was associated with improved DFS and did not increase treatment discontinuations or grade 3/4 AEs, with the exception of hypertension. Clin Cancer Res; 24(13); 3005-13. ©2018 AACRSee related commentary by Rini, p. 2979.

Management of QT prolongation induced by anti-cancer drugs: Target therapy and old agents. Different algorithms for different drugs

The side effects of anticancer drugs still play a critical role in survival and quality of life. Although the recent progresses of cancer therapies have significantly improved the prognosis of oncologic patients, side effects of antineoplastic treatments are still responsible for the increased mortality of cancer survivors. Cardiovascular toxicity is the most dangerous adverse effect induced by anticancer therapies. A survey conducted by the National Health and Nutrition Examination, showed that 1807 cancer survivors followed up for seven years: 51% died of cancer and 33% of heart disease (Vejpongsa and Yeh, 2014). Moreover, the risk of cardiotoxicity persists even with the targeted therapy, the newer type of cancer treatment, due to the presence of on-target and off-target effects related to this new class of drugs. The potential cardiovascular toxicity of anticancer agents includes: QT prolongation, arrhythmias, myocardial ischemia, stroke, hypertension (HTN), thromboembolism, left ventricular dysfunction and heart failure (HF). Compared to other cardiovascular disorders, the interest in QT prolongation and its complications is fairly recent. However, oncologists have to deal with it and to evaluate the risk-benefit ratio before starting the treatment or during the same. Electrolyte abnormalities, low levels of serum potassium and several drugs may favour the acquired QT prolongation. Treatment of marked QT prolongation includes cardiac monitoring, caution in the use or suspension of cancer drugs and correction of electrolyte abnormalities (hypokalaemia, hypomagnesaemia, hypocalcaemia). Syndrome of QT prolongation can be associated with potentially fatal cardiac arrhythmias and its treatment consists of intravenous administration of magnesium sulphate and the use of electrical cardioversion.

Systematic review and survival meta-analysis of real world evidence on first-line pazopanib for metastatic renal cell carcinoma

A systematic review was conducted to identify real world studies reporting outcomes after first-line pazopanib in patients with metastatic renal cell carcinoma. Studies had to be observational and report survival data in terms of progression-free survival and overall survival in order to conduct meta-analysis techniques. These real-world data were compared to those obtained in the phase II and III randomized controlled trials of pazopanib. Real world evidence showed that the clinical and safety outcomes were consistent with those observed in the clinical trials despite the inclusion of unselected patients with a wide spectrum of prognostic features and comorbidities. Similarly to the results of the pivotal studies, good prognosis patients had the most benefit from pazopanib. Further investigation is needed to complement evidence from clinical trials, in particular focused on patient-centered outcomes.