Circulating biomarkers for vascular endothelial growth factor inhibitors in renal cell carcinoma

Sunitinib resistance in renal cell carcinoma: From molecular mechanisms to predictive biomarkers

Currently, renal cell carcinoma (RCC) is the most prevalent type of kidney cancer. Targeted therapy has replaced radiation therapy and chemotherapy as the main treatment option for RCC due to the lack of significant efficacy with these conventional therapeutic regimens. Sunitinib, a drug used to treat gastrointestinal tumors and renal cell carcinoma, inhibits the tyrosine kinase activity of a number of receptor tyrosine kinases, including vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR), c-Kit, rearranged during transfection (RET) and fms-related receptor tyrosine kinase 3 (Flt3). Although sunitinib has been shown to be efficacious in the treatment of patients with advanced RCC, a significant number of patients have primary resistance to sunitinib or acquired drug resistance within the 6-15 months of therapy. Thus, in order to develop more efficacious and long-lasting treatment strategies for patients with advanced RCC, it will be crucial to ascertain how to overcome sunitinib resistance that is produced by various drug resistance mechanisms. In this review, we discuss: 1) molecular mechanisms of sunitinib resistance; 2) strategies to overcome sunitinib resistance and 3) potential predictive biomarkers of sunitinib resistance.

Development of a prognostic composite cytokine signature based on the correlation with nivolumab clearance: translational PK/PD analysis in patients with renal cell carcinoma

BACKGROUND

Although several therapeutic options for patients with renal cell carcinoma (RCC) have been approved over recent years, including immune checkpoint inhibitors, considerable need remains for molecular biomarkers to assess disease prognosis. The higher pharmacokinetic (PK) clearance of checkpoint inhibitors, such as the anti-programmed death-1 (PD-1) therapies nivolumab and pembrolizumab, has been shown to be associated with poor overall survival (OS) across several tumor types. However, determination of PK clearance requires the collection and analysis of post-treatment serum samples, limiting its utility as a prognostic biomarker. This report outlines a translational PK-pharmacodynamic (PD) methodology used to derive a baseline composite cytokine signature correlated with nivolumab clearance using data from three clinical trials in which nivolumab or everolimus was administered.

METHODS

Peripheral serum cytokine (PD) and nivolumab clearance (PK) data from patients with RCC were analyzed using a PK-PD machine-learning model. Nivolumab studies CheckMate 009 (NCT01358721) and CheckMate 025 (NCT01668784) (n = 480) were used for PK-PD analysis model development and cytokine feature selection (training dataset). Validation of the model and assessment of the prognostic value of the cytokine signature was performed using data from CheckMate 010 (NCT01354431) and the everolimus comparator arm of CheckMate 025 (test dataset; n = 453).

RESULTS

The PK-PD analysis found a robust association between the eight top-ranking model-selected baseline inflammatory cytokines and nivolumab clearance (area under the receiver operating characteristic curve = 0.7). The predicted clearance (high vs low) based on the cytokine signature was significantly associated with long-term OS (p < 0.01) across all three studies (training and test datasets). Furthermore, cytokines selected from the model development trials also correlated with OS of the everolimus comparator arm (p < 0.01), suggesting the prognostic nature of the composite cytokine signature for RCC.

CONCLUSIONS

Here, we report a PK-PD translational approach to identify a molecular prognostic biomarker signature based on the correlation with nivolumab clearance in patients with RCC. This composite biomarker signature may provide improved prognostic accuracy of long-term clinical outcome compared with individual cytokine features and could be used to ensure the balance of patient randomization in RCC clinical trials.

Phase 1 trial of ontuxizumab (MORAb-004) in children with relapsed or refractory solid tumors: A report from the Children's Oncology Group Phase 1 Pilot Consortium (ADVL1213)

BACKGROUND

Ontuxizumab is a humanized IgG monoclonal antibody that targets the cell-surface glycoprotein endosialin (tumor endothelial marker-1[TEM-1]/CD248) found on activated mesenchymal cells and certain tumors. Ontuxizumab binding to endosialin may interfere with platelet-derived growth factor signaling, prevent tumor stroma organization, and prevent new vessel formation.

METHODS

Ontuxizumab was administered intravenously on days 1, 8, 15, and 22 of a 28-day cycle at three dose levels (4, 8, and 12 mg/kg). Further dose escalation to 16 mg/kg was planned if the maximum tolerated dose (MTD) was not reached and the ontuxizumab systemic clearance was ≥30% higher in children compared to adults. Following determination of the MTD/recommended phase 2 dose, an additional cohort of six patients (<12 years) was enrolled for further pharmacokinetics (PK) evaluation.

RESULTS

Twenty-seven eligible patients (17 male, median age 15 years, range 3-21 years) were enrolled. Twenty-two patients (neuroblastoma [5], Ewing sarcoma [4], rhabdomyosarcoma [4], and other tumors [9]) were fully evaluable for toxicity. Five patients did not complete cycle 1 due to tumor progression. Two of 10 patients experienced dose-limiting toxicity of bacteremia (n = 1) and hyponatremia (n = 1) at 12 mg/kg. Grade ≤2 fever or infusion-related reactions occurred in 10 patients. Clearance was dose dependent and within 30% of adult value at 12 mg/kg.

CONCLUSION

Ontuxizumab administered weekly at 12 mg/kg appears to be well tolerated in children with relapsed or refractory solid tumors. The PK of ontuxizumab does not appear to be significantly different in children compared to adults.

Anti-angiogenesis target therapy for advanced osteosarcoma (Review)

Osteosarcomas (OS), especially those with metastatic or unresectable disease, have limited treatment options. The greatest advancement in treatments occurred in the 1980s when multi-agent chemotherapy, including doxorubicin, cisplatin, high-dose methotrexate, and, in some regimens, ifosfamide, was demonstrated to improve overall survival compared with surgery alone. However, standard chemotherapeutic options have been limited by poor response rates in patients with relapsed or advanced cases. It has been reported that VEGFR expression correlates with the outcome of patients with osteosarcoma and circulating VEGF level has been associated with the development of lung metastasis. At present, it seems to us that progress has not been made since Grignani reported a phase II cohort trial of sorafenib and sorafenib combined with everolimus for advanced osteosarcoma, which, in a sense, have become a milestone as a second-line therapy for osteosarcoma. Although the recognization of muramyltripepetide phosphatidyl-ethanolamine has made some progress based on its combination with standard chemotherapy, its effect on refractory cases is controversial. Personalized comprehensive molecular profiling of high-risk osteosarcoma up to now has not changed the therapeutic prospect of advanced osteosarcoma significantly. Thus, how far have we moved forward and what therapeutic strategy should we prefer for anti-angiogenesis therapy? This review provides an overview of the most updated anti-angiogenesis therapy in OS and discusses some clinical options in order to maintain or even improve progression-free survival.

A Pharmacometric Framework for Axitinib Exposure, Efficacy, and Safety in Metastatic Renal Cell Carcinoma Patients

The relationships between exposure, biomarkers (vascular endothelial growth factor (VEGF), soluble VEGF receptors (sVEGFR)-1, -2, -3, and soluble stem cell factor receptor (sKIT)), tumor sum of longest diameters (SLD), diastolic blood pressure (dBP), and overall survival (OS) were investigated in a modeling framework. The dataset included 64 metastatic renal cell carcinoma patients (mRCC) treated with oral axitinib. Biomarker timecourses were described by indirect response (IDR) models where axitinib inhibits sVEGFR-1, -2, and -3 production, and VEGF degradation. No effect was identified on sKIT. A tumor model using sVEGFR-3 dynamics as driver predicted SLD data well. An IDR model, with axitinib exposure stimulating the response, characterized dBP increase. In a time-to-event model the SLD timecourse predicted OS better than exposure, biomarker- or dBP-related metrics. This type of framework can be used to relate pharmacokinetics, efficacy, and safety to long-term clinical outcome in mRCC patients treated with VEGFR inhibitors. (ClinicalTrial.gov identifier NCT00569946.).

Resistance to sunitinib in renal cell carcinoma: From molecular mechanisms to predictive markers and future perspectives

The introduction of agents that inhibit tumor angiogenesis by targeting vascular endothelial growth factor (VEGF) signaling has made a significant impact on the survival of patients with metastasized renal cell carcinoma (RCC). Sunitinib, a tyrosine kinase inhibitor of the VEGF receptor, has become the mainstay of treatment for these patients. Although treatment with sunitinib substantially improved patient outcome, the initial success is overshadowed by the occurrence of resistance. The mechanisms of resistance are poorly understood. Insight into the molecular mechanisms of resistance will help to better understand the biology of RCC and can ultimately aid the development of more effective therapies for patients with this infaust disease. In this review we comprehensively discuss molecular mechanisms of resistance to sunitinib and the involved biological processes, summarize potential biomarkers that predict response and resistance to treatment with sunitinib, and elaborate on future perspectives in the treatment of metastasized RCC.

“Targeting” renal cell carcinoma patients with “targeted” agents: Are we there yet?

The rapid approval of several novel agents, targeting the vascular endothelial growth factor or mammalian target of rapamycin pathways (sunitinib, pazopanib, sorafenib, axitinib, bevacizumab, everolimus, temsirolimus) has given to metastatic renal cell carcinoma (mRCC) patients and their treating physicians many new and effective therapeutic options. The treatment paradigm for these patients is rapidly evolving, with future studies needed to define the optimal sequencing of these new agents. Despite progresses, no validated biomarkers able to predict clinical outcome or useful to guide patient selection for treatment are currently available. Recent studies have suggested that some biomarkers, including cytokines, circulating proangiogenic factors, markers of hypoxia or targets of signaling pathways are potentially promising prognostic or predictive factors in mRCC. We present an overview of the most recent developments in identifying biomarkers for targeted therapies in advanced RCC.

Prognostic or predictive plasma cytokines and angiogenic factors for patients treated with pazopanib for metastatic renal-cell cancer: a retrospective analysis of phase 2 and phase 3 trials

BACKGROUND

Several targeted drugs are approved for treatment of patients with metastatic renal-cell cancer, but no validated biomarkers are available for prediction of clinical outcome. We aimed to assess the prognostic and predictive associations of pretreatment plasma concentrations of cytokine and angiogenic factors (CAFs) with data from a phase 2 and a phase 3 trial of pazopanib treatment.

METHODS

We used a three-step approach for screening, confirmation, and validation of prospective CAF biomarkers. We screened 17 CAFs in 129 patients who had the greatest or least tumour shrinkage in a phase 2 trial of 215 patients treated with pazopanib. We confirmed associations of candidate CAFs (those identified in the screening and from previous studies) with tumour response and progression-free survival (PFS) in 215 patients from this phase 2 trial with an independent analytical platform. We validated confirmed markers in 344 patients from a randomised, placebo-controlled, phase 3 clinical study of pazopanib.

FINDINGS

Five candidate markers emerged from initial screening-interleukin 6, interleukin 8, hepatocyte growth factor (HGF), tissue inhibitor of metalloproteinases (TIMP)-1, and E-selectin. Confirmatory analyses identified associations of interleukin 6, interleukin 8, VEGF, osteopontin, E-selectin, and HGF with continuous tumour shrinkage or PFS in patients treated with pazopanib. In the validation set of samples from the phase 3 trial, patients treated with pazopanib who had high concentrations (relative to median) of interleukin 8 (p=0·006), osteopontin (p=0·0004), HGF (p=0·010), and TIMP-1 (p=0·006) had shorter PFS than did those with low concentrations. In the placebo group, high concentrations of interleukin 6 (p<0·0001), interleukin 8 (p=0·002), and osteopontin (p<0·0001) were all prognostically associated with shorter PFS. These factors were stronger prognostic markers than were standard clinical classifications (Eastern Cooperative Oncology Group, Memorial Sloan-Kettering Cancer Center, and Heng criteria). High concentrations of interleukin 6 were predictive of improved relative PFS benefit from pazopanib compared with placebo (p(interaction)=0·009); standard clinical classifications were not predictive of PFS benefit.

INTERPRETATION

CAF profiles could provide prognostic information beyond that of standard clinical classification and identify markers predictive of pazopanib benefit in patients with metastatic renal-cell carcinoma. Further studies of the predictive effects of these markers in different populations and with different drugs (eg, mTOR inhibitors) are warranted.

FUNDING

GlaxoSmithKline.

A cytokine and angiogenic factor (CAF) analysis in plasma for selection of sorafenib therapy in patients with metastatic renal cell carcinoma

BACKGROUND

We investigated cytokines and angiogenic factors (CAFs) in patients with metastatic renal cell carcinoma (mRCC) treated in a randomized phase II clinical trial of sorafenib versus sorafenib+ interferon-α (IFN-α) that yielded no differences in progression-free survival (PFS). We aimed to link the CAF profile to PFS and select candidate predictive and prognostic markers for further study.

METHODS

The concentrations of 52 plasma CAFs were measured pretreatment (n = 69), day 28, and day 56 using multiplex bead arrays and enzyme-linked immunosorbent assay. We investigated the association between baseline levels of CAFs with PFS and posttreatment changes.

RESULTS

Unsupervised CAF clustering analysis revealed two distinct mRCC patient groups with elevated proangiogenic or proinflammatory mediators. A six-marker baseline CAF signature [osteopontin, vascular endothelial growth factor (VEGF), carbonic anhydrase 9, collagen IV, VEGF receptor-2, and tumor necrosis factor-related apoptosis-inducing ligand] correlated with PFS benefit (hazard ratio 0.20 versus 2.25, signature negative versus positive, respectively; P = 0.0002). While changes in angiogenic factors were frequently attenuated by the sorafenib+ IFN combination, most key immunomodulatory mediators increased.

CONCLUSIONS

Using CAF profiling, we identified two mRCC patient groups, a candidate plasma signature for predicting PFS benefit, and distinct marker changes occurring with each treatment. This platform may provide valuable insights into renal cell carcinoma biology and the molecular consequences of targeted therapies.

The BATTLE to personalize lung cancer prevention through reverse migration

Agents can enter clinical development for cancer prevention either initially or after previous development for a different indication, such as arthritis, with both approaches consuming many years of development before an agent is fully evaluated for cancer prevention. We propose the following, third approach: reverse migration, that is, importing agents, targets, and study designs to personalize interventions and concepts developed in advanced cancer to the setting of cancer prevention. Importing these "ready-made" features from therapy will allow reverse migration to streamline preventive agent development. We recently reported the Biomarker-integrated Approaches of Targeted Therapy for Lung Cancer Elimination (BATTLE) trial of personalized lung cancer therapy and now propose the reverse migration development of personalized lung cancer prevention based on the BATTLE model.

Neoadjuvant and adjuvant strategies in renal cell carcinoma: more questions than answers

The current standard treatment for early stage (I-III) renal cell cancer (RCC) is surgery. While the prognosis of stage I tumors is excellent, stage II and particularly stage III have a high risk of relapse. The adjuvant treatment of patients with RCC remains an area of investigation, with patient selection being a key aspect. There are currently two prognostic nomograms to establish the risk of relapse in patients with resected RCC. The results of earlier studies of adjuvant therapy, including the use chemotherapy and/or immunotherapy after nephrectomy have failed to show any benefit in the outcome of patients at risk of developing local recurrence or distant metastases. Two recent phase III trials with vaccines (autologous tumor cell vaccine and autologous tumor-derived heat shock protein peptide complex-96) have shown promising, albeit still preliminary, results. In the metastatic RCC setting, recent advances in the molecular understanding of oncogenic pathways have led to the development of new therapeutic strategies with the use of targeted therapies in the adjuvant setting. Neoadjuvant treatment is another treatment modality currently being evaluated for patients with early disease and in patients with metastatic RCC with inoperable primary tumors. The questions that remain unanswered include activity of these agents in early stages of the disease, patient selection, optimal start time of the adjuvant treatment, and finally, the optimal length of treatment.

Plasma cytokine and angiogenic factor profiling identifies markers associated with tumor shrinkage in early-stage non-small cell lung cancer patients treated with pazopanib

There is an unmet need for pharmacodynamic and predictive biomarkers for antiangiogenic agents. Recent studies have shown that soluble vascular endothelial growth factor receptor 2 (sVEGFR2), VEGF, and several other soluble factors may be modulated by VEGF pathway inhibitors. We conducted a broad profiling of cytokine and angiogenic factors (CAF) to investigate the relationship between baseline CAF levels, CAF changes during treatment, and tumor shrinkage in early-stage non-small cell lung cancer (NSCLC) patients treated with pazopanib, an oral angiogenesis inhibitor targeting VEGFR, platelet-derived growth factor receptor, and c-kit. Plasma samples were collected before treatment and on the last day of therapy from 33 patients with early-stage NSCLC participating in a single-arm phase II trial. Levels of 31 CAFs were measured by suspension bead multiplex assays or ELISA and correlated with change in tumor volume. Pazopanib therapy was associated with significant changes of eight CAFs; sVEGFR2 showed the largest decrease, whereas placental growth factor underwent the largest increase. Increases were also observed in stromal cell-derived factor-1alpha, IP-10, cutaneous T-cell-attracting chemokine, monokine induced by IFN-gamma, tumor necrosis factor-related apoptosis-inducing ligand, and IFN-alpha. Posttreatment changes in plasma sVEGFR2 and interleukin (IL)-4 significantly correlated with tumor shrinkage. Baseline levels of 11 CAFs significantly correlated with tumor shrinkage, with IL-12 showing the strongest association. Using multivariate classification, a baseline CAF signature consisting of hepatocyte growth factor and IL-12 was associated with tumor response to pazopanib and identified responding patients with 81% accuracy. These data suggest that CAF profiling may be useful for identifying patients likely to benefit from pazopanib, and merit further investigation in clinical trials.

CD133+ circulating haematopoietic progenitor cells predict for response to sorafenib plus erlotinib in non-small cell lung cancer patients

BACKGROUND

Blood-based biomarkers may be particularly useful for patient selection and prediction of treatment response for angiogenesis inhibitors. Circulating endothelial cells (CECs) and haematopoietic progenitor cells (HPCs) might have a role in tumour angiogenesis and in tumour growth. Measurement of CECs and HPCs in the blood of patients could be a simple, non-invasive way to monitor or predict responses to treatment.

METHODS

(VEGFR2(+)) CECs(,) (CD133(+)) HPCs, plasma vascular endothelial growth factor (VEGF) and erythropoietin were measured in blood from 25 non-small cell lung cancer (NSCLC) patients before and during treatment with sorafenib plus erlotinib (SO/ER). In order to assess the drug specificity of changes in CECs and HPCs, 18 patients treated with bevacizumab plus erlotinib (BV/ER) and 10 patients with erlotinib (ER) monotherapy were studied. Response was measured in all patient groups by Response Evaluation Criteria in Solid Tumors (RECIST).

RESULTS

At day 7, SO/ER-treated patients showed a three-fold increase in CECs (P<0.0001) comparable to BV/ER-treated patients (P<0.01), and the CECs did not change with erlotinib treatment (P=0.8). At day 7, CD133(+)/HPCs decreased with SO/ER treatment (P<0.0001). HPC numbers did not change with either BV/ER or erlotinib. In SO/ER-treated patients pre-treatment CD133(+)/HPCs were significantly lower in responders (P=0.01) and pre-treatment CD133(+)/HPC numbers lower than the median correlated with a longer time-to-progression (TTP) (P=0.037).

CONCLUSION

Pre-treatment CD133(+)/HPCs are a promising candidate biomarker to further explore for use in selecting NSCLC patients who might benefit from SO/ER treatment.