Experience With Bevacizumab in the Management of Epithelial Ovarian Cancer

Acquisition of drug resistance in endothelial cells by tumor-derived extracellular vesicles and cancer progression

Angiogenesis by endothelial cells (ECs) is essential for tumor growth. Angiogenesis inhibitors are used in combination with anticancer drugs in many tumor types, but tumors eventually become resistant. Previously, the underlying mechanism for developing drug resistance was considered to be a change in the characteristics of tumor cells whereas ECs were thought to be genetically stable and do not contribute to drug resistance. However, tumor endothelial cells (TECs) have been shown to differ from normal endothelial cells (NECs) in that they exhibit chromosomal abnormalities, angiogenic potential, and drug resistance. Extracellular vesicles (EVs) secreted by tumor cells have recently attracted attention as a factor involved in the acquisition of such abnormalities. Various cells communicate with each other through EVs, and it has been reported that tumor-derived EVs act on other tumor cells or stromal cells to develop drug resistance. Drug-resistant tumor cells confer drug resistance to recipient cells by transporting mRNAs encoding ATP-binding cassette subfamily B member 1 (ABCB1) and ATP-binding cassette subfamily C member 1 (ABCC1) as well as miRNAs involved in signaling such as Akt, drug efflux transporters, and P-glycoprotein modulators via EVs. However, there are limited reports on the acquisition of drug resistance in ECs by tumor-derived EVs. Since drug resistance of ECs may induce tumor metastasis and support tumor cell proliferation, the mechanism underlying the development of resistance should be elucidated to find therapeutic application. This review provides insight into the acquisition of drug resistance in ECs via tumor EVs in the tumor microenvironment.

Severe hematuria in a patient receiving bevacizumab and pembrolizumab for metastatic cervical cancer: a case report

BACKGROUND

Bevacizumab is a monoclonal antibody drug targeting Vascular Endothelial Growth Factor (VEGF), which binds to VEGF receptors to inhibit vascular endothelial cell proliferation and angiogenesis, thus inhibiting tumorigenesis. Pembrolizumab is a monoclonal antibody that can bind to the programmed death-1 (PD-1) receptor, which can block the binding of the PD-1 receptor to its ligands PD-L1 and PD-L2, and release PD-1 pathway-mediated suppression of immune responses. By blocking the activity of PD-1, the purpose of inhibiting tumor growth is achieved.

CASE PRESENTATION

We report a severe hematuria of bevacizumab plus pembrolizumab, in a 58-year-old woman with metastatic cervical cancer. After three cycles every three weeks of consolidation chemotherapy (carboplatin, paclitaxel, bevacizumab) and following three cycles consolidation chemotherapy (carboplatin, paclitaxel, bevacizumab, pembrolizumab), the patient presented a worsening state. Manifested as massive gross hematuria with blood clots. After stopping chemotherapy, cefoxitin, tranexamic acid and hemocoagulase atrox therapy was administered resulting in rapid clinical improvement. The patient was a cervical cancer with bladder metastasis that increases the risk of development of hematuria. Inhibition of VEGF, which has anti-apoptotic, anti-inflammatory, and pro-survival influences on endothelial cells, weakens their regenerative capacity and increases expression of proinflammatory genes leading to weakened supporting layers of blood vessels and, hence, to damaged vascular integrity. In our patient, the development of hematuria may result from the anti-VEGF effect of bevacizumab. In addition, pembrolizumab may also cause bleeding, and the mechanism of bleeding caused by pembrolizumab is currently unclear, which may be related to immune mediation.

CONCLUSION

To our knowledge, this is the first case reporting on the development of severe hematuria during bevacizumab plus pembrolizumab treatment, which should alert the clinicians in case of bleeding adverse events onset in older patients under bevacizumab plus pembrolizumab therapy.

Safety Analysis of Bevacizumab in Ovarian Cancer Patients

Bevacizumab (BEV) is beneficial for ovarian cancer patients, but the real world's patient settings differ from those in clinical trials. This study tries to illustrate adverse events in the Taiwanese population. Patients with epithelial ovarian cancer treated with BEV at Kaohsiung Chang Gung Memorial Hospital between 2009 and 2019 were retrospectively reviewed. The receiver operating characteristic curve was adopted to identify the cutoff dose and the presence of BEV-related toxicities. A total of 79 patients receiving BEV in neoadjuvant, frontline, or salvage settings were enrolled. The median follow-up time was 36.2 months. Twenty patients (25.3%) had "De novo" hypertension or the worsening of a preexisting one. Twelve patients (15.2%) had "De novo" proteinuria. Five patients (6.3%) had thromboembolic events/hemorrhage. Four patients (5.1%) had gastrointestinal perforation (GIP), and one patient (1.3%) had wound-healing complications. Patients with BEV-related GIP had at least two risk factors for developing GIP, most of which were conservatively managed. This study revealed a compatible but distinct safety profile from those reported in clinical trials. The presence of BEV-related changes in blood pressure showed a dose-dependent trend. Most of the BEV-related toxicities were managed individually. Patients with potential risks for developing BEV-related GIP should use BEV with caution.

Disparity in the era of personalized medicine for epithelial ovarian cancer

The treatment of high-grade serous ovarian cancer and high-grade endometrioid ovarian cancer has seen significant improvements in recent years, with BRCA1/2 and homologous recombination status guiding a personalized approach which has resulted in improved patient outcomes. However, for other epithelial ovarian cancer subtypes, first-line treatment remains unchanged from the platinum-paclitaxel trials of the early 2000s. In this review, we explore novel therapeutic approaches being adopted in the treatment of clear cell, mucinous, carcinosarcoma and low-grade serous ovarian cancer and the biological rational behind them. We discuss why such disparities exist, the challenges faced in conducting dedicated trials in these rarer histologies and look towards new approaches being adopted to overcome them.

Exploiting epigenetic dependencies in ovarian cancer therapy

Ovarian cancer therapy has remained fundamentally unchanged for 50 years, with surgery and chemotherapy still the frontline treatments. Typically asymptomatic until advanced stages, ovarian cancer is known as “the silent killer.” Consequently, it has one of the worst 5‐year survival rates, as low as 30%. The most frequent driver mutations are found in well‐defined tumor suppressors, such as p53 and BRCA1/2. In recent years, it has become clear that, like the majority of other cancers, many epigenetic regulators are altered in ovarian cancer, including EZH2, SMARCA2/4 and ARID1A. Disruption of epigenetic regulators often leads to loss of transcriptional control, aberrant cell fate trajectories and disruption of senescence, apoptotic and proliferation pathways. These mitotically inherited epigenetic alterations are particularly promising targets for therapy as they are largely reversible. Consequently, many drugs targeting chromatin modifiers and other epigenetic regulators are at various stages of clinical trials for other cancers. Understanding the mechanisms by which ovarian cancer‐specific epigenetic processes are disrupted in patients can allow for informed targeting of epigenetic pathways tailored for each patient. In recent years, there have been groundbreaking new advances in disease modeling through ovarian cancer organoids; these models, alongside single‐cell transcriptomic and epigenomic technologies, allow the elucidation of the epigenetic pathways deregulated in ovarian cancer. As a result, ovarian cancer therapy may finally be ready to advance to next‐generation treatments. Here, we review the major developments in ovarian cancer, including genetics, model systems and technologies available for their study and the implications of applying epigenetic therapies to ovarian cancer.

Current Ovarian Cancer Maintenance Strategies and Promising New Developments

While ovarian cancer typically responds well to front line treatment, many patients will relapse within 5 years. Treatment options are less effective at each recurrence highlighting the need for novel maintenance therapies. PolyADP-ribose polymerase (PARP) inhibitors have recently gained approval in ovarian cancer maintenance. Niraparib was approved regardless of BRCA mutation status, however impact on overall survival is limited. Oliparib was approved for BRCA mutant and BRCA wildtype/homologous recombination deficient patients. This review will focus on current frontline ovarian cancer treatment as well molecularly based approaches to ovarian cancer management.

Synergistic Anti-Tumor Activity by Targeting Multiple Signaling Pathways in Ovarian Cancer

More effective therapy is needed to improve the survival of patients with advanced and recurrent ovarian cancer. Preclinical and early clinical studies with single molecular targeted agents have shown limited antitumor activity in ovarian cancer, likely due to compensation by alternative growth/survival pathways. An emerging strategy in overcoming resistance is to combine inhibitors targeting multiple pathways. In this study, we used a novel strategy of combining several FDA-approved targeted drugs, including sunitinib, dasatinib, and everolimus, in human ovarian cancers. Combination of the tyrosine kinase inhibitor sunitinib with the SRC inhibitor dasatinib showed synergistic anti-tumor activity in human ovarian cancer cells. The increased activity was associated with inhibition of the STAT3, SRC, and MAPK signaling pathways, but not AKT signaling. To inhibit the PI3K/AKT/mTOR pathway, we added the mTOR inhibitor everolimus, which further increased anti-tumor activity in cells. Combined treatment with sunitinib, dasatinib, and everolimus also resulted in greater inhibition of human ovarian tumor growth in mice. Furthermore, the triple combination also synergistically increased the anti-tumor activity of paclitaxel, both in vitro and in vivo. Taken together, our results demonstrate that simultaneous inhibition of several signaling pathways results in better anti-tumor activity compared to inhibiting any of these signaling pathways alone.

Clinical predictors of bevacizumab-associated intestinal perforation in non-small cell lung cancer

Background Bevacizumab (Bev) is generally well-tolerated, and Bev-associated intestinal perforation (BAP) is a rare albeit serious side effect in cases of non-small cell lung cancer (NSCLC). Therefore, the present study aimed to identify clinical predictors of BAP to help predict and manage the development of life-threatening intestinal complications among patients receiving Bev. Methods This retrospective study evaluated demographic, clinical, and treatment factors for patients with NSCLC who were treated with Bev between February 2010 and August 2015 at our center. Results We identified 314 regimens (208 patients; median age: 65 years; 115 women) for analysis, which included 119 first-line regimens, 74 s-line regimens, and 121 third-line or later regimens. BAP occurred in 7 cases (2.23% among all regimens and 3.37% among all patients), which generally occurred during first- or second-line treatment and was caused by ulcerative colitis (1 case), colon diverticulitis (1 case), and idiopathic perforations (5 cases). Univariate analyses revealed that BAP was significantly associated with deteriorating PS during the first cycle of chemotherapy (odd ratio [OR]: 11.07, 95% confidence interval [CI]: 2.37-51.63, p = 0.0022), grade ≥ 3 diarrhea (OR: 11.37, 95% CI: 2.37-54.50, p = 0.0024), febrile neutropenia (OR: 9.16, 95% CI: 1.98-42.49, p = 0.0047), and stomatitis (OR: 4.60, 95% CI: 1.01-21.04, p = 0.0492). Conclusions Among patients with NSCLC, BAP was associated with deteriorating PS during the first cycle of chemotherapy, grade ≥ 3 diarrhea, febrile neutropenia, and stomatitis. Therefore, careful observation is needed for patients with NSCLC who receive Bev in any line of treatment, especially if they develop serious side effects that affect their PS or mucous membrane.

Molecular targeted therapy in gynaecologic malignancies: primer for radiologists

The identification of characteristic genetic alteration in gynaecological malignancies has opened the door for molecular targeted therapy. The purpose of this review is to provide a primer for the radiologist on these agents with emphasis on the role of imaging in treatment response assessment and drug toxicities. The use of targeted therapy in gynaecological malignancies will likely increase in the future and make the role of the radiologist critical in response assessment and detection of toxicities.

A pilot study of JI-101, an inhibitor of VEGFR-2, PDGFR-β, and EphB4 receptors, in combination with everolimus and as a single agent in an ovarian cancer expansion cohort

JI-101 is an oral multi-kinase inhibitor that targets vascular endothelial growth factor receptor type 2 (VEGFR-2), platelet derived growth factor receptor β (PDGFR-β), and ephrin type-B receptor 4 (EphB4). None of the currently approved angiogenesis inhibitors have been reported to inhibit EphB4, and therefore, JI-101 has a novel mechanism of action. We conducted a pilot trial to assess the pharmacokinetics (PK), tolerability, and efficacy of JI-101 in combination with everolimus in advanced cancers, and pharmacodynamics (PD), tolerability, and efficacy of JI-101 in ovarian cancer. This was the first clinical study assessing anti-tumor activity of JI-101 in a combinatorial regimen. In the PK cohort, four patients received single agent 10 mg everolimus on day 1, 10 mg everolimus and 200 mg JI-101 combination on day 8, and single agent 200 mg JI-101 on day 15. In the PD cohort, eleven patients received single agent JI-101 at 200 mg twice daily for 28 day treatment cycles. JI-101 was well tolerated as a single agent and in combination with everolimus. No serious adverse events were observed. Common adverse events were hypertension, nausea, and abdominal pain. JI-101 increased exposure of everolimus by approximately 22%, suggestive of drug-drug interaction. The majority of patients had stable disease at their first set of restaging scans (two months), although no patients demonstrated a response to the drug per RECIST criteria. The novel mechanism of action of JI-101 is promising in ovarian cancer treatment and further prospective studies of this agent may be pursued in a less refractory patient population or in combination with cytotoxic chemotherapy.

Whole genome expression profiling of blood cells in ovarian cancer patients -prognostic impact of the CYP1B1, MTSS1, NCALD, and NOP14

Ovarian cancer patients with different tumor stages and cell differentiation might be distinguished from each other by gene expression profiles in whole blood cell mRNA by the Affymetrix Human Gene 1.0 ST Array. We also examined if there is any association with other clinical variables, response to therapy, and residual tumor burden after surgery. Patients were divided into two groups, one with poor prognosis, advanced stage and poorly differentiated tumors (n = 22), and one group with good prognosis, early stage and well- to medium differentiated tumors (n = 11). Six genes were found to be differentially expressed: the PDIA3, LYAR, NOP14, NCALD and MTSS1 genes were down-regulated and the CYP1B1 gene expression was up-regulated in the poor prognosis group, all with p value <0.05, adjusted for mass comparison. In survival analyses, CYP1B1, MTSS1, NCALD and NOP14 remained significantly different (p<0.05). Patient groups did not differ in any transcript related to acute phase or immune responses. This minimal gene expression signature of prognostic ovarian cancer-related genes opens up an avenue for more practicable monitoring of ovarian cancer patients by simple peripheral blood tests, which may evolve into a tool to guide selection of curative and postoperative supportive therapies.

VEGF Splicing and the Role of VEGF Splice Variants: From Physiological-Pathological Conditions to Specific Pre-mRNA Splicing

During this past decade, the vascular endothelial growth factor (VEGF) pathway has been extensively studied. VEGF is a paradigm of molecular regulation since its expression is controlled at all possible steps including transcription, mRNA stability, translation, and pre-mRNA splicing. The latter form of molecular regulation is probably the least studied. This field has been neglected; yet different forms of VEGF with different sizes and different physiological properties issued from alternative splicing have been described a long time ago. Recently a new level of complexity was added to the field of splicing of VEGF pre-mRNA. Whereas thousands of publications have described VEGF as a pro-angiogenic factor, an alternative splicing event generates specific anti-angiogenic forms of VEGF that only differ from the others by a modification in the last six amino acids of the protein. According to the scientists who discovered these isoforms, which are indistinguishable from the pro-angiogenic ones with pan VEGF antibodies, some of the literature on VEGF is at least inexact if not completely false. Moreover, the presence of anti-angiogenic forms of VEGF may explain the disappointing efficacy of anti-VEGF therapies on the overall survival of patients with different forms of cancers and with wet age-related macular degeneration. This review focuses on the existence of the different alternative splice variants of VEGF and the molecular mechanisms associated with their expression and function.

Incorporation of anti-angiogenesis therapy in the management of advanced ovarian carcinoma--mechanistics, review of phase III randomized clinical trials, and regulatory implications

Despite survival gains achieved nearly two decades ago with combination platinum- and taxane-based intravenous chemotherapy, overall survival curves have remained relatively unchanged during the 21st century using newer cytotoxic agents. Although combined intravenous-intraperitoneal (IV-IP) chemotherapy is promising, tolerability remains a significant issue. An emphasis has been placed on exploring dose dense schedules and targeted agents. Vascular endothelial growth factor (VEGF) has emerged as an important therapeutic target in several solid tumors including ovarian carcinoma. The monoclonal antibody, bevacizumab, binds VEGF, thus preventing activation of the VEGF receptor (VEGFR) leading to inhibition of tumor angiogenesis. To date eight phase 3 randomized controlled trials incorporating anti-angiogenesis therapy in the treatment of newly diagnosed and recurrent ovarian carcinoma have met their primary endpoints. Four of these trials included bevacizumab and were reported from 2010 to 2012. During 2013, the other four studies were reported, each studying one of the following novel anti-angiogenesis agents: pazopanib, cediranib, trebananib, and nintedanib. Importantly, none of these drugs have been approved by the United States Food and Drug Administration (US FDA) for the treatment of ovarian cancer. The purpose of this review will be to highlight both VEGF-dependent and non-VEGF dependent angiogenic pathways in ovarian cancer and discuss the phase 3 experiences and regulatory implications of targeting the tumor microenviroment with anti-angiogenesis therapy.

Sudden visual loss in the untreated eye of a patient with neovascular glaucoma following an intravitreal bevacizumab injection: A case report

The current study presents the case of a patient with a rare adverse event characterized by sudden vision loss in the untreated eye following an intravitreal injection of bevacizumab for neovascular glaucoma (NVG). The patient was diagnosed with NVG refractory to Ahmed glaucoma valve implantation and a vitreous hemorrhage in the right eye, which was treated with 1.25 mg intravitreal bevacizumab. Ten days after the bevacizumab injection, the left eye exhibited sudden visual loss. The patient's best-corrected visual acuity (BCVA) decreased from 80 to 25 letters [Early Treatment Diabetic Retinopathy Study (ETDRS) chart]. A fundus examination revealed a swollen optic disk with unclear boundaries, retinal hemorrhages and thinning retinal vessels. Fundus fluorescein angiography (FA) identified hyperfluorescence in the optic disk and an enlarged foveal avascular zone. The visual field revealed quadrantal defects that confirmed the diagnosis of anterior ischemic optic neuropathy associated with ischemic maculopathy. Six months later, following medical treatment, the patient's BCVA was increased to 44 letters. However, a clinical examination found neovessels with one papilla disk (PD) above the disk. Laser photocoagulation treatment was administered immediately. The area of neovessels above the disk was reduced to 1/4 PD at the last follow-up. In conclusion, although intravitreal anti-vascular endothelial growth factor (Bevacizumab) is an effective treatment for neovascular ocular diseases, its adverse effects must be taken into consideration for the treatment of NVG. Photocoagulation remains an effective treatment for proliferative diabetic retinopathy.

Considerations regarding the administration of systemic therapy for elderly patients with ovarian cancer

To improve the benefit and tolerability of cancer treatment, we must develop new geriatric-specific trials, better assessment tools, and encourage enrollment of older patients in clinical trials. Age is a strong predictor of survival in ovarian cancer and often influences the treatment plan. Elderly patients, broadly defined as older than age 65 years, are commonly not offered participation in clinical research or provided with substandard chemotherapy or surgical options. Because first-line, platinum-based chemotherapy with cytoreductive surgery is a potentially curative modality, all standard treatment options should be explored (intravenous, neoadjuvant, and/or intraperitoneal chemotherapy). However, one must balance the specific needs of the older patient and be aware of the increased risk of side effects. To be mindful and respectful, the oncologist should clearly define the goals (palliative vs. curative) and specific risks of treatment to patients and their families. As the field of geriatric oncology evolves and prospective trials tailored to older women with ovarian cancer are developed, specific guidelines will ultimately assist in these difficult decisions.

The combination of intravenous bevacizumab and metronomic oral cyclophosphamide is an effective regimen for platinum-resistant recurrent ovarian cancer

OBJECTIVE

To determine the efficacy, progression-free survival (PFS) and overall survival (OS) for the combination of intravenous bevacizumab and oral cyclophosphamide in heavily pretreated patients with recurrent ovarian carcinoma.

METHODS

A retrospective review was performed for all patients with recurrent ovarian carcinoma treated with intravenous bevacizumab 10 mg/kg every 14 days and oral cyclophosphamide 50 mg daily between January 2006 and December 2010. Response to treatment was determined by Response Evaluation Criteria in Solid Tumors criteria and/or CA-125 levels.

RESULTS

Sixty-six eligible patients were identified. Median age was 53 years. Fifty-five patients (83%) had undergone optimal cytoreduction. All patients were primarily or secondarily platinum resistant at the time of administration of bevacizumab and cyclophosphamide. The median number of prior chemotherapy treatments was 6.5 (range, 3 to 16). Eight patients (12.1%) had side effects which required discontinuation of bevacizumab and cyclophosphamide. There was one bowel perforation (1.5%). Overall response rate was 42.4%, including, complete response in 7 patients (10.6%), and partial response in 21 patients (31.8%), while 15 patients (22.7%) had stable disease and 23 patients (34.8%) had disease progression. Median PFS for responders was 5 months (range, 2 to 14 months). Median OS from initiation of bevacizumab and cyclophosphamide was 20 months (range, 2 to 56 months) for responders and 9 months (range, 2 to 51 months) for non-responders (p=0.004).

CONCLUSION

Bevacizumab and cyclophosphamide is an effective, well-tolerated chemotherapy regimen in heavily pretreated patients with recurrent ovarian carcinoma. This combination significantly improved PFS and OS in responders. Response rates were similar and favorable to the rates reported for similar patients receiving other commonly used second-line chemotherapeutic agents.

Safe and targeted anticancer therapy for ovarian cancer using a novel class of curcumin analogs

A diagnosis of advanced ovarian cancer is the beginning of a long and arduous journey for a patient. Worldwide, approximately half of the individuals undergoing therapy for advanced cancer will succumb to the disease, or consequences of treatment. Well-known and widely-used chemotherapeutic agents such as cisplatin, paclitaxel, 5-fluorouracil, and doxorubicin are toxic to both cancer and non-cancerous cells, and have debilitating side effects Therefore, development of new targeted anticancer therapies that can selectively kill cancer cells while sparing the surrounding healthy tissues is essential to develop more effective therapies. We have developed a new class of synthetic curcumin analogs, diarylidenyl-piperidones (DAPs), which have higher anticancer activity and enhanced bio-absorption than curcumin. The DAP backbone structure exhibits cytotoxic (anticancer) activity, whereas the N-hydroxypyrroline (-NOH) moiety found on some variants functions as a cellular- or tissue-specific modulator (antioxidant) of cytotoxicity. The anticancer activity of the DAPs has been evaluated using a number of ovarian cancer cell lines, and the safety has been evaluated in a number of non-cancerous cell lines. Both variations of the DAP compounds showed similar levels of cell death in ovarian cancer cells, however the compounds with the -NOH modification were less toxic to non-cancerous cells. The selective cytotoxicity of the DAP-NOH compounds suggests that they will be useful as safe and effective anticancer agents. This article reviews some of the key findings of our work with the DAP compounds, and compares this to some of the targeted therapies currently used in ovarian cancer therapy.

The relationship between tumor size and stage in early versus advanced ovarian cancer

BACKGROUND

Ovarian cancer has a different prognosis between early (I and II) and advanced stage (III and IV). The mechanism of disease progression is unknown, but patients with advanced disease may have a higher propensity for seeding of the abdominal cavity early in the disease process than those with early stage. Theoretically if this is so, then patients with advanced stage should have smaller sized tumors than patients with early stage.

METHODS

This was a retrospective chart review of patients in the tumor registry in 2003-2006. Patients had epithelial ovarian cancer, other cell types were excluded. Only cases with documentation of surgical and pathologic staging and measured dimensions on pathologic specimen were included. Patient stage and all available dimensions measured on diseased ovaries were recorded. The dimensions for each patient were averaged into a single dimension for that patient, and then these measurements were totaled and averaged.

RESULTS

There were 110 patients analyzed: 85 with advanced disease, 25 with early stage. The average measurement was 4.8 cm in advanced disease, and was 10.7 cm in early stage disease. This difference was statistically significant (p<0.001).

CONCLUSIONS

Overall, patients with early stage ovarian cancer have diseased ovaries that are more than twice as large as those found in advanced disease. This finding supports the fact that early versus advanced ovarian cancer are 2 separate disease processes. Early stage grows locally and does not disseminate, and advanced stage disseminates while the tumor is still relatively small. Theoretically there may be a factor that separates these 2 into different diseases, where advanced disease patients have a substance produced by their tumor that allows for early dissemination, and early stage lacks this substance and only grows locally. Basic science research comparing the tissue microarrays of early versus advanced stage disease may be able to identify this difference. If the difference is found, perhaps therapy can be targeted against this difference, and screening tests for advanced ovarian cancer can be improved.

Translational predictive biomarker analysis of the phase 1b sorafenib and bevacizumab study expansion cohort

Predictive biomarkers are needed to triage patients to the best therapy. We prospectively planned examination of sequential blood, biopsy, and functional imaging with which to confirm the mechanism and to identify potential predictive biomarkers in a phase Ib clinical trial expansion of patients with solid tumors receiving sorafenib/bevacizumab. The maximally tolerated doses of sorafenib at 200 mg twice daily with bevacizumab at 5 mg/kg every other week were given to biopsiable patients. Patients were randomized to receive either sorafenib or bevacizumab monotherapy for the first 28-day cycle with the second drug added with cycle 2. Biopsies, dynamic contrast-enhanced MRI, and fluorodeoxyglucose-proton emission tomography were done pre-therapy and at 2 and 6 weeks (2 weeks into combination therapy). Tumor and serum proteomics, Ras/Raf mutational analysis, and functional imaging results were examined individually and across the dataset to identify potential changes predictive of response to therapy and those that confirm the biochemical drug mechanism(s). Therapy with sorafenib/bevacizumab resulted in clinical benefit in 45% of this mixed solid tumor group. ERK activation and microvessel density were decreased with monotherapy treatment with sorafenib or bevacizumab, respectively; whereas a decreased signal over the group of total AKT, phospho(p)-VEGF receptor2, p-endothelial nitric-oxide synthase, b-RAF, and cleaved poly(ADP-ribose) polymerase was associated with earlier progression of disease. Tumor metabolic activity decreased in those patients with clinical benefits lasting longer than 4 months, and activity increased with progression of disease. Cleavage of caspase 3 and poly(ADP-ribose) polymerase was increased, and Ki67 expression decreased in patients with prolonged clinical benefits, consistent with decreased proliferation and increased apoptosis. The conglomerate analysis, incorporating pharmacodynamic and tumor biochemistry, demonstrated sorafenib/bevacizumab-targeted vascular activity in the tumor. Results suggest potential biomarkers for which changes, as a group, during early therapeutic exposure may predict clinical benefit.

Pneumatosis intestinalis and bowel perforation associated with molecular targeted therapy: an emerging problem and the role of radiologists in its management

OBJECTIVE

The purpose of this article is to study the imaging features, management, and outcome of pneumatosis intestinalis and bowel perforation associated with molecular targeted therapy.

MATERIALS AND METHODS

In this retrospective study, 48 patients with cancer who developed pneumatosis or intestinal perforation were found by searching a radiology database. Of these patients, 24 patients (13 women and 11 men; mean age, 61 years; range, 39-83 years) receiving molecular targeted therapy without any confounding factors for pneumatosis or perforation were selected. Initial and follow-up CT scans were evaluated by two radiologists; medical records were reviewed to note clinical features, management, and outcome.

RESULTS

Seventeen (70.8%) patients were asymptomatic. Colorectal cancer (n = 10) and renal cell carcinoma (n = 5) were the most common malignancies; bevacizumab (n = 14) and sunitinib (n = 6) were the most common associated drugs. Imaging findings included intestinal perforation (20 sites in 18 patients), pneumatosis (n = 10), ascites (n = 8), pneumoperitoneum (n = 7), fistula formation (n = 7), and fluid collections (six collections in five patients). Fifteen (62.5%) patients were treated conservatively, seven (29.2%) underwent surgery, and two (8.3%) underwent percutaneous drainage. Molecular targeted therapy was discontinued in 22 of 24 patients; findings resolved in 19 patients, remained stable in one, and worsened in one. One patient died after surgery. In both instances where the drug was continued, the abnormality worsened. Findings recurred in three of four patients in whom the drug was restarted after initial resolution.

CONCLUSION

Radiologists should be aware of intestinal complications associated with molecular targeted therapy, including pneumatosis, bowel perforation, and fistula formation. Most patients can be treated conservatively after discontinuation of molecular targeted therapy. Continuing or restarting molecular targeted therapy can cause worsening or recurrent pneumatosis or perforation.

Selective blockade of matrix metalloprotease-14 with a monoclonal antibody abrogates invasion, angiogenesis, and tumor growth in ovarian cancer

Most patients with ovarian cancer are diagnosed late in progression and often experience tumor recurrence and relapses due to drug resistance. Surface expression of matrix metalloprotease (MMP)-14 on ovarian cancer cells stimulates a tumor-stromal signaling pathway that promotes angiogenesis and tumor growth. In a cohort of 92 patients, we found that MMP-14 was increased in the serum of women with malignant ovarian tumors. Therefore, we investigated the preclinical efficacy of a MMP-14 monoclonal antibody that could inhibit the migratory and invasive properties of aggressive ovarian cancer cells in vitro. MMP-14 antibody disrupted ovarian tumor-stromal communication and was equivalent to Avastin in suppressing blood vessel growth in mice harboring Matrigel plugs. These effects on angiogenesis correlated with downregulation of several important angiogenic factors. Furthermore, mice with ovarian cancer tumors treated with anti-MMP-14 monotherapy showed a marked and sustained regression in tumor growth with decreased angiogenesis compared with immunoglobulin G (IgG)-treated controls. In a model of advanced peritoneal ovarian cancer, MMP-14-dependent invasion and metastasis was effectively inhibited by intraperitoneal administration of monoclonal MMP-14 antibody. Together, these studies provide a preclinical proof-of-concept for MMP-14 targeting as an adjuvant treatment strategy for advanced ovarian cancer.

Antiangiogenic agents as a maintenance strategy for advanced epithelial ovarian cancer

Bevacizumab is the first antiangiogenic agent to have demonstrated benefit as first-line and maintenance therapy in epithelial ovarian cancer (EOC), with the Gynecologic Oncology Group 218 and ICON 7 phase III trials revealing significantly prolonged progression-free survival (PFS) for carboplatin/paclitaxel plus bevacizumab followed by bevacizumab maintenance versus carboplatin/paclitaxel alone. Results are forthcoming from several phase III maintenance trials of investigational antiangiogenic agents, each evaluating PFS as the primary endpoint: AGO-OVAR12/LUME-Ovar1 (nintedanib [BIBF 1120]), AGO-OVAR16 (pazopanib), and TRINOVA-1, -2, and -3 (AMG 386). Here we review available data and ongoing clinical trials of investigational antiangiogenic agents as maintenance therapy for EOC. Current controversies, including uncertainties regarding the (1) most appropriate clinical trial endpoints, (2) optimal dosing, duration, and timing of therapy (e.g., with first-line chemotherapy and/or as maintenance monotherapy), and (3) feasibility, tolerability, and cost of adding these agents to platinum/taxane regimens are also highlighted.

Bevacizumab combination therapy: for the first-line treatment of advanced epithelial ovarian, fallopian tube or primary peritoneal cancer

Bevacizumab is a recombinant, humanized anti-vascular endothelial growth factor (VEGF) monoclonal antibody that neutralizes the biological activity of VEGF and inhibits tumour angiogenesis. In two pivotal, well designed, phase III, clinical trials (GOG-0218 and ICON7) in women with advanced epithelial ovarian, fallopian tube or primary peritoneal cancer, first-line treatment with bevacizumab in combination with standard chemotherapy (carboplatin plus paclitaxel) followed by maintenance treatment with bevacizumab alone significantly prolonged progression-free survival relative to standard chemotherapy. A subgroup analysis of ICON7 suggested that bevacizumab therapy may also be beneficial in patients at high risk of disease progression. In GOG-0218, health-related quality of life (HR-QOL) deteriorated temporarily (during the chemotherapy phase) and slightly, although statistically significantly, with bevacizumab in combination with standard chemotherapy followed by bevacizumab maintenance relative to standard chemotherapy plus placebo maintenance. In ICON7, HR-QOL did not differ to a clinically significant extent between patients receiving bevacizumab plus standard chemotherapy followed by bevacizumab maintenance and those receiving standard chemotherapy alone. Bevacizumab combination therapy had generally acceptable tolerability in these studies, with the nature of adverse events generally similar to that observed in previous clinical trials in patients with other solid tumours.

Intraperitoneal bevacizumab combined with cytoreductive surgery: a pre-clinical study of tolerance and pharmacokinetics in an animal model

INTRODUCTION

Cytoreductive Surgery (CRS) combined with Hyperthermic Intraperitoneal Chemotherapy (HIPEC) is currently the only potentially curative treatment for peritoneal carcinomatosis (PC). Systemic administration of bevacizumab improves survival in patients with metastatic colorectal or ovarian cancer. Intraperitoneal administration of bevacizumab has been shown to be safe and effective in treating malignant ascites. The combination of CRS with intraperitoneal (IP) bevacizumab could maximize local control and survival from PC, but the associated morbidity from this is unknown. The aim of this study was to evaluate the safety of the combination of CRS with IP bevacizumab and to determine the pharmacokinetics of the drug in a rabbit model.

METHODS

Twenty healthy rabbits underwent a standardized procedure of debulking surgery, including peritonectomy and gastrointestinal anastomosis and were randomized to receive IP bevacizumab (25 mg/kg) or placebo. Another group of three rabbits underwent an instillation of IP bevacizumab (25 mg/kg) without surgery.

RESULTS

One rabbit that received IP bevacizumab died with no complication associated with the use of bevacizumab at autopsy. There was no significant difference between IP bevacizumab and placebo in weight loss, length of surgery or morbidity. The plasma concentration of bevacizumab increased to a peak at 24 h post IP administration. Bevacizumab was not detected in the plasma of animals without surgery.

CONCLUSION

This study suggests that IP bevacizumab does not increase morbidity and mortality of debulking surgery in an animal model. When surgery is performed, the pharmacokinetics of IP bevacizumab are modified in plasma.

Targeting the insulin growth factor and the vascular endothelial growth factor pathways in ovarian cancer

Antiangiogenic therapy is emerging as a highly promising strategy for the treatment of ovarian cancer, but the clinical benefits are usually transitory. The purpose of this study was to identify and target alternative angiogenic pathways that are upregulated in ovarian xenografts during treatment with bevacizumab. For this, angiogenesis-focused gene expression arrays were used to measure gene expression levels in SKOV3 and A2780 serous ovarian xenografts treated with bevacizumab or control. Reverse transcription-PCR was used for results validation. The insulin growth factor 1 (IGF-1) was found upregulated in tumor and stromal cells in the two ovarian xenograft models treated with bevacizumab. Cixutumumab was used to block IGF-1 signaling in vivo. Dual anti-VEGF and IGF blockade with bevacizumab and cixutumumab resulted in increased inhibition of tumor growth. Immunohistochemistry measured multivessel density, Akt activation, and cell proliferation, whereas terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay measured apoptosis in ovarian cancer xenografts. Bevacizumab and cixutumumab combination increased tumor cell apoptosis in vivo compared with therapy targeting either individual pathway. The combination blocked angiogenesis and cell proliferation but not more significantly than each antibody alone. In summary, IGF-1 activation represents an important mechanism of adaptive escape during anti-VEGF therapy in ovarian cancer. This study provides the rationale for designing bevacizumab-based combination regimens to enhance antitumor activity.

Biologic therapies and personalized medicine in gynecologic malignancies

Through advances in human genomic sequencing, the unique molecular biology that predisposes certain individuals to either health or disease has now been illuminated. Although many malignancies behave similarly on a phenotypic level, biologically there exist multiple layers of interconnected molecular and cellular pathways that may make each patient’s disease significantly more unique than previously appreciated. In gynecologic oncology, the most progress in developing targeted biologics has been in the treatment of ovarian cancers. Future investigations will see further development in endometrial and cervical cancers. Technology such as whole genome sequencing can theoretically identify the individual tumor’s genetic profile; however, identifying the priority pathways for therapeutic interventions and subsequent complex interactions remains a significant challenge. New therapeutic technologies such as siRNA and immune modulators will also play a promising role in the movement toward individualized therapies. It is hoped that the identification and use of targeted agents will lead to individualized care that in turn will lead to significantly improved outcomes manifested by more cures and better quality of life through amelioration of toxicities.

Clinical trials and decision-making strategies for optimal treatment of relapsed ovarian cancer

The proportion of patients with advanced ovarian cancer who relapse has remained high and fairly constant over the last decade. Choosing treatment for recurrent ovarian cancer is complex. Many active therapeutic agents are available, and there are challenges in defining the optimal timing and sequencing of treatments. Furthermore, the explosion in the number of biological agents presents additional challenges in identifying their activity and place in the pathway of treatment. Establishing optimal treatment as monotherapy, or in combination with chemotherapy, or as maintenance treatment requires new approaches to trial design, selecting meaningful endpoints and conducting carefully conducted trials with translational studies. Patients with relapsed ovarian cancer can now survive several years; the aim is to increase this further.

L1-CAM-targeted antibody therapy and (177)Lu-radioimmunotherapy of disseminated ovarian cancer

The L1-cell adhesion molecule (L1-CAM) is highly expressed in various cancer types including ovarian carcinoma but is absent from most normal tissue. A chimeric monoclonal antibody, chCE7, specifically binds to human L1-CAM and exhibits anti-proliferative effects on L1-CAM-expressing tumor cells. The goal of this study was to evaluate the efficacy of a novel (177)Lu-chCE7 radioimmunotherapeutic agent and to compare it to a treatment protocol with unlabeled, growth-inhibiting chCE7 in a mouse xenograft model of disseminated ovarian cancer. chCE7agl, an aglycosylated IgG1 variant with improved pharmacokinetics, was conjugated with 1,4,7,10-tetraazacyclododecane-N-N'-N'-N‴-tetraacetic acid (DOTA) and labeled with the low-energy β-emitter (177)Lu. Tumor growth and survival were assessed after a single i.v. dose of 8 MBq (60 μg) radioimmunoconjugate in nude mice bearing either subcutaneous or intraperitoneal SKOV3.ip1 human ovarian cancer tumors. Therapeutic efficacy was compared with three times weekly i.p. administration of 10 mg/kg unconjugated chCE7. In vivo analysis of (177)Lu-chCE7agl biodistribution demonstrated high and specific accumulation of radioactivity at the tumor site with maximal tumor uptake of up to 48.0 ± 8.1% ID/g at 168 h postinjection. A single treatment with (177)Lu-DOTA-chCE7agl caused significant retardation of tumor growth and prolonged median survival from 33 to 71 days, while administration of a nontargeted (177)Lu-immunoconjugate had no beneficial effect. Three times weekly i.p. application of unlabeled chCE7 10 mg/kg similarly increased survival from 44 to 72 days. We conclude that a single dose of (177)Lu-DOTA-chCE7agl is as effective as repeated administration of nonradioactive chCE7 for treatment of small intraperitoneal tumors expressing L1-CAM.

Biological roles of the Delta family Notch ligand Dll4 in tumor and endothelial cells in ovarian cancer

Emerging evidence suggests that the Notch/Delta-like ligand 4 (Dll4) pathway may offer important new targets for antiangiogenesis approaches. In this study, we investigated the clinical and biological significance of Dll4 in ovarian cancer. Dll4 was overexpressed in 72% of tumors examined in which it was an independent predictor of poor survival. Patients with tumors responding to anti-VEGF therapy had lower levels of Dll4 than patients with stable or progressive disease. Under hypoxic conditions, VEGF increased Dll4 expression in the tumor vasculature. Immobilized Dll4 also downregulated VEGFR2 expression in endothelial cells directly through methylation of the VEGFR2 promoter. RNAi-mediated silencing of Dll4 in ovarian tumor cells and tumor-associated endothelial cells inhibited cell growth and angiogenesis, accompanied by induction of hypoxia in the tumor microenvironment. Combining Dll4-targeted siRNA with bevacizumab resulted in greater inhibition of tumor growth, compared with control or treatment with bevacizumab alone. Together, our findings establish that Dll4 plays a functionally important role in both the tumor and endothelial compartments of ovarian cancer and that targeting Dll4 in combination with anti-VEGF treatment might improve outcomes of ovarian cancer treatment.

Reducing excessive toxicity in ovarian cancer treatment: a personalized approach

The management of ovarian cancer is not only multifactorial, but also patient-specific. Different treatment modalities lead to varying levels of toxicity and individual patient responses, necessitating a personalized approach to each treatment plan. Surgical treatment along with first-line and salvage chemotherapies, are standard modalities but recent innovations in chemotherapy delivery and innovative therapy with mechanism of action are reviewed in this article. Extensive experience with standard chemotherapy has outlined algorithms for managing various toxicities. The focus of treatment may ultimately point towards palliative care and clinicians must be comfortable and well versed in addressing this important option. Overall, management of ovarian cancer requires a multi-faceted approach, keeping the patients’ overall health, curative goals and well-being at the forefront. It is nearly impossible to detail exact management plans for every possible toxicity for every patient; formulating personalized treatment plans should be based on evidence and clinician experience, all part of the art of medicine. The objective of this article is to highlight the most frequently encountered and most limiting toxicities of current standard therapies for epithelial ovarian cancer.

Emerging therapeutics for primary peritoneal cancer

INTRODUCTION

Primary peritoneal cancer describes a malignancy that originates from the peritoneal lining of the abdomen. The diagnosis is clearest when the ovaries are uninvolved; however, this is rarely the case and, as such, the declaration is often made pathologically by extrinsic or secondary involvement of the ovaries. The disease shares nearly all of the clinicopathologic features of primary ovarian cancer, most importantly, a molecular homology, which has made it unfruitful for considering it a different entity. Because of this, both standard of care treatment algorithms and contemporary drug development protocols nearly uniformly consider these cancers as primary ovarian cancers.

AREAS COVERED

A Medline search was performed as well as a review of trials presented in the National Cancer Institute clinical trials website (http://www.Clinicaltrials.gov). We also reviewed abstracts presented at recent oncology congresses, such as the 2010 Annual meetings of the Society of Gynecologic Oncologists and the American Society of Clinical Oncology. The purpose of this review is to highlight areas of current drug development for patients with primary peritoneal carcinoma. While there are numerous investigational agents being evaluated which follow patients with this disease, our review focuses on the most promising agents that are in mature clinical development. In addition, given the recent positive Phase III data of bevacizumab in the first-line setting for patients with this disease, we consider changes that we can anticipate in this field.

EXPERT OPINION

Numerous novel agents are being explored in this disease with the majority focusing on direct and indirect perturbations of tumor angiogenesis. Based on ongoing and recently completed investigations, targeted therapies are likely to become part of the armamentarium of first-line and recurrent treatment for patients with peritoneal cancers. Future studies of pathway-specific targeting will probably include pretreatment biomarker selection or eligibility criteria as well as combinatorial strategies.

Bevacizumab and its use in epithelial ovarian cancer

Bevacizumab is a monoclonal antibody that binds to VEGF, a circulating protein involved in the promotion of angiogenesis and probably tumor growth and progression. Bevacizumab has demonstrated anticancer activity in several cancers, either combined with chemotherapy or when used as a single agent, and has been approved by the US FDA as a treatment for several cancers. As VEGF has been implicated in ovarian cancer progression and ascites formation, and high levels of VEGF have been found in plasma and ascites in women with ovarian cancer, bevacizumab has been tested as an anticancer therapy in ovarian cancer. Documented single-agent activity of bevacizumab in recurrent ovarian cancer has led to combination studies with both biologic agents as well as other chemotherapy agents in both recurrent and newly diagnosed cancer. One trial in patients with recurrent, heavily pretreated ovarian cancer demonstrated a higher than predicted risk of gastrointestinal perforation, and although a lower incidence of gastrointestinal perforation has been reported in less heavily pretreated patients, patients and their physicians must be aware of this risk. Upfront studies testing the impact of adding bevacizumab to carboplatin and paclitaxel chemotherapy for the treatment of newly diagnosed cancer are currently underway, and one Phase III randomized study (Gynecologic Oncology Group study 218) was recently presented and will be discussed in this article.

Immune response in ovarian cancer: how is the immune system involved in prognosis and therapy: potential for treatment utilization

Ovarian cancer is one of the leading causes of cancer-related death among women. Resistance to the disease occurs in more than 70% of the cases even after treated with chemotherapy agents such as paclitaxel- and platinum-based agents. The immune system is increasingly becoming a target for intense research in order to study the host's immune response against ovarian cancer. T cell populations, including NK T cells and Tregs, and cytokines have been associated with disease outcome, indicating their increasing clinical significance, having been associated with prognosis and as markers of disease progress, respectively. Harnessing the immune system capacity in order to induce antitumor response remains a major challenge. This paper examines the recent developments in our understanding of the mechanisms of development of the immune response in ovarian cancer as well as its prognostic significance and the existing experience in clinical studies.

Targeted agents in ovarian cancer

Despite recent advances in the treatment of ovarian cancer, a large majority of women with this diagnosis will die from recurrence of their disease. Targeted therapies, in the form of monoclonal antibodies and small molecule tyrosine kinase inhibitors have significantly altered the management of many solid tumors and hematologic malignancies. No such agents have been approved by the US FDA for use in ovarian cancer, although Phase II data suggests excellent single-agent activity of some of these drugs. Antiangiogenic agents in combination with chemotherapy are being evaluated in Phase III clinical trials, both in the adjuvant setting and in recurrent platinum-sensitive disease. Poly-ADP-ribose polymerase inhibitors are promising agents in BRCA1/2-mutated breast and ovarian cancers. Ongoing clinical trials are exploring the anti-tumor effect of poly-ADP-ribose polymerase inhibitors administered as single agents and in combination with chemotherapy. Many other new drugs are in earlier grades of development. In this article, we review the state of the art in targeted therapies for ovarian cancer and identify future directions for their development in the management of this often devastating disease.

Bevacizumab in the treatment of ovarian cancer

Despite advances in surgical cytoreduction and cytotoxic chemotherapy, ovarian cancer continues to be the leading cause of death in women with gynecologic malignancy. Our understanding of the treatment of ovarian cancer was revolutionized with the discovery of platinum- and taxane-based adjuvant chemotherapy regimens. Since that time however, overall survival has been stable. Given the above, an emphasis has been placed on exploring alternative therapeutics. Recent research efforts have improved our understanding of the molecular biology of ovarian cancer and novel targeted treatment strategies have emerged. The most studied of these agents has been the monoclonal anti-vascular endothelial growth factor antibody bevacizumab. The purpose of this review is to discuss management issues related to the treatment of ovarian cancer, with a focus on the utilization of bevacizumab, summarizing applicable clinical trials, its potential benefits, and reported adverse events.