A phase I study of bevacizumab, everolimus and panitumumab in advanced solid tumors

Disorders of potassium homeostasis after kidney transplantation

Disturbances of potassium balance are often encountered when managing kidney transplant recipients (KTR). Both hyperkalemia and hypokalemia may present either as medical emergencies or chronic outpatient abnormalities. Despite the high incidence of hyperkalemia and its potential life-threatening implications, consensus on its management in KTR is lacking. Hypokalemia in KTR is also well-described, although it is given less attention by clinicians compared to hyperkalemia. This article discusses the etiology, pathophysiology and management of both types of potassium disorders in KTR. Once any emergent situation has been corrected, treatment approaches include correcting insulin deficiency if present, adjusting non-immunosuppressive and immunosuppressive medications, eliminating or supplementing potassium as needed, and dietary counselling. Although commonly of multifactorial etiology, ascertaining the specific cause in a particular patient will help guide successful management. Monitoring KTR through regular laboratory testing is essential to detect serious disturbances in potassium balance since patients are often asymptomatic.

High-Grade Endometrial Cancer: Molecular Subtypes, Current Challenges, and Treatment Options

Although many recent advancements have been made in women's health, perhaps one of the most neglected areas of research is the diagnosis and treatment of high-grade endometrial cancer (EnCa). The molecular classification of EnCa in concert with histology was a major step forward. The integration of profiling for mismatch repair deficiency and Human Epidermal Growth Factor 2 (HER2) overexpression, can further inform treatment options, especially for drug resistant recurrent disease. Recent early phase trials suggest that regardless of subtype, combination therapy with agents that have distinct mechanisms of action is a fruitful approach to the treatment of high-grade EnCa. Unfortunately, although the importance of diagnosis and treatment of high-grade EnCa is well recognized, it is understudied compared to other gynecologic and breast cancers. There remains a tremendous need to couple molecular profiling and biomarker development with promising treatment options to inform new treatment strategies with higher efficacy and safety for all who suffer from high-grade recurrent EnCa.

Molecular methods for increasing the effectiveness of ovarian cancer treatment: a systematic review

Background: The aim of the current study is to analyze and summarize the latest research on improving therapy in ovarian cancer. Materials & methods: Data analysis was based on a review of publications from 2011 to 2021 in the PubMed database with use of the search terms including 'EGFR ovarian cancer', 'folate receptor inhibitors ovarian cancer', 'VEGF ovarian cancer', 'PDGF ovarian cancer' and 'CTLA-4 ovarian cancer'. Results: 6643 articles were found; 238 clinical trials and randomized control trials were analyzed; 122 studies were rejected due to inconsistency with the topic of the work. Conclusion: Extensive research on the treatment of ovarian cancer increases the chance of developing the most effective therapy suited to the individual needs of the patient.

Angiogenesis in endometrial carcinoma: Therapies and biomarkers, current options, and future perspectives

Endometrial carcinoma is the most common gynecologic malignancy and the fourth most prevalent cancer in women in the modern world. Despite a relatively high chance of surgical cure, for patients with advanced or recurrent disease there are few therapeutic options. Angiogenesis has been extensively studied ever since vascular endothelial growth factor (VEGF) was discovered in the 1980s. Several clinical trials of anti-angiogenic therapy in endometrial carcinoma have been conducted, with mixed results, and many researchers have tried to determine prognostic and therapeutic biomarkers. Recent trials, which shed new light on possible treatment biomarkers and efficacious combination therapies, are reviewed in this text. While we are still far from effectively tailoring anti-angiogenic treatment to each patient, these data have provided valuable insight and have put us on track for the discovery of novel opportunities for angiogenesis therapy in endometrial carcinoma.

Toxicity of a combined therapy using the mTOR-inhibitor everolimus and PRRT with [177Lu]Lu-DOTA-TATE in Lewis rats

PURPOSE

Peptide receptor radionuclide therapy (PRRT) with [177Lu]Lu-DOTA0,TYR3-octreotate ([177Lu]Lu-DOTA-TATE) and the mechanistic target of rapamycin (mTOR) inhibitor everolimus are both approved for the treatment of neuroendocrine tumours (NET). However, tumour progression is still frequent, and treatment strategies need further improvement. One possible approach could be to combine different therapy options. In this study, we investigated the toxicity of a combined treatment with everolimus and [177Lu]Lu-DOTA-TATE in female Lewis rats.

METHODS

Animals received 200 MBq of [177Lu]Lu-DOTA-TATE once and/or 5 mg/kg body weight everolimus or placebo weekly for 16 weeks and were divided into four groups (group 1, placebo; group 2, everolimus; group 3, placebo + [177Lu]Lu-DOTA-TATE; group 4, everolimus + [177Lu]Lu-DOTA-TATE). Blood levels of creatinine and blood urea nitrogen (BUN) were assessed weekly to monitor nephrotoxicity, and a full blood count was performed at the time of euthanasia to monitor myelotoxicity. Additionally, renal function was analysed by sequential [99mTc]Tc-mercaptoacetyltriglycine ([99mTc]Tc-MAG3) scintigraphies. Histopathological examination was performed in all the kidneys using a standardized renal damage score (RDS).

RESULTS

Rats receiving everolimus showed a significantly lower increase in creatinine levels than those receiving placebo. Everolimus therapy reduced white blood count significantly, which was not observed for [177Lu]Lu-DOTA-TATE. Functional renal scintigraphies using [99mTc]Tc-MAG3 showed a compromised initial tracer uptake after PRRT and slower but still preserved excretion after everolimus. Histology showed no significant RDS differences between groups.

CONCLUSION

Renal scintigraphy is a highly sensitive tool for the detection of renal function impairment after a combination of everolimus and PRRT. Additional treatment with everolimus does not increase renal and haematological toxicity of PRRT with [177Lu]Lu-DOTA-TATE.

Stomatitis And Everolimus: A Review Of Current Literature On 8,201 Patients

Background

Oral toxicities, such as mucositis and stomatitis, are some of the most significant and unavoidable side effects associated with anticancer therapies. In past decades, research has focused on newer targeted agents with the aim of decreasing the rates of side effects on healthy cells. Unfortunately, even targeted anticancer therapies show significant rates of toxicity on healthy tissue. mTOR inhibitors display some adverse events, such as hyperglycemia, hyperlipidemia, hypophosphatemia, hematologic toxicities, and mucocutaneous eruption, but the most important are still stomatitis and skin rash, which are often dose-limiting side effects.

Aim

This review was performed to answer the question “What is the incidence of stomatitis in patients treated with everolimus?”

Methods

We conducted a systematic search on the PubMed and Medline online databases using a combination of MESH terms and free text: “everolimus” (MESH) AND “side effects” OR “toxicities” OR “adverse events”. Only studies fulfilling the following inclusion criteria were considered eligible for inclusion in this study: performed on human subjects, reporting on the use of everolimus (even if in combination with other drugs or ionizing radiation), written in the English language, and reporting the incidence of side effects.

Results

The analysis of literature revealed that the overall incidence of stomatitis after treatment with everolimus was 42.6% (3,493) and that of stomatitis grade G1/2 84.02% (2,935), while G3/4 was 15.97% (558).

Conclusion

Results of the analysis showed that the incidence of stomatitis of grade 1 or 2 is higher than grade 3 or 4. However, it must be taken into account that it is not possible to say if side effects are entirely due to everolimus therapy or combinations with other drugs.

Kinase Inhibitors and Ovarian Cancer

Ovarian cancer is fifth in the rankings of cancer deaths among women, and accounts for more deaths than any other gynecological malignancy. Despite some improvement in overall-(OS) and progression-free survival (PFS) following surgery and first-line chemotherapy, there is a need for development of novel and more effective therapeutic strategies. In this mini review, we provide a summary of the current landscape of the clinical use of tyrosine kinase inhibitors (TKIs) and mechanistic target of rapamycin (mTOR) inhibitors in ovarian cancer. Emerging data from phase I and II trials reveals that a combinatorial treatment that includes TKIs and chemotherapy agents seems promising in terms of PFS despite some adverse effects recorded; whereas the use of mTOR inhibitors seems less effective. There is a need for further research into the inhibition of multiple signaling pathways in ovarian cancer and progression to phase III trials for drugs that seem most promising.

Role of the PI3K/AKT/mTOR signaling pathway in ovarian cancer: Biological and therapeutic significance

Ovarian cancer (OC) is a lethal gynecological cancer. The phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway plays an important role in the regulation of cell survival, growth, and proliferation. Irregularities in the major components of the PI3K/AKT/mTOR signaling pathway are common in human cancers. Despite the availability of strong pre-clinical and clinical data of PI3K/AKT/mTOR pathway inhibitors in OC, there is no FDA approved inhibitor available for the treatment of OC. Here, we outline the importance of PI3K/AKT/mTOR signaling pathway in OC tumorigenesis, proliferation and progression, and pre-clinical and clinical experience with several PI3K/AKT/mTOR pathway inhibitors in OC.

Epidermal growth factor receptor blockers for the treatment of ovarian cancer

BACKGROUND

This is an update of a previously published version of the review (Issue 10, 2011).Epithelial ovarian cancer (EOC) is the seventh most common cause of cancer death among women worldwide. Treatment consists of a combination of surgical debulking and platinum-based chemotherapy. Between 55% and 75% of women who respond to first-line therapy experience relapse within two years. Second-line chemotherapy is palliative and aims to reduce symptoms and prolong survival. Improved understanding about the molecular basis of EOC has led to the development of novel agents, such as epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors and anti-EGFR antibodies.

OBJECTIVES

To compare the effectiveness and harmful effects of interventions that target the epidermal growth factor receptor in the treatment of epithelial ovarian cancer (EOC).

SEARCH METHODS

We searched the Cochrane Gynaecological Cancer Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL; 2010, Issue 4), MEDLINE, and Embase up to October 2010. We also searched registers of clinical trials, abstracts of scientific meetings, and reference lists of included studies, and we contacted experts in the field. This update includes further searches up to September 2017.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing anti-EGFR agents with or without conventional chemotherapy versus conventional chemotherapy alone or no treatment in women with histologically proven EOC.

DATA COLLECTION AND ANALYSIS

Two review authors independently abstracted data, assessed risk of bias, and performed GRADE assessment.

MAIN RESULTS

From 6105 references obtained through the literature search and an additional 15 references derived from grey literature searches, we identified seven RCTs that met our inclusion criteria and included 1725 participants. Trial results show that after first-line chemotherapy is provided, maintenance treatment with erlotinib (EGFR tyrosine kinase inhibitor (TKI)) probably makes little or no difference in overall survival (hazard ratio (HR) 0.99, 95% confidence interval (CI) 0.81 to 1.20; one study; 835 participants; low-certainty evidence) and may make little or no difference in progression-free survival (HR 1.05, 95% CI 0.90 to 1.23; one study; 835 participants; very low-certainty evidence). Less than 50% of participants provided quality of life data, and study authors reported these results incompletely. The certainty of evidence is very low, but treatment may reduce quality of life compared to observation.Treatment with an EGFR TKI (vandetanib) for women with relapsed EOC may make little or no difference in overall survival (HR 1.25, 95% CI 0.80 to 1.95; one study; 129 participants; low-certainty evidence) and may make little or no difference in progression-free survival (HR 0.99, 95% CI 0.69 to 1.42; one study; 129 participants; very low-certainty evidence). In treating patients with relapse, giving EGFR TKI may slightly increase some toxicities, such as severe rash (risk ratio (RR) 13.63, 95% CI 0.78 to 236.87; one study; 125 participants; very low-certainty evidence). Quality of life data were not available for meta-analysis.Anti-EGFR antibody treatment in relapsed EOC may or may not make a difference to overall survival (HR 0.93, 95% CI 0.74 to 1.18; four studies; 658 participants; moderate-certainty evidence) and may or may not have any effect on progression-free survival (HR 0.90, 95% CI 0.70 to 1.16; four studies; 658 participants; low-certainty evidence). Anti-EGFR antibody treatment may or may not increase side effects, including severe nausea and/or vomiting (RR 1.27, 95% CI 0.56 to 2.89; three studies; 503 participants; low-certainty evidence), severe fatigue (RR 1.06, 95% CI 0.66 to 1.73; I² = 0%; four studies; 652 participants; low-certainty evidence), and hypokalaemia (RR 2.01, 95% CI 0.80 to 5.06; I² = 0%; three studies; 522 participants; low-certainty evidence). Severe diarrhoea rates were heterogeneous across studies (RR 2.87, 95% CI 0.59 to 13.89; four studies; 652 participants; low-certainty evidence), and subgroup analysis revealed that severe diarrhoea was more likely with pertuzumab (RR 6.37, 95% CI 1.89 to 21.45; I² = 0%; three studies; 432 participants; low-certainty evidence) than with seribantumab treatment (RR 0.38, 95% CI 0.07 to 2.23; I² = 0%; one study; 220 participants; very low-certainty evidence). Quality of life data were incompletely reported, and we were unable to combine them in a meta-analysis.

AUTHORS' CONCLUSIONS

Current evidence suggests that an anti-EGFR single-agent biological treatment (EGFR TKI or anti-EGFR antibody) makes little or no difference to survival, either as maintenance treatment after first-line chemotherapy or in association with chemotherapy in recurrent cancer. Anti-EGFR therapy may increase some side effects and may or may not reduce quality of life.

Monepantel considerably enhances the therapeutic potentials of PEGylated liposomal doxorubicin and gemcitabine in ovarian cancer: in vitro and in vivo studies

Ovarian cancer is a lethal disease since treated patients often die from relapse. Resistance to current treatment regime involving doxorubicin and gemcitabine is well known. Hence, we set forth to develop a more effective therapy by combining current treatment drugs with monepantel, an antihelminth drug with proven anticancer effect. In vitro cytotoxicity were first investigated with pegylated liposomal doxorubicin (PLD), gemcitabine, monepantel as single agents and then in combination with monepantel on ovarian tumor cells. Drug effect on oncogenic proteins was determined by western blot analysis and resistance to drugs by colony formation assays. Using in vivo model (nude mice), a similar study, as above, was carried out to determine correlation to in vitro findings. Close correlation existed between in vitro and in vivo studies with the latter indicating that combination of monepantel with either low or high dose PLD was more effective compared to single drug therapy. A similar finding existed for gemcitabine, with gemcitabine showing a more superior efficacy (100% ablation) in combination with MPL. Western blot analysis indicated p-mTOR, p70s6K and 4E-BP1 were severely inhibited by combination of MPL with either PLD or gemcitabine. Colony formation assay indicated a dramatic reduction of colonies with combination treatment suggesting a considerable reduction of resistance. After 28 days, treatment using a combination of MPL with either PLD or gemcitabine showed tumor regression. Hence, the combination of gemcitabine or doxorubicin with monepantel may serve as a more effective therapy for ovarian cancer.

Origins based clinical and molecular complexities of epithelial ovarian cancer

Ovarian cancer is the most lethal of all common gynaecological malignancies in women worldwide. Ovarian cancer comprises of >15 distinct tumor types and subtypes characterized by histopathological features, environmental and genetic risk factors, precursor lesions and molecular events during oncogenesis. Recent studies on gene signature profiling of different subtypes of ovarian cancer have revealed significant genetic heterogeneity between and within each ovarian cancer histological subtype. Thus, an immense interest have shown towards a more personalized medicine for understanding the clinical and molecular complexities of four major types of epithelial ovarian cancer (serous, endometrioid, clear cell, and mucinous). As such, further in depth studies are needed for identification of molecular signalling network complexities associated with effective prognostication and targeted therapies to prevent or treat metastasis. Therefore, understanding the metastatic potential of primary ovarian cancer and therapeutic interventions against lethal ovarian cancer for the development of personalized therapies is very much indispensable. Consequently, in this review we have updated the key dysregulated genes of four major subtypes of epithelial carcinomas. We have also highlighted the recent advances and current challenges in unravelling the complexities of the origin of tumor as well as genetic heterogeneity of ovarian cancer.

Emerging growth factor receptor antagonists for ovarian cancer treatment

INTRODUCTION

Epithelial Ovarian Cancer (EOC) is the most lethal gynecological malignancy. EOC outcomes remain unsatisfactory despite aggressive surgical approach, disease chemo-sensitivity and recent introduction of agents targeting angiogenesis and tumour genome instability. Advances in EOC research have allowed for a tailored treatment approach and accelerated development of novel treatments strategies from bench to bed side, anticipated to improve patient outcomes. Areas covered: Comprehensive review of growth factor receptor antagonists for EOC treatment currently in different stages of development was performed. English peer-reviewed articles and abstracts were searched in MEDLINE, PubMed, Embase and major conferences. We focused on agents that antagonize growth factors promoting sustained proliferative signaling, angiogenesis and evasion of immune destruction blocking the receptor or its stimulating factors. Expert opinion: Receptor signaling has been well characterized for most cancer generating pathways. Growth receptor antagonists are represented by both high receptor affinity monoclonal antibodies as well as tyrosine kinase inhibitors; both are especially effective when a related predictive biomarker of response is identified. Therefore, along with the promising development of novel receptor antagonists or modulators in EOC treatment, targeting essential growth pathways in the tumour and associated microenvironment, is fundamental for biomarker discovery and towards achieving significant improvements in response.

Advanced malignancies treated with a combination of the VEGF inhibitor bevacizumab, anti-EGFR antibody cetuximab, and the mTOR inhibitor temsirolimus

BACKGROUND

Bevacizumab and temsirolimus are active agents in advanced solid tumors. Temsirolimus inhibits mTOR in the PI3 kinase/AKT/mTOR pathway as well as CYP2A, which may be a resistance mechanism for cetuximab. In addition, temsirolimus attenuates upregulation of HIF-1α levels, which may be a resistance mechanism for bevacizumab.

RESULTS

The median age of patients was 60 years (range, 23-80 years). The median number of prior systemic therapies was 3 (range, 1-6). The maximum tolerated dose (MTD) was determined to be bevacizumab 10 mg/kg biweekly, temsirolimus 5 mg weekly and cetuximab 100/75 mg/m2 weekly. Grade 3 or 4 toxicities were seen in 52% of patients with the highest prevalence being hyperglycemia (14%) and hypophosphatemia (14%). Eighteen of the 21 patients were evaluable for response. Three patients were taken off the study before restaging for toxicities. Partial response (PR) was observed in 2/18 patients (11%) and stable disease (SD) lasting ≥ 6 months was observed in 4/18 patients (22%) (total = 6/18 (33%)). In 8 evaluable patients with squamous cell carcinoma of the head and neck (HNSCC) there were partial responses in 2/8 (25%) patients and SD ≥ 6 months in 1/8 (13%) patients (total = 3/8, (38%)).

PATIENTS AND METHODS

We analyzed safety and responses in 21 patients with advanced solid tumors treated with bevacizumab, cetuximab, and temsirolimus.

CONCLUSION

The combination of bevacizumab, cetuximab, and temsirolimus showed activity in HNSCC; however, there were numerous toxicities reported, which will require careful management for future clinical development.

PI3K/AKT/mTOR Pathway in Ovarian Cancer Treatment: Are We on the Right Track?

The high recurrence rate and the low overall survival in ovarian cancer suggest that a more specific therapeutic approach in addition to conventional treatment is required. Translational and clinical research is investigating new molecular targets in order to find an alternative way to affect tumor growth and to minimize the overlap of toxicity of antiblastic agents. Given its implication in many cellular activities including regulation of cell growth, motility, survival, proliferation, protein synthesis, autophagy, transcription, as well as angiogenesis, PI3K/AKT/mTOR is one of the most investigated intracellular signaling pathways. A dis-regulation of this pathway has been shown in several tumors, including ovarian cancer. In this setting, mTor proteins represent a potential target for inhibitors, which could ultimately play a pivotal role in counteracting cellular proliferation. Recently, mTor inhibitors have been approved in the treatment of pancreatic neuroendocrine tumors, mantle cell lymphoma and renal cancer. Clinical trials have assessed the safety of these drugs in ovarian cancer patients. Ongoing phase I and II studies are evaluating the oncologic outcome of mTor inhibitor treatment and its effect in combination with conventional chemotherapy and target agents.

PI3K/AKT/mTOR Pathway in Ovarian Cancer Treatment: Are We on the Right Track?

The high recurrence rate and the low overall survival in ovarian cancer suggest that a more specific therapeutic approach in addition to conventional treatment is required. Translational and clinical research is investigating new molecular targets in order to find an alternative way to affect tumor growth and to minimize the overlap of toxicity of antiblastic agents. Given its implication in many cellular activities including regulation of cell growth, motility, survival, proliferation, protein synthesis, autophagy, transcription, as well as angiogenesis, PI3K/AKT/mTOR is one of the most investigated intracellular signaling pathways. A dis-regulation of this pathway has been shown in several tumors, including ovarian cancer. In this setting, mTor proteins represent a potential target for inhibitors, which could ultimately play a pivotal role in counteracting cellular proliferation. Recently, mTor inhibitors have been approved in the treatment of pancreatic neuroendocrine tumors, mantle cell lymphoma and renal cancer. Clinical trials have assessed the safety of these drugs in ovarian cancer patients. Ongoing phase I and II studies are evaluating the oncologic outcome of mTor inhibitor treatment and its effect in combination with conventional chemotherapy and target agents.

PI3K/AKT/mTOR Pathway in Ovarian Cancer Treatment: Are We on the Right Track?

The high recurrence rate and the low overall survival in ovarian cancer suggest that a more specific therapeutic approach in addition to conventional treatment is required. Translational and clinical research is investigating new molecular targets in order to find an alternative way to affect tumor growth and to minimize the overlap of toxicity of antiblastic agents. Given its implication in many cellular activities including regulation of cell growth, motility, survival, proliferation, protein synthesis, autophagy, transcription, as well as angiogenesis, PI3K/AKT/mTOR is one of the most investigated intracellular signaling pathways. A dis-regulation of this pathway has been shown in several tumors, including ovarian cancer. In this setting, mTor proteins represent a potential target for inhibitors, which could ultimately play a pivotal role in counteracting cellular proliferation. Recently, mTor inhibitors have been approved in the treatment of pancreatic neuroendocrine tumors, mantle cell lymphoma and renal cancer. Clinical trials have assessed the safety of these drugs in ovarian cancer patients. Ongoing phase I and II studies are evaluating the oncologic outcome of mTor inhibitor treatment and its effect in combination with conventional chemotherapy and target agents.

The Potential of Targeting Ribosome Biogenesis in High-Grade Serous Ovarian Cancer

Overall survival for patients with ovarian cancer (OC) has shown little improvement for decades meaning new therapeutic options are critical. OC comprises multiple histological subtypes, of which the most common and aggressive subtype is high-grade serous ovarian cancer (HGSOC). HGSOC is characterized by genomic structural variations with relatively few recurrent somatic mutations or dominantly acting oncogenes that can be targeted for the development of novel therapies. However, deregulation of pathways controlling homologous recombination (HR) and ribosome biogenesis has been observed in a high proportion of HGSOC, raising the possibility that targeting these basic cellular processes may provide improved patient outcomes. The poly (ADP-ribose) polymerase (PARP) inhibitor olaparib has been approved to treat women with defects in HR due to germline BRCA mutations. Recent evidence demonstrated the efficacy of targeting ribosome biogenesis with the specific inhibitor of ribosomal RNA synthesis, CX-5461 in v-myc avian myelocytomatosis viral oncogene homolog (MYC)-driven haematological and prostate cancers. CX-5461 has now progressed to a phase I clinical trial in patients with haematological malignancies and phase I/II trial in breast cancer. Here we review the currently available targeted therapies for HGSOC and discuss the potential of targeting ribosome biogenesis as a novel therapeutic approach against HGSOC.

Targeting mTOR pathway in gynecological malignancies: Biological rationale and systematic review of published data

BACKGROUND

mTOR inhibitors are widely used in different malignancies with several trials testing their efficacy and safety in gynecological malignancies. We aimed to review the current evidence that support the expansion of using such drugs in the treatment of advanced gynecological cancers.

METHODS

A comprehensive systematic review of literature has been conducted to include prospective trials that used everolimus, temsirolimus or ridaforolimus in the management of gynecological cancers and have available efficacy and toxicity results.

RESULTS

A total of 23 studies including 980 patients were considered eligible for our review. Our review included 16 phase II and 7 phase I studies with the majority of patients having uterine cancers. Regarding Endometrial cancer, the CBR ranged from 21% to 60% and median PFS from 2.8 months to 7.3 months. In Ovarian cancers, CBR ranged from 24% to 50% and median PFS from 3.2 months to 5.9 months. In the single phase II study in cervical cancer the CBR was 61% and median PFS was 3.5 months. The toxicity profile was consistent with what was observed previously in other malignancies with fatigue, mucositis, and hematological toxicities being the most common adverse events observed.

CONCLUSION

mTOR inhibitors seem to be a promising option in the second line management of advanced gynecological cancers with best safety and efficacy outcomes when given as a single agent or in combination with hormonal treatment. More research is needed for better patient selection.

Therapeutic targets and new directions for antibodies developed for ovarian cancer

Antibody therapeutics against different target antigens are widely used in the treatment of different malignancies including ovarian carcinomas, but this disease still requires more effective agents. Improved understanding of the biological features, signaling pathways, and immunological escape mechanisms involved in ovarian cancer has emerged in the past few years. These advances, including an appreciation of the cross-talk between cancer cells and the patient's immune system, have led to the identification of new targets. In turn, potential antibody treatments with various mechanisms of action, including immune activation or toxin-delivery, that are directed at these targets have been developed. Here, we identify established as well as novel targets for antibodies in ovarian cancer, and discuss how they may provide fresh opportunities to identify interventions with enhanced therapeutic potential.

Targeted therapy in ovarian cancer

Among female-specific cancers worldwide, ovarian cancer is the leading cause of death from gynecologic malignancy in the western world. Despite radical surgery and initial high response rates to first-line chemotherapy, up to 70% of patients experience relapses with a median progression-free survival of 12-18 months. There remains an urgent need for novel targeted therapies to improve clinical outcomes in ovarian cancer. This review aims to assess current understanding of targeted therapy in ovarian cancer and evaluate the evidence for targeting growth-dependent mechanisms involved in its pathogenesis. Of the many targeted therapies currently under evaluation, the most promising strategies developed thus far are antiangiogenic agents and PARP inhibitors.

The use of combinations of monoclonal antibodies in clinical oncology

Treatment with monoclonal antibodies is becoming increasingly important in clinical oncology. These antibodies specifically inhibit signaling pathways in tumor growth and/or induce immunological responses against tumor cells. By combining monoclonal antibodies several pathways may be targeted simultaneously, potentially leading to additive or synergistic effects. Theoretically, antibodies are very suitable for use in combination therapy, because of limited overlapping toxicity and lack of pharmacokinetic interactions. In this article an overview is given of preclinical and clinical data on twenty-five different combinations of antibodies in oncology. Some of these combinations have proven clinical benefit, for example the combination of trastuzumab and pertuzumab in HER2-positive breast cancer, which exemplifies an additive or synergistic effect on antitumor activity in clinical studies and the combination of nivolumab and ipilimumab, which results in significant increases in progression-free and overall survival in patients with advanced melanoma. However, other combinations may lead to unfavorable results, such as bevacizumab with cetuximab or panitumumab in advanced colorectal cancer. These combinations result in shorter progression-free survival and increased toxicity compared to therapy with a single antibody. In summary, the different published studies showed widely varying results, depending on the combination of antibodies, indication and patient population. More preclinical and clinical studies are necessary to unravel the mechanisms behind synergistic or antagonistic effects of combining monoclonal antibodies. Most research on combination therapies is still in an early stage, but it is expected that for several tumor types the use of combination therapy of antibodies will become standard of care in the near future.

8‑bromo‑7‑methoxychrysin induces apoptosis by regulating Akt/FOXO3a pathway in cisplatin‑sensitive and resistant ovarian cancer cells

8-bromo-7-methoxychrysin (BrMC), a novel chrysin analog, was reported to have anti-cancer activities. The aim of the present study was to investigate the molecular mechanism of 8-bromo-7-methoxychrysin (BrMC)-induced apoptosis via the Akt/forkhead box O3a (FOXO3a) pathway in cisplatin (DDP)-sensitive and -resistant ovarian cancer cells. The human ovarian cancer cell lines A2780 and A2780/DDP were cultured in vitro. Various molecular techniques were used to assess the expression of FOXO3a and B cell lymphoma 2 (Bcl-2)-interacting mediator of cell death (Bim) in cisplatin-sensitive and -resistant ovarian cancer cells. Different concentrations of BrMC induced apoptosis in cisplatin-sensitive and -resistant ovarian cancer cells. BrMC-induced apoptotic cell death occurred mainly by the activation of Akt, which was accompanied by the overexpression of transcription factor FOXO3a, with a concomitant increase in the expression levels of Bim. Silencing Bim expression by using small interfering RNA, attenuated the induction of apoptosis by BrMC treatment. The results indicated that BrMC-induced apoptosis in cisplatin-sensitive and -resistant ovarian cancer cells may occur via the regulation of Akt/FOXO3a, leading to Bim transcription.

Direct Evidence of Target Inhibition with Anti-VEGF, EGFR, and mTOR Therapies in a Clinical Model of Wound Healing

PURPOSE

In early clinical testing, most novel targeted anticancer therapies have limited toxicities and limited efficacy, which complicates dose and schedule selection for these agents. Confirmation of target inhibition is critical for rational drug development; however, repeated tumor biopsies are often impractical and peripheral blood mononuclear cells and normal skin are often inadequate surrogates for tumor tissue. Based upon the similarities of tumor and wound stroma, we have developed a clinical dermal granulation tissue model to evaluate novel targeted therapies.

EXPERIMENTAL DESIGN

A 4-mm skin punch biopsy was used to stimulate wound healing and a repeat 5-mm punch biopsy was used to harvest the resulting granulation tissue. This assay was performed at pretreatment and on-treatment evaluating four targeted therapies, bevacizumab, everolimus, erlotinib, and panitumumab, in the context of three different clinical trials. Total and phosphorylated levels VEGFR2, S6RP, and EGFR were evaluated using ELISA-based methodologies.

RESULTS

Significant and consistent inhibition of the VEGF pathway (using VEGFR2 as the readout) was observed in granulation tissue biopsies from patients treated with bevacizumab and everolimus. In addition, significant and consistent inhibition of the mTOR pathway (using S6RP as the readout) was observed in patients treated with everolimus. Finally, significant inhibition of the EGFR pathway (using EGFR as the readout) was observed in patients treated with panitumumab, but this was not observed in patients treated with erlotinib.

CONCLUSIONS

Molecular analyses of dermal granulation tissue can be used as a convenient and quantitative pharmacodynamic biomarker platform for multiple classes of targeted therapies.

The PI3K/Akt/mTOR pathway in ovarian cancer: therapeutic opportunities and challenges

The phosphatidylinositol 3 kinase (PI3K) pathway is frequently altered in cancer, including ovarian cancer (OC). Unfortunately, despite a sound biological rationale and encouraging activity in preclinical models, trials of first-generation inhibitors of mammalian target of rapamycin (mTOR) in OC have demonstrated negative results. The lack of patient selection as well as resistance to selective mTOR complex-1 (mTORC1) inhibitors could explain the disappointing results thus far. Nonetheless, a number of novel agents are being investigated, including dual mTORC1/mTORC2, Akt, and PI3K inhibitors. Although it is likely that inhibition of the PI3K/Akt/mTOR pathway may have little effect in unselected OC patients, certain histological types, such as clear cell or endometrioid OC with frequent phosphatidylinositol-4,5-biphosphate 3-kinase, catalytic subunit alpha (PIK3CA) and/or phosphatase and tensin homolog (PTEN) alterations, may be particularly suited to this approach. Given the complexity and redundancy of the PI3K signaling network, PI3K pathway inhibition may be most useful in combination with either chemotherapy or other targeted therapies, such as MEK inhibitors, anti-angiogenic therapy, and hormonal therapy, in appropriately selected OC patients. Here, we discuss the relevance of the PI3K pathway in OC and provide an up-to-date review of clinical trials of novel PI3K inhibitors alone or in combination with cytotoxics and novel therapies in OC. In addition, the challenges of drug resistance and predictive biomarkers are addressed.

The PI3K/Akt/mTOR pathway in ovarian cancer: therapeutic opportunities and challenges

The phosphatidylinositol 3 kinase (PI3K) pathway is frequently altered in cancer, including ovarian cancer (OC). Unfortunately, despite a sound biological rationale and encouraging activity in preclinical models, trials of first-generation inhibitors of mammalian target of rapamycin (mTOR) in OC have demonstrated negative results. The lack of patient selection as well as resistance to selective mTOR complex-1 (mTORC1) inhibitors could explain the disappointing results thus far. Nonetheless, a number of novel agents are being investigated, including dual mTORC1/mTORC2, Akt, and PI3K inhibitors. Although it is likely that inhibition of the PI3K/Akt/mTOR pathway may have little effect in unselected OC patients, certain histological types, such as clear cell or endometrioid OC with frequent phosphatidylinositol-4,5-biphosphate 3-kinase, catalytic subunit alpha (PIK3CA) and/or phosphatase and tensin homolog (PTEN) alterations, may be particularly suited to this approach. Given the complexity and redundancy of the PI3K signaling network, PI3K pathway inhibition may be most useful in combination with either chemotherapy or other targeted therapies, such as MEK inhibitors, anti-angiogenic therapy, and hormonal therapy, in appropriately selected OC patients. Here, we discuss the relevance of the PI3K pathway in OC and provide an up-to-date review of clinical trials of novel PI3K inhibitors alone or in combination with cytotoxics and novel therapies in OC. In addition, the challenges of drug resistance and predictive biomarkers are addressed.

DT-13, a saponin of dwarf lilyturf tuber, exhibits anti-cancer activity by down-regulating C-C chemokine receptor type 5 and vascular endothelial growth factor in MDA-MB-435 cells

AIM

To investigate the anticancer activity of DT-13 under normoxia and determine the underlying mechanisms of action.

METHODS

MDA-MB-435 cell proliferation, migration, and adhesion were performed to assess the anticancer activity of DT-13, a saponin from Ophiopogon japonicus, in vitro. In addition, the effects of DT-13 on tumor growth and metastasis in vivo were evaluated by orthotopic implantation of MDA-MB-435 cells into nude mice; mRNA levels of vascular endothelial growth factor (VEGF), C-C chemokine receptor type 5 (CCR5) and hypoxia-inducible factor 1α (HIF-1α) were evaluated by real-time quantitative PCR; and CCR5 protein levels were detected by Western blot assay.

RESULTS

At 0.01 to 1 μmol·L(-1), DT-13 inhibited MDA-MB-435 cell proliferation, migration, and adhesion significantly in vitro. DT-13 reduced VEGF and CCR5 mRNAs, and decreased CCR5 protein expression by down-regulating HIF-1α. In addition, DT-13 inhibited MDA-MB-435 cell lung metastasis, and restricted tumor growth slightly in vivo.

CONCLUSION

DT-13 inhibited MDA-MB-435 cell proliferation, adhesion, and migration in vitro, and lung metastasis in vivo by reducing VEGF, CCR5, and HIF-1α expression.

PI3K/AKT/mTOR signaling pathway as a therapeutic target for ovarian cancer

BACKGROUND

Ovarian cancer is one of the major causes of death in women worldwide. Despite improvements in conventional treatment approaches, such as surgery and chemotherapy, a majority of patients with advanced ovarian cancer experience relapse and eventually succumb to the disease; the outcome of patients remains poor. Hence, new therapeutic strategies are urgently required. The phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) is activated in approximately 70 % of ovarian cancers, resulting in hyperactive signaling cascades that relate to cellular growth, proliferation, survival, metabolism, and angiogenesis. Consistent with this, a number of clinical studies are focusing on PI3K pathway as an attractive target in the treatment of ovarian cancer. In this review, we present an overview of PI3K pathway as well as its pathological aberrations reported in ovarian cancer. We also discuss inhibitors of PI3K pathway that are currently under clinical investigations and the challenges these inhibitors face in future clinical utility.

METHODS

PubMed was searched for articles of relevance to ovarian cancer and the PI3K pathway. In addition, the ClinicalTrials.gov was also scanned for data on novel therapeutic inhibitors targeting the PI3K pathway.

RESULTS

Genetic aberrations at different levels of PI3K pathway are frequently observed in ovarian cancer, resulting in hyperactivation of this pathway. The alterations of this pathway make the PI3K pathway an attractive therapeutic target in ovarian cancer. Currently, several inhibitors of PI3K pathway, such as PI3K/AKT inhibitors, rapamycin analogs for mTOR inhibition, and dual PI3K/mTOR inhibitors are in clinical testing in patients with ovarian cancer.

CONCLUSIONS

PI3K pathway inhibitors have shown great promise in the treatment of ovarian cancer. However, further researches on selection patients that respond to PI3K inhibitors and exploration of effective combinatorial therapies are required to improve the management of ovarian cancer.

Cytotoxic enhancement of hexapeptide-conjugated micelles in EGFR high-expressed cancer cells

OBJECTIVES

The aim of this study was to develop the hexapeptide-conjugated active targeting micelles for delivery of doxorubicin (DOX) and paclitaxel (PTX) to EGFR high-expressed cancer cells.

METHODS

A hexapeptide, which mimicked the EGFR, was applied as a targeting ligand. The active targeting micelles were prepared using the synthesized poly(D,L-lactide-co-glycolide)-PEG copolymer conjugated with the hexapeptide. The micelles were used for encapsulating DOX and/or PTX, and the cellular uptake, in vitro drug release and cellular viability of drug-loaded peptide-conjugated and peptide-free micelles were investigated.

RESULTS

The particle size of drug-loaded peptide-conjugated and peptide-free micelles was < 150 nm with narrow size distribution. The uptake of peptide-conjugated micelles was more efficient in EGFR high-expressed MDA-MB-468 and SKOV3 cells than in EGFR low-expressed HepG2 cells. The in vitro release of DOX and PTX was faster in pH 4.0 (500 U lipase) than in pH 7.4 release medium. The cytotoxicity in terms of IC50 of DOX/PTX-loaded peptide-conjugated micelles was 4.8-folds lower than that of peptide-free micelles and 18.2-folds lower than DOX/PTX drug solution in SOKV3 cells.

CONCLUSION

The peptide-conjugated micelles acted as a nanocarrier to increase intracellular accumulation of anticancer drugs in EGFR high-expressed SKOV3 cancer cells to enhance cell cytotoxicity.

Phase I study of capecitabine, oxaliplatin, bevacizumab, and everolimus in advanced solid tumors

PURPOSE

To define maximum tolerated dose (MTD), toxicities, and pharmacodynamics of capecitabine, oxaliplatin, bevacizumab, and everolimus in advanced solid tumor patients.

DESIGN

This was a standard "3 + 3" dose-escalation trial. All subjects received bevacizumab 7.5 mg/kg on day 1 of each cycle. Doses for capecitabine, oxaliplatin and everolimus were modified per dose limiting toxicity (DLT). Baseline and on-treatment plasma biomarkers were analyzed. Archived tumor mRNA levels were evaluated for NRP1, NRP2 and VEGF-A isoforms.

RESULTS

Twenty-nine patients were evaluable for toxicity and 30 for efficacy. Two DLTs were observed in cohort 1 and one DLT each was observed in cohort -1 and -1b. Grade ≥3 toxicities included neutropenia, hypertension, perforation/fistula/hemorrhage, hypertriglyceridemia, diarrhea, and thromboembolism. Twelve subjects experienced partial response (PR); 12 had stable disease as best response. Three of seven chemorefractory metastatic colorectal cancer (mCRC) subjects experienced PR; 8 of 15 chemonaive mCRC subjects experienced PR. Plasma TβRIII and IL-6 increased on treatment but without correlation to outcome. Increased VEGF165 levels significantly correlated with longer progression free survival.

CONCLUSIONS

Everolimus with full dose capecitabine, oxaliplatin, and bevacizumab had unacceptable toxicity. MTD was: everolimus 5 mg daily; capecitabine 680 mg/m(2) BID days 1-14; oxaliplatin 100 mg/m(2) and bevacizumab 7.5 mg/kg, day 1. Activity was noted in mCRC.

Casticin induces ovarian cancer cell apoptosis by repressing FoxM1 through the activation of FOXO3a

Casticin, a polymethoxyflavone, is reported to have anticancer activities. The aim of the present study was to examine the molecular mechanisms by which casticin induces apoptosis in ovarian cancer cells. The human ovarian cancer cell lines SKOV3 and A2780 were cultured in vitro. Various molecular techniques, including histone/DNA enzyme-linked immunosorbent assay (ELISA), reverse transcription polymerase chain reaction (RT-PCR), western blot analysis and gene transfection, were used to assess the expression of FOXO3a and forkhead box protein M1 (FoxM1) in casticin-treated ovarian cancer cell lines. Casticin-induced apoptotic cell death was accompanied by the activation of transcription factor FOXO3a, with a concomitant decrease in the expression levels of FoxM1 and its downstream target factors, namely survivin and polo-like kinase 1 (PLK1), and an increase in p27^KIP1. A small inhibitory RNA (siRNA) knockout of FoxM1 potentiated casticin-induced apoptosis in ovarian cancer cells. Silencing FOXO3a expression using siRNA increased FoxM1 expression levels and clearly attenuated the induction of apoptosis by casticin treatment. These results show that casticin-induced apoptosis in ovarian cancer may be caused by the activation of FOXO3a, leading to FoxM1 inhibition.

Everolimus in colorectal cancer

INTRODUCTION

There has been a strong preclinical rationale for studying mammalian target of rapamycin (mTOR) inhibitors as single agents or in combination, in multiple malignancies and colorectal cancer in particular.

AREAS COVERED

The authors summarize the complete clinical experience to date of all trials, both published and in abstract form, of everolimus in colorectal cancer. While initial Phase I trials showed promise, further studies have confirmed that single agent everolimus is not active in advanced metastatic colorectal carcinoma with trials showing single agent tolerability, but without significant hints of efficacy in terms of either objective tumor responses or prolonged stable disease. Combination regimens, including combinations with cytotoxic chemotherapy, and inhibitors of VEGF, EGFR and HDAC have been tested specifically in the colorectal setting in Phase I and Phase II clinical trials. The authors discuss the potential reasons for mixed results and suggest future directions for the development of everolimus in colorectal malignancies.

EXPERT OPINION

Studies demonstrate limited clinical activity of everolimus for the treatment of advanced colorectal cancer and have been complicated by increases in toxicity. However, the central role of the PI3K/mTOR pathway in cancer biology suggests that other drug combinations with mTOR inhibition may still merit evaluation.