Antitumor activity of BIBF 1120, a triple angiokinase inhibitor, and use of VEGFR2+pTyr+ peripheral blood leukocytes as a pharmacodynamic biomarker in vivo

Investigation of effect of nintedanib in experimental uveitis model

PURPOSE

This study aims to investigate the protective efficacy of nintedanib in experimental uveitis induced by endotoxins.

MATERIALS AND METHODS

In this study, 24 Wistar albino rats were randomly divided into three groups: Group I was the healthy control with no uveitis that did not receive any treatment, Group II (sham) group did not receive treatment, and Group III (nintedanib) received oral nintedanib for 10 days. On the 10th day, endotoxin-induced uveitis (EIU) was induced by lipopolysaccharide (LPS) injection in Groups II and III. The clinical activity score was evaluated in all groups at the 24th hour, when uveitis formation was thought to be the most intense after LPS injection. All rats were then killed via anaesthesia. Tumour necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) levels were measured in their right eyes using the enzyme-linked immunosorbent assay (ELISA) method. Further, histopathological examinations were performed on their left eyes.

RESULTS

For Groups I, II, and III, the IL-6 levels were 30.88 ± 1.79, 36.77 ± 1.21, and 30.93 ± 3.96 mg/pr, respectively, and TNF-α levels were 50.20 ± 3.24, 59.87 ± 2.98, and 50.23 ± 4.83 mg/pr, respectively. IL-6, TNF-α levels and clinical activity score were higher in the sham group compared to the other groups, and it decreased significantly in the treatment group (p < 0.05). Intense inflammatory cell infiltration of the ciliary body, edema and hyperaemia were evident in the sham group compared to the healthy control group (p < 0.05). These pathological findings were significantly decreased in the treatment group compared to the sham group (p < 0.05).

CONCLUSION

Nintedanib may be preferable as a new agent for treating non-infectious uveitis. However, further studies are needed to evaluate its long-term effects, effects on other antiinflammatory pathways, side-effects, and ideal dose optimization.

Development, Optimization, and Pharmacokinetics Study of Bufalin/Nintedanib Co-loaded Modified Albumin Sub-microparticles Fabricated by Coaxial Electrostatic Spray Technology

Coaxial electrostatic spray technology has received extensive attention in fabricating micro/nanoparticles for drug delivery. However, there are few reports on applying this technology in preparing albumin nanoparticles. In this study, the bufalin (BF) and nintedanib (NDNB) co-loaded ursodeoxycholic acid and p-biguanides benzoic acid decorated albumin sub-microparticles (BN-DUB subMPs) were fabricated by coaxial electrostatic spray technology and optimized by central composite design. Five percent of albumin (contained 0.7% polyethylene oxide) solution was selected as the shell solution which ejected through outer axis with the flow rate of 0.07 mm/min, while the core solution which contained by BF and NDNB ethanol solution was ejected through inner axis with the flow rate of 0.05 mm/min. In vitro cell studies revealed that the modified albumin possessed good biocompatibility. What's more, the BN-DUB subMPs enhanced the inhibitory effect on the growth of LLC cells efficiently. The pharmacokinetics study showed that the t_1/2 and AUC_0-t of BN-DUB subMPs increased significantly compared with that of the drug solution, which indicated the improved in vivo stability of modified albumin nanoparticles. Thus, this study provided a novel and simple technical platform for the development of albumin-based drug carriers.

Advances of Targeted Therapy for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the common and fatal malignancies, which is a significant global health problem. The clinical applicability of traditional surgery and other locoregional therapies is limited, and these therapeutic strategies are far from satisfactory in improving the outcomes of advanced HCC. In the past decade, targeted therapy had made a ground-breaking progress in advanced HCC. Those targeted therapies exert antitumor effects through specific signals, including anti-angiogenesis or cell cycle progression. As a standard systemic therapy option, it tremendously improves the survival of this devastating disease. Moreover, the combination of targeted therapy with immune checkpoint inhibitor (ICI) has demonstrated more potent anticancer effects and becomes the hot topic in clinical studies. The combining medications bring about a paradigm shift in the treatment of advanced HCC. In this review, we presented all approved targeted agents for advanced HCC with an emphasis on their clinical efficacy, summarized the advances of multi-target drugs in research for HCC and potential therapeutic targets for drug development. We also discussed the exciting results of the combination between targeted therapy and ICI.

Pharmacogenetic-Based Interactions between Nutraceuticals and Angiogenesis Inhibitors

Background: Angiogenesis inhibitors (AIs) have become established as an effective cancer treatment. Whereas their interactions with antineoplastic drugs have extensively been investigated, little is known of the effect of their co-administration with nutraceuticals/dietary supplements (N/DSs), which are often self-prescribed. N/DSs comprise a wide range of products such as herbs, nutrients, vitamins, minerals, and probiotics. Assessment of their interactions with cancer drugs, particularly AIs, is hampered by the difficulty of gauging the amount of active substances patients actually take. Moreover, there is no agreement on which approach should be used to determine which N/DSs are most likely to influence AI treatment efficacy. We present a comprehensive review of the metabolic routes of the major AIs and their possible interactions with N/DSs. Methods: The PubMed and Cochrane databases were searched for papers describing the metabolic routes of the main AIs and N/DSs. Results: Data from the 133 studies thus identified were used to compile a diagnostic table reporting known and expected AI-N/DS interactions based on their metabolization pathways. AIs and N/DSs sharing the cytochrome P450 pathway are at risk of negative interactions. Conclusions: Recent advances in pharmacogenetics offer exceptional opportunities to identify prognostic and predictive markers to enhance the efficacy of individualized AI treatments. The table provides a guide to genotyping patients who are due to receive AIs and is a promising tool to prevent occult AI-N/DS interactions in poor metabolizers. N/DS use by cancer patients receiving AIs is a topical problem requiring urgent attention from the scientific community.

Protective Effects of Nintedanib against Polyhexamethylene Guanidine Phosphate-Induced Lung Fibrosis in Mice

Nintedanib (NDN), a tyrosine kinase inhibitor, has been shown to have anti-tumor, anti-inflammatory, and anti-fibrotic effects in several reports. We investigated the protective effects of NDN against polyhexamethylene guanidine phosphate (PHMG)-induced lung fibrosis in mice. The following three experimental groups were evaluated: (1) vehicle control; (2) PHMG (1.1 mg/kg); and (3) PHMG & NDN (60 mg/kg). PHMG induced pulmonary inflammation and fibrosis by intratracheal instillation in mice. In contrast, NDN treatment effectively alleviated the PHMG induced lung injury, and attenuated the number of total cells and inflammatory cells in the bronchoalveolar lavage fluid, including the fibrotic histopathological changes, and also reduced the hydroxyproline content. NDN also significantly decreased the expression of inflammatory cytokines and fibrotic factors, and the activation of the NLRP3 inflammasome in lung tissues. These results suggest that NDN may mitigate the inflammatory response and development of pulmonary fibrosis in the lungs of mice treated with PHMG.

A Phase I/Randomized Phase II Study to Evaluate the Safety, Pharmacokinetics, and Efficacy of Nintedanib versus Sorafenib in Asian Patients with Advanced Hepatocellular Carcinoma

BACKGROUND

Nintedanib is an oral, triple angiokinase inhibitor of vascular endothelial growth factor/platelet-derived growth factor/fibroblast growth factor receptors. This randomized, multicenter, open-label, phase I/II study evaluated the safety, pharmacokinetics, maximum tolerated dose (MTD) in terms of dose-limiting toxicities (DLTs), and efficacy of nintedanib versus sorafenib in Asian patients with unresectable advanced hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

For the phase I portion, patients were stratified into two groups according to their alanine aminotransferase/aspartate aminotransferase (ALT/AST) and Child-Pugh score at baseline. For phase I, the primary endpoint was determination of the MTD in terms of DLTs. For phase II, patients with a Child-Pugh score of 5-6, an Eastern Cooperative Oncology Group performance score ≤2, and an ALT/AST ≤2× the upper limit of normal were enrolled and randomized 2: 1 to nintedanib 200 mg twice daily (b.i.d.) (the MTD determined in phase I) or sorafenib 400 mg b.i.d. continuously in 28-day cycles until intolerable adverse events (AEs) or disease progression (PD); treatment beyond PD was allowed if clinical benefit was perceived. The primary endpoint for phase II was time to progression (TTP) by central independent review (CIR; by Response Evaluation Criteria in Solid Tumors v1.0); the secondary endpoints included overall survival (OS). All analyses were exploratory.

RESULTS

The MTD was 200 mg in both groups. For phase II, 95 patients were randomized to nintedanib (n = 63) or sorafenib (n = 32). For nintedanib and sorafenib, respectively, the median CIR TTP was 2.8 vs. 3.7 months (hazard ratio [HR] = 1.21, 95% confidence interval [CI] 0.73-2.01) and the median OS 10.2 vs. 10.7 months (HR = 0.94, 95% CI 0.59-1.49). Nintedanib-treated patients had fewer grade 3 or higher AEs (56 vs. 84%), serious AEs (46 vs. 56%), and AEs leading to dose reduction (19 vs. 59%) and drug discontinuation (24 vs. 34%). AEs associated more frequently with nintedanib were vomiting and nausea, whereas those associated more frequently with sorafenib were ALT/AST increases, diarrhea, rash, and palmar-plantar erythrodysesthesia syndrome.

CONCLUSIONS

Nintedanib showed numerically similar efficacy to sorafenib for CIR TTP and OS in Asian patients with advanced HCC and adequate liver function. AEs were generally manageable.

A multicentre, open-label, phase-I/randomised phase-II study to evaluate safety, pharmacokinetics, and efficacy of nintedanib vs. sorafenib in European patients with advanced hepatocellular carcinoma

Background

This multicentre, open-label, phase-I/randomised phase-II trial evaluated safety, pharmacokinetics, maximum-tolerated-dose (MTD) per dose-limiting toxicities (DLTs), and efficacy of nintedanib vs. sorafenib in European patients with unresectable advanced hepatocellular carcinoma (aHCC).

Methods

Phase I: Patients were stratified into two groups per baseline aminotransferase/alanine aminotransferase and Child-Pugh score; MTD was determined. Phase II: Patients were randomised 2:1 to nintedanib (MTD) or sorafenib (400-mg bid) in 28-day cycles until intolerance or disease progression. Time-to-progression (TTP, primary endpoint), overall survival (OS) and progression-free survival (PFS) were determined.

Results

Phase-I: no DLTs observed; nintedanib MTD in both groups was 200 mg bid. Phase-II: patients (N = 93) were randomised to nintedanib (n = 62) or sorafenib (n = 31); TTP was 5.5 vs. 4.6 months (HR = 1.44 [95% CI, 0.81–2.57]), OS was 11.9 vs. 11.4 months (HR = 0.88 [95% CI, 0.52–1.47]), PFS was 5.3 vs. 3.9 months (HR = 1.35 [95% CI, 0.78–2.34]), respectively (all medians). Dose intensity and tolerability favoured nintedanib. Fewer patients on nintedanib (87.1%) vs. sorafenib (96.8%) had drug-related adverse events (AEs) or grade ≥ 3 AEs (67.7% vs. 90.3%), but more patients on nintedanib (28 [45.2%]) had AEs leading to drug discontinuation than did those on sorafenib (7 [22.6%]).

Conclusions

Nintedanib may have similar efficacy to sorafenib in aHCC.

Nintedanib treatment delays prostate dorsolateral lobe cancer progression in the TRAMP model: contribution to the epithelial-stromal interaction balance

Prostate cancer (PCa) progression mechanism has been linked to epithelial proliferation, tumor invasion ability, and growth factors. Nintedanib (BIBF 1120) has been reported as being FGF and VEGF pathway inhibitors, exhibiting antitumor activity. Thus, the objective herein was to characterize the early Nintedanib treatment effects on the structure and molecules involved in the basal membrane, the extracellular matrix (ECM) maintenance, in addition to the angiogenesis and mitogenic processes at different grades of prostatic tumor development in TRAMP mice. Therefore, 45 male TRAMP mice were divided into control groups: 8-week-old mice (TC8), 12-week-old mice (TC12), and 16-week-old mice (TC16); and treated groups with 10 mg/kg/day Nintedanib dose for 4 weeks. The treated groups were euthanized at 12 (TN12) and 16 (TN16) weeks of age. Samples from the dorsolateral lobe were collected and processed for light microscopy, immunohistochemistry, Western blotting, and microvessel density analysis. The results showed that early Nintedanib treatment led to an increase of healthy epithelium frequency and a reduction of LGPIN and a maximum vascularization density in the TN12 group. Also, treatment led to a well-differentiated adenocarcinoma decrease and an α and β dystroglycan and also laminin 1 increase in the TN16 group. IGFR1 decreased in the TN16 group. To conclude, early Nintedanib treatment led to a reduction in cancer severity, interfering in both ECM compounds and angiogenesis process to then contribute to a balance, not only in the prostatic epithelium and stroma, but also in the epithelial-stromal interaction during PCa progression.

Targeting VEGFR and FGFR in head and neck squamous cell carcinoma in vitro

Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous disease characterized by a tumor microenvironment (TME) that overexpresses vascular endothelial growth factor receptor (VEGFR) and fibroblast growth factor receptor (FGFR), which can lead to neovascularization, tumor growth and metastasis. Therapeutic strategies inhibiting these signaling pathways might lead to innovative HNSCC treatments. Five HNSCC cell lines were characterized based on VEGFR1-3 and FGFR1-4 expression by sqRT-PCR and treated with three different tyrosine kinase inhibitors (TKIs) (nintedanib, dovitinib and pazopanib), all of which are effective against VEGFR and FGFR family members. Crystal violet assays were performed to analyze the effect of the treatments on cell growth (viability). Additionally, VEGFR1-3 and FGFR1-4 expression data were retrieved from The Cancer Genome Atlas (TCGA), and statistical analyses were performed to investigate the receptor expression level in the different cell lines and the efficacy of the single-agent treatments. A correlation analysis was performed to quantify the degree of relationship between receptor expression and drug efficacy. With the exception of VEGFR2, the targeted receptors were expressed at different levels in all of the cell lines. The cell lines exhibited concentration-dependent responses with cell line-specific differences toward two of the three TKIs (nintedanib and dovitinib). Notably, all of the cell lines were resistant to pazopanib. TKIs have potential as therapeutic agents for HNSCC. Cell line-specific differences were observed in our in vitro experiments. The observed pazopanib resistance could be explained by receptor expression. Further investigation is required to determine TKI efficacy in HNSCC.

Nintedanib antiangiogenic inhibitor effectiveness in delaying adenocarcinoma progression in Transgenic Adenocarcinoma of the Mouse Prostate (TRAMP)

Background

In recent times, anti-cancer treatments have focused on Fibroblast Growth Factor (FGF) and Vascular-Endothelial Growth Factor (VEGF) pathway inhibitors so as to target tumor angiogenesis and cellular proliferation. One such drug is Nintedanib; the present study evaluated the effectiveness of Nintedanib treatment against in vitro proliferation of human prostate cancer (PCa) cell lines, and growth and progression of different grades of PCa lesions in pre-clinical PCa transgenic adenocarcinoma for the mouse prostate (TRAMP) model.

Methods

Both androgen-independent (LNCaP) and androgen-dependent (PC3) PCa cell lines were treated with a range of Nintedanib doses for 72 h, and effect on cell growth and expression of angiogenesis associated VEGF receptors was analyzed. In pre-clinical efficacy evaluation, male TRAMP mice starting at 8 and 12 weeks of age were orally-fed with vehicle control (10% Tween 20) or Nintedanib (10 mg/Kg/day in vehicle control) for 4 weeks, and sacrificed immediately after 4 weeks of drug treatment or sacrificed 6–10 weeks after stopping drug treatments. At the end of treatment schedule, mice were sacrificed and ventral lobe of prostate was excised along with essential metabolic organ liver, and subjected to histopathological and extensive molecular evaluations.

Results

The total cell number decreased by 56–80% in LNCaP and 45–93% in PC3 cells after 72 h of Nintedanib treatment at 2.5–25 μM concentrations. In pre-clinical TRAMP studies, Nintedanib led to a delay in tumor progression in all treatment groups; the effect was more pronounced when treatment was given at the beginning of the glandular lesion development and continued till study end. A decreased microvessel density and VEGF immunolocalization was observed, besides decreased expression of Androgen Receptor (AR), VEGFR-1 and FGFR-3 in some of the treated groups. No changes were observed in the histological liver analysis.

Conclusions

Nintedanib treatment was able to significantly decrease the growth of PCa cell lines and also delay growth and progression of PCa lesions to higher grades of malignancy (without inducing any hepatotoxic effects) in TRAMP mice. Furthermore, it was observed that Nintedanib intervention is more effective when administered during the early stages of neoplastic development, although the drug is capable of reducing cell proliferation even after treatment interruption.

Angiogenesis Inhibitors for the Treatment of Hepatocellular Carcinoma

Background: Angiogenesis inhibitors have become an important therapeutic approach in the treatment of hepatocellular carcinoma (HCC) patients. The therapeutic inhibition of angiogenesis of Sorafenib in increasing overall survival of patients with HCC is a fundamental element of the treatment of this disease. Considering the heterogeneous aspects of HCC and to boost therapeutic efficacy, prevail over drug resistance and lessen toxicity, adding antiangiogenic drugs to antiblastic chemotherapy (AC), radiation therapy or other targeted drugs have been evaluated. The matter is additionally complicated by the combination of antiangiogenesis with further AC or biologic drugs. To date, no planned approach to understand which patients are more responsive to a given type of antiangiogenic treatment is available.

Conclusion: Large investments in the clinical research are essential to improve treatment response and minimize toxicities for patients with HCC. Future investigations will need to focus on utilizing patterns of genetic information to classify HCC into groups that display similar prognosis and treatment sensitivity, and combining targeted therapies with AC producing enhanced anti-tumor effect. In this review the current panel of available antiangiogenic therapies for the treatment of HCC have been analyzed. In addition current clinical trials are also reported herein.

Effect of a novel oral chemotherapeutic agent containing a combination of trifluridine, tipiracil and the novel triple angiokinase inhibitor nintedanib, on human colorectal cancer xenografts

Trifluridine/tipiracil (TFTD) is a combination drug that is used for the treatment of metastatic colorectal cancer and was formerly known as TAS-102. It is a combination of two active pharmaceutical compounds, trifluridine, an antineoplastic thymidine-based nucleoside analog, and tipiracil, which enhances the bioavailability of trifluridine in vivo. TFTD is used for the treatment of patients with unresectable advanced or recurrent colorectal cancer that is resistant to standard therapies. In the present study, the anticancer effects of trifluridine in combination with nintedanib, an oral triple angiokinase inhibitor, on human colorectal cancer cell lines were investigated. The cytotoxicity against DLD-1, HT-29, and HCT116 cell lines was determined by the crystal violet staining method. The combination of trifluridine and nintedanib exerted an additive effect on the growth inhibition of DLD-1 and HT-29 cells and a sub-additive effect on HCT116 cells, as determined by isobologram analyses. Subsequently, the human colorectal cancer cell lines were implanted subcutaneously into nude mice to allow the evaluation of the in vivo tumor growth inhibitory effects of TFTD and nintedanib combination therapy. TFTD (150 mg/kg/day) and/or nintedanib (40 mg/kg/day) were orally administered to the mice twice daily from day 1 to day 14. The tumor growth inhibition with combination therapy was 61.5, 72.8, 67.6 and 67.5% for the DLD-1, DLD-1/5-FU, HT-29, and HCT116 xenografts, respectively. This was significantly (P<0.05) higher than the effects of monotherapy with either TFTD or nintedanib. These results demonstrated the effectiveness of the combination of TFTD and nintedanib in the treatment of colorectal cancer xenografts. The concentration of trifluridine incorporated into DNA in the HT-29 and HCT116 tumors was determined by liquid chromatography-tandem mass spectrometry. The incorporation levels following treatment with TFTD and nintedanib for 14 consecutive days were higher than those associated with TFTD treatment alone. The preclinical findings indicate that the combination therapy with TFTD and nintedanib is a promising treatment option for colorectal cancer.

Therapeutic Approach to Adult Fibrotic Lung Diseases

Among the interstitial lung diseases (ILDs), idiopathic pulmonary fibrosis (IPF), chronic hypersensitivity pneumonitis, and fibrotic connective tissue disease-related ILD are associated with a worse prognosis, with death occurring as a result of both respiratory failure and serious associated comorbidities. The recent development and approval of the antifibrotic agents nintedanib and pirfenidone, both of which reduced the rate of decline in lung function in patients with IPF in clinical trials, offer hope that it may be possible to alter the increased mortality associated with IPF. Although chronic hypersensitivity pneumonitis and connective tissue disease related-ILD may be associated with an inflammatory component, the evidence for the use of immunosuppressive agents in their treatment is largely limited to retrospective studies. The lack of benefit of immunosuppressive therapy in advanced fibrosis argues for rigorous clinical trials using antifibrotic therapies in these types of ILD as well. Patients with fibrotic ILD may benefit from identification and management of associated comorbid conditions such as pulmonary hypertension, gastroesophageal reflux, and OSA, which may improve the quality of life and, in some cases, survival in affected individuals. Because early assessment may optimize posttransplantation outcomes, lung transplant evaluation should occur early in patients with IPF and those with other forms of fibrotic ILD.

Activity of nintedanib in germ cell tumors

Germ cell tumors (GCTs) are the most frequent malignancy in male patients between 15 and 45 years of age. Cisplatin-based chemotherapy shows excellent cure rates, but patients with cisplatin-resistant GCTs have a poor prognosis. Nintedanib (BIBF 1120, Vargatef) inhibits the receptor classes vascular endothelial growth factor receptor, platelet derived growth factor receptor, and fibroblast growth factor receptor, and has shown activity against many tumors, as well as in idiopathic lung fibrosis and bleomycin-induced lung injury. Here, we investigated the antineoplastic and antiangiogenic properties of nintedanib in cisplatin-resistant and cisplatin-sensitive GCT cells, both alone and in combination with classical cytotoxic agents such as cisplatin, etoposide, and bleomycin. The half-maximal inhibitory concentration (IC50) of nintedanib was 4.5 ± 0.43 μmol/l, 3.1 ± 0.45 μmol/l, and 3.6 ± 0.33 μmol/l in cisplatin-sensitive NTERA2, 2102Ep, and NCCIT cells, whereas the IC50 doses of the cisplatin-resistant counterparts were 6.6 ± 0.37 μmol/l (NTERA2-R), 4.5 ± 0.83 μmol/l (2102Ep-R), and 6.1 ± 0.41 μmol/l (NCCIT-R), respectively. Single treatment with nintedanib induced apoptosis and resulted in a sustained reduction in the capacity of colony formation in both cisplatin-sensitive and cisplatin-resistant GCT cells. Cell cycle analysis showed that nintedanib induced a strong G0/G1-phase arrest in all investigated cell lines. Combination treatment with cisplatin did not result in additive, synergistic, or antagonistic effects. The in-vivo activity was studied using the chorioallantoic membrane assay and indicated the antiangiogenic potency of nintedanib with markedly reduced microvessel density. Topical treatment of inoculated tumor plaques resulted in a significant reduction of the tumor size. This indicates that nintedanib might be a promising substance in the treatment of GCT.

Efficacy of BIBF 1120 or BIBF 1120 plus chemotherapy on nasopharyngeal carcinoma in vitro and in vivo

Purpose

BIBF 1120 is a potent triple angiokinase inhibitor now being evaluated in many types of tumors. We examine the antitumor effects of BIBF 1120 on nasopharyngeal carcinoma (NPC) in vitro and in vivo.

Materials and methods

The effect of BIBF 1120 on NPC cell proliferation was evaluated using the Cell Counting Kit 8 assay. The activities of BIBF 1120 as a single agent and in combination with cisplatin (DDP) in NPC tumor xenografts were evaluated by measuring microvessel density and expression of vascular endothelial growth factor signaling.

Results

BIBF 1120 exhibited limited inhibition of the growth of three NPC cell lines. Concurrent administration of BIBF 1120 and DDP provided greater antitumor effects compared to that observed with the use of either inhibitor as a single agent in the NPC xenograft model. Microvessel density and expression of vascular endothelial growth factor signaling were significantly reduced.

Conclusion

BIBF 1120, either as a single agent or in combination with DDP, demonstrates significant antitumor and antiangiogenic effects in the NPC xenograft model. Our results indicate that BIBF 1120 administered in conjunction with chemotherapy might provide an effective treatment method for NPC.

Role of the fibroblast growth factor receptor axis in cholangiocarcinoma

Advanced cholangiocarcinoma (CCA) is a highly lethal disease with limited therapeutic options beyond cytotoxic chemotherapy. Molecular profiling of CCA has provided insights into the pathogenesis of this disease and identified potential therapeutic targets. The fibroblast growth factor receptor (FGFR) axis is important for maintaining tissue homeostasis. Aberrations in FGFR activity have been implicated in the development and progression of CCA and other malignancies, which has generated significant interest in exploring FGFR's therapeutic potential. FGFR2 fusion events are present in up to 17% of intrahepatic CCAs and appear to predict sensitivity to FGFR inhibitors even after progression on chemotherapy. These observations have led to a clinical trial evaluating FGFR inhibition in patients with CCA enriched for FGFR alterations. This review summarizes current knowledge about the role of the FGFR pathway in cholangiocarcinogenesis and ongoing work in developing FGFR-directed therapies as an antineoplastic strategy for CCA.

Targeting Angiogenesis in Cancer Therapy: Moving Beyond Vascular Endothelial Growth Factor

Angiogenesis, or the formation of new capillary blood vessels, occurs primarily during human development and reproduction; however, aberrant regulation of angiogenesis is also a fundamental process found in several pathologic conditions, including cancer. As a process required for invasion and metastasis, tumor angiogenesis constitutes an important point of control of cancer progression. Although not yet completely understood, the complex process of tumor angiogenesis involves highly regulated orchestration of multiple signaling pathways. The proangiogenic signaling molecule vascular endothelial growth factor (VEGF) and its cognate receptor (VEGF receptor 2 [VEGFR-2]) play a central role in angiogenesis and often are highly expressed in human cancers, and initial clinical efforts to develop antiangiogenic treatments focused largely on inhibiting VEGF/VEGFR signaling. Such approaches, however, often lead to transient responses and further disease progression because angiogenesis is regulated by multiple pathways that are able to compensate for each other when single pathways are inhibited. The platelet-derived growth factor (PDGF) and PDGF receptor (PDGFR) and fibroblast growth factor (FGF) and FGF receptor (FGFR) pathways, for example, provide potential escape mechanisms from anti-VEGF/VEGFR therapy that could facilitate resumption of tumor growth. Accordingly, more recent treatments have focused on inhibiting multiple signaling pathways simultaneously. This comprehensive review discusses the limitations of inhibiting VEGF signaling alone as an antiangiogenic strategy, the importance of other angiogenic pathways including PDGF/PDGFR and FGF/FGFR, and the novel current and emerging agents that target multiple angiogenic pathways for the treatment of advanced solid tumors.

IMPLICATIONS FOR PRACTICE

Significant advances in cancer treatment have been achieved with the development of antiangiogenic agents, the majority of which have focused on inhibition of the vascular endothelial growth factor (VEGF) pathway. VEGF targeting alone, however, has not proven to be as efficacious as originally hoped, and it is increasingly clear that there are many interconnected and compensatory pathways that can overcome VEGF-targeted inhibition of angiogenesis. Maximizing the potential of antiangiogenic therapy is likely to require a broader therapeutic approach using a new generation of multitargeted antiangiogenic agents.

Chemotherapy and target therapy for hepatocellular carcinoma: New advances and challenges

Primary liver cancer is one of the commonest causes of death. Hepatocellular carcinoma (HCC) accounts for 90% of primary liver cancers. For patients with unresectable or metastatic HCC, conventional chemotherapy is of limited or no benefit. Sorafenib is the only systemic treatment to demonstrate a statistically significant but modest overall survival benefit, leading to an era of targeted agents. Many clinical trials of targeted drugs have been carried out with many more in progress. Some drugs like PTK787 showed potential benefits in the treatment of HCC. Despite these promising breakthroughs, patients with HCC still have a dismal prognosis. Recently, both a phase III trial of everolimus and a phase II clinical trial of trebananib failed to demonstrate effective antitumor activity in advanced HCC. Sorafenib still plays a pivotal role in advanced HCC, leading to further explorations to exert its maximum efficacy. Combinations targeted with chemotherapy or transarterial chemoembolization is now being tested and might bring about advances. New targeted agents such as mammalian target of rapamycin inhibitors are under investigation, as well as further exploration of the mechanism of hepatocarcinogenesis.

Nintedanib: examining the development and mechanism of action of a novel triple angiokinase inhibitor

Antiangiogenic agents are effective standard-of-care options in several malignancies, but are generally associated with only modest improvements in survival, as well as leading to additional toxicities. Furthermore, almost all patients develop acquired resistance to therapy, possibly due to the activation of alternative proangiogenic pathways. Here we discuss: the rationale for developing nintedanib, an agent that simultaneously inhibits signaling pathways activated by platelet-derived growth factor, FGF, as well as VEGF; how its distinctive inhibitory and pharmacokinetic profile could underlie promising efficacy and tolerability observed in Phase II trials in patients with relapsed/refractory non-small cell lung cancer, advanced ovarian cancer and metastatic colorectal cancer; the ongoing Phase III program that is assessing nintedanib in these areas of major unmet medical need; and recent progress in the development of biomarkers that may predict response to nintedanib.

Melanoma transition is frequently accompanied by a loss of cytoglobin expression in melanocytes: a novel expression site of cytoglobin

The tissue distribution and function of hemoglobin or myoglobin are well known; however, a newly found cytoglobin (CYGB), which also belongs to the globin family, remains to be characterized. To assess its expression in human malignancies, we sought to screen a number of cell lines originated from many tissues using northern blotting and real time PCR techniques. Unexpectedly, we found that several, but not all, melanoma cell lines expressed CYGB mRNA and protein at much higher levels than cells of other origins. Melanocytes, the primary origin of melanoma, also expressed CYGB at a high level. To verify these observations, immunostaining and immunoblotting using anti-CYGB antibody were also performed. Bisulfite-modified genomic sequencing revealed that several melanoma cell lines that abrogated CYGB expression were found to be epigenetically regulated by hypermethylation in the promoter region of CYGB gene. The RNA interference-mediated knockdown of the CYGB transcript in CYGB expression-positive melanoma cell lines resulted in increased proliferation in vitro and in vivo. Flow cytometric analysis using 2'-, 7'-dichlorofluorescein diacetate (DCFH-DA), an indicator of reactive oxygen species (ROS), revealed that the cellular ROS level may be involved in the proliferative effect of CYGB. Thus, CYGB appears to play a tumor suppressive role as a ROS regulator, and its epigenetic silencing, as observed in CYGB expression-negative melanoma cell lines, might function as an alternative pathway in the melanocyte-to-melanoma transition.

The interaction between prognostic and pharmacodynamic biomarkers

Background:

Interactions between prognostic and pharmacodynamic (PD) biomarkers have received little attention.

Methods:

Prognostic and PD utilities were assessed with linear mixed-effects models using published data on repeated measurements of circulating caspase-cleaved (ctCK18) and total (tCK18) cytokeratin 18, in 57 patients with metastatic colorectal cancer undergoing chemotherapy.

Results:

The model for tCK18 (but not cCK18) separated the prognostic/PD interaction from the pure prognostic effect, illustrating the principle of dual prognostic and PD characteristics for a given biomarker.

Conclusion:

These models provide the framework for the analysis and interpretation of longitudinal data to detect prognostic/PD biomarker interactions.

BIBF 1120 (nintedanib), a triple angiokinase inhibitor, induces hypoxia but not EMT and blocks progression of preclinical models of lung and pancreatic cancer

Signaling from other angiokinases may underlie resistance to VEGF-directed therapy. We evaluated the antitumor and biologic effects of BIBF 1120 (nintedanib), a tyrosine kinase inhibitor that targets VEGF receptor, platelet-derived growth factor receptor, and fibroblast growth factor receptor in preclinical models of lung and pancreatic cancer, including models resistant to VEGF-targeted treatments. In vitro, BIBF 1120 did not show antiproliferative effects, nor did it sensitize tumor cells to chemotherapy. However, in vivo BIBF 1120 inhibited primary tumor growth in all models as a single agent and in combination with standard chemotherapy. Analysis of tumor tissue posttreatment revealed that BIBF 1120 reduced proliferation (phospho-histone 3) and elevated apoptosis (cleaved caspase-3) to a greater extent than chemotherapy alone. Furthermore, BIBF 1120 showed potent antiangiogenic effects, including decreases in microvessel density (CD31), pericyte coverage (NG2), vessel permeability, and perfusion, while increasing hypoxia. Despite the induction of hypoxia, markers of epithelial-to-mesenchymal transition (EMT) were not elevated in BIBF 1120-treated tumors. In summary, BIBF 1120 showed potent antitumor and antiangiogenic activity in preclinical models of lung and pancreatic cancer where it induced hypoxia but not EMT. The absence of EMT induction, which has been implicated in resistance to antiangiogenic therapies, is noteworthy. Together, these results warrant further clinical studies of BIBF 1120.

Slug increases sensitivity to tubulin-binding agents via the downregulation of βIII and βIVa-tubulin in lung cancer cells

Transcription factor Slug/SNAI2 (snail homolog 2) plays a key role in the induction of the epithelial mesenchymal transition in cancer cells; however, whether the overexpression of Slug mediates the malignant phenotype and alters drug sensitivity in lung cancer cells remains largely unclear. We investigated Slug focusing on its biological function and involvement in drug sensitivity in lung cancer cells. Stable Slug transfectants showed typical morphological changes compared with control cells. Slug overexpression did not change the cellular proliferations; however, migration activity and anchorage-independent growth activity with an antiapoptotic effect were increased. Interestingly, stable Slug overexpression increased drug sensitivity to tubulin-binding agents including vinorelbine, vincristine, and paclitaxel (5.8- to 8.9-fold increase) in several lung cancer cell lines but did not increase sensitivity to agents other than tubulin-binding agents. Real-time RT-PCR (polymerase chain reaction) and western blotting revealed that Slug overexpression downregulated the expression of βIII and βIVa-tubulin, which is considered to be a major factor determining sensitivity to tubulin-binding agents. A luciferase reporter assay confirmed that Slug suppressed the promoter activity of βIVa-tubulin at a transcriptional level. Slug overexpression enhanced tumor growth, whereas Slug overexpression increased drug sensitivity to vinorelbine with the downregulation of βIII and βIV-tubulin in vivo. Immunohistochemistry of Slug with clinical lung cancer samples showed that Slug overexpression tended to be involved in response to tubulin-binding agents. In conclusion, our data indicate that Slug mediates an aggressive phenotype including enhanced migration activity, anoikis suppression, and tumor growth, but increases sensitivity to tubulin-binding agents via the downregulation of βIII and βIVa-tubulin in lung cancer cells.

Targeting fibroblast growth factor receptor signaling in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the primary type of liver cancer, and both the age-adjusted incidence and mortality of HCC have steadily increased in recent years. Advanced HCC is associated with a very poor survival rate. Despite accumulating data regarding the risk factors for HCC, the mechanisms that contribute to HCC tumorigenesis remain poorly understood. Signaling through the fibroblast growth factor (FGF) family is involved in fibrosis and its progression to cirrhosis of the liver, which is a risk factor for the development of HCC. Furthermore, several alterations in FGF/FGF receptor (FGFR) signaling correlate with the outcomes of HCC patients, suggesting that signaling through this family of proteins contributes to the development or progression of HCC tumors. Currently, there are no established systemic treatments for patients with advanced HCC in whom sorafenib treatment has failed or who were unable to tolerate it. Recently, several multikinase inhibitors that target FGFRs have demonstrated some early evidence of antitumor activity in phase I/II trials. Therefore, this review discusses the molecular implications of FGFR-mediated signaling in HCC and summarizes the clinical evidence for novel FGFR-targeted therapies for HCC currently being studied in clinical trials.