Phase I/II and pharmacodynamic study of dovitinib (TKI258), an inhibitor of fibroblast growth factor receptors and VEGF receptors, in patients with advanced melanoma

VEGF/VEGFR axis and its signaling in melanoma: Current knowledge toward therapeutic targeting agents and future perspectives

Melanoma is responsible for most skin cancer-associated deaths globally. The progression of melanoma is influenced by a number of pathogenic processes. Understanding the VEGF/VEGFR axis, which includes VEGF-A, PlGF, VEGF-B, VEGF-C, and VEGF-D and their receptors, VEGFR-1, VEGFR-2, and VEGFR-3, is of great importance in melanoma due to its crucial role in angiogenesis. This axis generates multifactorial and complex cellular signaling, engaging the MAPK/ERK, PI3K/AKT, PKC, PLC-γ, and FAK signaling pathways. Melanoma cell growth and proliferation, migration and metastasis, survival, and acquired resistance to therapy are influenced by this axis. The VEGF/VEGFR axis was extensively examined for their potential as diagnostic/prognostic biomarkers in melanoma patients and results showed that VEGF overexpression can be associated with unfavorable prognosis, higher level of tumor invasion and poor response to therapy. MicroRNAs linking to the VEGF/VEGFR axis were identified and, in this review, divided into two categories according to their functions, some of them promote melanoma angiogenesis (promotive group) and some restrict melanoma angiogenesis (protective group). In addition, the approach of treating melanoma by targeting the VEGF/VEGFR axis has garnered significant interest among researchers. These agents can be divided into two main groups: anti-VEGF and VEGFR inhibitors. These therapeutic options may be a prominent step along with the modern targeting and immune therapies for better coverage of pathological processes leading to melanoma progression and therapy resistance.

The Application of Artificial Intelligence and Drug Repositioning for the Identification of Fibroblast Growth Factor Receptor Inhibitors: A Review

Artificial intelligence talks about modeling intelligent behavior through a computer with the least human involvement. Drug repositioning techniques based on artificial intelligence accelerate the research process and decrease the cost of experimental studies. Dysregulation of fibroblast growth factor (FGF) receptors as the tyrosine kinase family of receptors plays a vital role in a wide range of malignancies. Because of their functional significance, they were considered promising drug targets for the therapy of various cancers. This review has summarized small molecules capable of inhibiting FGF receptors that progressed using artificial intelligence and repositioning drugs examined in clinical trials associated with cancer therapy. This review is based on a literature search in PubMed, Web of Science, Scopus EMBASE, and Google Scholar databases to gather the necessary information in each chapter by employing keywords like artificial intelligence, computational drug design, drug repositioning, and FGF receptor inhibitors. To achieve this goal, a spacious literature review of human studies in these fields-published over the last 20 decades-was performed. According to published reports, nonselective FGF receptor inhibitors can be used for cancer management, and multitarget kinase inhibitors are the first drug class approved due to more advanced clinical studies. For example, AZD4547 and BGJ398 are gradually entering the consumption cycle and are good options as combined treatments. Artificial intelligence and drug repositioning methods can help preselect suitable drug targets more successfully for future inhibition of carcinogenicity.

Role of Basic Fibroblast Growth Factor in Cancer: Biological Activity, Targeted Therapies, and Prognostic Value

Cancer is the leading cause of death worldwide; thus, it is necessary to find successful strategies. Several growth factors, such as vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF, FGF2), and transforming growth factor beta (TGF-β), are involved in the main processes that fuel tumor growth, i.e., cell proliferation, angiogenesis, and metastasis, by activating important signaling pathways, including PLC-γ/PI3/Ca2+ signaling, leading to PKC activation. Here, we focused on bFGF, which, when secreted by tumor cells, mediates several signal transductions and plays an influential role in tumor cells and in the development of chemoresistance. The biological mechanism of bFGF is shown by its interaction with its four receptor subtypes: fibroblast growth factor receptor (FGFR) 1, FGFR2, FGFR3, and FGFR4. The bFGF–FGFR interaction stimulates tumor cell proliferation and invasion, resulting in an upregulation of pro-inflammatory and anti-apoptotic tumor cell proteins. Considering the involvement of the bFGF/FGFR axis in oncogenesis, preclinical and clinical studies have been conducted to develop new therapeutic strategies, alone and/or in combination, aimed at intervening on the bFGF/FGFR axis. Therefore, this review aimed to comprehensively examine the biological mechanisms underlying bFGF in the tumor microenvironment, the different anticancer therapies currently available that target the FGFRs, and the prognostic value of bFGF.

Small Molecule Inhibitors for Hepatocellular Carcinoma: Advances and Challenges

According to data provided by World Health Organization, hepatocellular carcinoma (HCC) is the sixth most common cause of deaths due to cancer worldwide. Tremendous progress has been achieved over the last 10 years developing novel agents for HCC treatment, including small-molecule kinase inhibitors. Several small molecule inhibitors currently form the core of HCC treatment due to their versatility since they would be more easily absorbed and have higher oral bioavailability, thus easier to formulate and administer to patients. In addition, they can be altered structurally to have greater volumes of distribution, allowing them to block extravascular molecular targets and to accumulate in a high concentration in the tumor microenvironment. Moreover, they can be designed to have shortened half-lives to control for immune-related adverse events. Most importantly, they would spare patients, healthcare institutions, and society as a whole from the burden of high drug costs. The present review provides an overview of the pharmaceutical compounds that are licensed for HCC treatment and other emerging compounds that are still investigated in preclinical and clinical trials. These molecules are targeting different molecular targets and pathways that are proven to be involved in the pathogenesis of the disease.

Preformulation studies of dovitinib free base: Solubility, lipophilicity and stability

Dovitinib has been investigated as an anti-tumor drug due to its ability to inhibit multiple receptor tyrosine kinases. Dovitinib free base has a poor water solubility leading to poor absorption. Salts and lipid-based formulations have been used to improve drug availability. Here, we investigated the physiochemical properties of the dovitinib free base in the presence of some pharmaceutical excipients. We sought to study the effect of acidic counterions on the aqueous solubility and lipophilicity of dovitinib and how pH, buffer species, and cyclodextrin (CD) influenced dovitinib stability. pH-solubility studies were performed by titration against five different acids. Aqueous solubility of dovitinib salt depended on the counterion. Lactic acid greatly increased the aqueous solubility of dovitinib. The counterion effect on the solubility was also investigated in the aqueous complexing media. Unexpected synergistic solubilization was found with γ-CD/phosphoric acid and γ-CD/maleic acid. The counterion did not affect the lipophilicity of dovitinib at physiological pH. Accelerated degradation of dovitinib was carried out at high temperature. Stability was studied across a range of pH values, buffer species and in the presence of two CDs. Dovitinib was most stable at pH 4 in the phosphate buffer species. γ-CD stabilized the drug at relatively low pH.

FGF7-FGFR2 autocrine signaling increases growth and chemoresistance of fusion-positive rhabdomyosarcomas

Rhabdomyosarcomas are aggressive pediatric soft-tissue sarcomas and include high-risk PAX3-FOXO1 fusion-gene-positive cases. Fibroblast growth factor receptor 4 (FGFR4) is known to contribute to rhabdomyosarcoma progression; here, we sought to investigate the involvement and potential for therapeutic targeting of other FGFRs in this disease. Cell-based screening of FGFR inhibitors with potential for clinical repurposing (NVP-BGJ398, nintedanib, dovitinib, and ponatinib) revealed greater sensitivity of fusion-gene-positive versus fusion-gene-negative rhabdomyosarcoma cell lines and was shown to be correlated with high expression of FGFR2 and its specific ligand, FGF7. Furthermore, patient samples exhibit higher mRNA levels of FGFR2 and FGF7 in fusion-gene-positive versus fusion-gene-negative rhabdomyosarcomas. Sustained intracellular mitogen-activated protein kinase (MAPK) activity and FGF7 secretion into culture media during serum starvation of PAX3-FOXO1 rhabdomyosarcoma cells together with decreased cell viability after genetic silencing of FGFR2 or FGF7 was in keeping with a novel FGF7-FGFR2 autocrine loop. FGFR inhibition with NVP-BGJ398 reduced viability and was synergistic with SN38, the active metabolite of irinotecan. In vivo, NVP-BGJ398 abrogated xenograft growth and warrants further investigation in combination with irinotecan as a therapeutic strategy for fusion-gene-positive rhabdomyosarcomas.

Inhibition of FGFR Reactivates IFNγ Signaling in Tumor Cells to Enhance the Combined Antitumor Activity of Lenvatinib with Anti-PD-1 Antibodies

Combination therapies consisting of immune checkpoint inhibitors plus anti-VEGF therapy show enhanced antitumor activity and are approved treatments for patients with renal cell carcinoma (RCC). The immunosuppressive roles of VEGF in the tumor microenvironment are well studied, but those of FGF/FGFR signaling remain largely unknown. Lenvatinib is a receptor tyrosine kinase inhibitor that targets both VEGFR and FGFR. Here, we examine the antitumor activity of anti-PD-1 mAb combined with either lenvatinib or axitinib, a VEGFR-selective inhibitor, in RCC. Both combination treatments showed greater antitumor activity and longer survival in mouse models versus either single agent treatment, whereas anti-PD-1 mAb plus lenvatinib had enhanced antitumor activity compared with anti-PD-1 mAb plus axitinib. Flow cytometry analysis showed that lenvatinib decreased the population of tumor-associated macrophages and increased that of IFNγ-positive CD8⁺ T cells. Activation of FGFR signaling inhibited the IFNγ-stimulated JAK/STAT signaling pathway and decreased expression of its target genes, including B2M, CXCL10, and PD-L1. Furthermore, inhibition of FGFR signaling by lenvatinib restored the tumor response to IFNγ stimulation in mouse and human RCC cell lines. These preclinical results reveal novel roles of tumor FGFR signaling in the regulation of cancer immunity through inhibition of the IFNγ pathway, and the inhibitory activity of lenvatinib against FGFRs likely contributes to the enhanced antitumor activity of combination treatment comprising lenvatinib plus anti-PD-1 mAb. SIGNIFICANCE: FGFR pathway activation inhibits IFNγ signaling in tumor cells, and FGFR inhibition with lenvatinib enhances antitumor immunity and the activity of anti-PD-1 antibodies.

Ginsenoside Rh2 inhibits thyroid cancer cell migration and proliferation via activation of miR-524-5p

INTRODUCTION

Thyroid cancer is an important disease that threatens the health of humans. Ginsenoside Rh2 is known as an anticancer molecule; however, its function in thyroid cancer cells has not been reported. In the present study, we identified that Rh2 treatment of the thyroid cancer cell line K1 inhibited cell migration and proliferation.

MATERIAL AND METHODS

We determined the Rh2 function in thyroid cancer cell lines. By RT-PCR, expression of miR-524-5p and related genes were determined. The cell phenotype including cell migration and proliferation were detected after serials treatment. The relevant protein level were checked by Western blot.

RESULTS

Interestingly, we observed that miR-524-5p, a type of miRNA, had lower expression in the thyroid cancer cell lines TPC-1, K1, and NPA than in the normal thyroid cell line Nthyri3-1. Additionally, Rh2 treatment induced miR-524-5p expression. Further examination using overexpression of miR-524-5p identified that the miR-524-5p mimic inhibited cell migration and proliferation of the K1 line. Similar to Rh2-treated cells, the miR-524-5p mimic-expressing cells had increased E-cadherin and reduced vimentin levels compared to the control cells. Next, we examined the relationship between Rh2 and miR-524-5p with respect to thyroid cell migration and proliferation. Treatment with Rh2 and miR-524-5p inhibitor suppressed Rh2 action on K1 thyroid cell migration and proliferation, and the rates were similar to those in control cells, suggesting that Rh2 might induce miR-524-5p expression to inhibit thyroid cancer cell migration and proliferation.

CONCLUSIONS

Our analyses identified Rh2 and miR-524-5p action on thyroid cancer cell migration and proliferation as well as the linkage between Rh2 and miR-524-5p in thyroid cancer cell development.

Targeted FGFR/VEGFR/PDGFR inhibition with dovitinib enhances the effects of nab-paclitaxel in preclinical gastric cancer models

Standard chemotherapy regimens for gastric adenocarcinoma (GAC) have limited efficacy and considerable toxicity profiles. Nab-paclitaxel has shown promising antitumor benefits in previous GAC preclinical studies. Dovitinib inhibits members of the receptor tyrosine kinase family including FGFR, VEGFR and PDGFR, and has exhibited antitumor effects in many solid tumors including GAC. Based on the antimitotic, antistromal and EPR effects of nab-paclitaxel, we investigated augmentation of nab-paclitaxel response by dovitinib in multiple GAC preclinical models. In MKN-45 subcutaneous xenografts, inhibition in tumor growth by nab-paclitaxel and dovitinib was 75% and 76%, respectively. Dovitinib plus nab-paclitaxel had an additive effect on tumor growth inhibition and resulted in tumor regression (85% of its original value). Dovitinib monotherapy resulted in minimal improvement in animal survival (25 days) compared to control (23 days), while nab-paclitaxel monotherapy or dovitinib plus nab-paclitaxel combination therapy led to a clinically significant lifespan extension of 83% (42 days) and 187% (66 days), respectively. IHC analysis of subcutaneous tumors exhibited reduced tumor cell proliferation and tumor vasculature by dovitinib. In vitro studies demonstrated that dovitinib and nab-paclitaxel individually reduced tumor cell proliferation, with an additive effect from combination therapy. Immunoblot analyses of MKN-45 and KATO-III cells revealed that dovitinib decreased phospho-FGFR, phospho-AKT, phospho-ERK, phospho-p70S6K, phospho-4EBP1, Bcl-2 and increased cleaved PARP-1, cleaved-caspase-3, p27, Bax, Bim, with an additive effect from combination therapy. These results demonstrate that the FGFR/VEGFR/PDGFR inhibitor, dovitinib, has the potential to augment the antitumor effects of nab-paclitaxel, with implications for use in the advancement of clinical GAC therapy.

Neoadjuvant Treatment with Angiogenesis-Inhibitor Dovitinib Prior to Local Therapy in Hepatocellular Carcinoma: A Phase II Study

BACKGROUND

Hepatocellular carcinoma (HCC) recurrence rates following locoregional treatment are high. As multireceptor tyrosine kinase inhibitors targeting vascular endothelial growth factor receptors (VEGFRs) are effective in advanced HCC, we assessed the efficacy and safety of neoadjuvant systemic treatment with dovitinib in early- and intermediate-stage HCC.

MATERIALS AND METHODS

Twenty-four patients with modified Child-Pugh class A early- and intermediate-stage HCC received neoadjuvant oral dovitinib 500 mg daily (5 days on/2 days off) for 4 weeks, followed by locoregional therapy. Primary endpoints were objective response rates and intratumoral blood flow changes. Secondary endpoints were safety, pharmacodynamical plasma markers of VEGFR-blockade, time to progression (TTP), and overall survival (OS).

RESULTS

Modified RECIST overall response rate was 48%, including 13% complete remission, and despite dose reduction/interruption in 83% of patients, intratumoral perfusion index decreased significantly. Grade 3-4 adverse events, most frequently (on-target) hypertension (54%), fatigue (25%), and thrombocytopenia (21%), occurred in 88% of patients. Plasma VEGF-A, VEGF-D, and placental growth factor increased significantly, whereas sTie-2 decreased, consistent with VEGFR-blockade. Following neoadjuvant dovitinib, all patients could proceed to their original planned locoregional treatment. No delayed toxicity occurred. Seven patients (three early, four intermediate stage) underwent orthotopic liver transplant after median 11.4 months. Censoring at transplantation, median TTP and OS were 16.8 and 34.8 months respectively; median cancer-specific survival was not reached.

CONCLUSION

Already after a short 4-week dovitinib treatment period, intratumoral blood flow reduction and modest antitumor responses were observed. Although these results support use of systemic neoadjuvant strategies, the poor tolerability indicates that dovitinib dose adaptations are required in HCC.

IMPLICATIONS FOR PRACTICE

Orthotopic liver transplantation may cure early and intermediate-stage hepatocellular carcinoma. Considering the expected waiting time >6 months because of donor liver scarcity, there is an unmet need for effective neoadjuvant downsizing strategies. Angiogenesis inhibition by dovitinib does not negatively affect subsequent invasive procedures, is safe to administer immediately before locoregional therapy, and may provide a novel treatment approach to improve patient outcomes if tolerability in patients with hepatocellular carcinoma can be improved by therapeutic drug monitoring and personalized dosing.

Pharmacodynamic Biomarkers Predictive of Survival Benefit with Lenvatinib in Unresectable Hepatocellular Carcinoma: From the Phase III REFLECT Study

PURPOSE

In REFLECT, lenvatinib demonstrated an effect on overall survival (OS) by confirmation of noninferiority to sorafenib in unresectable hepatocellular carcinoma. This analysis assessed correlations between serum or tissue biomarkers and efficacy outcomes from REFLECT.

EXPERIMENTAL DESIGN

Serum biomarkers (VEGF, ANG2, FGF19, FGF21, and FGF23) were measured by ELISA. Gene expression in tumor tissues was measured by the nCounter PanCancer Pathways Panel. Pharmacodynamic changes in serum biomarker levels from baseline, and associations of clinical outcomes with baseline biomarker levels, were evaluated.

RESULTS

Four hundred and seven patients were included in the serum analysis set (lenvatinib n = 279, sorafenib n = 128); 58 patients were included in the gene-expression analysis set (lenvatinib n = 34, sorafenib n = 24). Both treatments were associated with increases in VEGF; only lenvatinib was associated with increases in FGF19 and FGF23 at all time points. Lenvatinib-treated responders had greater increases in FGF19 and FGF23 versus nonresponders at cycle 4, day 1 (FGF19: 55.2% vs. 18.3%, P = 0.014; FGF23: 48.4% vs. 16.4%, P = 0.0022, respectively). Higher baseline VEGF, ANG2, and FGF21 correlated with shorter OS in both treatment groups. OS was longer for lenvatinib than sorafenib [median, 10.9 vs. 6.8 months, respectively; HR, 0.53; 95% confidence interval (CI), 0.33-0.85; P-interaction = 0.0397] with higher baseline FGF21. In tumor tissue biomarker analysis, VEGF/FGF-enriched groups showed improved OS with lenvatinib versus the intermediate VEGF/FGF group (HR, 0.39; 95% CI, 0.16-0.91; P = 0.0253).

CONCLUSIONS

Higher baseline levels of VEGF, FGF21, and ANG2 may be prognostic for shorter OS. Higher baseline FGF21 may be predictive for longer OS with lenvatinib compared with sorafenib, but this needs confirmation.

Is more better? An analysis of toxicity and response outcomes from dose-finding clinical trials in cancer

BACKGROUND

The overwhelming majority of dose-escalation clinical trials use methods that seek a maximum tolerable dose, including rule-based methods like the 3+3, and model-based methods like CRM and EWOC. These methods assume that the incidences of efficacy and toxicity always increase as dose is increased. This assumption is widely accepted with cytotoxic therapies. In recent decades, however, the search for novel cancer treatments has broadened, increasingly focusing on inhibitors and antibodies. The rationale that higher doses are always associated with superior efficacy is less clear for these types of therapies.

METHODS

We extracted dose-level efficacy and toxicity outcomes from 115 manuscripts reporting dose-finding clinical trials in cancer between 2008 and 2014. We analysed the outcomes from each manuscript using flexible non-linear regression models to investigate the evidence supporting the monotonic efficacy and toxicity assumptions.

RESULTS

We found that the monotonic toxicity assumption was well-supported across most treatment classes and disease areas. In contrast, we found very little evidence supporting the monotonic efficacy assumption.

CONCLUSIONS

Our conclusion is that dose-escalation trials routinely use methods whose assumptions are violated by the outcomes observed. As a consequence, dose-finding trials risk recommending unjustifiably high doses that may be harmful to patients. We recommend that trialists consider experimental designs that allow toxicity and efficacy outcomes to jointly determine the doses given to patients and recommended for further study.

GZD824 overcomes FGFR1-V561F/M mutant resistance in vitro and in vivo

Abnormallyactivated FGFR1 has been validated as a therapeutic target for differentcancers. Although a variety of FGFR inhibitors have shown benefit in manyclinical patients with FGFR1 aberration, FGFR1 mutant resistance such as V561Mmutation, has been reported. To date however, no FGFR inhibitors have beenapproved to treat patients with FGFR mutant resistance. Herein, we report that GZD824, athird generation ABL inhibitor (Phase II, China), overcomes FGFR1‐V561F/M mutant resistance in vitro and in vivo. GZD824potently suppresses FGFR1/2/3 with an IC₅₀ value of 4.14 ± 0.96, 2.77 ± 0.082, and 8.10 ± 0.15 nmol/L. It effectively overcomes FGFR1‐V561F/M and other mutantresistance in Ba/F3 stable cells (IC₅₀:8.1–55.0 nM), and effectively inhibits the growth of Ba/F3‐FGFR1‐V561F/M mutantxenograft tumors in vivo (TGI=73.4%, 49.8% at20mg/kg, p.o, q2d). GZD824may be considered to be an effective drug to treat patients with FGFR1 abnormalactivation or mutant resistance in clinical trials.

Small molecules in targeted cancer therapy: advances, challenges, and future perspectives

Due to the advantages in efficacy and safety compared with traditional chemotherapy drugs, targeted therapeutic drugs have become mainstream cancer treatments. Since the first tyrosine kinase inhibitor imatinib was approved to enter the market by the US Food and Drug Administration (FDA) in 2001, an increasing number of small-molecule targeted drugs have been developed for the treatment of malignancies. By December 2020, 89 small-molecule targeted antitumor drugs have been approved by the US FDA and the National Medical Products Administration (NMPA) of China. Despite great progress, small-molecule targeted anti-cancer drugs still face many challenges, such as a low response rate and drug resistance. To better promote the development of targeted anti-cancer drugs, we conducted a comprehensive review of small-molecule targeted anti-cancer drugs according to the target classification. We present all the approved drugs as well as important drug candidates in clinical trials for each target, discuss the current challenges, and provide insights and perspectives for the research and development of anti-cancer drugs.

Effects of FGFR Tyrosine Kinase Inhibition in OLN-93 Oligodendrocytes

Fibroblast growth factor (FGF) signaling is involved in the pathogenesis of multiple sclerosis (MS). Data from neuropathology studies suggest that FGF signaling contributes to the failure of remyelination in MS. In MOG_35–55-induced EAE, oligodendrocyte-specific deletion of FGFR1 and FGFR2 resulted in a less severe disease course, reduced inflammation, myelin and axon degeneration and changed FGF/FGFR and BDNF/TrkB signaling. Since signaling cascades in oligodendrocytes could not be investigated in the EAE studies, we here aimed to characterize FGFR-dependent oligodendrocyte-specific signaling in vitro. FGFR inhibition was achieved by application of the multi-kinase-inhibitor dovitinib and the FGFR1/2/3-inhibitor AZD4547. Both substances are potent inhibitors of FGF signaling; they are effective in experimental tumor models and patients with malignancies. Effects of FGFR inhibition in oligodendrocytes were studied by immunofluorescence microscopy, protein and gene analyses. Application of the tyrosine kinase inhibitors reduced FGFR1, phosphorylated ERK and Akt expression, and it enhanced BDNF and TrkB expression. Furthermore, the myelin proteins CNPase and PLP were upregulated by FGFR inhibition. In summary, inhibition of FGFR signaling in oligodendrocytes can be achieved by application of tyrosine kinase inhibitors. Decreased phosphorylation of ERK and Akt is associated with an upregulation of BDNF/TrkB signaling, which may be responsible for the increased production of myelin proteins. Furthermore, these data suggest that application of FGFR inhibitors may have the potential to promote remyelination in the CNS.

Inhibition of FGF-FGFR and VEGF-VEGFR signalling in cancer treatment

The sites of targeted therapy are limited and need to be expanded. The FGF‐FGFR signalling plays pivotal roles in the oncogenic process, and FGF/FGFR inhibitors are a promising method to treat FGFR‐altered tumours. The VEGF‐VEGFR signalling is the most crucial pathway to induce angiogenesis, and inhibiting this cascade has already got success in treating tumours. While both their efficacy and antitumour spectrum are limited, combining FGF/FGFR inhibitors with VEGF/VEGFR inhibitors are an excellent way to optimize the curative effect and expand the antitumour range because their combination can target both tumour cells and the tumour microenvironment. In addition, biomarkers need to be developed to predict the efficacy, and combination with immune checkpoint inhibitors is a promising direction in the future. The article will discuss the FGF‐FGFR signalling pathway, the VEGF‐VEGFR signalling pathway, the rationale of combining these two signalling pathways and recent small‐molecule FGFR/VEGFR inhibitors based on clinical trials.

Update on the systemic management of radioactive iodine refractory differentiated thyroid cancer (Review)

The incidence of differentiated thyroid cancer (DTC) has increased over the last few decades, though it remains to be a rare disease. The prognosis of DTC is excellent; its treatment includes surgery (near-/total thyroidectomy), which is usually followed by remnant thyroid bed ablation using radio-iodine, as well as a risk-stratified follow-ups, including hormone replacement. Treatment of patients who are non-responsive to radioactive iodine (RAI) remains a challenge. Targeted therapies for RAI refractory DTC act primarily through inhibition of cell proliferation, survival and angiogenesis. Tyrosine kinase inhibitors (TKI) have achieved prolonged responses and improved progression-free survival, thereby representing a shift in the treatment of advanced thyroid cancer. There will be number of targeted treatment options for this patient population in the near future. Evidence regarding which drug should be used first and whether there is crossover drug resistance between these drugs is still lacking. Clinicians should be able to choose precisely which patients should be treated with novel targeted therapies after taking into account the following facts: i) TKIs have still not demonstrated a survival benefit. ii) The adverse effects of long-lasting treatment with TKIs could worsen quality of life, which is mostly excellent in these patients before starting treatment with these agents.

Discovery and optimization of novel pyrazole-benzimidazole CPL304110, as a potent and selective inhibitor of fibroblast growth factor receptors FGFR (1-3)

The FGFR family is characterized by four receptors (FGFR 1-4), binding to 18 ligands called fibroblast growth factors (FGFs). Aberrant activation of FGFs and their FGFRs has been implicated in a broad spectrum of human tumors. We employed the scaffolds hybridization approach, scaffold-hopping concept to synthesize a series of novel pyrazole-benzimidazole derivatives 56 (a-x). Compound 56q (CPL304110) was identified as a selective and potent pan-FGFR inhibitor for FGFR1, -2, -3 with IC₅₀s of 0.75 nM, 0.50 nM, 3.05 nM respectively, whereas IC₅₀ of 87.90 nM for FGFR4. Due to its favorable pharmacokinetic profile, low toxicity and potent anti-tumor activity in vivo, compound 56q is currently under evaluation in phase I clinical trial for the treatment of bladder, gastric and squamous cell lung cancers (01FGFR2018; NCT04149691).

A New Validated HPLC-MS/MS Method for Quantification and Pharmacokinetic Evaluation of Dovitinib, a Multi-Kinase Inhibitor, in Mouse Plasma

Background

Dovitinib (TKI 258) is a small-molecule multi-kinase inhibitor for the treatment of different types of cancer. There is currently no validated method for its quantitative determination; therefore, we aimed to develop a reliable method to assay dovitinib.

Method and Results

An electrospray ionization tandem mass spectrometry (ESI-MS/MS) method was used to separate dovitinib using an analytical C18 column (50 × 2.1 mm, 1.8 μm) at 25°C. Bosutinib was used as the internal standard (IS). Dovitinib was extracted from mouse plasma using a precipitation procedure. The mobile phase consisted of 10 mM ammonium formate: acetonitrile (68:32, v/v, pH 4.3) run at a rate of 0.3 mL min⁻¹. MS detection was performed in the positive ion mode. Multiple reaction monitoring transitions were 393→337 and 393→309 for dovitinib, and 530→141 and 530→113 for bosutinib. The investigated method was validated as a bio-analytical method based on FDA guidelines. The linearity of the developed method was over the range of 5–500 ng mL,⁻¹ coefficient of determination (r²= 0.9998). The average intra-day recovery and relative standard deviation (RSD) of the quality control (QC) sample were 97.24% and 1.32%, whereas the overall inter-day accuracy and precision were 97.99% and 0.54%, respectively. Dovitinib was stable during sample storage and handling conditions. Furthermore, the dilution integrity of the method was demonstrated by good recovery (97–99%) and RSD values (0.5–0.7%).

Conclusion

This method was selectively sensitive and exhibited no matrix effect, with an acceptable accuracy and precision according to the FDA guidelines. The developed method could be efficiently used for pharmacokinetic studies of dovitinib.

Early Changes in Circulating FGF19 and Ang-2 Levels as Possible Predictive Biomarkers of Clinical Response to Lenvatinib Therapy in Hepatocellular Carcinoma

Predictive biomarkers of the response of hepatocellular carcinoma (HCC) to Lenvatinib therapy have not yet been clarified. The aim of this study was to identify clinically significant biomarkers of response to Lenvatinib therapy, to target strategies against HCC. Levels of circulating angiogenic factors (CAFs) were analyzed in blood samples collected at baseline and after introducing lenvatinib, from 74 Child-Pugh class A HCC patients who received lenvatinib. As CAF biomarkers, serum vascular endothelial growth factor (VEGF), fibroblast growth factor 19 (FGF19), FGF23, and angiopoietin-2 (Ang-2) were measured using enzyme-linked immunosorbent assays. Results: Significantly increased FGF19 (FGF19-i) levels and decreased Ang-2 (Ang-2-d) levels were seen in Lenvatinib responders as compared to non-responders (ratio of FGF19 level at 4 weeks/baseline in responders vs. non-responders: 2.09 vs. 1.32, respectively, p = 0.0004; ratio of Ang-2 level at four weeks/baseline: 0.584 vs. 0.810, respectively, p = 0.0002). Changes in FGF23 and VEGF levels at four weeks versus baseline, however, were not significantly different in responders versus non-responders. In multivariate analysis, the combination of serum FGF19-i and Ang-2-d was the most independent predictive factor for Lenvatinib response (Odds ratio, 9.143; p = 0.0012). Furthermore, this combination biomarker showed the greatest independent association with progression-free survival (Hazard ratio, 0.171; p = 0.0240). Early changes in circulating FGF19 and Ang-2 levels might be useful for predicting clinical response and progression-free survival in HCC patients on Lenvatinib therapy.

A Phase Ib Study of the FGFR/VEGFR Inhibitor Dovitinib With Gemcitabine and Capecitabine in Advanced Solid Tumor and Pancreatic Cancer Patients

OBJECTIVES

Preclinical studies demonstrated antitumor activity of dovitinib in pancreatic cancer models. This phase Ib study aimed to determine the maximum tolerated dose (MTD) of dovitinib in combination with gemcitabine and capecitabine and to characterize the safety and pharmacokinetic profile in patients with advanced pancreatic and biliary tract cancers and solid malignancies.

MATERIALS AND METHODS

Patients received gemcitabine 1000 mg/m² intravenously on days 1 and 8, capecitabine 1300 mg/m² oral daily from day 1 to 14, and dovitinib oral daily 5 days on and 2 days off, every 21-day cycle. The standard 3+3 dose escalation design was utilized and the study expanded to treat an additional 20 advanced pancreatic and biliary tract cancers patients at MTD.

RESULTS

A total of 29 patients were enrolled. One patient experienced dose-limiting grade 3 colitis. Two patients developed clinically significant neuropathy after the first cycle requiring dose reduction. The MTD was not reached and dovitinib 300 mg was declared the recommended dose for expansion. The most frequent grade 2 or worse adverse events were fatigue (45%), neutropenia (41%), thrombocytopenia (34%), anemia (24%), nausea (24%), and palmer-plantar erythrodysaesthesia syndrome (21%). Partial responses were observed in 5 patients. Pharmacokinetic studies showed no drug-drug interaction between dovitinib, capecitabine and gemcitabine. Fibroblast growth factor 23 plasma level increased in 4 of 5 patients during the first cycle of treatment.

CONCLUSIONS

Dovitinib 300 mg daily is the recommended dose when combined with gemcitabine and capecitabine, achieving clinically relevant plasma concentrations. The study combination demonstrated encouraging efficacy signals in advanced pancreatic cancer.

Estimation of Percentage of Patients With Fibroblast Growth Factor Receptor Alterations Eligible for Off-label Use of Erdafitinib

IMPORTANCE

When a novel drug is granted accelerated approval, both its on-label and off-label uses must be taken into account.

OBJECTIVES

To estimate the potential upper bound of off-label use of erdafitinib to treat advanced cancer with fibroblast growth factor receptor gene (FGFR) alterations, compare it to the upper bound of on-label use in urothelial cancer, and to review studies that may support off-label use.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study used frequency data on FGFR alterations by cancer type and the estimated number of deaths from all cancers for 2019 in the United States. Mortality statistics were used as surrogates for patients with advanced cancer. Analysis was conducted in May 2019.

EXPOSURE

Percentage of patients with an FGFR2 or FGFR3 alteration.

MAIN OUTCOMES AND MEASURES

Estimated number of patients with advanced cancer expressing an FGFR2 or FGFR3 alteration eligible for off-label use of erdafitinib by cancer type; number of studies investigating FGFR-targeting drugs for patients with cancer; and number of ongoing clinical trials on erdafitinib by cancer type.

RESULTS

A total of 15 cancer types had reported FGFR alterations. Of 455 440 estimated patients who died of cancer in 2019, 17 019 (3.7%) were estimated to have FGFR2 or FGFR3 alterations. Of these patients, 12 955 (76.1%) could be eligible for off-label treatment with erdafitinib. A total of 29 completed studies evaluated FGFR-targeting drugs in 11 cancer types, and 10 ongoing studies are studying erdafitinib for different oncological indications.

CONCLUSIONS AND RELEVANCE

This study indicates that the potential for off-label use of FGFR inhibitors such as erdafitinib spans a number of cancer types and a large patient population. Systematic trials exploring off-label uses may be desirable for drugs that target clear, identifiable molecular alterations because this may be more efficient than off-label use in identifying clinical scenarios where the agent has activity.

Dovitinib Triggers Apoptosis and Autophagic Cell Death by Targeting SHP-1/p-STAT3 Signaling in Human Breast Cancers

Breast cancer is the most common cancer and the leading cause of cancer deaths in women worldwide. The rising incidence rate and female mortality make it a significant public health concern in recent years. Dovitinib is a novel multitarget receptor tyrosine kinase inhibitor, which has been enrolled in several clinical trials in different cancers. However, its antitumor efficacy has not been well determined in breast cancers. Our results demonstrated that dovitinib showed significant antitumor activity in human breast cancer cell lines with dose- and time-dependent manners. Downregulation of phosphor-(p)-STAT3 and its subsequent effectors Mcl-1 and cyclin D1 was responsible for this drug effect. Ectopic expression of STAT3 rescued the breast cancer cells from cell apoptosis induced by dovitinib. Moreover, SHP-1 inhibitor reversed the downregulation of p-STAT3 induced by dovitinib, indicating that SHP-1 mediated the STAT3 inhibition effect of dovitinib. In addition to apoptosis, we found for the first time that dovitinib also activated autophagy to promote cell death in breast cancer cells. In conclusion, dovitinib induced both apoptosis and autophagy to block the growth of breast cancer cells by regulating the SHP-1-dependent STAT3 inhibition.

Surufatinib in Advanced Well-Differentiated Neuroendocrine Tumors: A Multicenter, Single-Arm, Open-Label, Phase Ib/II Trial

PURPOSE

No antiangiogenic treatment is yet approved for extrapancreatic neuroendocrine tumors (NET). Surufatinib (HMPL-012, previously named sulfatinib) is a small-molecule inhibitor targeting vascular endothelial growth factor receptors, fibroblast growth factor receptor 1 and colony-stimulating factor 1 receptor. We conducted a single-arm phase Ib/II study of surufatinib in advanced NETs.

PATIENTS AND METHODS

Patients with histologically well-differentiated, low or intermittent grade, inoperable or metastatic NETs were enrolled into a pancreatic or extrapancreatic NET cohort. Patients were treated with surufatinib 300 mg orally, once daily. The primary endpoints were safety and objective response rate (ORR) according to Response Evaluation Criteria in Solid Tumors (version 1.1).

RESULTS

Of the 81 patients enrolled, 42 had pancreatic NETs and 39 had extrapancreatic NETs. Most patients had radiologic progression within 1 year prior to enrollment (32 patients in each cohort). In the pancreatic and extrapancreatic NET cohorts, ORRs were 19% [95% confidence intervals (CI), 9-34] and 15% (95% CI, 6-31), disease control rates were 91% (95% CI, 77-97) and 92% (95% CI, 79-98), and median progression-free survival was 21.2 months (95% CI, 15.9-24.8) and 13.4 months (95% CI, 7.6-19.3), respectively. The most common grade ≥3 treatment-related adverse events were hypertension (33%), proteinuria (12%), hyperuricemia (10%), hypertriglyceridemia, and diarrhea (6% for each), and increased alanine aminotransferase (5%).

CONCLUSIONS

Surufatinib showed encouraging antitumor activity and manageable toxicities in patients with advanced NETs. Two ongoing phase III studies, validating the efficacy of surufatinib in patients with NETs, will contribute to the clinical evidence.

Combined targeting of SET and tyrosine kinases provides an effective therapeutic approach in human T-cell acute lymphoblastic leukemia

Recent evidence suggests that inhibition of protein phosphatase 2A (PP2A) tumor suppressor activity via the SET oncoprotein contributes to the pathogenesis of various cancers. Here we demonstrate that both SET and c-MYC expression are frequently elevated in T-ALL cell lines and primary samples compared to healthy T cells. Treatment of T-ALL cells with the SET antagonist OP449 restored the activity of PP2A and reduced SET interaction with the PP2A catalytic subunit, resulting in a decrease in cell viability and c-MYC expression in a dose-dependent manner. Since a tight balance between phosphatases and kinases is required for the growth of both normal and malignant cells, we sought to identify a kinase inhibitor that would synergize with SET antagonism. We tested various T-ALL cell lines against a small-molecule inhibitor screen of 66 compounds targeting two-thirds of the tyrosine kinome and found that combined treatment of T-ALL cells with dovitinib, an orally active multi-targeted small-molecule receptor tyrosine kinase inhibitor, and OP449 synergistically reduced the viability of all tested T-ALL cell lines. Mechanistically, combined treatment with OP449 and dovitinib decreased total and phospho c-MYC levels and reduced ERK1/2, AKT, and p70S6 kinase activity in both NOTCH-dependent and independent T-ALL cell lines. Overall, these results suggest that combined targeting of tyrosine kinases and activation of serine/threonine phosphatases may offer novel therapeutic strategies for the treatment of T-ALL.

Phase II Study of Dovitinib in Patients with Castration-Resistant Prostate Cancer (KCSG-GU11-05)

Purpose

Fibroblast growth factor (FGF) signals are important in carcinogenesis and progression of prostate cancer. Dovitinib is an oral, pan-class inhibitor of vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor, and fibroblast growth factor receptor (FGFR). We evaluated the efficacy and toxicity of dovitinib in men with metastatic castration resistant prostate cancer (mCRPC).

Materials and Methods

This study was a single-arm, phase II, open-label, multicenter trial of dovitinib 500 mg/day (5-days-on/2-days-off schedule). The primary endpoint was 16-week progression-free survival (PFS). Secondary endpoints were overall survival (OS), toxicity and prostate-specific antigen (PSA) response rate. Biomarker analyses for VEGFR2, FGF23, and FGFR2 using multiplex enzyme-linked immunosorbent assay was performed.

Results

Forty-four men were accrued from 11 hospitals. Eighty percent were post-docetaxel. Median PSA was 100 ng/dL, median age was 69, 82% had bone metastases, and 23% had liver metastases. Median cycles of dovitinib was 2 (range, 0 to 33). Median PFS was 3.67 months (95% confidence interval [CI], 1.36 to 5.98) and median OS was 13.70 months (95% CI, 0 to 27.41). Chemotherapy-naïve patients had longer PFS (17.90 months; 95% CI, 9.23 to 28.57) compared with docetaxel-treated patients (2.07 months; 95% CI, 1.73 to 2.41; p=0.001) and the patients with high serum VEGFR2 level over median level (7,800 pg/mL) showed longer PFS compared with others (6.03 months [95% CI, 4.26 to 7.80] vs. 1.97 months [95% CI, 1.79 to 2.15], p=0.023). Grade 3 related adverse events were seen in 40.9% of patients. Grade 1-2 nausea, diarrhea, fatigue, anorexia, and all grade thrombocytopenia are common.

Conclusion

Dovitinib showed modest antitumor activity with manageable toxicities in men with mCRPC. Especially, patients who were chemo-naïve benefitted from dovitinib.

Immunobiological efficacy and immunotoxicity of novel synthetically prepared fluoroquinolone ethyl 6-fluoro-8-nitro-4-oxo-1,4-dihydroquinoline-3-carboxylate

The present study examined the cytotoxicity, anti-cancer reactivity, and immunomodulatory properties of new synthetically prepared fluoroquinolone derivative 6-fluoro-8-nitro-4-oxo-1,4-dihydroquinoline-3-carboxylate (6FN) in vitro. The cytotoxicity/toxicity studies (concentrations in the range 1-100μM) are focused on the cervical cancer cells HeLa, murine melanoma cancer cells B16, non-cancer fibroblast NIH-3T3 cells and reconstructed human epidermis tissues EpiDerm™. The significant growth inhibition of cancer cells HeLa and B16 was detected. The cytotoxicity was mediated via apoptosis-associated with activation of caspase-9 and -3. After 72h of treatment, the two highest 6FN concentrations (100 and 50μM) induced toxic effect on epidermis tissue EpiDerm™, even the structural changes in tissue were observed with concentration of 100μM. The effective induction of RAW 264.7 macrophages cell-release of pro- and anti-inflammatory T_H1, T_H2 and T_H17 cytokines, with anti-cancer and/or anti-infection activities, respectively, has been revealed even following low-dose exposition.

Circulating microRNAs in patients with hormone receptor-positive, metastatic breast cancer treated with dovitinib

BACKGROUND

Serial analysis of biomarkers in the circulation of patients undergoing treatment ("liquid biopsies") can provide new insights into drug effects. In particular the analysis of cell-free, circulating nucleic acids such as microRNAs (miRs) can reveal altered expression patterns indicative of mechanism of drug action, cancer growth, and tumor-stroma interactions.

RESULTS

Here we analyzed plasma miRs in patients with hormone receptor positive, metastatic breast cancer with prior disease progression during aromatase inhibitor therapy (n = 8) in a phase I/II trial with the multiple tyrosine kinase inhibitor dovitinib (TKI258). Plasma miR levels were measured by quantitative RT-qPCR before and after treatment with dovitinib. A candidate miR signature of drug response was established from a 379 miR screen for detectable plasma miRs as well as from the published literature. Changes in miR expression patterns and tumor sizes were compared. In this analysis we identified miR-21-5p, miR-100-5p, miR-125b-5p, miR-126-3p, miR-375 and miR-424-5p as potential indicators of a response to dovitinib. The altered expression patterns observed for the six circulating miRs separated patients with resistant disease from those with drug responsive disease. There was no relationship between adverse effects of dovitinib treatment and identifiable changes in miR patterns.

CONCLUSION

We conclude that changes in the expression patterns of circulating miRs can be indicators of drug responses that merit prospective studies for validation.

First-in-human phase I study of oral S49076, a unique MET/AXL/FGFR inhibitor, in advanced solid tumours

BACKGROUND AND OBJECTIVES

S49076 is a novel ATP-competitive tyrosine kinase inhibitor of MET, AXL and FGFR with a unique selectivity profile. A phase I open-label study was undertaken to establish the tolerability profile and determine the recommended dose (RD) and administration schedule.

MATERIALS AND METHODS

Patients with advanced solid tumours received S49076 orally once-daily (qd) or twice-daily (bid) in continuous 21-day cycles at escalating doses guided by a 3 + 3 design and followed by an expansion phase at the RD. Pharmacokinetic (PK) parameters were assessed and pharmacodynamic end-points were evaluated in pre- and post-treatment tumour biopsies. Preliminary anti-tumour activity was evaluated as per the Response Evaluation Criteria In Solid Tumours 1.1 criteria.

RESULTS

A total of 103 patients were treated: 79 in the dose-escalation and 24 in the expansion. Doses from 15 to 900 mg were evaluated. Dose-limiting toxicities were reported in 9 patients and occurred at 30, 760 and 900 mg in the qd arm and at 180, 225 and 285 mg in the bid arm. The RD was defined at 600 mg qd. Adverse events (AEs) occurred with similar frequency in both regimens at an equivalent total daily dose. Overall, 83 patients (81.4%) had drug-related AEs, the majority (93%) of which were grade I-II (National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0) and only 3% led to drug discontinuation. Intratumoural PK analysis at the RD suggested hitting of MET, AXL and FGFR.

CONCLUSION

S49076 demonstrated a tolerable safety profile with limited single-agent activity. PK/pharmacodynamic readouts of S49076 are encouraging for further investigation of S49076 in combination therapies.

TRIAL REGISTRATION NUMBER

ISRCTN00759419.

Dovitinib enhances temozolomide efficacy in glioblastoma cells

The multikinase inhibitor and FDA‐approved drug dovitinib (Dov) crosses the blood–brain barrier and was recently used as single drug application in clinical trials for GB patients with recurrent disease. The Dov‐mediated molecular mechanisms in GB cells are unknown. We used GB patient cells and cell lines to show that Dov downregulated the stem cell protein Lin28 and its target high‐mobility group protein A2 (HMGA2). The Dov‐induced reduction in pSTAT3^Tyr705 phosphorylation demonstrated that Dov negatively affects the STAT3/LIN28/Let‐7/HMGA2 regulatory axis in GB cells. Consistent with the known function of LIN28 and HMGA2 in GB self‐renewal, Dov reduced GB tumor sphere formation. Dov treatment also caused the downregulation of key base excision repair factors and O⁶‐methylguanine‐DNA‐methyltransferase (MGMT), which are known to have important roles in the repair of temozolomide (TMZ)‐induced alkylating DNA damage. Combined Dov/TMZ treatment enhanced TMZ‐induced DNA damage as quantified by nuclear γH2AX foci and comet assays, and increased GB cell apoptosis. Pretreatment of GB cells with Dov (‘Dov priming’) prior to TMZ treatment reduced GB cell viability independent of p53 status. Sequential treatment involving ‘Dov priming’ and alternating treatment cycles with TMZ and Dov substantially reduced long‐term GB cell survival in MGMT+ patient GB cells. Our results may have immediate clinical implications to improve TMZ response in patients with LIN28⁺/HMGA2⁺GB, independent of their MGMT methylation status.

Emerging growth factor receptor antagonists for the treatment of advanced melanoma

INTRODUCTION

Therapy for metastatic melanoma has undergone a rapid transformation over the past 5-10 years. Advances in immunotherapy with checkpoint inhibitors, including both anti-CTLA-4 and anti-PD-1/PD-L1, have led to durable responses in up to 50% of patients. As our understanding of the processes driving the transformation of melanocytes has improved, progress in targeted therapies has also continued. Areas covered: Angiogenesis and the tumor's dependence on an expanded vascular supply has been a target for novel therapies since the 1970's, as this tissue is derived from endothelial cells that are genetically stable in adults. A phase II trial studying combined therapy with bevacizumab (an inhibitor of angiogenesis) and ipilimumab found promising results. Other agents such as sorafenib have not been as successful, failing to extend progression free or overall survival in clinical trials. In this paper other targeted growth factor inhibitors will also be discussed. Expert opinion: Ultimately, melanoma may not be vulnerable solely to chemotherapy or targeted therapy, but may be efficaciously treated with immunotherapy due to its high mutational rate resulting in the expression of numerous neo-antigens. Therapies with combinations of agents including growth factor receptor and either other targeted therapies or immunotherapy may be a promising complimentary approach.

Human melanoma inhibitory protein binds to the FN12-14 Hep II domain of fibronectin

The heparin binding site (Hep II) of fibronectin plays a major role in tumor cell metastasis. Its interaction with heparan sulfate proteoglycans occurs in a variety of physiological processes including focal adhesion and migration. The melanoma inhibitory activity (MIA) is an important protein that is functionally involved in melanoma development, progression, and tumor cell invasion. After its secretion by malignant melanoma cells, MIA interacts with fibronectin and thereby actively facilitates focal cell detachment from surrounding structures and strongly promotes tumor cell invasion and the formation of metastases. In this report, the authors have determined the molecular basis of the interaction of MIA with the Hep II domain of fibronectin based on nuclear magnetic resonance spectroscopic binding assays. The authors have identified the type III modules 12 to 14 of fibronectin's Hep II as the major MIA binding sites. These results now provide a new target protein-protein binding interface for the discovery of novel antimetastatic agents against malignant melanoma in the future.

Exploratory analysis of biomarkers associated with clinical outcomes from the study of lenvatinib in differentiated cancer of the thyroid

BACKGROUND

Lenvatinib significantly prolonged progression-free survival (PFS) versus placebo in the phase III Study of (E7080) LEnvatinib in differentiated Cancer of the Thyroid (SELECT) of patients with radioiodine-refractory differentiated thyroid cancer. This exploratory analysis investigated potential predictive biomarkers of lenvatinib efficacy and target engagement.

PATIENTS AND METHODS

Circulating cytokine/angiogenic factors (CAFs) in blood samples collected at baseline and throughout treatment were analysed from patients randomised to receive lenvatinib or placebo from August 5, 2011 to October 4, 2012. For CAF biomarker analyses, patients were dichotomised by baseline levels. Tumour tissues were analysed for BRAF and NRAS/KRAS/HRAS mutations.

RESULTS

Tumours and CAFs were analysed from 183/392 (47%) and 387/392 (99%) patients, respectively. Lenvatinib PFS benefit was maintained in all assessments. For lenvatinib-treated patients, interaction-term analyses revealed that low baseline Ang2 level was predictive of tumour shrinkage (P_interaction = 0.016) and PFS (P_interaction = 0.018). Vascular endothelial growth factor and fibroblast growth factor 23 (FGF23) were significantly upregulated with lenvatinib, and FGF23 upregulation on cycle 1/day 15 was associated with longer PFS. In mutation analyses, no significant differences in clinical outcomes were observed. BRAF^WT may be a negative prognostic factor for PFS in placebo-treated patients with papillary thyroid cancer (P = 0.019).

CONCLUSION

The lenvatinib PFS benefit was maintained regardless of baseline CAF or BRAF/RAS status. Baseline Ang2 was predictive of PFS in a subgroup of lenvatinib-treated patients, indicating that Ang2 may be predictive of lenvatinib sensitivity. BRAF^WT may be a poor prognostic factor in patients with radioiodine-refractory papillary thyroid cancer. Improved PFS associated with upregulated FGF23 suggests that lenvatinib-induced FGF receptor inhibition contributes to lenvatinib efficacy. Trial registration ID of the main study, SELECT: ClinicalTrials.gov: NCT01321554.

Dose-finding designs for trials of molecularly targeted agents and immunotherapies

Recently, there has been a surge of early phase trials of molecularly targeted agents (MTAs) and immunotherapies. These new therapies have different toxicity profiles compared to cytotoxic therapies. MTAs can benefit from new trial designs that allow inclusion of low-grade toxicities, late-onset toxicities, addition of an efficacy endpoint, and flexibility in the specification of a target toxicity probability. To study the degree of adoption of these methods, we conducted a Web of Science search of articles published between 2008 and 2014 that describe phase 1 oncology trials. Trials were categorized based on the dose-finding design used and the type of drug studied. Out of 1,712 dose-finding trials that met our criteria, 1,591 (92.9%) utilized a rule-based design, and 92 (5.4%; range 2.3% in 2009 to 9.7% in 2014) utilized a model-based or novel design. Over half of the trials tested an MTA or immunotherapy. Among the MTA and immunotherapy trials, 5.8% used model-based methods, compared to 3.9% and 8.3% of the chemotherapy or radiotherapy trials, respectively. While the percentage of trials using novel dose-finding designs has tripled since 2007, the adoption of these designs continues to remain low.

Phase II Study of Dovitinib in Patients Progressing on Anti-Vascular Endothelial Growth Factor Therapy

BACKGROUND

Prior work identified the fibroblast growth factor (FGF) pathway as a mediator of resistance to anti-vascular endothelial growth factor (VEGF) therapy. We tested dovitinib, an inhibitor of both FGF and VEGF receptors, in patients progressing on anti-VEGF treatment.

METHODS

Patients with measurable advanced colorectal or non-small cell lung cancer with progression despite anti-VEGF treatment within 56 days, good performance status and adequate organ function were eligible. A research tumor biopsy was followed by treatment with dovitinib 500 mg on a 5-day on/2-day off schedule for 28-day cycles. The primary endpoint of tumor response was evaluated every 2 cycles. Secondary endpoints included toxicity and 8-week disease control rate. Intratumor mRNA expression of angiogenic mediators was analyzed using a next generation sequencing based expression array.

RESULTS

Ten patients treated previously with bevacizumab or ziv-aflibercept enrolled. The study closed with termination of dovitinib development. No responses were observed in 7 evaluable patients. The best response was stable disease in 1 patient. Common toxicities included gastrointestinal, metabolic, and biochemical derangements. All patients experienced at least one grade ≥ 3 treatment-related adverse event, most commonly fatigue, elevated GGT, and lymphopenia. Expression of multiple angiogenic mediators was common in tumors progressing on anti-VEGF therapy including high levels of FGFR1 and VEGFA.

CONCLUSIONS

We found no evidence for the activity of dovitinib in patients who had recently progressed on anti-VEGF therapy and toxicities were significant. In tumors progressing despite anti-VEGF therapy, a multitude of pro-angiogenic mediators are expressed, including members of the FGF pathway.

Identification of Existing Drugs That Effectively Target NTRK1 and ROS1 Rearrangements in Lung Cancer

PURPOSE

Efforts to discover drugs that overcome resistance to targeted therapies in patients with rare oncogenic alterations, such as NTRK1 and ROS1 rearrangements, are complicated by the cost and protracted timeline of drug discovery.

EXPERIMENTAL DESIGN

In an effort to identify inhibitors of NTRK1 and ROS1, which are aberrantly activated in some patients with non-small cell lung cancer (NSCLC), we created and screened a library of existing targeted drugs against Ba/F3 cells transformed with these oncogenes.

RESULTS

This screen identified the FDA-approved drug cabozantinib as a potent inhibitor of CD74-ROS1-transformed Ba/F3, including the crizotinib-resistant mutants G2032R and L2026M (IC50 = 9, 26, and 11 nmol/L, respectively). Cabozantinib inhibited CD74-ROS1-transformed Ba/F3 cells more potently than brigatinib (wild-type/G2032R/L2026M IC50 = 30/170/200 nmol/L, respectively), entrectinib (IC50 = 6/2,200/3,500 nmol/L), and PF-06463922 (IC50 = 1/270/2 nmol/L). Cabozantinib inhibited ROS1 autophosphorylation and downstream ERK activation in transformed Ba/F3 cells and in patient-derived tumor cell lines. The IGF-1R inhibitor BMS-536924 potently inhibited CD74-NTRK1-transformed compared with parental Ba/F3 cells (IC50 = 19 nmol/L vs. > 470 nmol/L). A patient with metastatic ROS1-rearranged NSCLC with progression on crizotinib was treated with cabozantinib and experienced a partial response.

CONCLUSIONS

While acquired resistance to targeted therapies is challenging, this study highlights that existing agents may be repurposed to overcome drug resistance and identifies cabozantinib as a promising treatment of ROS1-rearranged NSCLC after progression on crizotinib. Clin Cancer Res; 23(1); 204-13. ©2016 AACR.

A phase II trial of dovitinib in previously-treated advanced pleural mesothelioma: The Ontario Clinical Oncology Group

OBJECTIVES

Following failure of a platinum-antifolate combination regimen, there is no standard therapy for advanced malignant pleural mesothelioma (MPM). The fibroblast growth factor receptor (FGFR) signaling pathways may be a relevant target in MPM. Dovitinib inhibits multiple tyrosine receptor kinases, predominantly the vascular endothelial growth factor receptors (VEGFR), but also FGFRs, and could be active in MPM.

METHODS

This open-label multicentre phase II trial [NCT01769547] enrolled fit, consenting adult patients with advanced MPM who had previously received platinum-antifolate combination chemotherapy and up to one additional line of systemic therapy. Dovitinib was administered orally at 500mg/day for 5days on, 2days off, in 28-day cycles. Response was assessed every 2 cycles using RECIST 1.1 criteria modified for MPM. Correlative studies included FGFR-1 amplification on archival tumour and serum samples for circulating angiogenesis factors. The primary end-point was the proportion of patients progression-free at 3 months (PF3) using a two-stage design.

RESULTS

12 patients (10 males, median age 67) were enrolled. The median number of cycles administered was 2.5 (range 1-8). One unconfirmed partial response was observed. PF3 was 50% (95% confidence interval 28.4% to 88.0%); although the criterion for proceeding to stage II accrual was met, the trial was halted due to a combination of minimal activity with several early progression events and poor tolerability in this patient population. One of 12 tumour specimens had low amplification of FGFR-1.

CONCLUSIONS

Dovitinib has minimal activity in previously-treated MPM. The role of the FGFR pathway in MPM remains unclear.

Randomized phase 1 crossover study assessing the bioequivalence of capsule and tablet formulations of dovitinib (TKI258) in patients with advanced solid tumors

PURPOSE

A capsule formulation of the tyrosine kinase inhibitor dovitinib (TKI258) was recently studied in a phase 3 renal cell carcinoma trial; however, tablets are the planned commercial formulation. Therefore, this randomized 2-way crossover study evaluated the bioequivalence of dovitinib tablet and capsule formulations in pretreated patients with advanced solid tumors, excluding breast cancer.

METHODS

In this 2-part study, eligible patients received dovitinib 500 mg once daily on a 5-days-on/2-days-off schedule. During the 2-period bioequivalence phase, patients received their initial formulation (capsule or tablet) for 3 weeks before being switched to the alternative formulation in the second period. Patients could continue to receive dovitinib capsules on the same dosing schedule during the post-bioequivalence phase.

RESULTS

A total of 173 patients were enrolled into the bioequivalence phase of the study (capsule → tablet, n = 88; tablet → capsule, n = 85), and 69 patients had evaluable pharmacokinetics (PK) for both periods. PK analyses showed similar exposure and PK profiles for the dovitinib capsule and tablet formulations and supported bioequivalence [geometric mean ratios: AUC_last, 0.95 (90 % CI 0.88-1.01); C _max, 0.98 (90 % CI 0.91-1.05)]. The most common adverse events, suspected to be study drug related, included diarrhea (60 %), nausea (53 %), fatigue (45 %), and vomiting (43 %). Of 168 patients evaluable for response, 1 achieved a partial response, and stable disease was observed in 32 % of patients.

CONCLUSIONS

Dovitinib capsules and tablets were bioequivalent, with a safety profile similar to that observed in other dovitinib studies of patients with heavily pretreated advanced solid tumors.

Tyrosine kinase inhibitor TKI-258 inhibits cell motility in oral squamous cell carcinoma in vitro

BACKGROUND

Oral squamous cell carcinoma is extremely invasive, and this behavior is regulated by binding of extracellular molecules to the cell membrane receptors. The TKI-258 inhibits phosphorylation of FGFRs VEGFRs and PDGFRs. Our aim was to analyze the effect of TKI-258 treatment in cell movement using SCC-4 cell line from human oral squamous cell carcinoma.

METHODS

F-actin was stained with rhodamine phalloidin, and confocal analysis was performed. The migration and invasion (membrane covered with Matrigel^™ ) three-dimensional assays were performed, and control and cells treated with TKI-258 that migrated through the membrane were counted after 24 h.

RESULTS

Control cells presented abundant cytoplasm with F-actin wide distributed and evident cell cortex; however, treated (1, 5 and 10 μM TKI-258) cells showed round morphology, scanty cytoplasm, F-actin disorganized and preserved cell cortex. TKI-258 (1, 5, and 10 μM) treatment inhibits migrating cells (ANOVA, F = 97.749, d.f. = 3, 10; P < 0.0001), and it was concentration dependent. Invading cell treated with 5 μM TKI-258 was significantly lower (t = 6.708, d.f. = 5, P < 0.001).

CONCLUSIONS

These results suggest that the tyrosine kinase inhibitor TKI-258 has an inhibitory effect on cell motility, affecting F-actin, cell migration, and cell invasion, and probably, these processes are regulated by signaling pathways FGFRs and/or PDGFRs and/or VEGFRs.

Pharmacokinetic Aspects of Vascular Endothelial Growth Factor Tyrosine Kinase Inhibitors

Scientists have identified the impact of angiogenesis on tumor growth and survival. Among other efficient drugs, several small-molecule tyrosine kinase inhibitors (TKIs) targeting the vascular endothelial growth factor receptor (VEGFR) have been developed and have already been integrated into the treatment of various advanced malignancies. This review provides a compilation of current knowledge on the pharmacokinetic aspects of all VEGFR-TKIs already approved by the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) and of those still under investigation. Additional information on substance metabolism, potential for drug-drug interactions (DDIs), and the need for dose adaptation in patients with predominant renal and/or hepatic impairment has been included. All TKIs introduced in this review were administered orally, allowing for easy drug handling for healthcare professionals and patients. For almost all substances, the maximum plasma concentrations were reached within a short period of time. The majority of the substances showed a high plasma protein binding and their excretion occurred via the feces and, to a lesser extent, via the urine. In most cases, dose adaptation in patients with mild to moderate renal or hepatic impairment is not recommended. Cytochrome P450 (CYP) 3A4 was found to play a crucial role in the drug metabolic processes of many compounds. In order to prevent unwanted DDIs, co-administration of VEGFR TKIs together with CYP3A4 inhibitors or inducers should be avoided. Throughout all TKIs, the data indicate high inter-individual variability. The causes of this are still unclear and require further research to allow for individualization of treatment regimens.

Lenvatinib therapy for the treatment of patients with advanced renal cell carcinoma

Despite advances in metastatic renal cell carcinoma (mRCC) treatments, patients eventually progress and develop resistance to therapies targeting a single pathway. Lenvatinib inhibits VEGFR1–3, FGFR1–4, PDGFRβ, RET and KIT proto-oncogenes. In a randomized, Phase II trial evaluating patients with mRCC who had progressed after one prior VEGF-targeted therapy, progression-free survival was significantly improved with lenvatinib alone or in combination with everolimus versus everolimus alone. This review summarizes the clinical development of lenvatinib in mRCC, and how simultaneous targeting of multiple pathways involved in carcinogenesis and/or therapeutic resistance may improve patient outcomes. Lenvatinib plus everolimus may be a promising second-line treatment in patients with mRCC.

Integrated tumor and germline whole-exome sequencing identifies mutations in MAPK and PI3K pathway genes in an adolescent with rosette-forming glioneuronal tumor of the fourth ventricle

The integration of genome-scale studies such as whole-exome sequencing (WES) into the clinical care of children with cancer has the potential to provide insight into the genetic basis of an individual's cancer with implications for clinical management. This report describes the results of clinical tumor and germline WES for a patient with a rare tumor diagnosis, rosette-forming glioneuronal tumor of the fourth ventricle (RGNT). Three pathogenic gene alterations with implications for clinical care were identified: somatic activating hotspot mutations in FGFR1 (p.N546K) and PIK3CA (p.H1047R) and a germline pathogenic variant in PTPN11 (p.N308S) diagnostic for Noonan syndrome. The molecular landscape of RGNT is not well-described, but these data are consistent with prior observations regarding the importance of the interconnected MAPK and PI3K/AKT/mTOR signaling pathways in this rare tumor. The co-occurrence of FGFR1, PIK3CA, and PTPN11 alterations provides further evidence for consideration of RGNT as a distinct molecular entity from pediatric low-grade gliomas and suggests potential therapeutic strategies for this patient in the event of tumor recurrence as novel agents targeting these pathways enter pediatric clinical trials. Although RGNT has not been definitively linked with cancer predisposition syndromes, two prior cases have been reported in patients with RASopathies (Noonan syndrome and neurofibromatosis type 1 [NF1]), providing an additional link between these tumors and the mitogen-activated protein kinase (MAPK) signaling pathway. In summary, this case provides an example of the potential for genome-scale sequencing technologies to provide insight into the biology of rare tumors and yield both tumor and germline results of potential relevance to patient care.

Randomized, open-label phase 2 study comparing frontline dovitinib versus sorafenib in patients with advanced hepatocellular carcinoma

Angiogenesis inhibition by the vascular endothelial growth factor receptor (VEGFR) and platelet-derived growth factor receptor (PDGFR) inhibitor sorafenib provides survival benefit in hepatocellular carcinoma (HCC); however, angiogenic escape from sorafenib may occur due to angiogenesis-associated fibroblast growth factor receptor (FGFR) pathway activation. In addition to VEGFR and PDGFR, dovitinib inhibits FGFR. Frontline oral dovitinib (500 mg/day, 5 days on, 2 days off; n = 82) versus sorafenib (400 mg twice daily; n = 83) was evaluated in an open-label, randomized phase 2 study of Asian-Pacific patients with advanced HCC. The primary and key secondary endpoints were overall survival (OS) and time to tumor progression (TTP) as determined by a local investigator, respectively. Patients included in the study were ineligible for surgical and/or locoregional therapies or had disease progression after receiving these therapies. The median OS (95% confidence interval [CI]) was 8.0 (6.6-9.1) months for dovitinib and 8.4 (5.4-11.3) months for sorafenib. The median TTP (95% CI) per investigator assessment was 4.1 (2.8-4.2) months and 4.1 (2.8-4.3) months for dovitinib and sorafenib, respectively. Common any-cause adverse events included diarrhea (62%), decreased appetite (43%), nausea (41%), vomiting (41%), fatigue (35%), rash (34%), and pyrexia (30%) for dovitinib and palmar-plantar erythrodysesthesia syndrome (66%) and decreased appetite (31%) for sorafenib. Subgroup analysis revealed a significantly higher median OS for patients in the dovitinib arm who had baseline plasma soluble VEGFR1 (sVEGFR1) and hepatocyte growth factor (HGF) below median levels versus at or above the median levels (median OS [95% CI]: sVEGFR1, 11.2 [9.0-13.8] and 5.7 [4.3-7.0] months, respectively [P = .0002]; HGF, 11.2 [8.9-13.8] and 5.9 [5.0-7.6] months, respectively [P = 0.0002]).

CONCLUSION

Dovitinib was well tolerated, but activity was not greater than sorafenib as a frontline systemic therapy for HCC. Based on these data, no subsequent phase 3 study has been planned. (Hepatology 2016;64:774-784).

Role of Cytochrome P450 2C8 in Drug Metabolism and Interactions

During the last 10-15 years, cytochrome P450 (CYP) 2C8 has emerged as an important drug-metabolizing enzyme. CYP2C8 is highly expressed in human liver and is known to metabolize more than 100 drugs. CYP2C8 substrate drugs include amodiaquine, cerivastatin, dasabuvir, enzalutamide, imatinib, loperamide, montelukast, paclitaxel, pioglitazone, repaglinide, and rosiglitazone, and the number is increasing. Similarly, many drugs have been identified as CYP2C8 inhibitors or inducers. In vivo, already a small dose of gemfibrozil, i.e., 10% of its therapeutic dose, is a strong, irreversible inhibitor of CYP2C8. Interestingly, recent findings indicate that the acyl-β-glucuronides of gemfibrozil and clopidogrel cause metabolism-dependent inactivation of CYP2C8, leading to a strong potential for drug interactions. Also several other glucuronide metabolites interact with CYP2C8 as substrates or inhibitors, suggesting that an interplay between CYP2C8 and glucuronides is common. Lack of fully selective and safe probe substrates, inhibitors, and inducers challenges execution and interpretation of drug-drug interaction studies in humans. Apart from drug-drug interactions, some CYP2C8 genetic variants are associated with altered CYP2C8 activity and exhibit significant interethnic frequency differences. Herein, we review the current knowledge on substrates, inhibitors, inducers, and pharmacogenetics of CYP2C8, as well as its role in clinically relevant drug interactions. In addition, implications for selection of CYP2C8 marker and perpetrator drugs to investigate CYP2C8-mediated drug metabolism and interactions in preclinical and clinical studies are discussed.

A Receptor Tyrosine Kinase Inhibitor, Dovitinib (TKI-258), Enhances BMP-2-Induced Osteoblast Differentiation In Vitro

Dovitinib (TKI258) is a small molecule multi-kinase inhibitor currently in clinical phase I/II/III development for the treatment of various types of cancers. This drug has a safe and effective pharmacokinetic/pharmacodynamic profile. Although dovitinib can bind several kinases at nanomolar concentrations, there are no reports relating to osteoporosis or osteoblast differentiation. Herein, we investigated the effect of dovitinib on human recombinant bone morphogenetic protein (BMP)-2-induced osteoblast differentiation in a cell culture model. Dovitinib enhanced the BMP-2-induced alkaline phosphatase (ALP) induction, which is a representative marker of osteoblast differentiation. Dovitinib also stimulated the translocation of phosphorylated Smad1/5/8 into the nucleus and phosphorylation of mitogen-activated protein kinases, including ERK1/2 and p38. In addition, the mRNA expression of BMP-4, BMP-7, ALP, and OCN increased with dovitinib treatment. Our results suggest that dovitinib has a potent stimulating effect on BMP-2-induced osteoblast differentiation and this existing drug has potential for repositioning in the treatment of bone-related disorders.