Measurement of hepatocyte growth factor in serum and plasma

Phase II study of the c-MET inhibitor tivantinib (ARQ 197) in patients with relapsed or relapsed/refractory multiple myeloma

The hepatocyte growth factor/c-MET pathway has been implicated in the pathobiology of multiple myeloma, and c-MET inhibitors induce myeloma cell apoptosis, suggesting that they could be useful clinically. We conducted a phase II study with the c-MET inhibitor tivantinib in patients with relapsed, or relapsed and refractory myeloma whose disease had progressed after one to four prior therapies. Tivantinib, 360 mg orally per dose, was administered twice daily continuously over a 4-week treatment cycle without a cap on the number of allowed cycles, barring undue toxicities or disease progression. Primary objectives were to determine the overall response rate and the toxicities of tivantinib in this patient population. Sixteen patients were enrolled in a two-stage design. Notable grade 3 and 4 hematological adverse events were limited to neutropenia in five and four patients, respectively. Nonhematological adverse events of grade 3 or higher included hypertension (in four patients); syncope, infection, and pain (two each); and fatigue, cough, and pulmonary embolism (one each). Four of 11 evaluable patients (36%) had stable disease as their best response, while the remainder showed disease progression. Overall, tivantinib as a single agent did not show promise for unselected relapsed/refractory myeloma patients. However, the ability to achieve stable disease does suggest that combination regimens incorporating targeted inhibitors in patients with c-MET pathway activation could be of interest.

High circulating hepatocyte growth factor levels associate with epithelial to mesenchymal transition and poor outcome in small cell lung cancer patients

We have previously shown that Met activation through the hepatocyte growth factor (HGF) increases tumorogenesis, induces epithelial-to-mesenchymal transition (EMT) and chemoresistance in SCLC. We sought to evaluate circulating HGF levels in SCLC patients and assess correlation with outcome and EMT features in the tumor. Serum samples from patients with SCLC were prospectively obtained at diagnosis, response evaluation and progression. HGF serum (sHGF) was quantified by ELISA. EMT markers and p-Met/Met were assayed by immunohistochemistry in tumor samples. Clinical data were prospectively recorder. One-hundred twelve patients were included. High baseline levels of sHGF were associated with shorter overall survival (p=0.006) and remained independently associated with survival in the multivariate analysis (p=0.016). For stage IV patients, an increase of sHGF levels at response evaluation (p=0.042) and at progression (p=0.003) were associated with poor outcome. sHGF levels were associated (p<0.05) with a mesenchymal phenotype in the tumor. In conclusion, high sHGF at diagnosis and increases during the course of the disease predict for poor outcome in SCLC patients and associate with EMT in the tumor. These data provide novel evidence on a role of sHGF in the adverse clinical behavior of SCLC and supports testing Met inhibitors in patients with high sHGF.

Nonclinical evaluation of the serum pharmacodynamic biomarkers HGF and shed MET following dosing with the anti-MET monovalent monoclonal antibody onartuzumab

Onartuzumab, a humanized, monovalent monoclonal anti-MET antibody, antagonizes MET signaling by inhibiting binding of its ligand, hepatocyte growth factor (HGF). We investigated the effects of onartuzumab on cell-associated and circulating (shed) MET (sMET) and circulating HGF in vitro and nonclinically to determine their utility as pharmacodynamic biomarkers for onartuzumab. Effects of onartuzumab on cell-associated MET were assessed by flow cytometry and immunofluorescence. sMET and HGF were measured in cell supernatants and in serum or plasma from multiple species (mouse, cynomolgus monkey, and human) using plate-based immunoassays. Unlike bivalent anti-MET antibodies, onartuzumab stably associates with MET on the surface of cells without inducing MET internalization or shedding. Onartuzumab delayed the clearance of human xenograft tumor-produced sMET from the circulation of mice, and endogenous sMET in cynomolgus monkeys. In mice harboring MET-expressing xenograft tumors, in the absence of onartuzumab, levels of human sMET correlated with tumor size, and may be predictive of MET-expressing tumor burden. Because binding of sMET to onartuzumab in circulation resulted in increasing sMET serum concentrations due to reduced clearance, this likely renders sMET unsuitable as a pharmacodynamic biomarker for onartuzumab. There was no observed effect of onartuzumab on circulating HGF levels in xenograft tumor-bearing mice or endogenous HGF in cynomolgus monkeys. Although sMET and HGF may serve as predictive biomarkers for MET therapeutics, these data do not support their use as pharmacodynamic biomarkers for onartuzumab.

HGF as a circulating biomarker of onartuzumab treatment in patients with advanced solid tumors

The objective of this study was to evaluate circulating hepatocyte growth factor (cHGF) as a pharmacodynamic biomarker of Met inhibition for onartuzumab (MetMAb, OA5D5v2) in a phase I trial in patients with advanced cancers and a phase II trial in non-small cell lung cancer (NSCLC). The phase I study was a dose escalation trial with onartuzumab administered i.v. once every three weeks. The phase II study was a randomized two-arm trial in which onartuzumab or placebo was administered in combination with erlotinib in 137 patients with second and third line (2/3L) NSCLC. cHGF levels were evaluated by ELISA at multiple time points over the treatment period. Onartuzumab administration resulted in an acute and sustained rise in cHGF in both the phase I and phase II studies. Elevation in cHGF was independent of dose or drug exposure and was restricted to onartuzumab treatment. Neither higher baseline nor elevated change in cHGF levels upon treatment could simply be attributed to tumor burden or number of liver metastasis. We have shown that elevated cHGF can consistently and reproducibly be measured as a pharmacodynamic biomarker of onartuzumab activity. The elevation in cHGF is independent of tumor type, dose administered, or dose duration. Although these studies were not powered to directly address the contribution of cHGF as a predictive, on-treatment, circulating biomarker, these data suggest that measurement of cHGF in future expanded studies is warranted.

Evaluation of interleukin-6, interleukin-10 and human hepatocyte growth factor as tumor markers for hepatocellular carcinoma

AIM

Serum alpha-fetoprotein (AFP) is the most important tumor marker for hepatocellular carcinoma (HCC). Previous reports indicated that HCC was also associated with increased levels of interleukin (IL)-6, IL-10 and hepatocyte growth factor (HGF). This study investigated the role of these cytokines as tumor markers for HCC.

METHOD

A total of 128 adults were prospectively enrolled and categorized into four groups: normal subjects (n=29), chronic hepatitis B or C (n=50), non-HCC tumors (n=23) and HCC (n=26). Serum AFP, IL-6, IL-10 and HGF levels were determined in all subjects.

RESULTS

The expression of IL-6 or IL-10 (> or =3 pg/ml), or high level of HGF (>1000 pg/ml) or AFP (>20 ng/ml) was observed in only 0-3% of normal subjects. Patients with HCC more frequently had higher IL-6 and IL-10 levels (p<0.05), whereas HGF levels in HCC patients were not significantly elevated compared to patients with chronic hepatitis or non-HCC tumors. Among patients with low (<20 ng/ml) AFP level, IL-6 or IL-10 expression was significantly associated with the existence of HCC (p<0.05). Patients with large (>5 cm) HCC more often had increased IL-6, IL-10 or AFP levels (p values all <0.05).

CONCLUSIONS

Serum levels of IL-6 and IL-10 are frequently elevated in patients with HCC but not in benign liver disease or non-HCC tumors. IL-6 and IL-10 may help identify a subset of HCC patients with low AFP level, and may serve as complementary tumor markers in these patients.

Predicting treatment responses and disease progression in myeloma using serum vascular endothelial growth factor and hepatocyte growth factor levels

Angiogenesis is a crucial process in the progression of multiple myeloma (MM). Vascular endotholial growth factor (VEGF) and hepatocyte growth factor (HGF) are multifunctional cytokines that potently stimulate angiogenesis during tumor neovascularization. VEGF is secreted by MM cells. It induces proliferation of MM cells and stimulates IL-6 expression by microvascular endothelial cells and bone marrow stroma cells, suggesting both autocrine and paracrine functions for VEGF in MM. HGF and the HGF receptor, c-Met, are expressed simultaneously in MM cell lines and in freshly isolated MM cells, suggesting a possible role for HGF in MM cell proliferation. This review focuses on the clinical significance of serum levels of VEGF and HGF in MM.

Predicting treatment responses and disease progression in myeloma using serum vascular endothelial growth factor and hepatocyte growth factor levels

Angiogenesis is a crucial process in the progression of multiple myeloma (MM). Vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) are multifunctional cytokines that potently stimulate angiogenesis during tumor neovascularization. VEGF is secreted by MM cells. It induces proliferation of MM cells and stimulates IL-6 expression by microvascular endothelial cells and bone marrow stroma cells, suggesting both autocrine and paracrine functions for VEGF in MM. HGF and the HGF receptor, c-Met, are expressed simultaneously in MM cell lines and in freshly isolated MM cells, suggesting a possible role for HGF in MM cell proliferation. This review focuses on the clinical significance of serum levels of VEGF and HGF in MM.

High serum hepatocyte growth factor level in patients with non-Hodgkin's lymphoma

Higher pretreatment serum hepatocyte growth factor (HGF) levels were observed in patients with multiple myeloma and Hodgkin's disease, but not in those with non-Hodgkin's lymphoma (NHL). We examined patients' serum levels at diagnosis using enzyme-linked immunosorbent assay and histological expression of HGF in pathological specimens of lymphoma, in relation to clinical features. The subjects were 77 NHL patients and 40 healthy controls. The serum levels of HGF in NHL patients at diagnosis were significantly higher than those in healthy controls (median 1019 vs. 689 pg/mL, P < 0.001). At diagnosis, patients with more than two sites of extranodal involvement (P = 0.001), higher scores of international prognostic index (P = 0.015), and advanced Ann Arbor stage (P = 0.023) had a higher level of serum HGF. Although the association of pretreatment serum HGF level and survival was not significant, a correlation of serial change of serum HGF levels with treatment response was found in limited cases. Furthermore, HGF expression of lymphoma tissues was shown in 18 of 24 (75%) different NHL subtypes, including most of the diffuse large B cell lymphoma (12 of 15, 80%). In conclusion, our study showed higher pretreatment serum HGF levels in NHL patients, which was related to clinical features; and the serial change of HGF seemed to parallel the treatment response. The pathogenic role of HGF in NHL patients was further highlighted by a modest expression of HGF in most of the diffuse large B cell lymphoma.

Sample handling and stability of hepatocyte growth factor in blood samples

As regards clinical studies performed on hepatocyte growth factor (HGF) during recent years, we have aimed in the present study to investigate the eventual differences in sample handling of this cytokine that might influence the results of serum concentrations. Venous blood from patients with current infectious diseases and controls was used in different sub-studies. Compared with samples separated within one hour, no significant changes in serum HGF levels were observed when whole blood stayed 4, or 24h at 6 degrees C before or 6h in room temperature after separation but HGF levels were significantly higher (P<0.01) when whole blood was kept at room temperature 4 and 24h before separation. Serum HGF was stable up to 20 freeze-thaw cycles. The serum concentrations of HGF were significantly higher than levels in the plasma (19%; P<0.05). A significant increase in serum HGF levels (12%, P<0.05) was observed after shaking the whole blood sample to a visible haemolysis, although the HGF concentration in blood cells was around half of that in serum. HGF tolerated storage at -70 degrees C for at least 4 months. We conclude that standardized methods in sample handling are important in the study of HGF concentrations in blood samples.

Soluble hepatocyte growth factor (sHGF) and vascular endothelial growth factor (sVEGF) in adult acute myeloid leukemia: relationship to disease characteristics

There is little understanding of the factors controlling the mobilization of blast cells from bone marrow to peripheral blood and tissues. The aim of this study was to evaluate the soluble hepatocyte growth factor (sHGF) and vascular endothelial growth factor (sVEGF) levels in newly diagnosed patients with acute myeloid leukemia (AML) and to correlate these levels with the clinico-pathological features. Sixty-three patients with AML and 15 normal controls were included in this study. The levels of sHGF and sVEGF were determined by enzyme linked immunosorbent assay at diagnosis and after remission induction chemotherapy. Our results revealed significantly increased plasma levels of sHGF and sVEGF at diagnosis when compared to both control and remission levels (P=0.000 for both). The sHGF and sVEGF levels differed between AML FAB subtypes (P=0.000). The highest concentrations were found in M5 followed by M4. SHGF and sVEGF were directly correlated with peripheral white cell counts (WBC) (r=0.836, P=0.000, r=0.718; P=0.000, respectively), but inversely correlated with blast cell distribution ratio (BCDR) (r=-0.785, P=0.000, r=-0.664, P=0.000, respectively). Moreover, both sHGF and sVEGF levels were significantly elevated in AML patients with extra-medullary infiltration as compared to those without (P=0.000, 0.006, respectively). The sHGF but not sVEGF levels were significantly elevated in patients who died compared to those who relapsed and to patients in complete remission (P=0.02, 0.08, respectively). Logistic regression analysis revealed that the sHGF level at diagnoses is a powerful predictor of the patient outcome, compared to sVEGF.

IN CONCLUSION

our data support the hypothesis that angiogenic factors play a functional role in blast cell movement from the bone marrow to peripheral tissues. Assessment of sHGF at AML diagnosis is likely to be helpful in predicting patient outcome and selecting optimal therapeutic regimen.

Plasma hepatocyte growth factor is a prognostic factor in patients with acute myeloid leukemia but not in patients with myelodysplastic syndrome

Hepatocyte growth factor (HGF) is a potent angiogenic factor. The aim of our study was to evaluate plasma HGF levels and their prognostic significance in patients with newly diagnosed acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). The sandwich enzyme immunoassay technique was used to quantify HGF in stored samples obtained before treatment from patients with AML (59 patients) and MDS (42 patients) treated at The University of Texas MD Anderson Cancer Center. HGF levels were significantly higher in patients with AML or MDS than in healthy individuals (P < 0.0001). Higher HGF levels in both AML and MDS correlated significantly with white blood cell (P = 0.000001 for both groups) and monocyte counts (P = 0.0004 and 0.003, respectively), and with poor performance status (P = 0.03 and 0.001, respectively). Using Cox proportional hazard model and HGF levels as a continuous variable, plasma levels of HGF correlated with shorter survival of AML (P = 0.001), but not MDS (P = 0.34) patients. No significant correlation was observed between HGF levels and complete remission rate or duration. In the multivariate analysis HGF retained its significance as prognostic factor in AML (P = 0.02), along with age (P = 0.0005).