A phase I trial of the monoclonal antibody FG-3019 to connective tissue growth factor (CTGF) in locally advanced or metastatic pancreatic cancer

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Background: CTGF is highly expressed in pancreatic tumors and is thought to mediate local desmoplasia. FG-3019 is a fully human monoclonal antibody against CTGF. Studies using FG-3019 in murine xenograft models have shown reduced tumor growth and metastasis.

Methods: This open-label, dose escalation study assessed the safety and pharmacokinetics of FG-3019 (3, 10, 15, and 25 mg/kg q14D). FG-3019 was initiated on D1 to assess single-agent toxicity. Standard gemcitabine and erlotinib were added on D15. Chemotherapy-naive patients with locally advanced or metastatic adenocarcinoma were eligible. Seventeen subjects (median age 66 yrs) were enrolled: n=4, 3, and 10 at 3, 10, and 15 mg/kg respectively. Enrollment is ongoing in the 25 mg/kg cohort. Seven subjects were female; four were stage 3, and 13 were stage 4.

Results: No safety signals were detected with single-agent FG-3019. After beginning chemotherapy, four subjects experienced seven SAEs, which were deemed unrelated to FG-3019 including three deaths: sepsis, suicide, and disease progression. Nine subjects experienced grade 3 AEs, all of which were expected in patients with pancreatic cancer. There were no grade 4 hematologic abnormalities. AEs related to gemcitabine (hematologic, abnormal LFTs) and erlotinib (rash) occurred at a rate and severity consistent with the prescribing information (preliminary data). Steady-state Cmax (median 428, range 236-455 μg/mL), and T1/2 (median 6.6, range 6.3-6.7 days) at the 10 mg/kg dose level were comparable to PK data from subjects in non-oncological trials who received FG-3019 at the same dose level. One subject had a partial response by RECIST criteria for 9.7+ months. Another subject had a minor response for 7.7 months. Three of five subjects with PET scans at baseline and D15 experienced stable to reduced PET activity before starting chemotherapy. The median TTP across all cohorts was 3.7 months (95% CI 1.9-6.2), and the median OS was 9.4 months (95% CI 1.9-10.6).

Conclusions: FG-3019 is well tolerated and dose escalation continues. Reduced PET activity after treatment with single-agent FG-3019 may indicate a biological effect of the agent.

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Phase III trial of 5-fluorouracil and leucovorin plus either 3H1 anti-idiotype monoclonal antibody or placebo in patients with advanced colorectal cancer

BACKGROUND

The monoclonal antibody 3H1 mimics the external structure of the carcinoembryonic antigen (CEA). It therefore has the potential, via the anti-idiotypic network, to stimulate immune responses to CEA that may benefit colorectal cancer patients.

PATIENTS AND METHODS

A total of 630 patients with previously untreated metastatic colorectal cancer were randomised in a 2:1 fashion to receive bolus 5-fluorouracil (5-FU) and leucovorin (LV) plus either 3H1 (n = 422) or placebo (n = 208).

RESULTS

The addition of 3H1 to 5-FU and LV did not result in increased toxicity. Survival for the full intent-to-treat population was 14.7 months for the 3H1 arm and 15.2 months for the placebo arm (P = 0.80). Anti-CEA antibody responses were observed in 70% of patients treated with 3H1. Patients with a negative CEA response had a median survival of 8.3 months (95% CI 7.5-11.0) compared with patients with a strong response: median survival not reached (P <0.001).

CONCLUSION

3H1 is safe and effectively induces immune responses to CEA. Addition of 3H1 to 5-FU and LV was not shown to improve overall patient outcomes. However, improved survival in patients developing anti-CEA responses to 3H1 are provocative and should be studied in further clinical trials.

Rapid engraftment after allogeneic transplantation of density-enriched peripheral blood CD34+ cells in patients with advanced hematologic malignancies

BACKGROUND

Acute graft versus host disease (GVHD) remains a major cause of morbidity and mortality after allogeneic hematopoietic cell transplantation. Preclinical studies have suggested that a T-cell subset with a CD4-/CD8- double-negative (DN) T-cell phenotype is capable of suppressing GVHD. Double-negative T cells can be mobilized into the peripheral blood with granulocyte colony-stimulating factor (G-CSF) and enriched by density centrifugation. The current study was performed to study the feasibility and safety of applying a density gradient separation technique for enrichment of CD34+ and DN T cells, while depleting CD4+ and CD8+ single-positive (SP) T cells from peripheral blood progenitor cells (PBPCs) for the purpose of allogeneic transplantation.

METHODS

Twenty-five patients with advanced hematologic malignancies were treated with a myeloablative preparative regimen consisting of fractionated total body irradiation, etoposide, and cyclophosphamide. Human leukocyte antigen identical donors were mobilized with G-CSF PBPC collected by apheresis. The apheresis product was applied to a single-step density gradient, and the low-density cell population was collected. The low-density cell population was infused as the sole source of allogeneic cells after myeloablative therapy. Graft versus host disease prophylaxis consisted of cyclosporine with or without prednisone.

RESULTS

CD34 cell recovery was efficient with a median 72% yield, providing for a median CD34+ cell dose of 6.5 x 10(6)/kg (range,1.0- 13.9 x 10(6)/kg). CD3+CD4+ or CD3+CD8+ SP T cells were depleted by a median of 94.4% (range, 58.8- 99.2%), and the ratio of CD34+:SP T cells increased 10-fold. Double-negative T cells were depleted by 92% (range, 18.8- 99.4%), thus the ratio of DN:SP T cells increased less than 2-fold in 71% of apheresis samples tested. Hematopoietic engraftment was rapid, and there was no occurrence of graft failure in examinable patients. Median time to absolute neutrophil count greater than 0.5 x 10(9)/L and platelet count greater than 20 x 10(9)/L was 10.5 and 12 days, respectively. The incidence of Grade 2-4 acute GVHD was 26% (95% confidence interval [CI], 6-45%), although not all patients were examinable due to an unexpectedly high nonrecurrence mortality that at Day 180 was 62% (95% CI, 40-83%).

CONCLUSIONS

These data suggest that T-cell subset manipulation via density gradient separation is a safe procedure and allowed rapid hematopoietic recovery. Selective enrichment of a donor DN T-cell subset was observed in only a few and was not associated with a reduced incidence of GVHD. However, the low-density selected cells still resulted in GVHD, and there was a high treatment-related mortality.

Rapid debulking and CD34 enrichment of filgrastim-mobilized peripheral blood stem cells by semiautomated density gradient centrifugation in a closed system

Filgrastim-mobilized peripheral blood progenitor cells (PBPC) are used for hematopoietic reconstitution after myeloablative therapy for malignancies, but the large number of cells collected in a single apheresis frequently presents a problem for storage or further processing. We have evaluated the use of CD34 Buoyant Density Solution-PBPC, an ultralight-density colloidal silica suspension, for debulking and enrichment of CD34+ cells in PBPC preparations in a semiautomated system. Cells were collected from four filgrastim-treated normal donors using the COBE Spectra. The separation procedure was carried out with Plasma-Lyte A and DNase 5 U/ml using the COBE 2991. Following processing and washing, there was a 26% recovery of nucleated cells, 2.6-fold enrichment of CD34+ cells, 68% recovery of CD34+ cells, 88% recovery of CFU-GM, 73% recovery of BFU-E, 1 log depletion of CD3+ cells, 0.5 log depletion of CD56+ cells, and 1 log depletion of CD19+ cells. These results were not significantly different from those obtained when PBPC were separated over CD34 Buoyant Density Solution-PBPC by centrifugation in tubes. Using CD34 Buoyant Density Solution-PBPC, mononuclear preparations of PBPC can be enriched rapidly for CD34+ cells and depleted of lymphocytes in a semiautomated closed system using reagents produced according to good manufacturing practice (GMP).

Hepatic cancers and their response to chemoembolization therapy. Quantitative image-guided 31P magnetic resonance spectroscopy

RATIONALE AND OBJECTIVES

Hepatic embolization combined with intra-arterial administration of cytostatic drugs (chemoembolization) is frequently used to treat primary and metastatic cancers to the liver. Quantitative phosphorus-31 magnetic resonance spectroscopy (31P MRS) was used to assess the metabolic state of hepatic cancers and their metabolic response to chemoembolization.

METHODS

Fifteen localized 31P MRS studies were performed on five patients with liver tumors. Thirteen healthy volunteers served as controls. Metabolite ratios and molar metabolite concentrations were calculated.

RESULTS

Untreated hepatic tumors, relative to normal controls, showed elevated phosphomonoester/adenosine triphosphate (PME/ATP) ratios, reduced concentrations of ATP and inorganic phosphate (Pi), and normal phosphodiester (PDE) concentrations. As an acute response to chemoembolization, ATP, PME, and/or PDE concentrations diminished, whereas Pi concentrations increased or stayed relatively constant. Long-term follow-up after chemoembolization showed decreased PME/ATP and increased ATP concentrations in the absence of changes on standard magnetic resonance and computed tomographic images.

CONCLUSIONS

These preliminary spectroscopic data suggest that quantitative 31P MRS can be successfully used to monitor directly metabolic response to hepatic chemoembolization.

P-31 spectroscopy study of response of superficial human tumors to therapy

Studies were performed to characterize phosphorus-31 magnetic resonance (MR) spectra obtained from 10 superficial human tumors outside the brain and to determine whether P-31 MR spectroscopy could allow detection of a response to therapy before a change in tumor size was measured. The ratio of phosphomonoester to adenosine triphosphate peak intensities (PME/ATP) was unusually large in all tumors studied. The average PME/ATP in lymphomas (1.8 +/- 0.5) was greater than in nonlymphoma cancers (1.1 +/- 0.15). The average PME/ATP for all tumors studied (1.4 +/- 0.5) was much greater than that of underlying skeletal muscle (0.23 +/- .09). Eight of the tumors were studied before and after therapy. Responders were distinguished from nonresponders on the basis of changes in tumor size. PME/ATP decreased during therapy in three lymphomas that responded to therapy. In an adenocarcinoma and Ewing sarcoma that did not respond to therapy, PME/ATP increased. PME/ATP remained constant in two squamous cell carcinomas that responded to therapy and decreased in one squamous cell carcinoma that decreased in size by 40% but was classified as a nonresponder. Changes in PME/ATP did not always parallel changes in tumor size during therapy. In two patients, a decrease in PME/ATP preceded a decrease in tumor size. In four patients, PME/ATP increased transiently during periods when tumor size remained constant.

Interaction of platelet-activating factor with interferon-gamma in the stimulation of interleukin-1 production by human monocytes

Platelet-activating factor (PAF) produces both early and late inflammatory responses in vivo. The late and persistent responses to PAF may result from the production of cytokines, such as interleukin-1 (IL-1). The effects of PAF on IL-1 release by human monocytes were studied with PAF alone and in combination with interferon-gamma. These studies involved the use of D10.G4.1 cells in a proliferation assay to determine the actual concentration of active IL-1 in monocyte supernatant and pellet fractions. These studies confirmed that PAF stimulates IL-1 release at two different ranges of PAF concentrations, 100 fM to 1 pM and 100 pM to 1 nM. PAF inhibited IL-1 release at 1 or 10 pM. PAF effects on IL-1 release were specific to the form of PAF that is biologically active in most system; (S)-PAF and lyso-PAF had no effect. When monocytes were incubated with both PAF and interferon-gamma, IL-1 release was greatly stimulated at the same two ranges of PAF concentrations, 100 fM to 1 pM and 100 pM to 1 nM of PAF. PAF and interferon-gamma interacted synergistically to enhance significantly the release of IL-1.

Response of tumors to therapy studied by 31P magnetic resonance spectroscopy

Magnetic resonance (MR) methods have been used to study the metabolic and vascular response of model tumors to tumor necrosis factor (TNF). Magnetic resonance measurements demonstrated acute reductions in tumor blood flow, measured from tumor uptake of D2O, and in tumor adenosine triphosphate (ATP), measured by 31P magnetic resonance spectroscopy (MRS) following administration of TNF. The decrease in ATP generally followed reduction in tumor blood flow, and therefore was probably due to ischemia caused by damage to tumor vasculature. Superficial human tumors have been studied by MRS to characterize their 31P spectra, and to measure metabolic changes during therapy. The ratio of the intensities of the phosphomonoester (PME) and ATP resonances (PME/ATP) was much higher in tumors than in the normal tissue displaced by the tumors. During therapy, decreases in PME/ATP were detected that paralleled, but did not anticipate, decreases in tumor size. In some cases, a transient increase in PME/ATP was detected during therapy, which did not correlate with changes in tumor size, and which may reflect stimulation of cell growth in some tumor zones.

Doxorubicin in pregnancy: possible transplacental passage

Two pregnant women with lymphoproliferative disorders were treated with doxorubicin-containing regimens. Both patients delivered shortly after a dose of doxorubicin. One child was healthy and the other was stillborn. Measurements of anthracycline levels in placental, cord, and fetal tissues by high-performance liquid chromatography suggest that doxorubicin may be transported across the placenta.