Françoise Farace

Phase I trial of recombinant adenovirus gene transfer in lung cancer. Longitudinal study of the immune responses to transgene and viral products.

Animal studies indicate that the use of replication-deficient adenovirus for human gene therapy is limited by host antivector immune responses that result in transient recombinant protein expression and blocking of gene transfer when rechallenged. Therefore, we have examined immune responses to an adenoviral vector and to the beta-galactosidase protein in four patients with lung cancer given a single intratumor injection of 10(9) plaque-forming units of recombinant adenovirus. The beta-galactosidase protein was expressed in day-8 tumor biopsies from all patients at variable levels. Recombinant virus DNA was detected by PCR in day-30 and day-60 tumor biopsies from all patients except patient 1. A high level of neutralizing antiadenovirus antibodies was detected in patient 1 before Ad-beta-gal injection whereas it was low (patient 3) or undetectable in the other two patients. All patients developed potent CD4 type 1 helper T cell (Th1) responses to adenoviral particles which increased gradually over time after injection. Antiadenovirus cytotoxic T lymphocyte responses were consistently boosted in the two patients examined (patients 3 and 4). Sustained production of anti-beta-galactosidase IgG was observed in all patients except patient 1. Consistent with anti-beta-gal antibody production, all patients except patient 1 developed intense, dose-dependent Th1 responses to soluble beta-galactosidase which increased over time. Strong beta-galactosidase-specific cytotoxic T lymphocyte responses were detected in patients 2, 3, and 4. Our results clearly show that despite the intensity of antiadenovirus responses, transgene protein expression was sufficient to induce strong and prolonged immunity in three patients. Recombinant adenovirus injected directly into the tumor is a highly efficient vector for immunizing patients against the transgene protein.

Angiogenesis as a target in neuroblastoma

Several research investigations on neuroblastoma (NB) have shown the important dependency of this embryonic tumour on angiogenesis, especially in the advanced and aggressive stages. However, the first pre-clinical data on anti-angiogenic drugs in NB have not been published until recently and clinical trials with anti-angiogenic agents in NB treatment protocols are still missing. Here, we summarise current knowledge on the important role and mechanisms of angiogenesis in NB, and report available pre-clinical results of anti-angiogenic agents used to treat NB. This review clearly shows that angiogenesis is a target in NB and that clinical trials are urgently needed to bring forward promising anti-angiogenesis treatment strategies into NB therapy.

Efficacy, Safety, and Biomarkers of Single-Agent Bevacizumab Therapy in Patients with Advanced Hepatocellular Carcinoma

OBJECTIVE Hepatocellular carcinoma (HCC) is a highly vascularized tumor in which neoangiogenesis contributes to growth and metastasis. We assessed the safety, efficacy, and potential biomarkers of activity of bevacizumab in patients with advanced HCC. METHODS In this phase II trial, eligible patients received bevacizumab, 5 mg/kg or 10 mg/kg every 2 weeks. The disease-control rate at 16 weeks (16W-DCR) was the primary endpoint. Circulating endothelial cells (CECs) and plasma cytokines and angiogenic factors (CAFs) were measured at baseline and throughout treatment. RESULTS The 16W-DCR was 42% (95% confidence interval, 27%-57%). Six of the 43 patients who received bevacizumab achieved a partial response (objective response rate [ORR], 14%). Grade 3-4 asthenia, hemorrhage, and aminotransferase elevation occurred in five (12%), three (7%), and three (7%) patients, respectively. During treatment, placental growth factor markedly increased, whereas vascular endothelial growth factor (VEGF)-A dramatically decreased (p < .0001); soluble VEGF receptor-2 (p < .0001) and CECs (p = .03) transiently increased on day 3. High and increased CEC counts at day 15 were associated with the ORR (p = .04) and the 16W-DCR (p = .02), respectively. Lower interleukin (IL)-8 levels at baseline (p = .01) and throughout treatment (p ≤ .04) were associated with the 16W-DCR. High baseline IL-8 and IL-6 levels predicted shorter progression-free and overall survival times (p ≤ .04). CONCLUSION Bevacizumab is active and well tolerated in patients with advanced HCC. The clinical value of CECs, IL-6, and IL-8 warrants further investigation.

The selective VEGFR1‐3 inhibitor axitinib (AG‐013736) shows antitumor activity in human neuroblastoma xenografts

Tumor angiogenesis in childhood neuroblastoma is an important prognostic factor suggesting a potential role for antiangiogenic agents in the treatment of high‐risk disease. Within the KidsCancerKinome project, we evaluated the new oral selective pan‐VEGFR tyrosine kinase inhibitor axitinib (AG‐013736) against neuroblastoma cell lines and the subcutaneous and orthotopic xenograft model IGR‐N91 derived from a primary bone marrow metastasis. Axitinib reduced cell proliferation in a dose‐dependent manner with IC50 doses between 274 and >10,000 nmol/l. Oral treatment with 30 mg/kg BID for 2 weeks in advanced tumors yielded significant tumor growth delay, with a median time to reach five times initial tumor volume of 11.4 days compared to controls (p = 0.0006) and resulted in significant reduction in bioluminescence. Simultaneous inhibition of VEGFR downstream effector mTOR using rapamycin 20 mg/kg q2d×5 did not statistically enhance tumor growth delay compared to single agent activities. Axitinib downregulated VEGFR‐2 phosphorylation resulting in significantly decreased microvessel density (MVD) and overall surface fraction of tumor vessels (OSFV) in all xenografts as measured by CD34 immunohistochemical staining (mean MVD ± SD and OSFV at 14 days 21.27 ± 10.03 in treated tumors vs. 48.79 ± 17.27 in controls and 0.56% vs. 1.29%; p = 0.0006, respectively). We further explored the effects of axitinib on circulating mature endothelial cells (CECs) and endothelial progenitor cells (CEPs) measured by flow cytometry. While only transient modification was observed for CECs, CEP counts were significantly reduced during and up to 14 days after end of treatment. Axitinib has potent antiangiogenic properties that may warrant further evaluation in neuroblastoma.

Phase I Safety, Pharmacokinetic and Pharmacodynamic Evaluation of the Vascular Disrupting Agent Ombrabulin (AVE8062) in Patients with Advanced Solid Tumors

Purpose: The vascular disrupting agent ombrabulin rapidly reduces tumor blood flow and causes necrosis in vivo. A phase I dose-escalation study was designed to determine the recommended phase II dose (RP2D) of single-agent ombrabulin administered once every three weeks in patients with advanced solid malignancies. Experimental Design: Ombrabulin (30-minute infusion) was escalated from 6 to 60 mg/m2, with RP2D cohort expansion. Safety, tumor response, pharmacokinetics, and pharmacodynamic biomarkers were evaluated. Results: Eleven dose levels were evaluated in 105 patients. Two patients had dose-limiting toxicities in cycle 1 during escalation: grade 3 abdominal pain at 50 mg/m2, grade 3 tumor pain/grade 3 hypertension at 60 mg/m2, and the RP2D was 50 mg/m2 (39 patients). Common toxicities were headache, asthenia, abdominal pain, nausea, diarrhea, transient hypertension, anemia, and lymphopenia. No clinically significant QTc prolongations or left ventricular ejection fraction (LVEF) decreases occurred. Ombrabulin was rapidly converted to its active metabolite RPR258063 (half-life 17 minutes and 8.7 hours, respectively), both having dose-proportional exposure. Weak inhibition of CYP2C19-mediated metabolism occurred at the clinical doses used and there was no effect on CYP1A2 and CYP3A4. A patient with rectal cancer had a partial response and eight patients had stable disease lasting four months or more. Circulating endothelial cells (CEC), VEGF, and matrix metalloproteinase (MMP)-9 levels increased significantly six to 10 hours postinfusion in a subset of patients. Conclusions: The recommended schedule for single-agent ombrabulin is 50 mg/m2 every 3 weeks. CECs, VEGF, and MMP-9 are potential biomarkers of ombrabulin activity. Clin Cancer Res; 19(17); 4832–42. ©2013 AACR.

Combination of interleukin-2 and gamma interferon in metastatic renal cell carcinoma

The use of high-dose interleukin-2 (IL2), alone or in association with lymphokine activated killer cells in patients with metastatic renal cell carcinoma (MRCC) results in a 20-25% response rate. However, the toxicity of IL2 is substantial and despite many clinical trials, response rates initially reported have not been improved. The aim of this study was to evaluate a combination of IL2 and gamma interferon (IFN) in MRCC with respect to both efficacy and tolerance. IL2 was given by continuous intravenous infusion at a daily dose of 24 x 10(6) U/m2 for 2 consecutive days during 5 consecutive weeks. Gamma IFN was given subcutaneously at a daily dose of 5 x 10(6) U/m2 on the same days as IL2. 33 patients with MRCC entered the study. Clinical responses were comparable with other published series: 7 patients (21%) achieved partial response, 13 (39%) were stable and 13 had progression, despite therapy. Immunological profile observed with this regimen showed a major increase in natural killer cells which became the predominant lymphocyte population at the end of the therapy. Tolerance was good with 92.5% of the planned doses actually received by the patients. This was reflected by an early discharge from the hospital in 95% of the cycles, increasing acceptability of the regimen by the patients.

T-cell receptor CDR3 size distribution analysis to evaluate specific T-cell response to cancer vaccines.

To evaluate immunization procedures in cancer patients, it is important to define which biological parameters reflecting a specific immune response to the vaccine should be followed. One of these may be the recruitment or expansion of clonally amplified T‐cell subpopulations previously primed by tumor‐specific antigen that could be detected in tiny samples by CDR3 length analysis of T‐cell receptor Vβ transcripts. To evaluate this procedure, we studied one patient with metastatic colorectal adenocarcinoma who had received 4 intradermal injections of irradiated autologous tumor cells plus IL‐2 on days 1, 8, 15 and 36. Skin tests for delayed type hypersensitivity (DTH) reaction to irradiated autologous tumor cells were performed on days 1 and 43. Although no change was observed in day 43 PBMCs, some recurrent transcripts were detected with similar CDR3 size patterns in both vaccine and DTH sites. Fine analysis of these Vβ‐Cβ PCR products with Jβ primers confirmed that transcripts with similar length were recruited in both vaccine and DTH sites. Induction of an inflammatory response in both DTH and vaccine sites may therefore be associated with the recruitment of few T‐cell clonotypes. In addition, a Vβ15‐Jβ2.5 transcript similar to those detected in vaccine and DTH sites was also identified in enzymatically dissociated tumor cells and in a tumor fragment. Sequencing confirmed that an identical junctional sequence was shared by Vβ15‐Jβ2.5 transcripts from both DTH and tumor samples. Our results indicate that a T‐cell clone similar to the one amplified in the tumor was recruited at the vaccine and DTH reaction sites. We therefore suggest that such an approach would be useful in assessing specific expansion of T‐cell clones induced by cancer vaccines. Int. J. Cancer 71: 972‐977, 1997.

Evaluation of hematopoietic potential generated by transplantation of muscle-derived stem cells in mice.

Muscle tissue of adult mice has been shown to contain stem cells with hematopoietic repopulation ability in vivo. To determine the functional characteristics of stem cells giving rise to this hematopoietic activity, we have performed hematopoietic reconstitution experiments by the use of muscle versus marrow transplantation in lethally irradiated mice and followed the fate of transplanted cells by Y-chimerism using PCR and fluorescence in situ hybridization (FISH) analysis. We report here that transplantation of murine muscle generate a major hematopoietic chimerism at the level of CFU-C, CFU-S, and terminally-differentiated cells in three generations of lethally irradiated mice followed up to 1 year after transplantation. This potential is totally abolished when muscle grafts were performed by the use of muscle from previously irradiated mice. As compared to marrow transplantation, muscle transplants were able to generate similar potencies to give rise to myeloid, T, B, and natural killer (NK) cells. Interestingly, marrow stem cells that have been generated in primary and then in secondary recipients were able to contribute efficiently to myofibers in the muscle tissue of tertiary recipients. Altogether, our data demonstrate that muscle-derived stem cells present a major hematopoietic repopulating ability with evidence of self-replication in vivo. They are radiation-sensitive and similar to marrow-derived stem cells in terms of their ability to generate multilineage hematopoiesis. Finally, our data demonstrate that muscle-derived hematopoietic stem cells do not lose their ability to contribute to myofiber generation after at least two rounds of serial transplantation, suggesting a potential that is probably equivalent to that generated by marrow transplantation.

Studies on NK cell purification by negative selection in human peripheral blood

We have attempted to improve negative selection procedures for the large scale purification of human CDin3− CD56+ NK cells. In a series of experiments, purifications of NK cells from 108 PBMC were performed by T cell depletion using either direct or indirect anti-CD3 labeling and the Magnetic Activated Cell Separation (MACS) procedure. Contaminating CD3+ cells were still present using either one of these two different T cell depletion protocols as shown by phenotyping IL-2 supplemented cell cultures on day 12. A second cycle of purification was therefore added. When MACS and Dynabeads were compared as complementary procedures to the first MACS cycle starting with 108 cells, the Dynabeads method was found to be superior to the MACS with regard to the elimination of residual T cells. Starting from 109 PBMC, we showed that this MACS+Dynabeads procedure gave similar satisfactory results when compared to the scaling-up of a previously established two steps procedure using Dynabeads. These two approaches (MACS+Dynabeads and 2 cycles of Dynabeads) have been also tested in a clinical setting to purify NK cells from cancer patients prior toin vitro expansion. The results indicate that the two methods are equivalent with respect to purity and recovery rate; a slight advantage in terms of feasibility was found in favor of 2 cycles of Dynabeads.

Neuroblastome : intérêt des traitements anti-angiogéniques

Focus on new drug development over the last few years has yielded new agents that differ from unspecific classical chemotherapeutics and ionizing radiation, while still targeting the cancer cell itself. Antiangiogenesis is a totally distinct approach targeting the tumors blood vessels. This concept has now found its eligibility for the treatment of several adult solid tumors: the human antivascular endothelial growth factor (VEGF) antibody bevacizumab, as well as the VEGF receptor tyrosine kinase inhibitors, sunitinib and sorafinib, have recently been licensed by the US Food and Drug Administration (FDA) and the European Medicines Agency (EMEA) for the treatment of colorectal, renal, and lung cancer. Other antiangiogenic drugs are under preclinical and early clinical evaluation. However, what do we know of the use of these drugs in pediatric solid tumors, such as sarcomas and embryonal and neuronal tumors? For some time now, neuroblastoma has been shown to be dependent on angiogenesis. However, the first preclinical data on antiangiogenic drugs in neuroblastoma have not been published until recently, and clinical trials with antiangiogenic agents in neuroblastoma treatment protocols are scarce. This review adresses current knowledge on the important role and mechanisms of angiogenesis in neuroblastoma and summarizes available preclinical and clinical results of antiangiogenic agents used to treat neuroblastoma. Our review clearly demonstrates that clinical trials are urgently needed to bring forward promising antiangiogenesis concepts in neuroblastoma therapy.