[Show abstract][Hide abstract] ABSTRACT: This study was designed to evaluate the safety and feasibility of high-dose interleukin-2 (HD IL-2) followed by sorafenib in patients with metastatic melanoma (MM) and renal cell carcinoma (RCC). Biomarkers relevant to the antitumor effects of IL-2 that may be altered by sorafenib including the percentages of natural T-regulatory cells (Tregs), myeloid-derived suppressor cells (MDSC), and STAT5 phosphorylation (pSTAT5) in T cells were evaluated. We hypothesized that the proposed treatment schedule is feasible and safe and may lead to enhanced tumor response. A phase I dose escalation trial was conducted in patients with either metastatic RCC or MM. HD IL-2 (600,000 IU/kg IV q8h×8-12 doses) was administered on days 1-5 and 15-19, followed by sorafenib on days 29-82. The sorafenib dose was escalated. The percentage of Tregs, MDSC, and pSTAT5 in T cells were evaluated in peripheral blood by flow cytometry. Twelve of the 18 patients were evaluable for dose-limiting toxicity. No dose-limiting toxicity was observed. The treatment-related toxicity was predictable and did not seem to be additive with this schedule of administration. Partial responses were seen in 3 patients. No significant changes in the percentage of circulating Treg and MDSC were observed, whereas sorafenib did not adversely affect the ability of IL-2 to induce pSTAT5 in T cells. HD IL-2 followed by sorafenib was safe and feasible in patients with MM and RCC and did not adversely affect T-cell signaling through STAT5 in response to IL-2.This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivitives 3.0 License, where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially. http://creativecommons.org/licenses/by-nc-nd/3.0.
[Show abstract][Hide abstract] ABSTRACT: Optimal treatment of metastases to the central nervous system (CNS) in patients with malignant melanoma remains a clinical challenge. In particular, for patients with BRAF-mutant melanoma and CNS metastases, much remains unknown about the safety and efficacy of the novel BRAF-targeted agents when administered in close sequence with radiation. We report two cases of rapid development of CNS radiation necrosis in patients with metastatic melanoma treated with the BRAF inhibitor, vemurafenib, closely sequenced with stereotactic radiosurgery or fractionated stereotactic radiation therapy. In the absence of prospective safety data from clinical trials, we advise vigilance in monitoring patients with BRAF-mutant melanoma whose treatment plan includes CNS radiation and vemurafenib and caution when assessing treatment response within the CNS in these patients.
[Show abstract][Hide abstract] ABSTRACT: The possibility that cytokine administration could enhance the antitumor effects of proteasome inhibition was explored. It was found that coadministration of bortezomib and interferon-α (IFN-α) induced synergistic apoptosis in human melanoma cell lines and prolonged survival in a murine model of melanoma. A phase I study was conducted to determine the tolerability and the maximum tolerated dose of bortezomib when administered in combination with IFN-α-2b to patients with metastatic melanoma. Patients were treated on a 5-week cycle. In week 1 of cycle 1, patients received 5 million U/m IFN-α subcutaneously thrice weekly. During weeks 2-4 of cycle 1, bortezomib was administered intravenously weekly along with IFN-α thrice weekly. There was a treatment break during week 5. After cycle 1, bortezomib was administered in combination with IFN-α. Bortezomib was administered in escalating doses (1.0, 1.3, or 1.6 mg/m) to cohorts of 3 patients. Sixteen patients were treated (8 women, 8 men; median age 59 y). Common grade 3 toxicities included fatigue (5), vomiting (3), and diarrhea (3). Grade 4 toxicities included fatigue (3) and lymphopenia (1). The maximum tolerated dose for bortezomib was 1.3 mg/m. One patient had a partial response, and 7 had stable disease. Progression-free survival was 2.5 months, and overall survival was 10.3 months. Bortezomib administration did not augment the ability of IFN-α to induce phosphorylation of STAT1 in circulating immune cells; however, it did lead to reduced plasma levels of proangiogenic cytokines. The combination of bortezomib and IFN-α can be safely administered to melanoma patients.
[Show abstract][Hide abstract] ABSTRACT: XPO1/CRM1 is a key nuclear exporter protein that mediates translocation of numerous cellular regulatory proteins. We investigated whether XPO1 is a potential therapeutic target in melanoma using novel selective inhibitors of nuclear export (SINE). In vitro effects of SINE on cell growth and apoptosis were measured by MTS assay and flow cytometry [Annexin V/propidium iodide (PI)], respectively in human metastatic melanoma cell lines. Immunoblot analysis was used to measure nuclear localization of key cellular proteins. The in vivo activity of oral SINE was evaluated in NOD/SCID mice bearing A375 or CHL-1 human melanoma xenografts. SINE compounds induced cytostatic and pro-apoptotic effects in both BRAF wild type and mutant (V600E) cell lines at nanomolar concentrations. The cytostatic and pro-apoptotic effects of XPO1 inhibition were associated with nuclear accumulation of TP53, and CDKN1A induction in the A375 cell line with wild type TP53, while pMAPK accumulated in the nucleus regardless of TP53 status. The orally bioavailable KPT-276 and KPT-330 compounds significantly inhibited growth of A375 (p<0.0001) and CHL-1 (p = 0.0087) human melanoma cell lines in vivo at well tolerated doses. Inhibition of XPO1 using SINE represents a potential therapeutic approach for melanoma across cells with diverse molecular phenotypes by promoting growth inhibition and apoptosis.
PLoS ONE 01/2014; 9(7):e102983. · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A liquid chromatography-tandem mass spectrometry method for quantification of bendamustine in mouse brain tissue was developed and fully validated. Methanol was used to precipitate proteins in brain tissue. Bendamustine and internal standard (chlorambucil) were separated with reverse-phase chromatography on a C-18 column with a gradient of water and 95% methanol in 0.1% formic acid. Positive mode electrospray ionization was applied with selected reaction monitoring to achieve 5ng/ml lower limits of quantitation in mouse brain tissue. The calibration curve for bendamustine in mouse brain was linear between 5 and 2000ng/ml. The within- and between-batch accuracy and precision of the assay were within 15% at 10, 100 and 1000ng/ml. The recovery and matrix effect of bendamustine in mouse brain tissue ranged from 41.1% to 51.6% and 107.4% to 110.3%, respectively. The validated method was then applied to quantitate bendamustine in an animal study. Results indicate the assay can be applied to evaluate bendamustine disposition in mouse brain tissue. This assay will be applied in the future to detect and quantify bendamustine in human brain tissue samples.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences 08/2012; 905:141-4. · 2.78 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Reovirus, a replication competent RNA virus, has preclinical activity against melanoma lines and xenografts. We conducted a phase II trial of reovirus in metastatic melanoma patients. Patients received 3 × 10(10) TCID50 on days 1-5 of each 28 day cycle, administered intravenously. Twenty-one eligible patients were enrolled. Treatment was well tolerated without any dose reductions having to be implemented. Post-treatment biopsy samples were obtained in 15 patients, 13/15 contained adequate tumor for correlative analysis. In two patients, productive reoviral replication (viral antigen coexpression with tubulin) was demonstrated, despite increase in neutralizing antibody titers. There were no objective responses although 75-90% tumor necrosis, consistent with treatment effect, was observed in one patient who had metastatic lesions surgically removed. Median time to progression and survival were 45 days (range 13-96 days) and 165 days (range 15 days-15.8 months) respectively. In conclusion, reovirus treatment was well tolerated in metastatic melanoma patients; viral replication was demonstrated in biopsy samples. Based on preclinical data showing synergy with taxane and platinum compounds, a phase II combination trial in metastatic melanoma patients is ongoing.
[Show abstract][Hide abstract] ABSTRACT: Brain metastases from radioresistant histologies are perceived to be less responsive to WBRT compared to other histologies, and stereotactic radiosurgery (SRS) may provide better local control. The aim of this study was to examine the outcomes of patients with 1-4 brain metastasis from radioresistant histologies (renal cell carcinoma and melanoma) treated with SRS alone. Thirty-eight patients with 1-4 radioresistant brain metastases (66 lesions) were treated with SRS alone. The median age was 55 years. Fourteen and 24 patients had renal cell carcinoma (RCC) and melanoma brain metastases, respectively. Distribution of number of lesions was as follows: one lesion, 22 patients; 2 lesions, 8 patients; 3 lesions, 5 patients; and 4 lesions, 3 patients. Distribution of RTOG recursive partitioning analysis (RPA) classes was as follows: II, 37 patients and III, 1 patient. The median marginal dose was 20 Gy. The median follow-up was 6.1 months. The 3-, 6-, 9-, 12-, and 18-month local control (LC) rates were 87.9, 81.4, 67.9, 67.9, and 60.3%, respectively. The corresponding free-from-distant-brain failure (FFDBF) rates were 71.3, 58.1, 49.8, 40.2, and 27.6%. The corresponding progression-free survival (PFS) rates were 55.3, 41.9, 33, 23.3, and 13.3%. RCC histology was associated with better LC (P = 0.0055). Although SRS alone could yield reasonable LC in patients with 1-4 radioresistant brain metastases, the risk of distant brain failure was substantial. The approach of routine omission of WBRT outside of a trial setting should be used judiciously.
Medical Oncology 12/2011; 28 Suppl 1:S439-44. · 2.14 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: High-dose interleukin-2 (IL-2) therapy may cause acute myocarditis characterised by diffuse myocardial involvement and occasionally fulminant heart failure. Cardiac MRI (CMRI) provides a comprehensive assessment of myocardial function, inflammation and injury in a single examination and has shown value in the diagnosis of myocarditis. We report a case of a 54-year-old male with metastatic melanoma who developed acute severe myocarditis with fulminant heart failure after high-dose IL-2 therapy. CMRI using a combination of T(2) weighted imaging and T(1) weighted late post-gadolinium enhancement techniques played a key role in establishing the diagnosis. To our knowledge we present the first case report of the combined use of T(1) and T(2) weighted CMRI techniques to diagnose IL-2 induced myocarditis.
The British journal of radiology 05/2011; 84(1001):e99-e102. · 2.11 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Bevacizumab is a humanized recombinant monoclonal antibody that neutralizes vascular endothelial growth factor, an agent with proangiogenic effects in melanoma. Interferon alpha (IFN-α) has antiangiogenic properties through its ability to downregulate basic-fibroblast growth factor levels. We hypothesized that the coadministration of these agents would lead to tumor regression. Patients with metastatic melanoma received bevacizumab 15 mg/kg intravenously on day 1 of the 2-week cycle. IFN-α was administered thrice weekly at 5 MU/m subcutaneously during cycle 1 and was increased to 10 MU/m during cycle 2. Patients were restaged every 6 cycles. Patients with stable disease or a response continued with therapy. Baseline serum vascular endothelial growth factor and fibroblast growth factor were measured. Twenty-five patients were accrued. Mean age was 58.4 years. Eleven patients required IFN-α dose reductions due to toxicity. Common grade 3 toxicities associated with IFN-α included fatigue and myalgia. Bevacizumab administration was associated with grade 2-3 proteinuria in 6 patients. Grade 4 adverse events were pulmonary embolus (1), myocardial infarction (1), and stroke (1). Six patients had a partial response, and 5 patients exhibited stable disease that lasted more than 24 weeks (range: 30 to 122 wk). Median progression-free survival and overall survival were 4.8 and 17 months, respectively. Significantly lower fibroblast growth factor levels were observed in patients with a partial response compared to those with stable or progressive disease (P=0.040). Administration of bevacizumab with IFN led to a clinical response in 24% of patients with stage IV melanoma and stabilization of disease in another 20% of patients. This regimen has activity in advanced melanoma.
[Show abstract][Hide abstract] ABSTRACT: We hypothesized that administration of bevacizumab, a monoclonal antibody that neutralizes vascular endothelial growth factor, in combination with high-dose interferon-alpha2b (IFN-α2b), an inhibitor of basic fibroblast growth factor, would have clinical activity in patients with metastatic ocular melanoma.
Patients with metastatic ocular melanoma received bevacizumab (15 mg/kg intravenously every 2 weeks) plus IFN-α2b (5 MU/m subcutaneously 3 times weekly for 2 weeks followed by a dose of 10 MU/m subcutaneously thereafter). Patients exhibiting a clinical response or stabilization of disease were treated until disease progression.
In this pilot study, 5 patients were treated (3 men, 2 women) with a mean age of 63.8 years (range, 53-71 years). Overall, the regimen was well-tolerated. The following adverse events were noted: grade 3 dyspnea (2 patients), grade 3 and 4 fatigue (2), grade 3 muscle weakness (1), grade 3 anorexia (1), grade 1 and 2 proteinuria (2), and grade 3 diarrhea (1). All adverse events resolved with a treatment holiday or dose reduction. One patient had reduction in tumor burden of 23% by Response Evaluation Criteria in Solid Tumors criteria and 2 patients had stabilization of disease lasting 28 and 36 weeks, respectively. Two patients failed to respond and progressed after 6 and 7 weeks of therapy.
Bevacizumab and IFN-α2b were well tolerated in this patient population, and clinical activity was observed. Further study of high-dose IFN-α2b in combination with bevacizumab in this setting is warranted.
American journal of clinical oncology 05/2010; 34(1):87-91. · 2.21 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To examine the outcomes of patients with a single brain metastasis from radioresistant histologies (renal cell carcinoma and melanoma) treated with stereotactic radiosurgery (SRS) with or without whole brain radiotherapy (WBRT).
We reviewed the medical records of 27 patients treated at our institution between 2000 and 2007 with a single radioresistant brain metastasis. Patients were treated with Gamma Knife based SRS. Tumor histologies included renal cell carcinoma and melanoma.
Patients were treated to a median marginal dose was 20 Gy (range, 15-22 Gy). At follow-up intervals ranging from 1.8 to 23.2 months, the radiographic responses were as follows: progression in 7 patients; stable in 5 patients; and shrinkage in 15 patients. Fifteen patients (56%) developed distant brain failure. Seven of the 27 patients were alive at last follow-up. The 3-, 6-, 9-, 12-, and 18-months after SRS local control rates were 82.8%, 77.9%, 69.3%, 69.3%, and 55.4%, respectively. None of the 5 patients who received WBRT developed distant brain failure although the follow-up intervals were short (range, 3.5-13.7 months; median, 5.1 months). WBRT did not appear to affect local control, progression free survival, and overall survival (P = 0.32, 0.87, 0.69). One patient developed worsening of symptoms attributable to SRS.
Gamma Knife SRS is a safe and feasible strategy for treatment of patients with a single radioresistant brain metastasis. Radiosurgery alone is a reasonable treatment option, but may carry a greater likelihood of distant brain recurrence.
American journal of clinical oncology 08/2009; 33(1):70-4. · 2.21 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The precise molecular targets of IFN-alpha therapy in the context of malignant melanoma are unknown but seem to involve signal transducers and activators of transcription 1 signal transduction within host immune effector cells. We hypothesized that the in vitro transcriptional response of patient peripheral blood mononuclear cells (PBMC) to IFN-alpha would be similar to the in vivo response to treatment with high-dose IFN-alpha.
The gene expression profiles of PBMCs and immune cell subsets treated in vitro with IFN-alpha were evaluated, as were PBMCs obtained from melanoma patients receiving adjuvant IFN-alpha.
Twenty-seven genes were up-regulated in PBMCs from normal donors after treatment with IFN-alpha in vitro for 18 hours (>2-fold, P < 0.001). A subset of these genes (in addition to others) was significantly expressed in IFN-alpha-treated T cells, natural killer cells, and monocytes. Analysis of gene expression within PBMCs from melanoma patients (n = 13) receiving high-dose IFN-alpha-2b (20 MU/m(2) i.v.) revealed significant up-regulation (>2-fold) of 21 genes (P < 0.001). Also, the gene expression profile of in vitro IFN-alpha-stimulated patient PBMCs was similar to that of PBMCs obtained from the same patient after IFN-alpha therapy.
This report is the first to describe the transcriptional response of T cells, natural killer cells, and monocytes to IFN-alpha and characterize the transcriptional profiles of PBMCs from melanoma patients undergoing IFN-alpha immunotherapy. In addition, it was determined that microarray analysis of patient PBMCs after in vitro stimulation with IFN-alpha may be a useful predictor of the in vivo response of immune cells to IFN-alpha immunotherapy.
Clinical Cancer Research 10/2008; 14(18):5900-6. · 7.84 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Interleukin-2 (IL-2) activates extracellular signal-regulated protein kinase (ERK) within immune cells. To examine the profile of phosphorylated ERK (p-ERK) in IL-2 stimulated immune cells of normal donors and patients receiving IL-2 therapy, we developed a dual parameter flow-cytometric assay. An analysis of PBMCs stimulated with IL-2 indicated that IL-2 exposure induced p-ERK in CD56bright NK cells and CD14+ monocytes, but not in CD3+ T cells or CD21+ B cells. CD3+ T cells that were induced to express functional high-affinity IL-2R did not exhibit enhanced p-ERK following IL-2 treatment. Measurement of p-ERK within PBMCs from cancer patients 1 h following their first dose of IL-2 revealed a complete absence of circulating NK cells, consistent with earlier observations. However, the total number of circulating CD14+ monocytes increased in these samples and 97% of these cells exhibited ERK activation. p-ERK was not observed in T cells post-IL-2 therapy. Analysis of PBMCs obtained 3 weeks post-IL-2 therapy revealed high-p-ERK levels in CD56bright NK cells in a subset of patients, while levels of p-ERK returned to baseline in monocytes. These studies reveal an effective method to detect ERK activation in immune cells and demonstrate that IL-2 activates ERK in a subset of NK cells and monocytes but not T cells.
Cancer Immunology and Immunotherapy 09/2008; 57(8):1137-49. · 3.64 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: An anthracycline-based combination followed by, or combined with, a taxane is the sequence used in most adjuvant chemotherapy regimens. We hypothesized that administering the taxane before the anthracycline combination would be associated with fewer dose reductions and delays than the reverse sequence. To test this hypothesis, a randomized phase II multicenter adjuvant chemotherapy trial was performed.
Fifty-six patients with axillary node-positive, nonmetastatic breast cancer were randomly assigned either to group A (docetaxel [DOC] 75 mg/m(2) intravenously [IV] every 14 days for four cycles followed by doxorubicin 60 mg/m(2) and cyclophosphamide 600 mg/m(2) [AC] IV every 14 days for four cycles); or to group B (AC followed by DOC) at the identical doses and schedule. Pegfilgrastim 6 mg subcutaneous injection was administered 1 day after the chemotherapy in all treatment cycles. The primary objective was to administer DOC without dose reductions or delays before or after AC and calculate the relative dose intensity (RDI) of DOC and AC.
The majority of toxicities were grade 0 to 2 irrespective of sequence. The RDI for DOC was 0.96 and 0.82, respectively, in groups A (DOC followed by AC) and B (AC followed by DOC), with more frequent dose reductions occurring in group B (46% v 18%). The RDI for AC was 0.95 and 0.98 in groups A and B, respectively.
The administration of DOC before AC results in fewer DOC dose reductions and a higher RDI than the reverse sequence. Larger trials evaluating the sequence of DOC before anthracyclines are justified.
Journal of Clinical Oncology 05/2008; 26(10):1691-7. · 18.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The precise molecular targets of IFN-alpha therapy of melanoma are unknown but likely involve signal transducer and activator of transcription (STAT) 1 signal transduction within host immune effector cells. We hypothesized that intermediate and high doses of IFN-alpha would be equally effective in activating patient immune cells.
Eleven metastatic melanoma patients who were enrolled in a clinical trial of bevacizumab in combination with escalating doses of IFN-alpha-2b (5 megaunits/m(2) and then 10 megaunits/m(2)) were included in the study. Peripheral blood mononuclear cells (PBMC) were procured from patient blood just before therapy and again 1 h after each dose of IFN-alpha-2b and analyzed for the presence of phosphorylated STAT1, phosphorylated STAT2, and the induction of IFN-stimulated gene (ISG) transcripts.
Phosphorylated STAT1 was significantly greater at the 5 megaunits/m(2) dose compared with the 10 megaunits/m(2) dose of IFN-alpha-2b (P = 0.02). In contrast, no significant difference in phosphorylated STAT2 was observed at a dose of 5 megaunits/m(2) compared with 10 megaunits/m(2) (P = 0.20). There were also no significant differences in the induction of ISGs within PBMCs between the two doses (P > 0.4 for all ISGs). Suppressor of cytokine signaling 1 and 3 (two inhibitors of IFN-alpha signaling) transcripts were significantly higher among patient PBMCs following the 10 megaunits/m(2) dose of IFN-alpha (P < 0.001).
These results suggest that lower doses of IFN-alpha-2b are as effective as higher doses with respect to the induction of Janus-activated kinase-STAT signal transduction and the transcription of ISGs within immune effector cells.
Clinical Cancer Research 04/2008; 14(5):1438-45. · 7.84 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Vascular endothelial growth factor (VEGF) is a proangiogenic molecule produced by melanoma cells. We hypothesized that administration of bevacizumab (Bev), a monoclonal antibody that neutralizes VEGF, with low-dose interferon alfa-2b (IFN-alpha2b), an inhibitor of basic fibroblast growth factor (FGF), would lead to the regression of metastatic melanoma.
Patients with metastatic melanoma were randomized to receive Bev (15 mg/kg intravenously every 2 weeks) with or without low-dose IFN-alpha2b (1 MU/m2 subcutaneously daily). Patients exhibiting a clinical response or stable disease after 12 weeks were treated until disease progression.
Thirty-two patients (16 per arm) were accrued (18 male, 14 female; mean age 57.5 years). Both regimens were well tolerated. Six patients developed easily managed exacerbations of preexisting hypertension. Two patients developed grade 3 proteinuria that resolved after a treatment break. IFN-alpha2b therapy was associated with grade 1 to 2 constitutional symptoms. Arterial thromboembolic complications were observed in three patients (two mild myocardial infarctions, one transient ischemic attack), all of whom had risk factors. One patient (Bev plus IFN-alpha2b arm) had locally recurrent scalp disease that partially responded to therapy. Eight patients (five Bev, three Bev plus IFN-alpha2b) had prolonged disease stabilization (24 to 146 weeks). Plasma levels of VEGF and FGF did not correlate with any clinical parameter. The patient with the longest period of stable disease had the highest baseline VEGF and FGF.
Bev was well tolerated at this dose and prolonged disease stabilization was achieved in one-quarter of metastatic melanoma patients. Low-dose IFN-alpha2b did not augment the activity of Bev.
Annals of Surgical Oncology 09/2007; 14(8):2367-76. · 4.12 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Treatment with interleukin (IL)-2 (Proleukin) yields a 10% to 20% response rate in patients with metastatic melanoma or metastatic renal cell carcinoma. IL-2 is known to activate distinct signals within lymphocytes, including the Janus-activated kinase-signal transducer and activator of transcription (STAT) pathway. We examined the phosphorylation of STAT5 (P-STAT5) in IL-2-stimulated immune cells of normal subjects and in patients receiving IL-2 therapy using a novel flow cytometric assay to characterize the pattern and level of activation within immune subsets.
Normal peripheral blood mononuclear cells (PBMC) were treated in vitro with IL-2 and analyzed for P-STAT5 using an intracellular flow cytometric assay. PBMC were simultaneously evaluated for the induction of STAT5-regulated genes at the transcript level. PBMC were also obtained from patients immediately before and 1 hour after treatment with high-dose IL-2 and analyzed for the presence of P-STAT5 within immune cell subsets by dual-variable intracellular flow cytometry.
In vitro IL-2 treatment produced a rapid and dose-dependent increase in P-STAT5 within normal PBMC that correlated with the induction of transcript for the IL-2-responsive genes CIS, Pim-1, and SOCS1 (correlation coefficients 0.8628, 0.6667, and 0.7828, respectively). Dose-dependent induction of P-STAT5 was detected in PBMC for up to 18 hours following in vitro pulse stimulation with IL-2. P-STAT5 was detected within a subset of normal donor CD4(+) T cells (52.2 +/- 15.0%), CD8(+) T cells (57.6 +/- 25.8%), and CD56(+) natural killer (NK) cells (54.2 +/- 27.2%), but not CD14(+) monocytes or CD21(+) B cells, following in vitro IL-2 treatment. The generation of P-STAT5 within immune cell subsets after the therapeutic administration of IL-2 varied significantly between individuals. NK cells were noticeably absent in the posttreatment sample, a finding that was consistent for all patients examined. Surprisingly, activated STAT5 persisted within CD4(+) and CD8(+) T lymphocytes, as well as CD56(+) NK cells, for up to 3 weeks post-IL-2 treatment in three patients who exhibited a clinical response to therapy and in a fourth who exhibited a significant inflammatory response after 11 doses of therapy (first cycle).
The flow cytometric assay described herein is a highly efficient and reliable method by which to assess the cellular response to IL-2 within PBMC and specific immune effector subsets, both in vitro and in the clinical setting. Assessment of P-STAT5 in patient PBMC in response to therapeutic IL-2 administration reveals disparate responses between immune cell subsets as well as interpatient variation. Persistent activation of STAT5 within NK and T cells was an unexpected observation and requires further investigation.
Clinical Cancer Research 11/2006; 12(19):5850-8. · 7.84 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We conducted a phase I trial of interleukin 2 (IL-2) in combination with chimeric 14.18 (ch14.18) and murine R24 antibodies to determine the maximal tolerated dose (MTD), immunological effects, and toxicity of this treatment combination.
Twenty-seven patients with either melanoma (23 patients) or sarcoma (4 patients) were enrolled to receive a combination therapy with ch14.18 and R24 antibodies together with continuous infusion of Roche IL-2 (1.5 x 10(6) U/m(2)/day, 26 patients) or Chiron IL-2 (4.5 x 10(6) U/m(2)/day, 1 patient) given 4 days/week for 3 weeks. The antibodies ch14.18 (2-7.5 mg/m(2)/day) and R24 (1-10 mg/m(2)/day) were scheduled to be administered for 5 days during the second week of IL-2 therapy.
When given in combination in this study, the MTD for ch14.18 was 5 mg/m(2)/day and the MTD for R24 was 5 mg/m(2)/day. Dose-limiting toxicities were severe allergic reactions to both ch14.18 and R24 as well as pain related to ch14.18. This ch14.18 MTD was lower than the 7.5 mg/m(2)/day MTD previously determined for ch14.18 given alone with the same dose and schedule of IL-2. Immunological effects included the induction of lymphokine-activated killer (LAK) activity and antibody-dependent cell-mediated cytoxicity (ADCC). Anti-idiotype response to ch14.18 was seen in six patients, including two melanoma patients who had a partial response to treatment. In addition to two partial responses, four patients had a stable disease and one patient remained without any evidence of disease.
Immunotherapy with IL-2 in combination with ch14.18 and R24 antibodies augments LAK function and ADCC measured in vitro in all patients. While there exist theoretical advantages of combining these two antibodies, the MTD of ch14.18 and of R24 were lower than the MTD of each antibody in prior studies evaluating single antibody therapy with IL-2. As such, the combination of these two antibodies together with IL-2 therapy appeared to influence the MTD and toxicity of each of the administered antibodies.
Cancer Immunology and Immunotherapy 08/2006; 55(7):761-74. · 3.64 Impact Factor