Characterization of the cytolytic activity of CD4+ and CD8+ tumor-infiltrating lymphocytes in human renal cell carcinoma

Previously we showed that IL2 expanded tumor-infiltrating lymphocytes (TILs) from renal cell carcinoma mediated non-major histocompatibility complex-restricted cytotoxicity. Phenotypic analysis showed that cultured TILs were composed mostly of T-lymphocytes with varying numbers of CD4+, CD8+, and CD56+ (Leu19+) populations. Here we compared the cytolytic activity of the two predominant TIL subsets, CD3+CD4+ and CD3+CD8+, to that of the CD56+ populations. Using magnetic beads coated with antibodies to either CD4 or CD8, CD3+CD4+, and CD3+CD8+ TILs were isolated in a highly enriched form (greater than 92%) and could be expanded for over 40 days in vitro with 1000 units/ml IL2. In a 4-h 51Cr release assay the CD4+ and CD8+ TILs showed minimal lytic activity, whereas unseparated cells exhibited significant levels of non-major histocompatibility complex-restricted cytotoxicity. The lytic activity seen in the 4-h assay with unseparated TILs appeared to be related to the presence of CD56+ populations. With one exception none of the purified CD4+ or CD8+ TILs expressed any significant levels of CD56, while the unseparated TILs contained varying numbers of CD3+CD56+ and CD3-CD56+ populations. Cell-sorting experiments verified that the CD56+ populations were responsible for most of the lytic activity in 4 h even though CD3+CD56- cells represented the predominant cell type. Although CD3+CD56- TILs were minimally lytic in 4 h, we show here that both CD3+CD4+ and CD3+CD8+ subsets displayed substantial cytotoxicity in long-term assays. In the 18-h 51Cr release assay 5 of 6 CD4+ and 2 of 3 CD8+ TILs were lytic for the autologous tumor. In two cases, restimulation with the autologous tumor induced augmented cytolytic activity of TIL subsets and in one case induced lytic activity in 4 h. The cytotoxic activity of TIL subsets was further examined using a 72-h assay in which TILs were cocultured with a confluent layer of tumor cells. The degree of cytotoxicity was quantitated by measuring the amount of crystal violet dye that was incorporated by tumor cells which remained after the incubation period. CD4+ and CD8+ TILs typically caused greater than a 50% reduction of tumor cells in 3 days and the level of reduction was increased when IL2 was added to the cultures. All the CD4+ and CD8+ subset preparations were cytotoxic in the 3-day assay even though some were not lytic for certain targets in the 18-h 51Cr release assay.(ABSTRACT TRUNCATED AT 400 WORDS)     

Phase 1 trial of subcutaneous IL-6 in patients with refractory cancer: clinical and biologic effects

The authors evaluated the clinical and biologic effects of human recombinant interleukin-6 (rhIL-6) in patients with refractory cancer. A phase 1 trial using escalating doses of rhIL-6 (1-50 microg x kg(-1) x d(-1), Monday through Friday for 4 weeks) was performed in 30 patients. Toxicity was moderate and the maximum tolerated dose was determined to be 25 microg x kg(-1)x d(-1) based on cardiac and neurocortical toxicity in one patient each and thrombocytosis (platelets > 800,000/microL) in three patients. One patient with non-small-cell lung cancer had a partial response after three cycles of therapy. The biologic effects of rhIL-6 included anemia and dose-related thrombocytosis. Various proinflammatory activities were induced and included dose-related cyclical increases in peripheral blood monocytes and the CD14+/CD45RB+ +/- CD16C+ mononuclear cell populations. These increases were accompanied by increased levels of C-reactive protein, serum neopterin, and type I soluble tumor necrosis factor receptor. In contrast, rhIL-6 did not affect lymphocyte numbers or function (cytotoxicity, cytokine levels, immunoglobulin levels), with the possible exception of IL-2Ralpha mRNA induction in peripheral blood lymphocytes. rhIL-6 has pleiotropic proinflammatory actions in vivo and moderate toxicity when administered as long-term therapy.     

Phase I trial of oral MAC-321 in subjects with advanced malignant solid tumors

Purpose MAC-321 is a novel taxane that has demonstrated exceptional activity in human xenograft models when administered intravenously and orally. Preclinical studies of MAC-321 have shown antitumor activity in MDR-expressing and paclitaxel-resistant tumors. This phase I dose escalation study was performed to determine the safety, tolerability, and pharmacokinetic profile of orally administered MAC-321 given once every 21 days. Preliminary antitumor activity of MAC-321 was also examined. Methods Key eligibility criteria included adult subjects with refractory solid tumors or solid tumors for which conventional therapy was unsuitable or did not exist, good performance status (ECOG ( 2), and adequate hematologic, hepatic, and renal functions. Plasma pharmacokinetic (PK) sampling was performed during the first cycle of therapy. Results Five dose levels of MAC-321 ranging from 25 to 75 mg/m² were evaluated in 18 subjects (four women and 14 men). MAC-321 was well tolerated at the first three dose levels (25, 37, 50 mg/m²). Two subjects developed dose-limiting toxicities (DLTs) at 75 mg/m²; one subject with grade 3 and one subject with grade 4 neutropenia with fever. Three subjects treated at an intermediate dose level of 60 mg/m² had no DLTs. However, the study was terminated prior to completion of the maximal tolerated dose cohort after subjects treated with intravenous MAC-321 in a concurrent study experienced life-threatening toxicities. Other common toxicities included grades 1–2 fatigue and grades 1–2 diarrhea. There was substantial interpatient variability in the PK parameters. MAC-321 was rapidly absorbed with a mean C _max value of less than 1 h. Mean C _max and AUC values generally increased in a dose-related manner. The median terminal phase elimination half-life was 45 h (range 20–228 h). Disease stabilization was seen in four subjects with the following tumors: mesothelioma (14 cycles), chondrosarcoma (12 cycles), small cell carcinoma (10 cycles), and prostate carcinoma (6 cycles). Conclusions MAC-321 can be safely administered orally once every 21 days up to a dose of 60 mg/m². The major DLT was neutropenic fever. Four subjects had disease stabilization.     

Culture of C3A cells in alginate beads for fluidized bed bioartificial liver

Extracorporeal bioartificial liver has been designed to sustain the detoxification and synthetic function of the failed liver in patients suffering from acute liver failure until the time of liver allotransplantation or regeneration of their own. A fluidized bed, bioartificial liver improves the mass transfer velocity between the medium and the hepatocytes. Detoxification functions of the liver could be replaced by completely artificial systems, but the synthetic functions of hepatocytes may be obtained only by metabolically active cells. The aim of our study was to investigate the influence of C3A cell culture in alginate beads on synthetic function in a fluidized bed, bioartificial liver. Cells in alginate beads were prepared using an electrostatic droplet generator of our own design using low-viscosity alginate. Beads were cultured for 24 hours then 7 days in static conditions and then 24 hours of fluidization in the bioreactor to assess albumin production. We observed significantly increased albumin production by C3A cells entrapped in alginate beads during static culture. Fluidization increased albumin production compared with static culture. Fluidization performed after 7 days of static culture resulted in a significant increase in albumin synthesis. In conclusion, static culture of alginate beads hosting hepatic cells facilitates restoration of cell function.     

Sunitinib efficacy against advanced renal cell carcinoma

PURPOSE: We assessed the efficacy of the oral multitargeted tyrosine kinase inhibitor sunitinib in patients with metastatic clear cell renal cell carcinoma. MATERIALS AND METHODS: Patients with metastatic clear cell renal cell carcinoma were enrolled in this multicenter, phase II clinical trial. Major eligibility requirements were clear cell renal cell carcinoma histology, prior nephrectomy, measurable metastases and failed prior cytokine therapy as a result of disease progression. Sunitinib was given orally as second line therapy in 6-week cycles of 50 mg daily for 4 weeks, followed by 2 weeks off drug per treatment cycle. Response to sunitinib was rigorously assessed by an independent third party core imaging laboratory (central review). RESULTS: Of 106 patients enrolled in the study 105 were evaluated for response. As determined by independent third party assessment, the objective response rate was 33% (95% CI 24%-43%) with a median response duration of 14.0 months. Median time to progression and median progression-free survival in the 105 evaluable patients was 10.7 and 8.8 months, respectively. Median survival was 23.9 months and 43 patients remained alive at a median followup of 29.7 months. CONCLUSIONS: The results of this trial demonstrate the efficacy of sunitinib for metastatic renal cell carcinoma. The optimal integration of surgery and sunitinib treatment requires further prospective investigation.     

Hypothyroidism in patients with metastatic renal cell carcinoma treated with sunitinib

Sunitinib is an inhibitor of the vascular endothelial growth factor and platelet-derived growth factor receptors, and it has antitumor activity in metastatic renal cell carcinoma and gastrointestinal stromal tumors. To further investigate the fatigue associated with sunitinib therapy, thyroid function tests were performed on patients with metastatic renal cell carcinoma who were receiving sunitinib. Seventy-three patients with metastatic renal cell carcinoma were treated with sunitinib at the Cleveland Clinic Taussig Cancer Center, and 66 of them had thyroid function test results available. Fifty-six (85%) of the 66 patients had one or more abnormality in their thyroid function test results, consistent with hypothyroidism, and 47 (84%) of the 56 patients with abnormal thyroid function tests had signs and/or symptoms possibly related to hypothyroidism. Thyroid hormone replacement was undertaken in 17 patients, and symptoms improved in nine of them. Thyroid function test abnormalities appear to be common in patients with metastatic renal cell carcinoma treated with sunitinib, and routine monitoring is warranted.