Cox-2 inhibition enhances the activity of sunitinib in human renal cell carcinoma xenografts.

BACKGROUND: Sunitinib (Su), a tyrosine kinase inhibitor of VEGFR, is effective at producing tumour response in clear cell renal cell carcinoma (cRCC), but resistance to therapy is inevitable. As COX-2 is a known mediator of tumour growth, we explored the potential benefit of COX-2 inhibition in combination with VEGFR inhibition in attempts at delaying tumour progression on Su. METHODS: COX-2 expression was compared with areas of hypoxia in tumours that progressed on Su vs untreated tumours. Mice bearing human cRCC xenografts were treated with Su and the COX-2 inhibitor, celecoxib, and the effects on tumour growth were assessed. Sequential vs concurrent regimens were compared. RESULTS: COX-2 expression was increased in cRCC xenografts in areas of tumour hypoxia. The combination of Su and celecoxib achieved longer times to tumour progression compared to treatment with either agent alone or to untreated control animals in four models. This effect was seen with concurrent but not with sequential therapy. CONCLUSION: COX-2 inhibition can extend the effectiveness of VEGFR inhibition. This effect is dependent on the timing of therapy. Clinical trials combining Su and COX-2 inhibitors should be considered as a means delaying time to progression on sunitinib in patients with metastatic cRCC.

Human cutaneous T cell lymphoma and leukemia cell lines produce and respond to T cell growth factor.

Three cell lines of mature T cell origin derived from patients with cutaneous T cell lymphoma-leukemias (CTCL) were found to be constitutive producers of T cell growth factor (L-TCGF). These are the first reported human cell lines which constitutively produce TCGF. Biologically active TCGF could also be eluted from the surface of these cells using an acid glycine buffer under conditions that maintained cell viability, and subcellular fractionation showed that almost all the TCGF activity was associated with the plasma membrane. Over 30 other human hematopoietic cell lines derived from other disorders were unable to produce TCGF even after induction, and their acid eluates did not contain TCGF activity. L-TCGF from CTCL lines had the same biological activity as TCGF obtained from normal leukocytes (N-TCGF) in that they both supported the long-term growth of normal T cells only after the cells were previously activated by antigen or lectin. Both L-TCGF and N-TCGF increased the rate of proliferation of TCGF-independent and TCGF-dependent CTCL cell lines. The same three factor-independent cell lines that released TCGF adsorbed TCGF in a cell-concentration, time-, and temperature-dependent manner. Since the CTCL cell lines produce TCGF, adsorb TCGF, and increase their proliferative rate in response to TCGF or a related molecule, it is suggested that this endogenously produced factor plays a role in maintaining the abnormal proliferation of these cells in culture as permanently growing cell lines independent of exogenous TCGF. However, this does not mean that this is an essential aspect of neoplastic transformation. Since it is unusual to develop these cell lines in the absence of the continuous need for added TCGF, "autostimulation" may be one of the many unusual variant phenotypic properties sometimes associated with neoplastic cells that gives them a selective advantage for in vitro growth.

Antiinflammatory properties of hepatic acute phase proteins: preferential induction of interleukin 1 (IL-1) receptor antagonist over IL-1 beta synthesis by human peripheral blood mononuclear cells.

This study was undertaken to determine whether acute phase proteins (APP) induce the synthesis of interleukin 1 beta (IL-1 beta) and its specific antagonist, IL-1 receptor antagonist (IL-1Ra), in human peripheral blood mononuclear cells (PBMC). PBMC from healthy volunteers were incubated with C-reactive protein (CRP), alpha 1-antitrypsin (alpha 1-AT), or alpha 1-acid glycoprotein (AGP), and the levels of IL-1 beta and IL-1Ra produced were measured by specific radioimmunoassay. To evaluate the effects of alpha 1-AT further, a synthetic pentapeptide FVYLI corresponding to the minimal binding sequence for the serpine-enzyme complex receptor was also evaluated. PBMC incubated for 24 h with CRP, alpha 1-AT, or the pentapeptide FVYLI synthesized large quantities of IL-1Ra, 5-10-fold greater than the amount of IL-1 beta produced by these cells. AGP induced significantly less IL-1Ra than the other APP tested. These effects were shown to be specific, in that polyclonal antibodies against CRP, alpha 1-AT, and AGP eliminated the cytokine production induced by these respective proteins. CRP, alpha 1-AT, FVYLI, and AGP were synergistic with low concentrations of endotoxin in the induction of both IL-1Ra and IL-1 beta synthesis. We suggest that the preferential induction of IL-1Ra by APP may contribute to their antiinflammatory effects and provide an important regulatory signal for the acute phase response.

Calpain regulates actin remodeling during cell spreading.

Previous studies suggest that the Ca2+-dependent proteases, calpains, participate in remodeling of the actin cytoskeleton during wound healing and are active during cell migration. To directly test the role that calpains play in cell spreading, several NIH-3T3- derived clonal cell lines were isolated that overexpress the biological inhibitor of calpains, calpastatin. These cells stably overexpress calpastatin two- to eightfold relative to controls and differ from both parental and control cell lines in morphology, spreading, cytoskeletal structure, and biochemical characteristics. Morphologic characteristics of the mutant cells include failure to extend lamellipodia, as well as abnormal filopodia, extensions, and retractions. Whereas wild-type cells extend lamellae within 30 min after plating, all of the calpastatin-overexpressing cell lines fail to spread and assemble actin-rich processes. The cells genetically altered to overexpress calpastatin display decreased calpain activity as measured in situ or in vitro. The ERM protein ezrin, but not radixin or moesin, is markedly increased due to calpain inhibition. To confirm that inhibition of calpain activity is related to the defect in spreading, pharmacological inhibitors of calpain were also analyzed. The cell permeant inhibitors calpeptin and MDL 28, 170 cause immediate inhibition of spreading. Failure of the intimately related processes of filopodia formation and lamellar extension indicate that calpain is intimately involved in actin remodeling and cell spreading.

Melanotropin receptors demonstrated in situ in human melanoma.

Although some cultured human melanoma cell lines are responsive to melanotropins (melanocyte-stimulating hormones [MSH]), the prevalence and tissue distribution of MSH receptors in melanoma are unknown. We report here the use of an in situ binding technique to demonstrate specific MSH receptors in surgical specimens of human melanoma. The distribution and binding properties of specific MSH binding sites were determined by autoradiography and image analysis after incubation of frozen tumor tissue sections with a biologically active, radiolabeled analogue of alpha-MSH, [125I]iodo-Nle4, D-Phe7-alpha-MSH ([125I]NDP-MSH). In melanoma specimens from 11 patients, 3 showed high levels of specific binding, 5 showed low levels, and in 3 patients specific binding of [125I]NDP-MSH was not detectable. Specific MSH binding sites were present in melanoma cells, but not in adjacent connective or inflammatory tissues. Melanotropins, including alpha-MSH, NDP-MSH, and ACTH, inhibited [125I]NDP-MSH binding in a concentration-dependent manner, whereas unrelated peptides (somatostatin and substance P) did not. The apparent affinity of alpha-MSH for this binding site was in the nanomolar range (EC50 = 2 X 10(-9) M for inhibition of [125I]NDP-MSH binding in situ), similar to that recently described for the murine melanoma receptor. In one patient, analysis of multiple intratumor samples and tumors excised on three separate occasions revealed high levels of specific MSH binding in all samples. These results suggest that endogenous melanotropins may modulate the activities of human melanoma cells in vivo.

Multiple biological activities of human recombinant interleukin 1.

Complementary DNA coding for human monocyte interleukin 1 (IL-1), pI 7 form, was expressed in Escherichia coli. During purification, IL-1 activity on murine T cells was associated with the recombinant protein. Homogeneous human recombinant IL-1 (hrIL-1) was tested in several assays to demonstrate the immunological and inflammatory properties attributed to this molecule. hrIL-1 induced proliferative responses in a cloned murine T cell in the presence of suboptimal concentrations of mitogen, whereas no effect was observed with hrIL-1 alone. At concentrations of 0.05 ng/ml, hrIL-1 doubled the response to mitogen (5 X 10(6) half maximal units/mg). Human peripheral blood T cells depleted of adherent cells underwent a blastogenic response and released interleukin 2 in the presence of hrIL-1 and mitogen. hrIL-1 was a potent inflammatory agent by its ability to induce human dermal fibroblast prostaglandin E2 production in vitro and to produce monophasic (endogenous pyrogen) fever when injected into rabbits or endotoxin-resistant mice. These studies establish that the dominant pI 7 form of recombinant human IL-1 possesses immunological and inflammatory properties and acts on the central nervous system to produce fever.

Tropomyosin-2 cDNA lacking the 3' untranslated region riboregulator induces growth inhibition of v-Ki-ras-transformed fibroblasts.

The levels of high molecular weight isoforms of tropomyosin (TM) are markedly reduced in ras-transformed cells. Previous studies have demonstrated that the forced expression of tropomyosin-1 (TM-1) induces reversion of the transformed phenotype of ras-transformed fibroblasts. The effects of the related isoform TM-2 on transformation are less clear. To assess the effects of forced expression of the TM-2 protein on ras-induced tumorigenicity, we introduced a TM-2 cDNA lacking the 3' untranslated region riboregulator into ras-transformed NIH 3T3 fibroblasts. TM-2 expression resulted in a flatter cell morphology and restoration of stress fibers. TM-2 expression also significantly reduced growth rates in low serum, soft agar, and nude mice. The reduced growth rates were associated with a prolongation of G0-G1. To identify the mechanism of TM-2-induced growth inhibition, we analyzed the effects of TM-2 reexpression of ERK and c-jun N-terminal kinase (JNK) activities. Levels of ERK phosphorylation and activity in TM-2-transfected tumor cells were comparable to those in mock-transfected tumor cells. JNK activity was only modestly increased in ras-transformed cells relative to untransformed NIH 3T3 cells and only slightly reduced as result of forced TM-2 expression. We conclude that the partially restored expression of the TM-2 protein induces growth inhibition of ras-transformed NIH 3T3 cells without influencing ERK or JNK activities. Furthermore, the 3' untranslated region riboregulator of the alpha-tropomyosin gene is not needed for the inhibition of ras-induced growth.

Inhibitory effects of elevated temperature on human cytokine production and natural killer activity.

Febrile reactions often occur in cancer patients given various biological response modifiers such as alpha- or gamma-interferon or interleukin-2. The present studies were undertaken to determine the effects of moderately elevated temperatures (39 degrees C) on various immunological functions related to host defense against malignant cells. The production of the cytokines interleukin-1, interleukin-2, erythroid burst-promoting activity, and granulocyte-macrophage colony-stimulating factor from activated human mononuclear cells was assessed in vitro at 34, 37, and 39 degrees C and found to be reduced at 39 degrees C. The natural killer activity of human mononuclear cells preincubated for 18 h at various temperatures was also significantly reduced (P less than 0.001) at 39 degrees C. Although the addition of recombinant interleukin-1-beta, interleukin-2, and alpha-interferon during the 18-h incubation augmented natural killer activity at all temperatures, the enhancing effects were least apparent at 39 degrees C. Indomethacin increased cytokine-primed natural killer cell activity at all temperatures but did not reverse the inhibitory effects of elevated temperatures. These results suggest that the fever associated with treatment with pyrogenic cytokines may partially offset the direct stimulatory effects of these substances on cellular immune function.

Phase I evaluation of recombinant interleukin-2 in patients with advanced malignant disease.

Seventeen patients with refractory malignant tumors were treated with recombinant human interleukin-2 (IL-2) administered by weekly bolus intravenous (IV) injection in a phase I dose escalation trial. Patients received 10,000 to 1,000,000 U/m2 per injection over a course of 3 to 33 weeks. Toxicity was dose related and consisted primarily of fever, chills, nausea, and vomiting. Hypotension was observed at doses of 500,000 U/m2 or higher and in one instance was sufficiently severe to require pressors. No tumor regression was seen and all patients eventually developed progressive disease. Blood levels of cortisol, ACTH, prolactin, and growth hormone as well as the acute phase reactant C-reactive protein (CRP) increased after the administration of IL-2 in most patients. Serum IL-2 levels in excess of 250 U/mL were detected five minutes after an IV injection of 1,000,000 U/m2, after which the levels declined with a half-life of approximately 25 minutes. No alteration in lymphocyte surface phenotype or enhancement in natural cell-mediated cytotoxicity against natural killer (NK)-sensitive and resistant tumor cell lines was observed when these parameters were measured weekly just before the IL-2 injections. However, a dramatic but transient decline in circulating lymphocytes and NK activity was noted within hours of receiving IL-2. This effect was independent of fever and was not abrogated by pretreatment with ibuprofen or metyrapone. The majority of patients developed serum IgG antibodies of IL-2 detectable with a sensitive enzyme-linked immunosorbent assay (ELISA) and a nitrocellulose dot blot assay. The development of anti-IL-2 antibodies was not associated with symptoms suggestive of serum sickness, reductions in serum complement levels, or deterioration in lymphocyte tumoricidal activity. This investigation provides insight into the in vivo actions of this potent biological response modifier and will assist in the design of future studies with IL-2 administered alone or in conjunction with other treatment modalities.

Phase I evaluation of thrice-daily intravenous bolus interleukin-4 in patients with refractory malignancy.

PURPOSE: A phase I dose-escalation trial of recombinant human interleukin-4 (IL-4) was performed to determine its toxicity, biologic activity, and potential antineoplastic effects. PATIENTS AND METHODS: Ten patients with refractory malignancies received IL-4 by bolus intravenous injection every 8 hours on days 1 to 5 and 15 to 19 (maximum, 28 doses) of a 31-day study period. Three patients received 10 micrograms/kg per dose and seven received 15 micrograms/kg per dose of IL-4. RESULTS: Toxic symptoms noted at the second dose level included nasal congestion, diarrhea, nausea and vomiting, fatigue, anorexia, headache, dyspnea, and capillary leak syndrome (median weight gain, 6.1%; range, 3.4% to 11.7%). Fever or sustained hypotension sufficient to require pressors did not occur. Decreases in lymphocyte count and serum bicarbonate, sodium, albumin, fibrinogen and immunoglobulin (Ig) levels, and increases in hematocrit, prothrombin time/partial thromboplastin time (PT/PTT), soluble CD23, and, occasionally, serum creatinine and transaminases occurred. All side effects resolved by day 31. Phenotypic analysis of peripheral-blood mononuclear cells (PBMC) showed a decrease in the percentage of circulating CD16 and CD14(+) cells. Plasma tumor necrosis factor (TNF) and IL-1 beta levels were unaffected, whereas serum C-reactive protein (CRP) concentrations increased slightly and plasma IL-1 receptor antagonist (IL-1RA) levels increased markedly. No tumor responses were observed. CONCLUSIONS: We conclude that 10 micrograms/kg per dose of IL-4 is the maximum-tolerated dose for this schedule, although 15 micrograms/kg per dose can be tolerated if more intensive, but still non-intensive care unit level care is provided. The results of this study should aid in the design of future phase II trials that involve IL-4 alone or phase I studies that combine IL-4 with other cytokines such as IL-2.

Interleukin-2 and high-dose cisplatin in patients with metastatic melanoma: a pilot study.

In this pilot study of metastatic melanoma, interleukin-2 (IL-2) and cisplatin (CDDP) chemotherapy were combined using an alternating schedule designed to explore potential synergism between these modalities. Bolus IL-2 was given at a dose of 600,000 IU/kg intravenously (IV) every 8 hours, days 1 to 5 and 15 to 19, followed by high-dose CDDP administered by two different regimens: (A) 135 to 150 mg/m2 IV bolus over 30 minutes with the chemoprotectant WR-2721 910 mg/m2 or (B) 50 mg/m2 IV over 2 hours every day for 3 days. The trial design allowed an assessment of response to each phase of therapy. Among 27 assessable patients, there were 10 (37%) overall responses, including three (11%) complete responses (CRs) with durations of 9, 16, and 30+ months. Tumor regression was noted in seven patients (partial response [PR], four; minor response [MR], three; response rate [RR], four of 27 [15%]) after IL-2 administration and in 14 patients (PR, 12; MR, two; RR, 12 of 27 [44%]) after CDDP treatment, demonstrating noncrossresistance between the components of the regimen. Major PRs (greater than 90% reduction of tumor burden) or CRs were only seen in patients responding to IL-2. Toxicity during IL-2 therapy was typical for high-dose IL-2 protocols and was reversible. Among the first 20 patients treated with CDDP regimen A, there were eight episodes of grade IV nephrotoxicity (creatinine level greater than 5.0 mg/dL), including three of six patients treated with an initial CDDP dose of 135 mg/m2. This side effect was more frequent among patients with liver metastasis (P less than .05, Fisher's exact test). No significant nephrotoxicity was noted in seven patients treated on regimen B. Although ototoxicity was frequent, minimal bone marrow and neurologic toxicity was noted. There were no treatment-related deaths. This combination showed at least additive activity against melanoma, and the more protracted CDDP schedule was well tolerated. This regimen may serve as a model for future combined immunotherapy and chemotherapy trials in metastatic melanoma.

Randomized placebo-controlled clinical trial of high-dose interleukin-2 in combination with a soluble p75 tumor necrosis factor receptor immunoglobulin G chimera in patients with advanced melanoma and renal cell carcinoma.

PURPOSE: A randomized, double-blind, placebo-controlled trial was performed to compare the toxicity and biologic effects of treatment with high-dose intravenous (IV) bolus interleukin-2 (IL-2) plus the recombinant human soluble p75 tumor necrosis factor (TNF) receptor immunoglobulin G (IgG) chimera (rhuTNFR:Fc) with high-dose IL-2 alone in patients with advanced melanoma and renal cell carcinoma. PATIENTS AND METHODS: Twenty patients with advanced melanoma or renal cell carcinoma were randomized to receive IL-2 (Chiron, Emeryville, CA) 600,000 IU/kg every 8 hours on days 1 to 5 and 15 to 19 (maximum, 28 doses) combined with placebo or the rhuTNFR:Fc fusion protein (Immunex, Seattle, WA) 10 mg/m2 on days 1 and 15 and 5 mg/m2 on days 3, 5, 17, and 19. The impact of rhuTNFR:Fc on IL-2 toxicity and biologic effects was evaluated. RESULTS: No clinically significant difference in toxicity was observed in the two treatment arms. The adjusted median number of IL-2 doses administered during cycle 1 was 24.5 (range, seven to 28) and 21.5 (range, five to 27) for the placebo and rhuTNFR:Fc arms, respectively (P = .544). IL-2-induced TNF bioactivity, neutrophil chemotactic defect, and serum IL-6, IL-8, and IL-1 receptor antagonist (IL-1RA) induction were suppressed by rhuTNFR:Fc. Two of nine assessable patients (22%) on IL-2/placebo and three of 10 patients (30%) on IL-2/rhuTNFR:Fc responded. CONCLUSION: Despite evidence of in vitro neutralization of TNF functional activity and partial inhibition of other secondary biologic effects of IL-2, rhuTNFR:Fc does not reduce the clinical toxicity associated with high-dose IL-2 therapy. These results suggest that the toxicity and antitumor effects of IL-2 treatment are independent of circulating TNF.

Randomized phase II trial of high-dose interleukin-2 either alone or in combination with interferon alfa-2b in advanced renal cell carcinoma.

PURPOSE: To determine better the activity of high-dose interleukin-2 (IL-2) either alone or in combination with interferon alfa-2b (IFN; Schering-Plough, Kenilworth, NJ) in patients with metastatic renal cell carcinoma, the IL-2 Working Group initiated a randomized phase II trial. PATIENTS AND METHODS: Patients were randomly assigned to receive treatment with either IL-2 (Chiron Corp, Emeryville, CA) 1.33 mg/m2 (approximately 600,000 IU/kg) alone or IL-2 0.8 mg/m2 and IFN 3 x 10(6) U/m2 administered by bolus intravenous injection every 8 hours, days 1 to 5 and 15 to 19 (maximum, 28 doses). All patients had an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 and normal organ function. After 28 patients were entered onto each arm, the IL-2/IFN arm was closed because of a failure to meet predetermined efficacy criteria. An additional 43 patients (total, 71) were assigned to receive IL-2 alone. RESULTS: Toxicities were similar for both study arms. Hypotension requiring pressors was the most frequent dose-limiting toxicity. Only 11 of 99 patients experienced severe toxicity; there were no irreversible side effects or treatment-related deaths. Responses were seen in three of 28 patients (11%) on IL-2/IFN (three partial responses [PRs] lasting 14, 7, and 7 months) and 12 of 71 patients (17%) on IL-2 alone (four complete responses [CRs] and eight PRs). Six of the partial responders on IL-2 and two on IL-2/IFN experienced greater than 90% reduction in tumor mass. Ten of the 12 responders to IL-2 have ongoing responses of 12+ to 26+ months in duration. CONCLUSION: We conclude that both IL-2 and IL-2/IFN therapy have activity in metastatic renal cell carcinoma. In particular, therapy with high-dose IL-2 alone produces meaningful and durable responses with manageable and reversible toxicity. This study supports the contention that high-dose IL-2 represents the treatment of choice in selected patients with advanced renal cell carcinoma.

Multiinstitutional phase II trial of intensive combination chemoimmunotherapy for metastatic melanoma.

PURPOSE: To evaluate the activity and toxicity of combined high-dose cisplatin, dacarbazine (DTIC), and tamoxifen chemotherapy and high-dose bolus interleukin-2 (IL-2) in patients with metastatic melanoma. PATIENTS AND METHODS: Patients with metastatic melanoma, Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, and normal organ function were enrolled onto this multiinstitutional Cytokine Working Group trial. Patients received intensive chemoimmunotherapy consisting of cisplatin (50 mg/m2) and DTIC (350 mg/m2) intravenously (IV) on days 1 to 3 and 43 to 45, IL-2 600,000 IU/kg IV every 8 hours on days 12 to 16 and 26 to 30 (maximum, 28 doses), and tamoxifen 20 mg orally each day. Patients were evaluated for response at day 63 of each cycle, and responding patients were given a second cycle of therapy beginning on day 71 to 85. RESULTS: Thirty-eight patients were entered onto this study. Toxicities were as expected for the chemotherapy and immunotherapy components of this regimen. Overlapping toxicity consisted primarily of thrombocytopenia (76% of patients required platelet transfusions), neutropenia, anemia, fatigue, and weight loss. Despite these cytopenias, bleeding and infectious complications were rare. There were no treatment-related deaths. Three patients achieved a complete response (CR; 8%), and 13 achieved a partial response (PR). The overall objective response rate was 42% (95% confidence interval [CI], 26% to 58%). Six additional patients had greater than 50% tumor reduction at day 63, which did not persist until a subsequent evaluation. The median duration of response was 5 months (range, 2 to 20+), and the median survival duration was 11 months. CONCLUSION: This intensive treatment regimen appears to possess activity in metastatic melanoma comparable, but not superior, to that of other less intensive cisplatin- and IL-2-based chemoimmunotherapy regimens. Although the toxicity and complexity of this regimen make it unsuitable for phase III testing and impractical for more widespread use, the results of this study support a potential favorable interaction between IL-2 and chemotherapy in this disease and highlight the need for appropriately designed phase III trials.

Therapy of renal cell carcinoma with interleukin-2 and lymphokine-activated killer cells: phase II experience with a hybrid bolus and continuous infusion interleukin-2 regimen.

Forty-seven patients with metastatic or unresectable renal cell carcinoma were treated with interleukin-2 (IL-2) and lymphokine-activated killer (LAK)-cell therapy, using a hybrid IL-2 regimen. IL-2 was administered initially by intravenous bolus (10(5) U/kg [Cetus Corp, Emeryville, CA] every 8 hours for 3 days) during the priming phase, and subsequently by continuous infusion (3 x 10(6) U/m2 for 6 days); during this second treatment period, in vitro-generated LAK cells were administered. Despite selection of patients for good performance status (PS) (29, PS 0; 18, PS 1) prior nephrectomy (43 of the 47 patients), and low tumor burden, the response rate was low (two complete [CRs] and two partial responses [PRs], for an overall objective response rate of 9%). Toxicity was comparable to that experienced with the high-dose bolus regimen. These results suggest that the dose and schedule of IL-2 administration may influence the likelihood of response to IL-2 in renal cell carcinoma.

Phase I trial of twice-weekly intravenous interleukin 12 in patients with metastatic renal cell cancer or malignant melanoma: ability to maintain IFN-gamma induction is associated with clinical response.

The aim of this study was to examine the tolerability, antitumor activity, and biological effects of a new schedule of i.v. recombinant human interleukin 12 (rhIL-12). Twenty-eight patients were enrolled in a Phase I trial in which rhIL-12 was administered twice weekly as an i.v. bolus for 6 weeks. Stable or responding patients were eligible to receive additional 6-week cycles until there was no evidence of disease or until tumor progression. Patient cohorts were treated with escalating doses of rhIL-12 (30-700 ng/kg). The maximum tolerated dose (MTD) was 500 ng/kg, with dose-limiting toxicities consisting of elevated hepatic transaminases and cytopenias. At the MTD (n = 14), there was one partial response occurring after 6 cycles of rhIL-12 in a patient with renal cell cancer. Two additional renal cell cancer patients treated at the MTD had prolonged disease stabilization, with one of these exhibiting tumor regression after 8 cycles of rhIL-12. IFN-gamma, IL-15, and IL-18 were induced in patients treated with rhIL-12. Whereas IFN-gamma and IL-15 induction were attenuated midway through the first cycle in patients with disease progression, those patients with tumor regression or prolonged disease stabilization were able to maintain IFN-gamma, IL-15, and IL-18 induction. The down-modulation of IFN-gamma induction during rhIL-12 treatment did not relate to IL-10 production or alterations in rhIL-12 bioavailability but was associated with an acquired defect in lymphocyte IFN-gamma production in response to IL-12, IL-2, or IL-15. This defect could be partially overcome in vitro through combined stimulation with IL-12 plus IL-2. These findings show that the chronic administration of twice-weekly i.v. rhIL-12 is well-tolerated, stimulates the production of IL-12 costimulatory cytokines and IFN-gamma, and can induce delayed tumor regression. Strategies aimed at maintaining IFN-gamma induction, such as the addition of IL-2, may further augment the response rate to this schedule of rhIL-12.

A two-part phase I trial of high-dose interleukin 2 in combination with soluble (Chinese hamster ovary) interleukin 1 receptor.

Our purpose was to determine the maximum tolerated dose and toxicity associated with soluble Chinese hamster ovary [s(CHO)] recombinant human interleukin (IL) 1 receptor (IL-1R; Immunex, Seattle, WA) administration in humans and to determine the effective biological dose and/or maximum tolerated dose of the s(CHO) IL-1R in combination with high-dose IL-2 as determined by reduction in IL-2 toxicity and modulation of its biological effects. Twenty-seven patients with metastatic cancer were treated with escalating doses of s(CHO) IL-1R at 1, 1, 5, 10, 20, 40, and 55 mg/m2 i.v. on days -6 (except cohort 2), 1, and 15 and IL-2 at doses of 300,000 IU/kg (cohort 1) and 600,000 IU/kg (cohorts 2-7) i.v. every 8 h on days 1-5 and 15-19. No toxicity directly attributable to s(CHO) IL-1R was observed. The median number of IL-2 doses was 23. Hypotension and neurotoxicity were the major dose-limiting toxicities for the IL-2/s(CHO) IL-1R combination. Of the 24 patients treated with full-dose IL-2, there were six responses, three complete and three partial (response rate, 25%). Three patients developed thyroid dysfunction, and all 3 responding melanoma patients exhibited vitiligo. The t1/2 of s(CHO) IL-1R alone was 24-30 h and was not significantly altered by coadministration with IL-2. Whole-blood functional assays indicated that sufficient s(CHO) IL-1R was present in the circulation at top dose levels to inhibit the in vitro effects of IL-1beta on IL-8 induction; however, no effect on IL-2-induced IL-8 induction, or on the IL-1beta- or IL-2-induced tumor necrosis factor production, was observed. Suppression of IL-2-mediated tumor necrosis factor alpha and IL-6 induction in vivo during the first 24 h after IL-2 administration was observed, and the neutrophil chemotactic defect normally seen with IL-2 was not observed. IL-1R antagonist induction far exceeded that seen previously with IL-2 alone. No inhibition of either serum C-reactive protein induction or enhanced urinary nitrate excretion and no consistent effect on IL-2-related changes in peripheral blood mononuclear cell phenotype or endothelial adhesion molecule expression were seen. The coadministration of s(CHO) IL-1R produced no apparent reduction in IL-2 clinical toxicity manifested by either the ability to administer more IL-2 than anticipated or a reduction in the toxicity associated with a given amount of IL-2. Therefore, no effective biological dose could be identified for the s(CHO) IL-1R.

A phase II pilot trial of concurrent biochemotherapy with cisplatin, vinblastine, dacarbazine, interleukin 2, and interferon alpha-2B in patients with metastatic melanoma.

In an effort to develop a biochemotherapy regimen for metastatic melanoma suitable for testing in a cooperative group setting, we modified the concurrent biochemotherapy regimen of S. S. Legha et al. (J. Clin. Oncol., 16: 1752-1759, 1998) by providing enhanced supportive care and developing a strict, conservative approach to the management of treatment-related toxicities. Patients received cisplatin, vinblastine, and dacarbazine (CVD: cisplatin (20 mg/m2) and vinblastine (1.2 mg/m2) on days 1-4, dacarbazine (800 mg/m2) on day 1 only) concurrently with interleukin 2 (9 MIU/m2/day) by continuous i.v. infusion on days 1-4 and IFN-alpha (5 MU/m2/day) on days 1-5, 8, 10, and 12. Prophylactic antibiotics and a maximum of four cycles were administered. Routine granulocyte colony-stimulating factor and aggressive antiemetics were initiated after patients 7 and 14, respectively. Forty-four patients were enrolled in this study. No patients had received prior chemotherapy or interleukin 2; however, 23 (53%) had received prior IFN-alpha, mostly in the adjuvant setting. A total of 131 treatment cycles was administered. Significant toxicities requiring dose modification included: hypotension requiring pressors (15 episodes in 11 patients), grades 3/4 vomiting (12 episodes in 15 cycles; 5 episodes in 12 patients (6 episodes in 9 cycles after initiation of the modified antiemetic regimen), transient renal insufficiency (5 episodes in 5 patients), grade 4 thrombocytopenia (24 episodes, 1 associated with bleeding), neutropenia with or without fever (15 instances, only 11 in 112 cycles after routine use of granulocyte colony-stimulating factor), and catheter-related bacteremia (2 patients). Five (16%) of 30 patients who were treated after the last protocol modification experienced what we defined as unacceptable toxicity for a cooperative group setting. Responses were seen in 19 of 40 evaluable patients (relative risk, 48%) with 8 complete responses (20%). The median response duration was 7 months (range, 1-17+ months) with one currently ongoing. The central nervous system was the initial site of relapse in 11 responding patients. The median survival duration was 11 months (range, 2-31 months). This modified, concurrent biochemotherapy regimen is active and tolerable for use in a cooperative group setting. Central nervous system relapse, however, remains a concern for responders. This regimen is being compared with CVD in a Phase III Intergroup Trial (Eastern Cooperative Oncology Group/Southwest Oncology Group 3695).

Phase I trial of interleukin 2 in combination with the soluble tumor necrosis factor receptor p75 IgG chimera.

Our purpose was to determine the effective biological dose and/or maximum tolerated dose of recombinant human tumor necrosis factor receptor:IgG chimera (rhuTNFR:Fc; Immunex, Seattle, WA) in combination with interleukin 2 (IL-2) with regard to reduction in IL-2 toxicity and modulation of biological effects of high-dose IL-2 administration. Twenty-four patients with metastatic cancer were treated with escalating doses of rhuTNFR:Fc at 1, 1, 5, 10, and 20 mg/m2 i.v. on days 1 and 15 (dose levels 1-5) or 10, 20, and 30 mg/m2 days 1 and 15 plus 50% dose on days 3, 5, 17, and 19 (dose levels 6-8) prior to IL-2 at doses of 300,000 IU/kg (dose level 1) and 600,000 IU/kg (dose levels 2-8) i.v. every 8 h on days 1-5 and 15-19. The t1/2 of rhuTNFR in patients receiving IL-2 was 72 h. The median number of IL-2 doses was 24, and central nervous system, skin, and cardiac arrhythmias were the major dose-limiting toxicities. TNF bioactivity was inhibited, and the polymorphonuclear leukocyte chemotactic defect normally seen with IL-2 was not observed. Increases in C-reactive protein, IL-6, IL-8, and IL-1 receptor antagonist levels were partially suppressed relative to historical controls, whereas peripheral blood mononuclear cell phenotypes, urinary nitrate, endothelial adhesion molecule expression in skin biopsies, and cellular infiltrates in tumor biopsies were consistent with findings in patients treated with IL-2 alone. Four patients developed thyroid dysfunction. There were five responses: two complete responses (both melanoma) and three partial responses (response rate, 21%). rhuTNFR:Fc may modulate the toxicity and some of the biological effects of IL-2 while preserving antitumor activity. Dose level 6 (10 mg/m2 on days 1 and 15, and 5 mg/m2 on days 3, 5, 17, and 19) has been chosen for a randomized, double-blind, placebo-controlled trial of IL-2 with and without rhuTNFR:Fc.

Phase I evaluation of intravenous recombinant human interleukin 12 in patients with advanced malignancies.

A Phase I dose escalation trial of i.v. administered recombinant human interleukin 12 (rhIL-12) was performed to determine its toxicity, maximum tolerated dose (MTD), pharmacokinetics, and biological and potential antineoplastic effects. Cohorts of four to six patients with advanced cancer, Karnofsky performance >/=70%, and normal organ function received escalating doses (3-1000 ng/kg/day) of rhIL-12 (Genetics Institute, Inc.) by bolus i.v. injection once as an inpatient and then, after a 2-week rest period, once daily for five days every 3 weeks as an outpatient. Therapy was withheld for grade 3 toxicity (grade 4 hyperbilirubinemia or neutropenia), and dose escalation was halted if three of six patients experienced a dose-limiting toxicity (DLT). After establishment of the MTD, eight more patients were enrolled to further assess the safety, pharmacokinetics, and immunobiology of this dose. Forty patients were enrolled, including 20 with renal cancer, 12 with melanoma, and 5 with colon cancer; 25 patients had received prior systemic therapy. Common toxicities included fever/chills, fatigue, nausea, vomiting, and headache. Fever was first observed at the 3 ng/kg dose level, typically occurred 8-12 h after rhIL-12 administration, and was incompletely suppressed with nonsteroidal anti-inflammatory drugs. Routine laboratory changes included anemia, neutropenia, lymphopenia, hyperglycemia, thrombocytopenia, and hypoalbuminemia. DLTs included oral stomatitis and liver function test abnormalities, predominantly elevated transaminases, which occurred in three of four patients at the 1000 ng/kg dose level. The 500 ng/kg dose level was determined to be the MTD. This dose, administered by this schedule, was associated with asymptomatic hepatic function test abnormalities in three patients and an onstudy death due to Clostridia perfringens septicemia but was otherwise well tolerated by the 14 patients treated in the dose escalation and safety phases. The T1/2 elimination of rhIL-12 was calculated to be 5.3-9.6 h. Biological effects included dose-dependent increases in circulating IFN-gamma, which exhibited attenuation with subsequent cycles. Serum neopterin rose in a reproducible fashion regardless of dose or cycle. Tumor necrosis factor alpha was not detected by ELISA. One of 40 patients developed a low titer antibody to rhIL-12. Lymphopenia was observed at all dose levels, with recovery occurring within several days of completing treatment without rebound lymphocytosis. There was one partial response (renal cell cancer) and one transient complete response (melanoma), both in previously untreated patients. Four additional patients received all proposed treatment without disease progression. rhIL-12 administered according to this schedule is biologically and clinically active at doses tolerable by most patients in an outpatient setting. Nonetheless, additional Phase I studies examining different schedules and the mechanisms of the specific DLTs are indicated before proceeding to Phase II testing.