Cytokine Release Reactions Research Articles

Drug-Induced Anaphylaxis in Children.

Drug-induced anaphylaxis in children is less common than in adults and primarily involves beta-lactams and nonsteroidal anti-inflammatory drugs. Epidemiological studies show variable prevalence, influenced by age, gender, and atopic diseases. The pathophysiology includes IgE-mediated reactions and non-IgE mechanisms, like cytokine release reactions. We address drug-induced anaphylaxis in children, focusing on antibiotics, nonsteroidal anti-inflammatory drugs, neuromuscular blocking agents, and monoclonal antibodies. Diagnosis combines clinical criteria with in vitro, in vivo, and drug provocation tests. The immediate management of acute anaphylaxis primarily involves the use of adrenaline, coupled with long-term strategies, such as allergen avoidance and patient education. Desensitization protocols are crucial for children allergic to essential medications, particularly antibiotics and chemotherapy agents.

Differential presentation of hypersensitivity reactions to carboplatin and oxaliplatin: Phenotypes, endotypes, and management with desensitization.

Drug hypersensitivity reactions (DHRs) to platinum-based drugs are heterogenous and restrict their access, and drug desensitization (DD) has provided a ground-breaking procedure for their re-introduction, although the response is heterogeneous. We aimed to identify the phenotypes, endotypes, and biomarkers of reactions to carboplatin and oxaliplatin and their response to DD. Seventy-nine patients presenting with DHRs to oxaliplatin (N = 46) and carboplatin (N = 33) were evaluated at the Allergy Departments of two tertiary care hospitals in Spain. Patient symptoms, skin testing, biomarkers, and outcomes of 267 DDs were retrospectively analyzed. Oxaliplatin-reactive patients presented with type I (74%), cytokine release reaction (CRR) (11%), and mixed (Mx) (15%) phenotypes. In contrast, carboplatin reactive patients presented with predominantly type I (85%) and Mx (15%) but no CRRs. Out of 267 DDs, breakthrough reactions (BTRs) to oxaliplatin occurred twice as frequently as carboplatin (32% vs. 15%; p < .05). Phenotype switching from type I to another phenotype was observed in 46% of oxaliplatin DDs compared to 21% of carboplatin DDs. Tryptase was elevated in type I and Mx reactions, and IL-6 in CRR and Mx, indicating different mechanisms and endotypes. Carboplatin and oxaliplatin induced three different types of reactions with defined phenotypes and endotypes amendable to DD. Although most of the initial reactions for both were type I, oxaliplatin presented with unique CRR reactions. During DD, carboplatin reactive patients presented mostly type I BTR, while oxaliplatin-reactive patients frequently switched from type I to CRR, providing a critical difference and the need for personalized DD protocols.

Converter Phenotype: A New Profile That Is Not Exclusive to Taxanes.

Introduction: Phenotype I hypersensitivity reactions are the most commonly reported drug reactions; however, precision medicine has made it possible to characterize new phenotypes. A recent communication proposed the existence of a “converter phenotype,” which would affect patients who present non-immediate hypersensitivity reactions and in subsequent exposures develop immediate hypersensitivity reactions. This study aimed to describe the clinical characteristics of converter phenotype reactions and their evolution during desensitization to chemotherapeutic drugs and monoclonal antibodies.Methods: We retrospectively reviewed our database of patients undergoing desensitization to chemotherapy or biological agents and selected those with a converter phenotype. Demographic and clinical characteristics of the patients, the results of skin tests, tryptase and IL-6 levels, and desensitization outcomes were assessed.Results: Of 116 patients evaluated, 12 (10.3%) were identified as having a converter phenotype. The median interval between drug exposure and reaction was 90.6 h (range 8-288 h). After the conversion, phenotype I was the most frequent (58.3%), followed by cytokine release reactions (33.3%). Fifty-one desensitizations were undertaken and all treatments completed, with 10 (19.6%) breakthrough reactions. No new changes in the phenotype were detected.Conclusions: The symptoms of non-immediate drug hypersensitivity reactions may indicate the need for an early allergological evaluation to assess the risk of future immediate drug reactions. Clinical characteristics, skin test results, and biomarkers can help predict responses to rapid drug desensitization, guiding clinicians on how to optimize therapy delivery while maintaining patient safety.

Endophenotyping Oxaliplatin Hypersensitivity: Personalizing Desensitization to the Atypical Platin

Oxaliplatin causes a wider variety of immediate hypersensitivity reactions than do other platin-based chemotherapeutics. Some resemble type 1 reactions that respond to desensitization. Others are atypical, possibly mast cell-independent cytokine release reactions refractory to desensitization. Given this variability, clinicians need an evidence-based strategy to personalize therapy for oxaliplatin-hypersensitive patients. To develop a data-driven algorithm to optimize treatment of oxaliplatin-hypersensitive patients. We retrospectively analyzed the baseline clinical characteristics, biomarkers, and reactions of 48 oxaliplatin-hypersensitive patients who received a total of 266 oxaliplatin desensitizations. We characterized 4 endophenotypes: type 1, cytokine release, mixed, and either. A mean 40-fold increase in serum concentration of IL-6 helped define the cytokine release endophenotype. Younger patients were more likely to have a cytokine release endophenotype, whereas older patients were more likely to have a type 1 reaction. Skin testing was not informative for determining endophenotype or risk of reaction during desensitization, and did not associate with initial or desensitization grade of reaction. Patients with a history of atopy and an initial type 1 reaction responded to desensitization with antihistamine premedications, whereas nonatopic patients with the same initial reaction phenotype were more likely to convert to a cytokine release or mixed reaction during desensitization. We combined these reaction patterns with biomarker data and desensitization outcomes to construct an algorithm that helps tailor desensitization protocol design to meet individual patient needs. Endophenotyping oxaliplatin hypersensitivity reactions may help forecast desensitization outcomes and personalize treatment plans.

Biomarkers Associated with Hypersensitivity Reactions to Chemotherapeutic Agents.

New phenotypes of hypersensitivity reactions (HSR) have been described due to the wide use of chemotherapy, however, biomarkers other than tryptase to confirm the reaction are not feasible. Our goal was to determine the value of tryptase and IL-6 during desensitization to chemotherapy agents. The phenotype of the HSR was established according to the clinical characteristics, the result of the skin tests and the biomarkers (tryptase and IL-6) at the time of the initial reaction during desensitization. Tryptase were quantified by ImmunoCAP and IL-6 was quantified by flow cytometry using the CBA method. We compare the results of 8 patients, 4 of them presented HSR suggestive of phenotype 1 (Ph1); the other 4 patients had cytokine release reactions (CRR) over 55 desensitization procedures. The mean baseline tryptase level in Ph1 was 5.25±0.99 ng/ml vs 5.05±1.67 in CRR; while during the desensitization reactions were 9.2±4.79 vs 3.37±0.9 respectively (p<0.05). On the other hand, the mean baseline IL-6 levels was 10 pg/ml in both groups, but after reactions during desensitization in the CRR the levels were 6659pg/ml±9026.2 pg/ml, but no change was observed in patients with Ph1 (p<0.01). Tryptase increases were detected in patients with Ph1, while IL-6 elevations were observed in CRR. We didn’t have blended reactions until now. Tryptase elevation occurred in patients with IgE-mediated reactions, without changes in the IL-6 levels. But the opposite is true in CRR that raises IL-6 but no tryptase levels, thus IL-6 could be a potential biomarker for identifying cytokine-release reactions.

Biologics and anaphylaxis.

The use of biologicals as therapeutic agents in oncology and other inflammatory diseases has dramatically increased during the last years. Due to their biological nature and inherent immunological activity, they are able to induce important adverse events, such as cytokine release reactions (rapid release of proinflammatory cytokines), serum sickness disease, and immediate or delayed hypersensitivity reactions, including anaphylaxis. The aim of the current article is to review the state of the art of anaphylaxis because of biological agents. Different phenotypes, and potential underlying endotypes, have been described in anaphylactic reactions to biologicals. There seems to be a spectrum from type 1 reactions (IgE or non-IgE-mediated) to cytokine release reactions, with some reactions falling in between both. Management should be directed according to such phenotypes. There is ongoing research to further define immediate adverse reactions to biologicals and to find relevant biomarkers to aid in their diagnosis. Such information will serve in defining their immediate and long term management.

Serum cytokines elevated during gluten-mediated cytokine release in coeliac disease

Cytokines have been extensively studied in coeliac disease, but cytokine release related to exposure to gluten and associated symptoms has only recently been described. Prominent, early elevations in serum interleukin (IL)-2 after gluten support a central role for T cell activation in the clinical reactions to gluten in coeliac disease. The aim of this study was to establish a quantitative hierarchy of serum cytokines and their relation to symptoms in patients with coeliac disease during gluten-mediated cytokine release reactions. Sera were analyzed from coeliac disease patients on a gluten free-diet (n=25) and from a parallel cohort of healthy volunteers (n=25) who underwent an unmasked gluten challenge. Sera were collected at baseline and 2, 4 and 6h after consuming 10g vital wheat gluten flour; 187 cytokines were assessed. Confirmatory analyses were performed by high-sensitivity electrochemiluminescence immunoassay. Cytokine elevations were correlated with symptoms. Cytokine release following gluten challenge in coeliac disease patients included significant elevations of IL-2, chemokine (C-C motif) ligand 20 (CCL20), IL-6, chemokine (C-X-C motif) ligand (CXCL)9, CXCL8, interferon (IFN)-γ, IL-10, IL-22, IL-17A, tumour necrosis factor (TNF)-α, CCL2 and amphiregulin. IL-2 and IL-17A were earliest to rise. Peak levels of cytokines were generally at 4h. IL-2 increased most (median 57-fold), then CCL20 (median 10-fold). Cytokine changes were strongly correlated with one another, and the most severely symptomatic patients had the highest elevations. Early elevations of IL-2, IL-17A, IL-22 and IFN-γ after gluten in patients with coeliac disease implicates rapidly activated T cells as their probable source. Cytokine release after gluten could aid in monitoring experimental treatments and support diagnosis.

Abnormal Coagulation Function in Chimeric Antigen Receptor T Cell Treatment of Hematologic Malignancies

Chimeric Antigen Receptor T cell( CAR-T) is an effective treatment for refractory recurrent hematologic malignancies nowdays. However, CAR T cells can potentially damage normal tissues by specifically targeting a tumor-associated antigen that is also expressed on those tissues. Cytokine release syndrome (CRS), a systemic inflammatory response caused by cytokines, is the most common type of toxicity, including fever, hyoxemia, pain and so on. In our study, we found 6 cases abnormal coagulation function which was not very common complication after CAR-T infusion. 4 cases relapsed/refractory acute B lymphoblastic leukemia(B-ALL), including 2 female 53 and 45 years old, 2 male 20 and 6 years old. 1 case multiple myeloma(MM), female 65 years old and 1 case relapsed/refractory diffuse large B-cell lymphoma (DLBCL), male 17 years old. After conditioning chemotherapy with fludarabine and cyclophosphamide, CAR-T cells were infused into patients. In these cases, female 65 years old B-ALL patient had the most severe cytokine release reactions, multiple organ function damage, and abnormal coagulation function that prothrombin time (PT) and activated partial thromboplastin time (APTT) were prolonged and reached a peak (Too long to detect) on the 14th day after CAR-T infusion, while fibrinogen (FIB) was reduce d (peak on the 14 day, 0.328g/L) and D-Dimer, fibrinogen degradation products (FDP) significantly increased (peak on the 12th day, 28.7ug/mL and more than 10mg/L respectively). After positive hemostasis and other treatments with amperenic acid, vitamin K1 and so on, the level of PT, APTT, FIB, etc were returned to normal on the 19thday. The other 5 patients went through the same process, only slightly. Patients with severe abnormal coagulation function were prone to bleed and even life-threatening, and giving active treatment, finally they all recovered. For the first time, we reported the abnormal coagulation function after CAR-T infusion in hematologic malignancies. DisclosuresNo relevant conflicts of interest to declare.

Hypersensitivity reactions to therapeutic monoclonal antibodies: Phenotypes and endotypes

The increasing use of mAbs has led to a rise in hypersensitivity reactions (HSRs), which prevent their use as first-line therapy. HSRs' symptoms, diagnostic tools, and directed management approaches have not been standardized. We propose a novel evidence-based classification of HSRs to mAbs, based on the clinical phenotypes, underlying endotypes and biomarkers, as well as their management with desensitization. Phenotypes, endotypes, and biomarkers of HSRs to 16 mAbs for 104 patients were described and compared with the outcomes of 526 subcutaneous and intravenous desensitizations. Initial reactions presented with 4 patterns: type I-like reactions (63%), cytokine-release reactions (13%), mixed reactions (21%), and delayed type IV reactions (3%). In contrast, of the 23% breakthrough HSRs during desensitization, 52% were cytokine-release reactions, 32% were type 1, 12% were mixed, and 4% were type I with delayed type IV. Skin testing to 10 mAbs in 58 patients was positive in 41% of patients. Serum tryptase was elevated in 1 patient and IL-6 was elevated in 8 patients during desensitization and was associated with a cytokine-release phenotype. HSRs to mAbs can be defined as type I, cytokine-release, mixed (type I/cytokine-release), and type IV reactions, which are identified by biomarkers such as skin test, tryptase, and IL-6. These phenotypes can be used to improve personalized and precision medicine when diagnosing HSRs to mAbs and providing management recommendations with desensitization. Desensitization provides a safe and effective retreatment option to remain on culprit mAbs as first-line therapy.

Indications, Protocols, and Outcomes of Drug Desensitizations for Chemotherapy and Monoclonal Antibodies in Adults and Children

Advances in the understanding of various malignancies and chronic inflammatory diseases has led to the development of better treatment options for prolonging patient survival and minimizing morbidity. The recognition of "first-line" chemotherapy and monoclonal agents for these conditions has given more urgency to the need to re-administer these drugs in cases of drug hypersensitivity reactions. Therefore, in these cases, not only is desensitization considered when there is no alternative therapy available but also when alternative treatments are considered therapeutically inferior and/or more toxic. In this article, we describe the steps involved in the evaluation of these patients, factors to consider before making a decision to desensitize, the implementation of desensitization protocols, and the outcomes of such procedures.

Randomized Phase III Trial of Fludarabine Plus Cyclophosphamide With or Without Oblimersen Sodium (Bcl-2 antisense) in Patients With Relapsed or Refractory Chronic Lymphocytic Leukemia

Expression of Bcl-2 protein is associated with chemotherapy resistance and decreased survival in chronic lymphocytic leukemia (CLL). We evaluated whether oblimersen would improve response to chemotherapy in patients with relapsed or refractory CLL. Patients had received at least one prior fludarabine-containing regimen and were stratified on the basis of prior fludarabine response, number of prior regimens, and duration of response to last prior therapy. Patients were randomly assigned to 28-day cycles of fludarabine 25 mg/m2/d plus cyclophosphamide 250 mg/m2/d administered intravenously for 3 days with or without oblimersen 3 mg/kg/d as a 7-day continuous intravenous infusion (beginning 4 days before chemotherapy) for up to six cycles. The primary end point was the proportion of patients who achieved complete response (CR) or nodular partial response (nPR). Of 241 patients randomly assigned, CR/nPR was achieved in 20 (17%) of 120 patients in the oblimersen group and eight (7%) of 121 patients in the chemotherapy-only group (P = .025). Achievement of CR/nPR was correlated with both an extended time to progression and survival (P < .0001). In patients who remained sensitive to fludarabine, oblimersen was associated with a four-fold increase in the CR/nPR rate and a significant survival benefit (P = .05). Oblimersen was frequently associated with thrombocytopenia and, rarely, tumor lysis syndrome and cytokine release reactions; the incidence of opportunistic infections and second malignancies was similar in both groups. The addition of oblimersen to fludarabine plus cyclophosphamide significantly increases the CR/nPR rate in patients with relapsed or refractory CLL (particularly fludarabine-sensitive patients), as well as response duration among patients who achieve CR/nPR.

Clinical characterization of first cycle reactions in patients with chronic lymphocytic leukemia treated with oblimersen

16514 Background: Serious adverse reactions during the first treatment cycle characterize many drugs used for chronic lymphocytic leukemia (CLL), including rituximab, alemtuzumab, flavopiridol, lenalidomide, and oblimersen. Termed cytokine release reactions (CRRs), these events have occurred more commonly in pts with bulky disease and elevated leukocyte counts, and some have been fatal. Rapid increases in serum levels of tumor necrosis factor-α, interleukin-6, interleukin-2, interferon-γ, and other cytokines may result in symptoms including fever, chills, nausea, vomiting, hypotension, and dyspnea. Ex vivo treatment of CLL cells with oblimersen induce release of vasoactive interleukin-8. First cycle reactions, including tumor lysis syndrome (TLS), proved dose-limiting in a phase 1–2 trial of oblimersen in pts with relapsed or refractory CLL. To characterize these reactions, we evaluated data from this single-agent study and from a phase 3 randomized clinical trial of oblimersen with fludarabine and cyclophosphamide (Flu/Cy). Methods: Data on investigator assessment of CRR and TLS were obtained from both studies, which included 155 pts; 40 were treated with oblimersen alone (3–7mg/kg/d by CIV for 5–7 days) and 115 with oblimersen (3 mg/kg/d × 7 days) in combination with Flu/Cy. Results: Of 145 pts treated with oblimersen 3mg/kg/d, either alone or with Flu/Cy, 2 pts (1.3%) experienced CRR and TLS, respectively. Two CRRs occurred in 10 pts treated with 4–7mg/kg/d. Reactions typically began 24–48 hours after starting treatment. CCR was usually associated with spiking fever, nausea, dehydration, rigors, and back pain. Rarely pts developed hypotension, acidosis, or reversible renal insufficiency, usually with a reduction in WBC. Symptoms lasted 1 day to several weeks (1 pt). In most cases, reactions were reversible with intensive supportive care, including IV fluids, pressors, and antibiotics; 1 death from TLS and 1 from CCR occurred during cycle 1. There was no definitive correlation with baseline measures of disease burden. Conclusion: First cycle oblimersen reactions are uncommon but represent a risk. Early symptoms (fever, nausea, and dehydration) require aggressive treatment, which may prevent progression of the reaction. [Table: see text]

Pooled safety analysis of oblimersen alone or with fludarabine and cyclophosphamide in patients with advanced chronic lymphocytic leukemia

6611 Background: Bcl-2 is an antiapoptotic protein linked to chemotherapy resistance and poor prognosis in chronic lymphocytic leukemia (CLL) patients (pts). Oblimersen (Obl), an anti-Bcl-2 oligonucleotide, has been shown to enhance apoptosis induced by fludarabine (Flu) + cyclophosphamide (Cy) in pts with relapsed CLL. We combined safety results from 2 CLL clinical trials to determine the relative effect of Obl on treatment-emergent adverse events (TEAEs) in Obl+Flu+Cy therapy. Methods: This analysis included 30 pts who received Obl 3mg/kg/d alone by continuous IV on days 5–7 and 230 pts who received Flu 25mg/m2/d + Cy 250mg/m2/d on days 5–7, every 28th day, either with (n=115) or without (n=115) Obl 3mg/kg/d on days 1–7. Mean number of cycles initiated were 3.3, 3.6, and 4.0 for Obl, Obl+Flu+Cy, and Flu+Cy, respectively. Results: The most frequent (&gt;2% patients) grade 4 TEAEs were mainly hematologic: neutropenia (Obl alone, 0.0%; Flu+Cy, 11.3%; Obl+Flu+Cy 7.0%), thrombocytopenia (3.3%, 1.7%, 4.3%), anemia (0.0%, 5.2%, 3.5%), febrile neutropenia (0.0%, 0.9%, 2.6%), hypotension (0.0%, 0.0%, 2.6%), and leukopenia (0.0%, 2.6%, 0.0%). Thrombocytopenic events with Obl-Flu-Cy were reversible and were not associated with clinically significant bleeding events. The most frequent non-hematologic grade 3–4 TEAEs (&gt;5%) were nausea (0.0%, 1.7%, 7.8%), vomiting (0.0%, 0.9%, 6.1%), fatigue (3.3%, 4.3%, 6.1%), and dyspnea (3.3%, 1.7%, 5.2%). Serious TEAEs occurred at a rate of 23.3%, 32.2%, and 57.4%, respectively. TEAEs resulting in death occurred in 2 pts (Obl alone), 5 pts (Flu+Cy), and 9 pts (Obl+Flu+Cy). One Obl+Flu+Cy death was due to cytokine release reaction and one to tumor lysis syndrome. Discontinuation due to TEAEs occurred in 20.0% of pts who received Obl alone, in 34.8% of Flu+Cy pts, and in 34.8% of Obl+Flu+Cy pts. Conclusions: The addition of Obl to Flu+Cy was well tolerated, with similar low frequencies of grade 3+4 TEAEs, primarily the same type observed with Flu+Cy alone. Despite an increased incidence of serious TEAEs observed with Obl+Flu+Cy, the percentage of patients who discontinued protocol therapy due to a TEAE was the same in each group. First cycle reactions mandate close observation when initiating combination therapy. [Table: see text]

8. Drug allergy

Drug reactions can be considered as being either predictable or unpredictable. A predictable reaction would be the result of the pharmacologic action of the medication. An unpredictable reaction might be idiosyncratic, might be drug intolerance, or might have or imply an immunologic basis, such as being IgE mediated. Immediate reactions that are not IgE mediated can be considered as pseudoallergic (non-IgE-mediated mast cell activation). This review will discuss allergic and immunologic reactions to immunomodulators, penicillins and cephalosporins, sulfonamides, aspirin, and nonselective nonsteroidal anti-inflammatory drugs and consider the serious drug-related conditions of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). The field of drug "allergy" has expanded to include adverse reactions associated with immunosuppressive medications, anticytokine therapies, and mAbs. The cytokine release reaction that occurs with anti-CD20 antibody infusions in patients with leukemia and white blood cell counts of greater than 50 x 10(9)/L is associated with high concentrations of TNF, IL-6, and IL-8. Because of the findings of fever, dyspnea, rigors, and hypotension, this reaction resembles the Jarisch-Herxheimer reaction that occurs 60 to 90 minutes after penicillin administration in patients with secondary syphilis. Furthermore, the care of the patient with penicillin allergy has been made more difficult in the absence of the major determinant, penicilloyl-polylysine, in that from 34% to 84% of patients who have positive skin test reactions to penicillin have exclusively positive reactions to the major determinant. SJS and TEN typically are caused by medications within 1 to 8 weeks of initiation of therapy. Evidence for death of the keratinocytes through (1) drug-specific cytotoxicity with the perforin-granzyme B-mediated killing and (2) activation of Fas on keratinocytes have provided explanations for the sloughing of skin. Unfortunately, intravenous immunoglobulin therapy for SJS and TEN has been disappointing.

A Phase I Humanized Anti-CD40 Monoclonal Antibody (SGN-40) in Patients with Multiple Myeloma.

SGN-40, a humanized anti-CD40 monoclonal antibody, is being evaluated in a phase I dose escalation study for patients with relapsed and/or refractory multiple myeloma. This single-arm trial is designed to evaluate safety, pharmacokinetics, immunogenicity, antitumor activity, and the maximum tolerated dose. SGN-40 has demonstrated potent in vitro and in vivo efficacy against cell lines expressing CD40, a member of the tumor necrosis factor receptor family. CD40 is widely expressed on tumors of B-cell origin, including myeloma, non-Hodgkin's lymphoma, Hodgkin's disease, and chronic lymphocytic lymphoma. The original protocol called for cohorts of patients to be treated with four weekly infusions of 0.5, 1.0, 2.0, 4.0, 8.0, or 16.0 mg/kg. Sixteen patients were treated at doses ranging from 0.5 – 4.0 mg/kg/wk for four weeks. Enrollment of new patients was temporarily halted after two of three patients developed severe headaches and aseptic meningitis following the first dose at 4 mg/kg. Grade 1 headaches were seen after the first dose in three of six patients receiving 2 mg/kg, but no patients at lower doses reported headaches. We have determined that this drug-related event is a first-dose effect, and was not seen clinically after second or subsequent infusions of SGN-40. SGN-40 appears to trigger cytokine release, and TNF-alpha levels in the plasma are elevated following the first infusion only. Initial pharmacokinetic data in humans demonstrate that the half-life of SGN-40 depends on the dose given: mean values after the first and third infusions were 0.9 and 1.3 days, respectively, at 0.5 mg/kg; 1.7 and 2.6 days at 1.0 mg/kg; and 2.9 and 4.2 days at 2.0 mg/kg. This is consistent with results in non-human primates, in which the half-life was relatively short at low doses. These data suggest that there is a rapid elimination pathway and/or redistribution volume that has not been saturated at the doses used to date. Although human anti-human antibodies (HAHA) have not yet been measured, the preliminary analysis suggests that if antibodies were formed, they did not significantly affect pharmacokinetics. Even at the low doses tested thus far, there is preliminary evidence for antitumor activity; four of sixteen patients had declining serum and/or urine M-protein during treatment. Of note, these four individuals also demonstrated the most profound B-cell depletion during therapy, an expected consequence of SGN-40 activity. This protocol has been amended to include a drug-loading period that should eliminate first-dose cytokine release syndrome. Dose escalation is ongoing under the revised protocol, and no headaches have been seen in the first cohort at a peak dose of 3 mg/kg. In conclusion, SGN-40 demonstrated an apparent first-dose cytokine release reaction that required a modification in the dosing strategy. Pharmacokinetic data suggest that higher doses are required to saturate the elimination pathway, and preliminary antitumor activity is encouraging.

A Phase I Study of Humanized Anti-CD40 Immunotherapy with SGN-40 in Non-Hodgkin's Lymphoma.

The vast majority of B-cell malignancies express CD40, a member of the TNF receptor family. This receptor, along with the cognate ligand (CD154), mediates cell survival and proliferation of normal B-cells and can regulate apoptosis as well as survival in transformed cells, making this pathway an appealing target for B-cell lymphoma. Both in vitro and in vivo preclinical studies support the development of anti-CD40 immunotherapy for non-Hodgkin's lymphoma (NHL). Accordingly, a phase I single-arm dose escalation trial was initiated to test the safety, pharmacokinetics, and antitumor activity of SGN-40, a humanized anti-CD40 antibody, in patients with NHL. The protocol was designed to treat patients with follicular, mantle cell, diffuse large B-cell, small lymphocytic, and marginal zone lymphomas in cohorts using SGN-40 infusions at doses of 2, 4, 8, or 16 mg/kg/week for four weeks. We report results for cohort 1 (n = 6) treated at 2 mg/kg/week. Four of 6 patients completed the planned 4 weekly infusions. No grade 4 toxicity was observed. Two grade 3 toxicities were seen, both in the same patient (unilateral conjunctivitis and ipsilateral loss of vision in a patient with pre-existing macular degeneration). Grade 2 loss of balance was also seen in the same patient. Imaging studies with CT and MRI did not reveal a stroke or leptomeningeal disease nor were there inflammatory or malignant cells in the CSF. All these adverse events resolved over six weeks, including vision which returned to baseline acuity. The only other severe adverse event reported was a deep venous thrombosis in the setting of bulky ipsilateral pelvic adenopathy, which was considered to be unrelated to SGN-40. Dose escalation was temporarily suspended to evaluate these unexplained toxicities and the report of severe headaches, attributed to cytokine release reaction, at the next dose level (i.e. 4 mg/kg) in a parallel phase I protocol for multiple myeloma. Although none of the NHL patients in this study developed headaches or clinical symptoms, several patients demonstrated a significant increase in plasma cytokine levels (i.e. TNF-alpha, IL-6) following the first infusion but not subsequent treatments with SGN-40, raising the possibility that a first-dose cytokine release effect may be involved in the grade 3 toxicities observed. Pharmacokinetic samples for the NHL patients were collected and are currently being analyzed. Preliminary antitumor activity at the 2 mg/kg dose is reflected in one patient who had stable disease as determined by serial CT scans and in another patient who had subjective improvement in B symptoms during therapy but was found to have disease progression based on CT scans 4 weeks after completing therapy. An amended protocol is actively accruing patients that will address the concern for first-dose cytokine release and allow continued dose escalation. Clinical and pharmacokinetic data from these additional cohorts will be presented.

A potential role of YC-1 on the inhibition of cytokine release in peripheral blood mononuclear leukocytes and endotoxemic mouse models

To evaluate the anti-sepsis potential of YC-1, we have examined the effect of YC-1 on the regulation of cytokine production in human leukocytes and endotoxemic mice. The data demonstrated that YC-1 showed a preferential inhibition on proinflammatory cytokine production without inhibition of cell growth or induction of cytotoxicity in human leukocytes. On the other hand, in the septic mouse model, treatment with an intraperitoneal application of LPS caused a cumulative death within 27 hours. The post-treatment administration of YC-1 significantly increased the survival rate in endotoxemic mice. Furthermore, several mediators were detected and the data showed that YC-1 profoundly blocked LPS-induced NO as well as TNF-alpha production, and prevented lung damage by histological examination. Samples from the animal model showed that LPS-induced NF-kappaB/DNA binding activity and consequent up-regulation of iNOS expression in tissues were abolished by post-administration of YC-1. Furthermore, YC-1, by itself, did not modify cGMP content while significantly inhibit LPS-induced cGMP formation, suggesting that YC-1-mediated effect was not through a cGMP-elevating pathway. Taken together, it is evident that the post-treatment administration of YC-1 after LPS application significantly inhibits NF-kappaB activation, iNOS expression, NO over-production, and cytokine release reaction resulting in an improved survival rate in endotoxemic mice. It is suggested that YC-1 may be a potential agent for the therapeutic treatment of sepsis.

Use of basiliximab and daclizumab in kidney transplantation

Kidney transplantation represents a major medical victory in patients with whom dialysis and medical therapy have failed. To increase survival rates and optimize the use of limited organs, both patient care and immunosuppression therapy must be improved. Reduction in rejection episodes or severity of rejection may ultimately improve long-term allograft survival. Traditional engineered monoclonal antibodies have been associated with severe cytokine release reactions and an increased risk of opportunistic infections. Basiliximab and daclizumab are chimeric and humanized monoclonal antibodies which inhibit thymus-dependent lymphocyte proliferation. Interleukin-2 also affects the proliferation of natural killer cells, macrophages and monocytes, bursa-equivalent lymphocytes, epidermal dendritic cells, and lymphokine-activated killer cells. Interleukin-2 receptor antagonists have been shown to reduce the incidence of acute rejection without increasing the incidence of opportunistic infections or malignancy. Further studies are needed to evaluate the overall effect of these agents on long-term patient and allograft survival.

DACLIZUMAB (ZENAPAX) IN PEDIATRIC (PED) RENAL TRANSPLANTATION AT UCLA.

701 Acute rejection (AR) precedes the development of chronic rejection and graft failure in up to 90% of ped renal transplant (Tx) patients (pts). Higher potency immunosuppressive (IMS) agents may be associated with higher rates of infectious complications and malignancy. Daclizumab (Dac) is a humanized monoclonal antibody with specificity for the α-subunit (CD25) of the IL-2 receptor (IL-2R) expressed on activated T cells. We retrospectively analyzed the data for 36 ped pts treated with Dac. Pts received Dac 1 mg/kg/dose IV within 24 hrs before Tx, and then biweekly for a total of 5 doses. Maintenance IMS consisted of triple therapy with cyclosporine (CsA), mycophenolate mofetil (MMF), and prednisone (PR) in all but one pt who received FK506 and prednisone. 14 pts (39%) received living related donor Tx. 33 were primary Tx and 3 were re-Tx. 4 pts (11%) were seronegative for CMV and received Tx from seropositive donors. Mean age was 13 yrs; 5 pts were 1-5 yrs, 8 were 6-12 yrs, and 23 were >12 yrs old. The mean follow-up was 484 days; 14 pts (39%) completed 1 yr, and 6 pts (17%) completed 6 months of follow-up. No first-dose or cytokine-release reactions were observed. No graft was lost to rejection, only one graft was lost immediately due to vascular thrombosis. Only 2 pts (5%) developed AR at days 67 and 41, both responded to solu-medrol. Infectious complications were infrequent: Bacteremia, peritonitis, and wound infection occurred each in 4 pts (11%), 8 pts (22%) developed urinary tract infections. Only 2 pts (5%) developed CMV viremia, both were seronegative for CMV and received Tx from seropositive donors. No pt developed EBV infection, post-Tx lymphoproliferative disease or other malignancy. IL-2R saturation studies with anti-CD25 and 7G7/B6 antibodies were available for the first 16 pts. IL-2R saturation was present after the first dose of Dac, and remained so for at least one month after the last dose. There was no increase in CD25 expression in the 2 pts who developed AR at the time of rejection. We conclude that the use of Dac in addition to the current triple therapy with CsA, PR, and MMF reduces the occurrence of AR without increasing the risk for adverse reactions or infections.