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Background New therapies are needed to manage the increasing incidence, severity, and high rate of recurrence of Clostridium difficile infection. Methods We performed a randomized, double-blind, placebo-controlled study of two neutralizing, fully human monoclonal antibodies against C. difficile toxins A (CDA1) and B (CDB1). The antibodies were administered together as a single infusion, each at a dose of 10 mg per kilogram of body weight, in patients with symptomatic C. difficile infection who were receiving either metronidazole or vancomycin. The primary outcome was laboratory-documented recurrence of infection during the 84 days after the administration of monoclonal antibodies or placebo. Results Among the 200 patients who were enrolled (101 in the antibody group and 99 in the placebo group), the rate of recurrence of C. difficile infection was lower among patients treated with monoclonal antibodies (7% vs. 25%; 95% confidence interval, 7 to 29; P

Objective: Ipilimumab is a fully human, anti–cytotoxic T-lymphocyte antigen-4 (CTLA-4) monoclonal antibody that has demonstrated antitumor activity in advanced melanoma. We evaluated the safety and efficacy of ipilimumab alone and in combination with dacarbazine (DTIC) in patients with unresectable, metastatic melanoma. Methods: Chemotherapy-naive patients were randomized in this multicenter, phase II study to receive ipilimumab at 3 mg/kg every 4 weeks for four doses either alone or with up to six 5-day courses of DTIC at 250 mg/m2/day. The primary efficacy endpoint was objective response rate. Results: Seventy-two patients were treated per-protocol (ipilimumab plus DTIC, n = 35; ipilimumab, n = 37). The objective response rate was 14.3% (95% CI, 4.8–30.3) with ipilimumab plus DTIC and was 5.4% (95% CI, 0.7–18.2) with ipilimumab alone. At a median follow-up of 20.9 and 16.4 months for ipilimumab plus DTIC (n = 32) and ipilimumab alone (n = 32), respectively, median overall survival was 14.3 months (95% CI, 10.2–18.8) and 11.4 months (95% CI, 6.1–15.6); 12-month, 24-month, and 36-month survival rates were 62%, 24% and 20% for the ipilimumab plus DTIC group and were 45%, 21% and 9% for the ipilimumab alone group, respectively. Immune-related adverse events were, in general, medically manageable and occurred in 65.7% of patients in the combination group versus 53.8% in the monotherapy group, with 17.1% and 7.7% ≥grade 3, respectively. Conclusion: Ipilimumab therapy resulted in clinically meaningful responses in advanced melanoma patients, and the results support further investigations of ipilimumab in combination with DTIC.

Background An improvement in overall survival among patients with metastatic melanoma has been an elusive goal. In this phase 3 study, ipilimumab — which blocks cytotoxic T-lymphocyte–associated antigen 4 to potentiate an antitumor T-cell response — administered with or without a glycoprotein 100 (gp100) peptide vaccine was compared with gp100 alone in patients with previously treated metastatic melanoma. Methods A total of 676 HLA-A*0201–positive patients with unresectable stage III or IV melanoma, whose disease had progressed while they were receiving therapy for metastatic disease, were randomly assigned, in a 3:1:1 ratio, to receive ipilimumab plus gp100 (403 patients), ipilimumab alone (137), or gp100 alone (136). Ipilimumab, at a dose of 3 mg per kilogram of body weight, was administered with or without gp100 every 3 weeks for up to four treatments (induction). Eligible patients could receive reinduction therapy. The primary end point was overall survival. Results The median overall survival was 10.0 months among patients receiving ipilimumab plus gp100, as compared with 6.4 months among patients receiving gp100 alone (hazard ratio for death, 0.68; P

Purpose: Immunotherapeutic agents produce antitumor effects by inducing cancer-specific immune responses or by modifying native immune processes. Resulting clinical response patterns extend beyond those of cytotoxic agents and can manifest after an initial increase in tumor burden or the appearance of new lesions (progressive disease). Response Evaluation Criteria in Solid Tumors or WHO criteria, designed to detect early effects of cytotoxic agents, may not provide a complete assessment of immunotherapeutic agents. Novel criteria for the evaluation of antitumor responses with immunotherapeutic agents are required. Experimental Design: The phase II clinical trial program with ipilimumab, an antibody that blocks CTL antigen-4, represents the most comprehensive data set available to date for an immunotherapeutic agent. Novel immune therapy response criteria proposed, based on the shared experience from community workshops and several investigators, were evaluated using data from ipilimumab phase II clinical trials in patients with advanced melanoma. Results: Ipilimumab monotherapy resulted in four distinct response patterns: (a) shrinkage in baseline lesions, without new lesions; (b) durable stable disease (in some patients followed by a slow, steady decline in total tumor burden); (c) response after an increase in total tumor burden; and (d) response in the presence of new lesions. All patterns were associated with favorable survival. Conclusion: Systematic criteria, designated immune-related response criteria, were defined in an attempt to capture additional response patterns observed with immune therapy in advanced melanoma beyond those described by Response Evaluation Criteria in Solid Tumors or WHO criteria. Further prospective evaluations of the immune-related response criteria, particularly their association with overall survival, are warranted. (Clin Cancer Res 2009;15(23):7412–20)

Therapeutic cancer vaccines are a heterogeneous group of complex biologics with distinctly different clinical characteristics than cytotoxic agents. The current clinical development paradigm used for oncology drug development is based on criteria developed for cytotoxic agents. More flexible and focused developmental guidelines are needed to address the unique characteristics of therapeutic cancer vaccines. Over the course of 1 year, the Cancer Vaccine Clinical Trial Working Group, representing academia and the pharmaceutical and biotechnology industries with participation from the US Food and Drug Administration, defined in a consensus process the cornerstones of a new clinical development paradigm for cancer vaccines and related biologics. Four major topics were addressed: (1) end points for clinical trials, (2) trial designs and statistical methods, (3) technical and developmental challenges, and (4) combination therapy. The proposed paradigm suggests therapeutic cancer vaccines to be investigated in 2 general types of clinical studies: proof-of-principle trials and efficacy trials. Proof-of-principle trials, which introduce a novel cancer vaccine into humans, should include a minimum of 20 or more patients in a homogenous, well-defined population in an adjuvant setting or without rapidly progressive disease in a metastatic setting to allow vaccines adequate time to induce biologic activity and should incorporate immune and molecular markers. Objectives should include initiation of a safety database, determination of dose and schedule, and demonstration of biologic activity as proof-of-principle. Biologic activity is defined as any effect of the vaccine on the target disease or host immune system using biologic markers as study end points, for example, clinical, molecular, or immune response. Immune response is demonstrated if determined in 2 separate, established and reproducible assays at 2 consecutive follow-up time points after the baseline assessment. If proof-of-principle trials show such immune response, or other biologic or clinical activity, efficacy trials may be initiated. If none of these end points is met, the clinical development plan should be reevaluated to decide if further development is warranted. Efficacy trials formally establish clinical benefit either directly or through a surrogate and are encouraged to be randomized studies. This is in contrast to single-arm phase 2 trials used for cytotoxic agents, which often use tumor response rate as the primary end point and historical controls as a comparator. Efficacy trials may use prospectively planned adaptive designs to expand from randomized phase 2 into phase 3 studies if well-defined trigger-point criteria are met, but the cost of incorporating such design elements should be carefully evaluated. Efficacy trials can also be exploratory randomized phase 2 trials or conventional phase 3 trials. In addition, conventional clinical end points can be adjusted to account for biologic features of cancer vaccines. The concept of efficacy trials allows for an early assessment of vaccine efficacy based on credible prospective data. This 2-phase developmental paradigm supports a more flexible, expeditious, and focused clinical developmental process with early and informed decision making. In addition, this report addresses clinical development challenges and issues for combination therapies.

PurposeNineteen patients with high-risk resected stage III and IV melanoma were immunized with three tumor antigen epitope peptides from gp100, MART-1, and tyrosinase emulsified with adjuvant Montanide ISA 51 and received a fully human anti-cytotoxic T-lymphocyte antigen-4 (anti–CTLA-4) monoclonal antibody MDX-010. Each of three cohorts received escalating doses of antibody with vaccine primarily to evaluate the toxicities and maximum-tolerated dose (MTD) of MDX-010 with vaccine. MDX-010 pharmacokinetics and immune responses were secondary end points.Patients and MethodsPeptide immunizations with MDX-010 were administered every 4 weeks for 6 months and then every 12 weeks for 6 months. A leukapheresis to obtain peripheral-blood mononuclear cells for immune analyses was performed before treatment and after the sixth vaccination. Patients were observed until relapse.ResultsGrade 3 gastrointestinal (GI) toxicity (diarrhea or abdominal pain) was observed in three patients in the highest dose cohort and one in the middle dose cohort who seemed to be autoimmune. That defined the MTD with vaccine on this schedule at 1 mg/kg. Of eight patients with evidence of autoimmunity, three have experienced disease relapse. Of 11 patients without autoimmune symptoms, nine have experienced disease relapse. Significant immune responses were measured by tetramer and enzyme-linked immunospot assays against gp100 and MART-1.ConclusionDose-related autoimmune adverse events, predominantly skin and GI toxicities, were reversible. Patients mounted an antigen-specific immune response to a peptide vaccine when combined with a human anti–CTLA-4 antibody.

3018 Background: Ipilimumab is a fully human monoclonal antibody directed against cytotoxic T-lymphocyte antigen-4 (CTLA-4), a critical suppressor of antitumor immune activity. Previously presented...

9022 Background: Ipilimumab is a fully human monoclonal antibody targeting cytotoxic T-lymphocyte antigen-4 (CTLA-4) that gave durable complete/partial responses [CR/PR] and stable disease [SD]) in...

20004 Background: Ipilimumab is a fully human, anti-CTLA-4 monoclonal antibody that has been associated with complete and partial responses when administered as monotherapy or in combination with a...

8523 Background: Ipilimumab, a fully human monoclonal antibody that blocks cytotoxic T-lymphocyte antigen-4 (CTLA-4), enhances antitumor immune responses resulting in durable objective responses. In this study we examined the efficacy and safety of different ipilimumab preparations and regimens in patients with unresectable metastatic melanoma. Methods: In this study (MDX010–15), 34 patients received either 2.8 or 5 mg/kg transfectoma- or 3 mg/kg hybridoma-derived ipilimumab on days 1, 57 and 85. Additionally, 30 patients received single doses of 7.5 (6 pts), 10 (7 pts), 15 (6 pts) or 20 mg/kg (11 pts) transfectoma-derived ipilimumab. Once single doses up to 20 mg/kg were found to be well tolerated, 24 additional patients were given up to 4 doses of 10 mg/kg ipilimumab on days 1, 22, 43 and 64. Complete or partial responses (CR, PR), stable disease (SD) and adverse events (AEs) were monitored. Results: 1 CR, 3 PRs and 10 durable SDs were confirmed in 88 treated patients at the time of analysis. ORs were durable (∼29+, 34, 38+ and 39+ weeks [w]) and ongoing in 3 patients at study completion. PR in 1 patient was observed after ∼18.5w and developed to an ongoing CR at ∼51w. In another, SD for ∼16w preceded a ∼30w+ PR. Durable SD ranged from ∼21 to 79+w and is ongoing in 4 patients. Patients with OR or SD had immune-related AEs including rash, pruritis (G1/2), diarrhea (G1/2/3) or colitis (G2). AEs were severe in 27 patients, and considered ipilimumab-related (mostly G3/G4 colitis and diarrhea) in 9 (10% of all treated patients). Conclusions: Preliminary results suggest ipilimumab is generally safe and well tolerated. Late-onset ORs can occur, sometimes preceded by months of SD. ORs and SDs tend to be durable. Drug-related AEs of an immune nature are probably related to the biologic effects of ipilimumab, and are similar to those reported previously. No obvious dose relationship to AEs has been seen to date. [Table: see text]

8525 Background: Ipilimumab, a fully human monoclonal antibody that blocks cytotoxic T-lymphocyte antigen-4 (CTLA-4), enhances immune responses to tumor-associated antigens resulting in durable objective responses (OR). This abstract describes the kinetics of response after ipilimumab treatment. Methods: 5 studies (2 complete; 3 ongoing) in 269 treated patients with stage III/IV melanoma were reviewed and analyzed to determine the kinetics and duration of response after ipilimumab. Patients received ipilimumab alone or with dacarbazine, IL-2 or gp100 peptide vaccine. Ipilimumab doses ranged from 0.3–10mg/kg/dose (single or multiple). Complete and partial response (CR, PR), stable and progressive disease (SD, PD) were evaluated. Results: 41 patients (15%) had a confirmed OR at analysis. CR and PR was of late onset in some patients and occurred from ∼10–106 and ∼5–62 weeks (w) post-treatment initiation, respectively. In 28 patients onset of CR or PR occurred after >∼12w of treatment. PD preceded OR (without additional therapy) in 4 patients. In 2 patients, PD measured at ∼6w post-treatment initiation was followed by a PR at ∼12w. In 1 patient the PR changed to a CR at ∼24w and lasted for ∼188w+; the other patient maintained a PR for ∼17w. In the other 2 patients, PD at ∼12w was followed by SD at ∼17–20w and a PR after ∼30 and 62w; PRs in both patients lasted for ∼17 and 40w+, respectively. Duration of OR ranged from ∼6–187w+; ORs are ongoing in 25 patients. Late onset occurred irrespective of dose, regimen and therapeutic partner. Conclusions: Preliminary results suggest that ORs with ipilimumab may be later in onset and more durable than with traditional chemotherapy and may occur after progression. This late onset of effect likely reflects the immune-related mechanism of action of ipilimumab, and suggests that continued treatment/observation may be beneficial despite initial PD or SD. Acknowledgement: Dr. S. Rosenberg [Table: see text]

2510 Background: Ipilimumab is a human anti-CTLA-4 antibody shown to have clinical activity in melanoma and renal cancer that is associated with inflammatory-type adverse events termed immune breakthrough events (IBEs). Methods: 25 patients with resected stages IIIC/IV melanoma received MART-1/gp100/tyrosinase peptides with adjuvant Montanide ISA 51 12 times injected subcutaneously with Ipilimumab at 3 mg/kg intravenously every eight weeks for 12 months. The primary endpoints were toxicity and the achievement of a 40% rate of tolerable IBEs, and 20% or less rate of intolerable adverse events. Immune responses measured by ELISPOT and peptide-tetramer assays, and time to relapse were also assessed. The three melanoma peptides differed from wild type by one amino acid modification to increase HLA binding, and were administered at 1000 mcg/dose each. Results: Median age was 55, with 13 men and 12 women. 15 patients had stage IV, and 10 had stage IIIC resected disease. Thus far, 12/25 (48%) patients had grades 2–3 IBEs; 5 (20%) were dose limiting; 7 had GI toxicity, of which 2 were dose limiting; four had skin toxicity, of which 2 were dose limiting; one patient had hypopituitarism, which was also dose limiting. No patient with dose limiting toxicity required hospitalization and all returned to baseline status with the use of systemic steroids. Serologic assays of IBD-related microbial and auto-antibodies showed that seven of eight patients tested had increases in ANCA IgG or I2 IgA, and 5/8 had increases in ASCA IgA. Four of 25 patients have relapsed with a median of 10 months of follow-up. Two were again rendered NED surgically. The two remaining patients were treated with biochemotherapy, with one CR and one PR. All 25 patients are alive, one with disease. No patient with grade 2–3 IBEs has relapsed. ELISPOT assays showed that 10/11 patients tested responded in fresh PBMC to MART-1 and gp100. Conclusions: These data suggest that IBEs are associated with clinical benefit in patients with resected high-risk melanoma receiving Ipilimumab at 3 mg/kg with a peptide vaccine, and support testing the current regimen in a larger randomized trial. [Table: see text]

7525 Background: CTLA-4 is a negative regulator of cytotoxic T cell responses and may contribute to tumor escape from immune surveillance. MDX-010 is an IgG1κ fully human monoclonal antibody that blocks CTLA-4 function and is being studied in patients with metastatic melanoma and other malignancies. The current Phase II study was conducted to determine the safety and efficacy of MDX-010 when given alone or in combination with dacarbazine in chemotherapy and vaccine naive patients with unresectable metastatic melanoma. Dacarbazine is an FDA approved agent for metastatic melanoma with an approximate 10% objective response rate (ORR) but no demonstrable survival benefit. Long-term follow-up data on response duration and median progression-free survival for this Phase II study is now reported. Methods: Patients were randomized to receive MDX-010 at 3 mg/kg monthly x 4 (arm A; n=37) or MDX-010 in combination with dacarbazine 250 mg/m2 for 5 days monthly x 4 (arm B; n=35). Clinical response was measured by RECI...

Since 1978 we have taken an interest in lower respiratory tract infections associated with Branhamella catarrhalis in Christchurch, New Zealand. In a preliminary trial, 20 patients with bronchopulmonary infection caused by beta-lactamase-producing B. catarrhalis were treated with a combination tablet of amoxycillin 500 mg and clavulanic acid 125 mg ('Augmentin') 3 times daily for 5 days. Sputum cultures were negative for B. catarrhalis within 3 days in all patients. Two of 7 patients whose sputum cultures were positive for this organism at a review 2 to 4 weeks later were successfully treated with a further course of amoxycillin/clavulanic acid.

After the resection of a localized lung carcinoma, a 65-year-old veteran developed jejunal perforation and pneumonia, both of which subsequently were shown to be caused by infection with Strongyloides stercoralis. The patient recovered after jejunal resection and treatment with thiabendazole. Several unusual aspects of the case are discussed.