Terminal complement inhibitor eculizumab in atypical hemolytic-uremic syndrome.

BACKGROUND: Atypical hemolytic-uremic syndrome is a genetic, life-threatening, chronic disease of complement-mediated thrombotic microangiopathy. Plasma exchange or infusion may transiently maintain normal levels of hematologic measures but does not treat the underlying systemic disease. METHODS: We conducted two prospective phase 2 trials in which patients with atypical hemolytic-uremic syndrome who were 12 years of age or older received eculizumab for 26 weeks and during long-term extension phases. Patients with low platelet counts and renal damage (in trial 1) and those with renal damage but no decrease in the platelet count of more than 25% for at least 8 weeks during plasma exchange or infusion (in trial 2) were recruited. The primary end points included a change in the platelet count (in trial 1) and thrombotic microangiopathy event-free status (no decrease in the platelet count of >25%, no plasma exchange or infusion, and no initiation of dialysis) (in trial 2). RESULTS: A total of 37 patients (17 in trial 1 and 20 in trial 2) received eculizumab for a median of 64 and 62 weeks, respectively. Eculizumab resulted in increases in the platelet count; in trial 1, the mean increase in the count from baseline to week 26 was 73×10(9) per liter (P<0.001). In trial 2, 80% of the patients had thrombotic microangiopathy event-free status. Eculizumab was associated with significant improvement in all secondary end points, with continuous, time-dependent increases in the estimated glomerular filtration rate (GFR). In trial 1, dialysis was discontinued in 4 of 5 patients. Earlier intervention with eculizumab was associated with significantly greater improvement in the estimated GFR. Eculizumab was also associated with improvement in health-related quality of life. No cumulative toxicity of therapy or serious infection-related adverse events, including meningococcal infections, were observed through the extension period. CONCLUSIONS: Eculizumab inhibited complement-mediated thrombotic microangiopathy and was associated with significant time-dependent improvement in renal function in patients with atypical hemolytic-uremic syndrome. (Funded by Alexion Pharmaceuticals; C08-002 ClinicalTrials.gov numbers, NCT00844545 [adults] and NCT00844844 [adolescents]; C08-003 ClinicalTrials.gov numbers, NCT00838513 [adults] and NCT00844428 [adolescents]).

The safety and efficacy of B-domain deleted recombinant factor VIII concentrate in patients with severe haemophilia A.

BACKGROUND: B-domain-deleted recombinant factor VIII (BDDrFVIII) was developed when the B-domain was found to be redundant for maintaining haemostasis. This allows formulation of the final product without albumin added as a stabilizer. METHODS: Three multicentre clinical studies and one pharmacokinetic study were conducted in 218 patients to evaluate the safety and haemostatic efficacy of BDDrFVIII. RESULTS: Previously treated patients (n = 113; median duration, 1711 days; median exposure days, 385; total 98,096,287 IU infused) rated 97-99% of all infusions as good or excellent efficacy. FVIII inhibitor was noted in one patient in the previously treated patient cohort after 113 exposure days. Among 101 previously untreated patients, responses to BDDrFVIII were rated as excellent or good in 92-95% of infusions (median duration, 1413 days; median exposure days, 148; total 12,636,458 IU infused). Thirty-two previously untreated patients developed inhibitors after a median duration of 12 exposure days (range, 3-49). Sixteen of 32 (50%) patients had low levels (< or = 5 Bethesda units) and 16 had high levels of inhibitors. Inhibitors disappeared in six of 14 (43%) of the high-level and six of eight (75%) of the low-level patients who underwent immune tolerance induction therapy. A total of 42 patients underwent surgery and the overall efficacy of BDDrFVIII was rated as excellent or good for 99.6% of infusions. CONCLUSIONS: The results of these clinical studies indicate that BBDrFVIII is safe and effective and has haemostatic activity similar to that of full-length FVIII concentrates.

Clinical evaluation of B-domain deleted recombinant factor VIII in previously treated patients.

The pharmacokinetics, safety, and efficacy of B-domain deleted recombinant factor VIII (BDDrFVIII) were evaluated in patients with hemophilia A. In an initial 12-month study with subsequent yearly extensions over a 5-year period, 113 previously treated patients (PTPs) received on-demand and/or prophylactic treatment with BDDrFVIII, including treatment during surgery, if required. Half-life and recovery of factor VIII activity remained unchanged over the study period. The mean elimination half-life was 10.5 +/- 2.6 hours at baseline and 10.4 +/- 3.3 hours at month 12. A total of 7,310 hemorrhages occurred for patients who received on-demand treatment, with 71% resolving after a single infusion. Of the 11,655 rated infusions given for hemorrhages, 92% were rated by investigators and patients as providing an "excellent" or "good" response. These results are consistent with efficacy data from other trials using recombinant factor VIII products. During the prophylactic period, 12% of patients experienced no bleeding episodes, and 17% of the patients had no on-demand treatment. The mean dose was 28 IU/kg for prophylactic treatment and 30 IU/kg for on-demand treatment. The efficacy of administering BDDrFVIII in conjunction with surgery was assessed to be "very useful" or "useful" in all cases. Few adverse events were reported, and only one patient developed inhibitors to factor VIII activity. The results show that BDDrFVIII provides a safe and effective treatment of hemophilia A when given as on-demand therapy, in routine or intermittent prophylaxis, or during surgery.

Clinical evaluation of B-domain deleted recombinant factor VIII in previously untreated patients.

The safety and efficacy of B-domain deleted recombinant factor VIII (BDDrFVIII) were evaluated in previously untreated patients (PUPs) with severe hemophilia A. In an open-label multicenter study, 101 PUPs received routine prophylactic and/or on-demand treatment with BDDrFVIII, including treatment related to surgery for 50 exposure days for up to 5 years. The pharmacokinetic measurements (ie, elimination half-life and in vivo mean recovery) assessed at baseline and 12 months were stable for BDDrFVIII over time. A total of 1,362 hemorrhages occurred. Ninety-two percent (1,258/1,362) of bleeding episodes resolved after three infusions or fewer. Of the 2,375 infusions rated by investigators, 93% (2,215/2,375) were rated as providing an "excellent" or "good" response. Twenty-seven patients received routine prophylactic treatment, which significantly reduced breakthrough bleeding episodes by twofold when compared with patients who were treated on-demand. Administration in conjunction with 40 surgical procedures showed no adverse effects, and the overall assessment was either "very useful" or "useful." The mean dose was 56 IU/kg for routine primary prophylaxis and 53 IU/kg for on-demand therapy for bleeding episodes in patients who were assessed to be inhibitor-free at the time of infusion. Thirty-two percent of patients developed inhibitors. Of these, 16 patients were high responders (peak titer > or = 5 Bethesda units [BU]). The inhibitor risk was comparable to that seen with full-length recombinant products. BDDrFVIII was found to be effective, safe, and well tolerated.

Defining mechanisms of action of interleukin-11 on the progression of radiation-induced oral mucositis in hamsters.

Oral ulcerative mucositis is a common toxicity associated with drug and radiation therapy for cancer. It impacts on quality of life and economic outcomes, as well as morbidity and mortality. Mucositis is often associated with dose limitations for chemotherapy or is a cause for dose interruption for radiation. The complexity of mucositis as a biological process has only been recently appreciated. It has been suggested that the condition represents a sequential interaction of oral mucosal cells and tissues, pro-inflammatory cytokines and local factors such as saliva and the oral microbiota. The recognition that the pathophysiology of mucositis is a multifactorial process was partially suggested by the observation that interleukin-11 (IL-11), a pleotropic cytokine, favorably altered the course of chemotherapy-induced mucositis in an animal model. In the current study, we evaluated a series of biologic and morphologic outcomes to determine their roles and sequence in the development of experimental radiation-induced mucositis and to evaluate the effects of IL-11 in attenuating them. Our results suggest that IL-11 favorably modulates acute radiation-induced mucositis by attenuating pro-inflammatory cytokine expression. Data are also presented which help define the pathobiological sequence of mucositis.

Analysis of factors that correlate with mucositis in recipients of autologous and allogeneic stem-cell transplants.

PURPOSE: To identify predictors of oral mucositis and gastrointestinal toxicity after high-dose therapy. PATIENTS AND METHODS: Mucositis and gastrointestinal toxicity were prospectively evaluated in 202 recipients of high-dose therapy and autologous or allogeneic stem-cell rescue. Of 10 outcome variables, three were selected as end points: the peak value for the University of Nebraska Oral Assessment Score (MUCPEAK), the duration of parenteral nutritional support, and the peak daily output of diarrhea. Potential covariates included patient age, sex, diagnosis, treatment protocol, transplantation type, stem-cell source, and rate of neutrophil recovery. The three selected end points were also examined for correlation with blood infections and transplant-related mortality. RESULTS: A diagnosis of leukemia, use of total body irradiation, allogeneic transplantation, and delayed neutrophil recovery were associated with increased oral mucositis and longer parenteral nutritional support. No factors were associated with diarrhea. Also, moderate to severe oral mucositis (MUCPEAK > or = 18 on a scale of 8 to 24) was correlated with blood infections and transplant-related mortality: 60% of patients with MUCPEAK > or = 18 had positive blood cultures versus 30% of patients with MUCPEAK less than 18 (P =.001); 24% of patients with MUCPEAK > or = 8 died during the transplantation procedure versus 4% of patients with MUCPEAK less than 18 (P =.001). CONCLUSION: Gastrointestinal toxicity is a major cause of transplant-related morbidity and mortality, emphasizing the need for corrective strategies. The peak oral mucositis score and the duration of parenteral nutritional support are useful indices of gastrointestinal toxicity because these end points are correlated with clinically significant events, including blood infections and treatment-related mortality.

Use of peripheral nerve stimulators to monitor patients with neuromuscular blockade in the ICU.

BACKGROUND: Neuromuscular blockade is a frequently used therapy in the ICU. However, recent reports of prolonged paralysis and general muscular weakness in patients treated with this procedure have raised concerns about its use in intensive care. OBJECTIVE: The purpose of this study was to assess current monitoring practices of nurses who care for patients treated with neuromuscular blockade. METHODS: In January 1995, questionnaires were mailed to a random national sample of 2000 critical care nurses. Of the 2000 questionnaires mailed, 744 were returned. RESULTS: The number of patients per month who were treated with neuromuscular blockade in ICU settings ranged from 0 to 75 (mean = 6.82, SD = 9.15). For each patient, the average number of days of blockade ranged from less than 1 to 63 (mean = 4.12, SD = 3.36). The most common indications for neuromuscular blockade were to assist in mechanical ventilation, reduce oxygen consumption, and treat agitation. Only 41% of respondents (n = 306) reported using train-of-four stimuli and a peripheral nerve stimulator to monitor patients. Depth of neuromuscular blockade was routinely monitored by using clinical assessment (31%), a peripheral nerve stimulator (16%), or both (52%). CONCLUSIONS: Among the respondents, variations existed in monitoring practices and in the use of peripheral nerve stimulators, including the frequency of monitoring and use of the baseline milliamperage. Appropriate monitoring and titration of neuromuscular blocking agents by ICU nurses may aid in preventing adverse effects, including the potential for prolonged neuromuscular blockade. The existing variations in practice may affect patients' outcomes.

A phase I/II trial of twice daily irradiation and concurrent chemotherapy for locally advanced squamous cell carcinoma of the head and neck.

PURPOSE: This study was designed to test the toxicity and efficacy of a regimen of twice daily irradiation and concurrent multiagent chemotherapy for patients with locally advanced squamous cell carcinoma of the head and neck. METHODS AND MATERIALS: This was a prospective Phase I/II trial. Patients received 125 cGy b.i.d. to 7000 cGy with a 6 hr interfraction interval. Chemotherapy was given during weeks 1 and 6 of irradiation and consisted of a 5 day infusion of 5-fluorouracil at 600 mg/M2/day and 5 daily injections of cisplatin at 12 mg/M2/day. Two additional cycles of chemotherapy were given after the completion of radiotherapy. RESULTS: Forty-six patients were evaluable: 28 had technically unresectable disease and 18 had resectable tumors. All had Stage III or IV disease: 84% had T3 or T4 primaries while 53% had > or = N2 neck disease. The primary acute toxicity, confluent mucositis, was seen in 74% of patients. Late side effects occurred in four patients. Median follow-up is 36 months (range 25-44 months). Kaplan-Meier estimates of 2-year disease-free survival and overall survival are 65% and 73%, respectively, while 2-year local regional control and distant disease-free survival are 72% and 88%, respectively. Multivariate analysis revealed that resectability and receiving > 2 cycles of chemotherapy significantly influenced local regional control while age < 60 significantly influenced disease-free survival. CONCLUSION: This form of treatment can be delivered safely. The encouraging results have led to the initiation of a Phase III trial comparing this regimen with b.i.d. radiation alone.

Escherichia coli replication terminator protein impedes simian virus 40 (SV40) DNA replication fork movement and SV40 large tumor antigen helicase activity in vitro at a prokaryotic terminus sequence.

We have discovered that the Escherichia coli terminator protein (Ter) impedes replication fork movement, initiated in vitro from the simian virus 40 replication origin by the large tumor antigen (TAg), at the terminator site (tau R) of the prokaryotic plasmid R6K preferentially when tau R is present in one orientation with respect to the origin. We also have discovered that Ter impedes helicase activity of TAg at the tau R site, when tau R is in this same orientation. In contrast with Ter, a mutant EcoRI protein (EcoRIgln111) that binds with high affinity to but does not cleave at EcoRI recognition sequences impedes both simian virus 40 fork movement and the helicase activity of TAg in an EcoRI-site-orientation-independent manner. These results suggest that a feature common to both TAg and prokaryotic helicases may recognize the Ter-tau R complex resulting in a polarized pause in fork propagation and DNA unwinding. In contrast, the effect of EcoRIgln111-DNA complex on these reactions may be based on steric hindrance.

The DNA-binding domain of HPV-16 E2 protein interaction with the viral enhancer: protein-induced DNA bending and role of the nonconserved core sequence in binding site affinity.

We expressed the carboxy-terminal portion of the E2 open reading frame (ORF)-encoded protein of human papillomavirus type 16 (HPV-16) and purified it to near homogeneity. Using DNase I footprinting techniques, we show that like the homologous protein from bovine papillomavirus type 1 (BPV-1), HPV-18, HPV-11, it binds DNA at the enhancer consensus motif ACCN6GGT. Base and phosphate backbone contact points were determined using methylation protection and interference and ethylation interference assays. This HPV-16 E2 DNA-binding domain protein contacts the site at the outermost conserved GG residues which is similar to the interaction of the BPV-1 E2 system. However, there are many fewer phosphate backbone contacts. Using gel retardation assays, the HPV-16 E2 protein interaction with the consensus motif was characterized further based on the specific sequence of the noncontacted, nonconserved internal bases. Affinity of this E2 protein for the consensus site increased dramatically with an A.T-rich core sequence. Like the homologous BPV-1 protein, HPV-16 E2 protein induces DNA bending at its binding site. Furthermore, examination of the DNA region containing a single consensus motif far upstream from the major promoter, P97, revealed naturally bent DNA that was further bent upon interaction with the HPV-16 E2 protein.

Antifibrinolytic therapy in the management of the Kasabach Merritt syndrome.

The Kasabach Merritt syndrome consists of thrombocytopenia, microangiopathic hemolytic anemia, and a localized consumption coagulopathy that develops within the abnormal vascular channels of a hemangioma. In general, these patients demonstrate only mild abnormalities of screening clotting tests, but they can potentially develop life-threatening complications. We present a patient who developed a severe anemia that was refractory to erythrocyte transfusions. Treatment with epsilon-aminocaproic acid to inhibit fibrinolysis and cryoprecipitate to replenish his deficient circulating fibrinogen interrupted the cycle of his systemic coagulopathy and enabled us to transfuse him to a normal hematocrit.

Cold hemagglutinin disease in the operating room.

Cold hemagglutinin disease is infrequently recognized before complications ensue. We describe a patient with chronic cold hemagglutinin disease who sustained an acute hemolytic crisis during a routine operative procedure in a cool operating room. Cold agglutinins were present during routine preoperative blood cross matching with the Coombs' test positive for C3d. Analysis of the offending cold agglutinin revealed a high-titer monoclonal IgM-kappa antibody with anti-I specificity and broad thermal amplitude. Major complications from the presence of cold agglutinins have been poorly documented and are often thought to be of only theoretic concern. This case and literature review show that such complications may occur and emphasize the importance of careful preoperative plans when the Coombs' test suggests that cold agglutinins exist.