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Published ahead of print on July 19, 2002, doi:10.1164/rccm.200204-302OC
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American Journal of Respiratory and Critical Care Medicine Vol 166. pp. 1197-1205, (2002)
© 2002 American Thoracic Society


Original Article

Risk and the Efficacy of Antiinflammatory Agents

Retrospective and Confirmatory Studies of Sepsis

Peter Q. Eichacker, Chantal Parent, Andre Kalil, Claire Esposito, Xizhong Cui, Steven M. Banks, Eric P. Gerstenberger, Yvonne Fitz, Robert L. Danner and Charles Natanson

Critical Care Medicine Department, National Institutes of Health, Bethesda, Maryland

Correspondence and requests for reprints should be addressed to Peter Q. Eichacker, M.D., Critical Care Medicine Department, National Institutes of Health, Building 10, Room 7D43, 10 Center Drive, MSC 1662, Bethesda, MD 20892–1662. E-mail: peichacker{at}nih.gov


    ABSTRACT
 TOP
 ABSTRACT
 INTRODUCTION
 METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
We investigated whether a relationship between risk of death and treatment effect could explain the disparate results between the preclinical and clinical sepsis trials of antiinflammatory agents over the last decade. A metaregression analysis of cited preclinical studies showed that the treatment effects of these agents were highly dependent on risk of death (p = 0.0001) and that animals were studied at significantly higher control mortality rates than humans (median [25th–75th quartile], 88% [79–96%] versus 39% [32–42%], p = 0.0001). An analysis of the clinical trials showed that antiinflammatory agents were also significantly more efficacious in septic patients with higher risk of death (p = 0.002) and were harmful in those with low risk. To test this relationship prospectively, we studied antiinflammatory agents in models employing differing doses of bacterial challenge to produce the full range of risk of death. We found that the efficacy of these agents, although very beneficial at high control mortality rates, was much reduced (p = 0.0001) and similar to those in human trials at moderate control mortality rates (i.e., 30 to 40%). The efficacy of antiinflammatory agents during sepsis is dependent on the risk of death, an observation that explains the apparent contradiction between preclinical and clinical trial results. Accounting for this relationship may be necessary for the safe and effective development of antiinflammatory therapies for sepsis.

Key Words: septic shock • preclinical and clinical trials • metaregression analysis • antiinflammatory therapies


    INTRODUCTION
 TOP
 ABSTRACT
 INTRODUCTION
 METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
Despite promising preclinical testing (138) and the expenditure of several billion dollars, antiinflammatory agents designed to inhibit specific host mediators during sepsis failed to show benefit in 22 clinical trials involving over 10,000 patients (Table 1) (3960). This failure for the global pharmaceutical industry and academic community has been much discussed but never adequately explained. The underlying hypothesis of this therapeutic approach—that the intense host inflammatory response becomes pathogenic in severe sepsis and septic shock—has been questioned but not refuted (6165). Even if this hypothesis is incorrect or its successful application requires the blockade of different or multiple targets in the host response to infection, it would not explain the marked disparity in the efficacy of these mediator-specific antiinflammatory agents comparing animal models of sepsis to infected patients. Identifying factors underlying this difference between clinical and preclinical trials would likely strengthen the development and application not only of antiinflammatory agents but also of other new therapies for sepsis.


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TABLE 1. Results of clinical trials of mediator-specific antiinflammatory agents tested in septic patients

 
Clinical investigators have suggested that the severity of the underlying septic process and its associated risk of death may be linked to the treatment effect of antiinflammatory agents in sepsis (66). If preclinical and clinical testing was performed at very different control group mortality rates, then a strong relationship between risk of death and efficacy could explain why animal studies and patient trials of antiinflammatory agents produced such divergent results. For example, a drug with this profile might be effective only at high and not at low risks of death. The results of preclinical testing would be misleading unless clinical studies were conducted at a risk of death similar to those found in clinical trials. Also, at some levels of risk, agents might become harmful, leading to excess deaths in clinical trials. Such a relationship between the treatment effect of an agent and risk of death has been previously proposed for several other potentially fatal conditions (67) such as antiarrhythmics for sudden death (68), magnesium for myocardial infarction (69), cholesterol-lowering drugs for atherosclerosis (70), and tocolytic agents (71) for premature birth.

To test the potential relationship between risk of death and the efficacy of antiinflammatory agents in sepsis, we first examined the published preclinical trials used to support testing mediator-specific antiinflammatory agents in septic patients. None of these individual animal studies examined this relationship. We then analyzed the treatment effect across published studies in a metaregression analysis to see whether it changed as risk of death varied. This led us to perform a similar analysis of the clinical trials themselves, looking separately at those trials that stratified patients' treatment effect based on their predicted risk of death and then those that did not. Finally, we prospectively tested in our own laboratories the influence of risk of death on antiinflammatory agents by altering the dose of bacterial-challenge animals received and thereby mortality rates. This allowed us to examine animal studies at lower risks of death more similar to human sepsis studies. In addition, the route and type of challenge and type of antiinflammatory agent studied were varied because these factors had also been proposed as a basis for the differing effects of antiinflammatory agents (6165). As a control, we tested the influence of risk of death on fluid therapy, a conventional treatment for sepsis not known to have antiinflammatory effects.

Our metaregression analyses of published preclinical and clinical sepsis trials and confirmatory prospective animal sepsis studies each showed similarly that the risk of death influences the effects of antiinflammatory agents in sepsis. This relationship explains the contradictory results noted in prior preclinical and clinical trials. More importantly, accounting for this relationship may be necessary for the safe and effective development of new agents for the treatment of sepsis and septic shock.


    METHODS
 TOP
 ABSTRACT
 INTRODUCTION
 METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
Analysis of Published Preclinical Studies
Twenty-two clinical trials (3960) were conducted between January 1986 and January 2000 that tested the effects of seven different nonsteroidal mediator-specific antiinflammatory agents (i.e., anti-TNF [tumor necrosis factor] antibodies, P-55 and P-80 TNF-soluble receptors [sometimes referred to as the P-75 TNF-soluble receptor], interleukin-1 receptor antagonist, platelet-activating factor receptor antagonist, antibradykinin, and antiprostaglandin) (see online data supplement) (72). To investigate the basis for the differing effects that these agents were reported to have in animal models versus human trials, all preclinical studies cited to support their use in clinical trials were reviewed for this metaregression analysis (138). All reported experiments in these studies were included provided that survival rates of the treatment agent were directly compared with a survival rate of a placebo or lower dose treatment group. In addition, in all experiments, the type and route of septic challenge, the regimen of treatment employed, including both timing and dose, the species studied, and the duration of observation were recorded for analysis.

For each experiment, treatment mortality rate was plotted on the y axis and the corresponding control mortality rate on the x axis, yielding a graph on the unit square in which each axis represents fully independent measures. To avoid constraining data at the extremes of the mortality rate ranges, we reparameterized the unit square to occupy the whole plane (73). The y axis was transformed to become the log of the odds of treatment mortality and the x axis to become the log of the odds of control mortality. A weighted linear regression based on the number of animals in each study was performed. Although the analysis was always done with the y axis expressed as the log of the odds of treatment mortality, for ease of presentation, the results are presented with the y axis expressed as the log odds ratio of survival. The odds ratio of survival is the odds of survival in the treatment group divided by the odds of survival in the control group. The odds ratio of survival is mathematically equivalent and is a commonly used measure of efficacy in clinical trial literature. No other factor examined (i.e., type or route of septic challenge, regimen of treatment, including timing and dose, duration of observation, or species studied) significantly changed (all p > 0.20) the relationship between treatment effect and control mortality rate (74).

Analysis of Published Clinical Trials
We assessed the consistency of the clinical trials by determining whether the odds ratios of the 22 human sepsis trials fell within the 95% confidence interval for the mean regression line calculated with the preclinical animal studies. In addition, two trials stratified patients based on the predicted risk of death, and these trials, along with the remaining 20 studies, were analyzed in a manner similar to the published preclinical studies.

Prospective Preclinical Studies
To examine prospectively the relationship between risk of death and treatment effect with antiinflammatory agents in sepsis, Sprague-Dawley rats (n = 1,296) were randomized to be challenged intravenously or intrabronchially with varying doses of Escherichia coli 0111:B4, Staphylococcus aureus (0.25 to 100 x 109 CFU · kg-1 body weight), or E. coli 0111:B4 endotoxin (0.75 to 2 µg · kg-1; Sigma, St. Louis, MO). These differing bacterial doses, types, and routes of challenge were studied to attempt to simulate the diverse types of infection that would be present in a population of septic patients producing a wide range of mortality rates. We studied antiinflammatory agents with different mechanisms of action to examine prospectively whether the effect of risk of death is dependent on one type of immunomodulator. After challenge, one group of animals (n = 653) was treated with high molecular weight TNF-soluble receptor (P-80 TNF-soluble receptor; 100 µg · kg-1 intravenously; Immunex, Seattle, WA) or placebo. This agent was significantly harmful in a clinical sepsis trial (48) after animal studies had shown it to be beneficial in a highly lethal gram-negative bacterial or bacterial toxin model (23). Another group of animals (n = 638) received a tyrosine kinase inhibitor (7581) (tyrphostin AG556, 2.5 µg · kg-1, intraperitoneally) or placebo given immediately and 6 hours after challenge to examine an antiinflammatory agent that blocks the release of multiple inflammatory mediators simultaneously (7581) rather than directly neutralizing circulating TNF. To investigate whether risk of death affected the efficacy of a conventional sepsis treatment, an additional group of rats (n = 192) was challenged with varying doses of E. coli and then treated with or without normal saline (20 ml · kg-1h-1 intravenously for 24 hours) (82). All animals received daily antibiotics for 3 days, and after 7 days, animals were considered survivors as previously described (83).

The relationship between risk of death and treatment efficacy was examined in a manner similar to the published animal studies, and these relationships were not significantly changed (p > 0.20) by any of the other variables studied. The consistency of this data with published preclinical and clinical trials was assessed as previously described.

All animal protocols used in these studies were approved by the Animal Care and Use Committee of the Clinical Center of the National Institutes of Health. Every effort was made to minimize animal suffering during these protocols. The research protocols required the veterinarian staff or principle investigators to euthanize any animal that experienced unexpected severe pain or distress.


    RESULTS
 TOP
 ABSTRACT
 INTRODUCTION
 METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
Published Preclinical Studies of Antiinflammatory Agents
In 22 human sepsis trials of antiinflammatory agents (Table 1) (3960), a total of 38 animal sepsis studies were cited (95 individual experiments; Figures 1A–1C) (138). Animals were studied at much higher control mortality rates than humans (median [25th–75th quartile] 88% [79–96%] versus 39% [32–43%], p = 0.0001) (Figures 1B and 1C). Regardless of the type of challenge, timing or dose of treatment, species studied, or duration of observation, the odds ratio of survival with all mediator-specific antiinflammatory agents diminished as the risk of death (control mortality rate studied) decreased (p = 0.0001) (Figure 1). Notably, anti-TNF antibodies were found to be significantly harmful in two animal studies cited with very low (less than 15%) control mortality rates that were below those studied in most clinical and preclinical sepsis trials (17, 18). Each of these two studies significantly increased the slope of the relationship between risk of death and treatment. Although shown with other data, because these two studies were overly influential, they were excluded from analysis; however, inclusion would make this relationship even stronger. Among all factors examined, risk of death explained the majority of the variability (70%) in the treatment effects of antiinflammatory agents comparing these 95 experiments.



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Figure 1. (A–C) The weighted regression line in A shows the relationship between control odds and the odds ratio of survival with treatment for 95 experiments (open circles) in 38 published animal studies cited (138) in 22 clinical sepsis trials of mediator-specific antiinflammatory agents (Table 1) (3960). B is the same as A but also shows the control odds and odds ratio for survival for the 22 clinical trials (open diamonds) (3960) testing mediator-specific antiinflammatory agents. C divides the data in B by type of antiinflammatory agent. The circle size in each panel is adjusted for the number of animals in each experiment, but not the diamond size in B and C because the number of patients in each trial was not used to calculate the weighted regression line.

 
Published Clinical Trials of Mediator-Specific Antiinflammatory Therapies
Control mortality rates in clinical trials were lower and studied over a narrower range than in preclinical trials (Figures 1B and 1C). At comparable control mortality rates, the effects of mediator-specific antiinflammatory therapies in 19 (3941, 4346, 4854, 5660) of the 22 (3960) clinical trials fit within the 95% confidence interval for the odds ratio for survival predicted from the 95 published preclinical experiments (Figure 2A) . However, two clinical trials provided data that categorized patients at study entry into subgroups based on predicted risk of death (50, 53). The differing control mortality rates reported for these subgroups allowed us to examine the relationship between risk of death and treatment effect over a wider range. In a phase III trial of interleukin-1 receptor antagonist (53, 66) and a phase III trial of P-55 TNF-soluble receptor (50), patients were categorized into groups with increasing risks of death as determined by physiology-based scoring systems (modified Acute Physiology and Chronic Health Evaluation III score and Stratified Acute Physiology score, respectively) (Figures 3A and 3C) . Stratifying by the risk of death score, we found that the treatment effect of these two antiinflammatory agents was significantly (p = 0.0002) related to the risk of death (Figures 3A and 3C). The effect of these antiinflammatory agents in septic humans at higher risks of death was very similar to the effects seen with these agents in published animal studies with the same high risks (Figure 1A). The 20 remaining clinical trials studied control mortality rates over a significantly narrower range of overall control mortality rates than the two trials categorizing patients by risk of death (29 to 60% versus 10 to 78%, p = 0.0001) (Figures 3A and 3B). Despite this, the relationship between risk of death and the treatment effect for these 20 remaining clinical trials had an identical slope and intercept to the one based on patients segregated by risk of death in the other two trials (both p = 0.85 comparing the two groups of trials) (Figures 3A and 3B). Moreover, even within the narrower range of control mortality rates studied in these other 20 trials, the slope for this relationship between risk of death and treatment effect approached being significant (p = 0.07).



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Figure 2. A compares the treatment effect of mediator-specific antiinflammatory agents in 22 clinical trials (3960) (open diamonds) (Table 1) to the 95% confidence interval (gray bar) for the regression line describing their effects in cited animal studies (138) from Figure 1A. B and C compare these same 22 clinical trials to the 95% confidence interval (gray bars) for the regression line describing their effects in prospective animal studies testing either antiinflammatory agents from Figure 4A or fluid support in animals from Figure 4B, respectively. Because preclinical trials included fewer subjects than clinical ones, for ease of presentation, these confidence intervals are adjusted for the median number of patients in clinical trials. However, all comparisons in the results section were based on actual numbers of animals or patients in each trial.

 


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Figure 4. (A–C) This format is similar to Figure 1 except that here each circle represents an experiment in which we prospectively challenged animals with a dose of bacterial challenge designed to produce a range of mortality rates and then treated them with an antiinflammatory agent or placebo (A). In B, the format is similar to A except now each circle represents an experiment in which we prospectively challenged animals with a differing dose of bacteria and then either did or did not treat with fluids. C divides the data in A by type of antiinflammatory agent used as well as by the type and route of bacterial challenge.

 


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Figure 3. (A–C) In one phase III trial of interleukin-1 receptor antagonist and one of P-55 TNF-soluble receptors, septic patients were categorized at study entry into groups based on their predicted risks of death, as determined by a modified Acute Physiology and Chronic Health Evaluation II or Stratified Acute Physiology score, respectively (open diamonds) (50, 53, 66). Using the same format as Figure 1, A shows the observed control odds and odds ratio of survival with antiinflammatory treatment for these risk categories as well as the weighted regression line for the relationship. B shows the relationship between the overall control odds and odds ratio of survival for the remaining 20 trials of antiinflammatory agents (3949, 51, 52, 5460) that did not provide segregated data like that shown in A. C divides the data from A by type of antiinflammatory agent. The size of the diamonds in each panel is adjusted to the number of patients in each subgroup (A and C) or trial (B) because a weighted regression analysis was done.

 
Prospective Preclinical Studies with Antiinflammatory Therapies or Fluids
In prospective experiments testing P-80 TNF-soluble receptor and tyrphostin AG556 in rats, increasing the dose of each type of challenge (E. coli, S. aureus, or endotoxin) caused mortality rates to increase (combined; r + 0.83; p = 0.0001) (data not shown). Regardless of the type or route of challenge or the type of antiinflammatory agent used, as the control mortality rates increased, the odds ratio of survival with antiinflammatory therapy increased (combined, p = 0.0002) (Figures 4A and 4C) .

For our prospective and previously unpublished studies (Figure 4A) and the published preclinical studies from other laboratories (Figure 1A) of antiinflammatory therapies, the slopes of this regression relationship comparing risk of death and treatment effect were similar (0.40 versus 0.48, respectively, p = NS). However, the y intercept was greater in the published compared with the prospective preclinical studies (2.95 versus 1.17, respectively, p = 0.0001) (Figures 1A and 4A). The greater beneficial effects and increases in y intercept in published versus prospective studies can be partially explained as positive results are more likely to be published, causing an overestimation of treatment effects (84). All 22 clinical trials fit within the 95% confidence interval for the odds of survival in these prospective preclinical trials of antiinflammatory agents (Figure 2B).

In this preclinical model, fluid therapy had a significantly different relationship (i.e., slope and intercept) between risk of death and treatment effect (Figure 4B) compared with antiinflammatory agents in prospective studies (p = 0.008 for both slope and intercept) (Figure 4A). After E. coli challenges, fluids produced significant beneficial effects that were similar regardless of control mortality rate. At comparable control mortality rates, only 4 (39, 45, 51, 57) of the 22 (3960) clinical trials fit within the 95% confidence interval for the effects of fluid therapy in animals (Figure 2C). Notably, more of the 22 clinical trials fit within the 95% confidence intervals for survival with antiinflammatory therapies than with fluid therapy in animals (22 of 22 versus 4 of 22, respectively; p = 0.0001) (Figures 2B and 2C).

Comparison of Time of Observation Used to Calculate Survival Rates in Animals and Human Sepsis Studies
In this meta-analysis, we analyzed survival rates and not survival times because this was the only outcome measure universally reported. Differences in follow-up times within species or differing life spans across species could potentially produce differences in control mortality rates and thereby alter the relationship between control mortality rate and treatment effect. The median (range) duration of follow-up for determining survival rates in published animal studies was 168 hours (24 to 288 hours) in rats, 75 hours (24 to 360 hours) in mice, 72 hours (24 to 336 hours) in primates, and 24 hours (5 to 168 hours) in rabbits. For these previously published animal studies, there was no significant correlation between control mortality rate and the length of follow-up time within or across these species (r values, 0.30 to -0.14; p values, 0.40 to 0.98). Therefore, in the published animal studies, differences in follow-up times cannot explain the significant relationship found between increasing control mortality rate and the treatment effects of antiinflammatory agents. All of our prospective animal studies were based on 7-day survival rates, and all of the human clinical sepsis trials were based on 28- to 30-day survival rates. Therefore, differences in follow-up times also cannot explain the significant relationship found between control mortality rate and treatment effects of antiinflammatory agents in either our animal studies or the human sepsis trials. Finally, because the time of observation after treatment was actually much longer in human sepsis trials than all of the preclinical sepsis studies examined, it is unlikely that this variable caused the significantly higher control mortality rates found in animal compared with human sepsis studies.


    DISCUSSION
 TOP
 ABSTRACT
 INTRODUCTION
 METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
In a retrospective analysis of clinical and preclinical trials and confirmatory animal studies, we found that risk of death altered the efficacy of antiinflammatory agents during sepsis. This relationship provides an explanation for the contradictory results noted with this therapeutic approach in preclinical (138) and clinical sepsis trials (3960) over the past decade. Antiinflammatory agents had greater treatment effects in animal models compared with clinical trials because preclinical studies were done at significantly higher risks of death (Figure 1). Furthermore, human trials of antiinflammatory therapies failed because they enrolled patients at a level of risk where these agents have minimal effects (Figure 1 and Table 1). Animal studies we conducted at low risks of death produced the same results seen in septic patients (Figure 2B). A small number of published animal studies conducted at low control mortality rates (Figure 1) (17, 18) demonstrated that antiinflammatory agents in sepsis have the potential to be harmful in less severely ill subjects. This effect is consistent with the adverse outcome seen after P-80 TNF-soluble receptor administration in a subgroup of patients with gram-positive infection that had a low control mortality rate (13%) (48) (Figure 4C).

Two clinical trials provided data that categorized patients into groups based on their predicted risk of death (50, 53, 66). These trials allowed us to evaluate the effects of two different agents over a range of control mortality rates similar to the animal studies. Just as in animal studies, these agents were most beneficial in those groups of patients with high risks of death and were harmful in those with low risks (Figure 3A). The other 20 sepsis trials (3949, 51, 52, 5460), studied over a more limited range of control mortality rates, showed a very similar relationship between risk of death and treatment effects (Figure 3B). We believe that this consistency among preclinical studies from different laboratories and clinical trials strongly supports our hypothesis that risk of death alters the effects of antiinflammatory agents during sepsis.

Results of a phase III sepsis trial of activated protein C (APC), an agent with antiinflammatory and antithrombotic properties, could be an exception to our findings because of a highly significant (p = 0.005) beneficial effect. Therefore, this agent deserves comparison to these clinical trials even though published after completion of this metaregression analysis (Figure 5A) (85, 86). Although APC significantly improved survival rates compared with standard sepsis therapies, its treatment effect was not significantly different compared with the combined effects of all these previously studied mediator-specific antiinflammatory agents (n = 22) (p = 0.10) (Figure 5A) or the phase III trials of these agents (n = 9) (odds ratio [95% confidence interval]; 1.36 [1.10, 1.68] versus 1.13 [1.03, 1.24], respectively, p = 0.20) (Table 1) (3960). Furthermore, a prospective analysis divided the 1,690 patients in the clinical APC trial into four equal groups based on Acute Physiology and Chronic Health Evaluation II scores (8587). Similar to clinical trials of the other antiinflammatory agents, APC was less beneficial (odds ratio of survival 1.56, 1.82, 1.19, and 0.77, respectively) as control mortality rates (49, 36, 26, and 12%, respectively) and Acute Physiology and Chronic Health Evaluation scores decreased (52–30, 29–25, 24–20, 19–3, respectively) (Figure 5B). Accordingly, APC was licensed for use by the Food and Drug Administration for only patients with severe sepsis (sepsis associated with acute organ dysfunction) and a high risk of death (e.g., as determined by Acute Physiology and Chronic Health Evaluation II scores) (87). Because of the consistency of the APC data to our findings (Figure 5) examining other antiinflammatory agents, it must be considered that in patients with a low risk of death, APC may not only be ineffective but also harmful.



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Figure 5. (A and B) This figure shows the results of the clinical (85) and cited preclinical (86) sepsis trial of APC (open diamond and circle in A) as well as the effects of APC in patients categorized based on their predicted risk of death (87) (open diamonds in B). For comparison, in A, data are included from Figure 1 (gray diamonds and circles) and in B from Figure 3 (gray diamonds).

 
Even though all of these agents may work through different biologic pathways, we found that the slopes for the relationship between risk of death and treatment efficacy were similar (0.32 to 0.48). One possible explanation for this consistency is that regardless of the type of immunomodulator, when the overwhelming majority of subjects are going to die from sepsis, inhibiting an excessive and lethal inflammatory response improves outcome. Conversely, if the majority of subjects with sepsis are likely to survive, disrupting an inflammatory response that is working well is harmful. In this case, an immunosuppressive effect may disrupt well-regulated inflammatory pathways and weaken protective host defense mechanisms. When a mixture of subjects either destined to survive or die from sepsis are treated, harm caused by inhibiting inflammation in subjects that would have otherwise survived may negate the potential benefit of inhibiting inflammation in subjects that would have died. This would explain the smaller treatment effects evident with all of these agents in our analysis when control mortality rates were in the mid-range.

Our model also has a term predicting the treatment efficacy of an agent at a 50% control mortality rate. If this value had actually been very high for the agents we analyzed, then the slopes for the regression lines reported might have been of little consequence. In this case, although the efficacy of antiinflammatory agents might decrease as risk of death decreased, it would still be beneficial throughout the entire range of control mortality rates. However, in most of our analyses, these terms were relatively small. With such small treatment effects at a 50% control mortality rate (odds ratio, 1.17 to 1.48), any significant change in efficacy as control mortality rate decreases becomes worrisome because at low risks of death (i.e., less than a 50% control mortality rate) these agents become harmful. It would be ideal to find an antiinflammatory agent for sepsis that functions as fluids did, with a relatively large treatment effect at a 50% control mortality and a relatively small slope. Such an agent would be beneficial over the full range of control mortality rates.

For a highly lethal disease such as sepsis, use of preclinical studies conducted over a wide range of risk may provide a transformative method for the preclinical testing of new agents. They permit an estimation of an agent's treatment effect at a 50% mortality rate and can demonstrate the influence risk of death may have on the agent's efficacy. Together, these data suggest whether there is a level of risk below which an agent may produce harm. Ideally, drugs taken into clinical testing would be those that have significant beneficial effects over a wide range of competing risks. However, a different approach must be considered if preclinical or later clinical testing indicates that an agent is beneficial above, but harmful below, a particular risk of death. Subsequent clinical trials should then incorporate entry and exclusion criteria such as risk prediction scores to ensure that patients likely to benefit are included and that those likely to be harmed are excluded. Examining this relationship between risk of death and treatment effect preclinically and then using this information to optimally design the clinical trial are likely to reduce the size and expense of human research in highly lethal disease and may also help minimize the risk of drug-related fatalities.


    FOOTNOTES
 
This article has an online data supplement, which is accessible from this issue's table of contents online at www.atsjournals.org

Received in original form April 9, 2002; accepted in final form July 16, 2002


    REFERENCES
 TOP
 ABSTRACT
 INTRODUCTION
 METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 

  1. Beutler B, Milsark IW, Cerami AC. Passive immunization against cachectin/tumor necrosis factor protects mice from lethal effect of endotoxin. Science 1985;229:869–871.[Abstract/Free Full Text]
  2. Suitters AJ, Foulkes R, Opal SM, Palardy JE, Emtage JS, Rolfe M, Stephens S, Morgan A, Holt AR, Chaplin LC, et al. Differential effect of isotype on efficacy of anti-tumor necrosis factor alpha chimeric antibodies in experimental septic shock. J Exp Med 1994;179:849–856.[Abstract/Free Full Text]
  3. Bagby GJ, Plessala KJ, Wilson LA, Thompson JJ, Nelson S. Divergent efficacy of antibody to tumor necrosis factor-alpha in intravascular and peritonitis models of sepsis. J Infect Dis 1991;163:83–88.[Medline]
  4. Mathison JC, Wolfson E, Ulevitch RJ. Participation of tumor necrosis factor in the mediation of gram negative bacterial lipopolysaccharide-induced injury in rabbits. J Clin Invest 1988;81:1925–1937.
  5. Fiedler VB, Loof I, Sander E, Voehringer V, Galanos C, Fournel MA. Monoclonal antibody to tumor necrosis factor-alpha prevents lethal endotoxin sepsis in adult rhesus monkeys. J Lab Clin Med 1992;120:574–588.[Medline]
  6. Opal SM, Cross AS, Sadoff JC, Collins HH, Kelly NM, Victor GH, Palardy JE, Bodmer WM. Efficacy of antilipopolysaccharide and anti-tumor necrosis factor monoclonal antibodies in a neutropenic rat model of Pseudomonas sepsis. J Clin Invest 1991;88:885–890.
  7. Stack AM, Saladino RA, Thompson C, Sattler F, Weiner DL, Parsonnet J, Nariuchi H, Siber GR, Fleisher GR. Failure of prophylactic and therapeutic use of a murine anti-tumor necrosis factor monoclonal antibody in Escherichia coli sepsis in the rabbit. Crit Care Med 1995;23:1512–1518.[CrossRef][Medline]
  8. Tracey KJ, Fong Y, Hesse DG, Manogue KR, Lee AT, Kuo GC, Lowry SF, Cerami A. Anti-cachectin/TNF monoclonal antibodies prevent septic shock during lethal bacteraemia. Nature 1987;330:662–664.[CrossRef][Medline]
  9. Cross AS, Opal SM, Palardy JE, Bodmer MW, Sadoff JC. The efficacy of combination immunotherapy in experimental Pseudomonas sepsis. J Infect Dis 1993;167:112–118.[Medline]
  10. Opal SM, Cross AS, Kelly NM, Sadoff JC, Bodmer MW, Palardy JE, Victor GH. Efficacy of a monoclonal antibody directed against tumor necrosis factor in protecting neutropenic rats from lethal infection with Pseudomonas aeruginosa. J Infect Dis 1990;161:1148–1152.[Medline]
  11. Hinshaw LB, Emerson TE Jr, Taylor FB Jr, Chang AC, Duerr M, Peer GT, Flournoy DJ, White GL, Kosanke SD, Murray CK, et al. Lethal Staphylococcus aureus-induced shock in primates: prevention of death with anti-TNF antibody. J Trauma 1992;33:568–573.[Medline]
  12. Hinshaw LB, Tekamp-Olson P, Chang AC, Lee PA, Taylor FB Jr, Murray CK, Peer GT, Emerson TE Jr, Passey RB, Kuo GC. Survival of primates in LD100 septic shock following therapy with antibody to tumor necrosis factor (TNF alpha). Circ Shock 1990;30:279–292.[Medline]
  13. Jesmok G, Lindsey C, Duerr M, Fournel M, Emerson T Jr. Efficacy of monoclonal antibody against human recombinant tumor necrosis factor in E. coli-challenged swine. Am J Pathol 1992;141:1197–1207.[Abstract]
  14. Silva AT, Bayston KF, Cohen J. Prophylactic and therapeutic effects of a monoclonal antibody to tumor necrosis factor-alpha in experimental gram-negative shock. J Infect Dis 1990;162:421–427.[Medline]
  15. Eskandari MK, Bolgos G, Miller C, Nguyen DT, DeForge LE, Remick DG. Anti-tumor necrosis factor antibody therapy fails to prevent lethality after cecal ligation and puncture or endotoxemia. J Immunol 1992;148:2724–2730.[Abstract]
  16. Jin H, Yang R, Marsters SA, Bunting SA, Wurm FM, Chamow SM, Ashkenazi A. Protection against rat endotoxic shock by p55 tumor necrosis factor (TNF) receptor immunoadhesion: comparison with anti-TNF monoclonal antibody. J Infect Dis 1994;170:1323–1326.[Medline]
  17. Echtenacher B, Falk W, Mannel DN, Krammer PH. Requirement of endogenous tumor necrosis factor/cachectin for recovery from experimental peritonitis. J Immunol 1990;145:3762–3766.[Abstract]
  18. Mastroeni P, Arena A, Costa GB, Liberto MC, Bonina L, Hormaeche CE. Serum TNF alpha in mouse typhoid and enhancement of a Salmonella infection by anti-TNF alpha antibodies. Microb Pathog 1991;11: 33–38.[CrossRef][Medline]
  19. Ashkenazi A, Marsters SA, Capon DJ, Chamow SM, Figari IS, Pennica D, Goeddel DV, Palladino MA, Smith DH. Protection against endotoxic shock by a tumor necrosis factor receptor immunoadhesion. Proc Natl Acad Sci USA 1991;88:10535–10539.[Abstract/Free Full Text]
  20. Van Zee KJ, Kohno T, Fischer E, Rock CS, Moldawer LL, Lowry SF. Tumor necrosis factor soluble receptors circulate during experimental and clinical inflammation and can protect against excessive tumor necrosis factor alpha in vitro and in vivo. Proc Natl Acad Sci USA 1992;89:4845–4849.[Abstract/Free Full Text]
  21. Lesslauer W, Tabuchi H, Gentz R, Brockhaus M, Schlaeger EJ, Grau G, Piguet PF, Pointaire P, Vassalli P, Loetscher H. Recombinant soluble tumor necrosis factor receptor proteins protect mice from lipopolysaccharide-induced lethality. Eur J Immunol 1991;21:2883–2886.[Medline]
  22. Russell DA, Tucker KK, Chinookoswong N, Thompson RC, Kohno T. Combined inhibition of interleukin-1 and tumor necrosis factor in rodent endotoxemia: improved survival and organ function. J Infect Dis 1995;171:1528–1538.[Medline]
  23. Mohler KM, Torrance DS, Smith CA, Goodwin RG, Stremler KE, Fung VP, Madani H, Widmer MB. Soluble tumor necrosis factor (TNF) receptors are effective therapeutic agents in lethal endotoxemia and function simultaneously as both TNF carriers and TNF antagonists. J Immunol 1993;151:1548–1561.[Abstract]
  24. Evans TJ, Moyes D, Carpenter A, Martin R, Loetscher H, Lesslauer W, Cohen J. Protective effect of 55- but not 75-kD soluble tumor necrosis factor receptor-immunoglobulin G fusion proteins in an animal model of gram-negative sepsis. J Exp Med 1994;180:2173–2179.[Abstract/Free Full Text]
  25. Ohlsson K, Bjork P, Bergenfeldt M, Hageman R, Thompson RC. Interleukin-1 receptor antagonist reduces mortality from endotoxin shock. Nature 1990;348:550–552.[CrossRef][Medline]
  26. Wakabayashi G, Gelfand JA, Burke JF, Thompson RC, Dinarello CA. A specific receptor antagonist for interleukin 1 prevents Escherichia coli-induced shock in rabbits. FASEB J 1991;5:338–343.[Abstract]
  27. Fischer E, Marano MA, Van Zee KJ, Rock CS, Hawes AS, Thompson WA, DeForge L, Kenney JS, Remick DG, Bloedow DC, et al. Interleukin-1 receptor blockade improves survival and hemodynamic performance in Escherichia coli septic shock, but fails to alter host responses to sublethal endotoxemia. J Clin Invest 1992;89:1551–1557.
  28. Myers AK, Robey JW, Price RM. Relationships between tumour necrosis factor, eicosanoids and platelet-activating factor as mediators of endotoxin-induced shock in mice. Br J Pharmacol 1990;99:499–502.[Medline]
  29. Chang SW, Feddersen CO, Henson PM, Voelkel NF. Platelet-activating factor mediates hemodynamic changes and lung injury in endotoxin-treated rats. J Clin Invest 1987;79:1498–1509.
  30. Etienne A, Hecquet F, Guilmard C, Soulard C, Braquet P. Inhibition of rat endotoxin-induced lethality by BN 52021 and BN 52063, compounds with PAF antagonistic effect and protease-inhibitory activity. Int J Tissue React 1987;9:19–26.[Medline]
  31. Rabinovici R, Yue TL, Farhat M, Smith EF III, Esser KM, Slivjak M, Feuerstein G. Platelet activating factor (PAF) and tumor necrosis factor-alpha (TNF alpha) interactions in endotoxemic shock: studies with BN 50739, a novel PAF antagonist. J Pharmacol Exp Ther 1990; 255:256–263.[Abstract/Free Full Text]
  32. Feuerstein G, Leader P, Siren AL, Braquet P. Protective effect of a PAF-acether antagonist, BN 52021, in trichothecene toxicosis. Toxicol Lett 1987;38:271–274.[CrossRef][Medline]
  33. Whalley ET, Solomon JA, Modafferi DM, Bonham KA, Cheronis JC. CP-0127, a novel potent bradykinin antagonist, increases survival in rat and rabbit models of endotoxin shock. Agents Actions Suppl 1992; 38:413–420.
  34. Fletcher JR, Ramwell PW. Indomethacin improves survival after endotoxin in baboons. Adv Prostaglandin Thromboxane Res 1980;7:821–828.[Medline]
  35. Parratt JR, Sturgess RM. E. coli endotoxin shock in the cat: treatment with indomethacin. Br J Pharmacol 1975;53:485–488.[Medline]
  36. Wise WC, Cook JA, Eller T, Halushka PV. Ibuprofen improves survival from endotoxic shock in the rat. J Pharmacol Exp Ther 1980;215:160–164.[Abstract/Free Full Text]
  37. Jacobs ER, Soulsby ME, Bone RC, Wilson FJ Jr, Hiller FC. Ibuprofen in canine endotoxin shock. J Clin Invest 1982;70:536–541.
  38. Fletcher JR, Ramwell PW. Modification, by aspirin and indomethacin, of the haemodynamic and prostaglandin releasing effects of E. coli endotoxin in the dog. Br J Pharmacol 1977;61:175–181.[Medline]
  39. Kay CA. Reducing mortality to patients and suppliers. Paper presented at: Cambridge Health Institute's Designing Better Drugs and Clinical Trials for Sepsis/SIRS; 1996; Washington, DC.
  40. Dhainaut JF, Vincent JL, Richard C, Lejeune P, Martin C, Fierobe L, Stephens S, Ney UM, Sopwith M. CDP571, a humanized antibody to human tumor necrosis factor-alpha: safety, pharmacokinetics, immune response, and influence of the antibody on cytokine concentrations in patients with septic shock: CPD571 Sepsis Study Group. Crit Care Med 1995;23:1461–1469.[CrossRef][Medline]
  41. Fisher CJ Jr, Opal SM, Dhainaut JF, Stephens S, Zimmerman JL, Nightingale P, Harris SJ, Schein RM, Panacek EA, Vincent JL, et al. Influence of an anti-tumor necrosis factor monoclonal antibody on cytokine levels in patients with sepsis: the CB0006 Sepsis Syndrome Study Group. Crit Care Med 1993;21:318–327.[Medline]
  42. Reinhart K, Wiegand-Lohnert C, Grimminger F, Kaul M, Withington S, Treacher D, Eckart J, Willatts S, Bonza C, Krausch D, et al. Assessment of the safety and efficacy of the monoclonal anti-tumor necrosis factor antibody-fragment, MAK 195F, in patients with sepsis and septic shock: a multicenter, randomized, placebo-controlled, dose-ranging study. Crit Care Med 1996;24:733–742.[CrossRef][Medline]
  43. Cohen J, Carlet J. INTERSEPT: an international, multicenter, placebo-controlled trial of monoclonal antibody to human tumor necrosis factor-alpha in patients with sepsis: International Sepsis Trial Study Group. Crit Care Med 1996;24:1431–1440.[CrossRef][Medline]
  44. Abraham E, Wunderink R, Silverman H, Perl TM, Nasraway S, Levy H, Bone R, Wenzel RP, Balk R, Allred R, et al. Efficacy and safety of monoclonal antibody to human tumor necrosis factor alpha in patients with sepsis syndrome: a randomized, controlled, double-blind, multicenter clinical trial: TNF-alpha MAb Sepsis Study Group. JAMA 1995;273:934–941.[Abstract]
  45. Clark MA, Plank LD, Connolly AB, Streat SJ, Hill AA, Gupta R, Monk DN, Shenkin A, Hill GL. Effect of a chimeric antibody to tumor necrosis factor-alpha on cytokine and physiologic responses in patients with severe sepsis: a randomized, clinical trial. Crit Care Med 1998;26: 1650–1659.[CrossRef][Medline]
  46. Reinhart K, Menges T, Gardlund B, Harm Zwaveling J, Smithes M, Vincent JL, Tellado JM, Salgado-Remigio A, Zimlichman R, Withington S, et al. Randomized, placebo-controlled trial of the anti-tumor necrosis factor antibody fragment afelimomabin hyperinflammatory response during sepsis: the RAMSES Study. Crit Care Med 2001;29: 765–769.[CrossRef][Medline]
  47. Abraham E, Anzueto A, Gutierrez G, Tessler S, San Pedro G, Wunderink R, Dal Nogare A, Nasraway S, Berman S, Cooney R, et al. Double-blind randomised controlled trial of monoclonal antibody to human tumour necrosis factor in treatment of septic shock: NORASEPT II Study Group. Lancet 1998;351:929–933.[Medline]
  48. Fisher CJ Jr, Agosti JM, Opal SM, Lowry SF, Balk RA, Sadoff JC, Abraham E, Schein RM, Benjamin E. Treatment of septic shock with the tumor necrosis factor receptor: Fc fusion protein: the Soluble TNF Receptor Sepsis Study Group. N Engl J Med 1996;334:1697–1702.[Abstract/Free Full Text]
  49. Abraham E, Glauser MP, Butler T, Garbino J, Gelmont D, Laterre PF, Kudsk K, Bruining HA, Otto C, Tobin E, et al. p55 tumor necrosis factor receptor fusion protein in the treatment of patients with severe sepsis and septic shock: a randomized controlled multicenter trial: Ro 45-2081 Study Group. JAMA 1997;277:1531–1538.[Abstract]
  50. Abraham E, Laterre P-F, Garbino J, Pingleton S, Butler T, Dugernier T, Margolis B, Kudsk K, Zimmerli W, Anderson P, et al. Lenercept (p55 tumor necrosis factor receptor fusion protein) in severe sepsis and early septic shock: a randomized, double-blind, placebo-controlled, multicenter phase III trial with 1,342 patients. Crit Care Med 2001;39: 503–510.
  51. Fisher CJ Jr, Slotman GJ, Opal SM, Pribble JP, Bone RC, Emmanuel G, Ng D, Bloedow DC, Catalano MA. Initial evaluation of human recombinant interleukin-1 receptor antagonist in the treatment of sepsis syndrome: a randomized, open-label, placebo-controlled multicenter trial: the IL-1RA Sepsis Syndrome Study Group. Crit Care Med 1994;22:12–21.[Medline]
  52. Opal SM, Fisher CJ Jr, Dhainaut JF, Vincent JL, Brase R, Lowry SF, Sadoff JC, Slotman GJ, Levy H, Balk RA, et al. Confirmatory interleukin-1 receptor antagonist trial in severe sepsis: a phase III, randomized, double-blind, placebo-controlled, multicenter trial: the Interleukin-1 Receptor Antagonist Sepsis Investigator Group. Crit Care Med 1997;25:1115–1124.[CrossRef][Medline]
  53. Fisher CJ Jr, Dhainaut JF, Opal SM, Pribble JP, Balk RA, Slotman GJ, Iberti TJ, Rackow EC, Shapiro MJ, Greenman RL, et al. Recombinant human interleukin 1 receptor antagonist in the treatment of patients with sepsis syndrome: results from a randomized, double-blind, placebo-controlled trial: Phase III rhIL-1ra Sepsis Syndrome Study Group. JAMA 1994;271:1836–1843.[Abstract]
  54. Dhainaut JF, Tenaillon A, Le Tulzo Y, Schlemmer B, Solet JP, Wolff M, Holzapfel L, Zeni F, Dreyfuss D, Mira JP, et al. Platelet-activating factor receptor antagonist BN 52021 in the treatment of severe sepsis: a randomized, double-blind, placebo-controlled, multicenter clinical trial: BN 52021 Sepsis Study Group. Crit Care Med 1994;22:1720–1728.[Medline]
  55. Dhainaut JF, Tenaillon A, Hemmer M, Damas P, Le Tulzo Y, Radermacher P, Schaller MD, Sollet JP, Wolff M, Holzapfel L, et al. Confirmatory platelet-activating factor receptor antagonist trial in patients with severe gram-negative bacterial sepsis: a phase III, randomized, double-blind, placebo-controlled, multicenter trial: BN 52021 Sepsis Investigator Group. Crit Care Med 1998;26:1963–1971.[CrossRef][Medline]
  56. Bernard GR, Reines HD, Halushka PV, Higgins SB, Metz CA, Swindell BB, Wright PE, Watts FL, Vrbanac JJ. Prostacyclin and thromboxane A2 formation is increased in human sepsis syndrome: effects of cyclooxygenase inhibition. Am Rev Respir Dis 1991;144:1095–1101.[Medline]
  57. Haupt MT, Jastremski MS, Clemmer TP, Metz CA, Goris GB. Effect of ibuprofen in patients with severe sepsis: a randomized, double-blind, multicenter study: the Ibuprofen Study Group. Crit Care Med 1991;19:1339–1347.[Medline]
  58. Bernard GR, Wheeler AP, Russell JA, Schein R, Summer WR, Steinberg KP, Fulkerson WJ, Wright PE, Christman BW, Dupont WD, et al. The effects of ibuprofen on the physiology and survival of patients with sepsis: the Ibuprofen in Sepsis Study Group. N Engl J Med 1995; 336:912–918.[Abstract/Free Full Text]
  59. Rodell TC, Scharschmidt LA, Knaus WA. CP-0127 SIRS and Sepsis Study Group: results of a multi-center randomized, placebo-controlled trial of CP-0127, a novel bradykinin antagonist, in patients with SIRS and sepsis. Shock 1995;3:60.
  60. Fein AM, Bernard GR, Criner GJ, Fletcher EC, Good JT Jr, Knaus WA, Levy H, Matuschak GM, Shaines HM, Taylor RW, et al. Treatment of severe systemic inflammatory response syndrome and sepsis with a novel bradykinin antagonist, deltibant (CP-0127): results of a randomized, double-blind, placebo-controlled trial. CP-0127 SIRS and Sepsis Study Group. JAMA 1997;277:482–487.[Abstract]
  61. Stephenson J. Reflecting and regrouping after failed trials, sepsis researchers forge on. JAMA 1996;275:823–824.[CrossRef][Medline]
  62. Piper RD, Cook DJ, Bone RC, Sibbald WJ. Introducing critical appraisal to studies of animal models investigating novel therapies in sepsis. Crit Care Med 1996;24:2059–2070.[CrossRef][Medline]
  63. Heumann D, Glauser MP. Anticytokine strategies for the treatment of septic shock: relevance of animal models. Curr Top Microbiol Immunol 1996;216:299–311.[Medline]
  64. From the bench to the bedside: the future of sepsis research: executive summary of an American College of Chest Physicians, National Institute of Allergy and Infectious Disease, and National Heart, Lung, and Blood Institute Workshop. Chest 1997;111:744–753.[Free Full Text]
  65. Opal SM, Cross AS. Clinical trials for severe sepsis: past failures and future hopes. Infect Dis Clin North Am 1999;13:285–297.[CrossRef][Medline]
  66. Knaus WA, Harrell FE, LaBrecque JF, Wagner DP, Pribble JP, Draper EA, Fisher CJ Jr, Soll L. Use of predicted risk of mortality to evaluate the efficacy of anticytokine therapy in sepsis: the rhIL-1ra Phase III Sepsis Syndrome Study Group. Crit Care Med 1996;24:46–56.[CrossRef][Medline]
  67. Schmid CH, Lau J, McIntosh MW, Cappelleri JC. An empirical study of the effect of the control rates a predictor of treatment efficacy in meta-analysis of clinical trials. Stat Med 1998;17:1923–1942.[CrossRef][Medline]
  68. Boissel JP, Collet JP, Lievre M, Girard P. An effect model for the assessment of drug benefit: example of antiarrhythmic drugs in postmyocardial infarction patients. J Cardiovasc Pharmacol 1993;22:356–363.[Medline]
  69. Antman EM, Seelig MS, Fleischmann K, Lau J, Kuntz K, Berkey CS, McIntosh WM. Magnesium in acute myocardial infarction: scientific, statistical, and economic rationale for its use. Cardiovasc Drugs Ther 1996;10:297–301.[Medline]
  70. Smith GD, Song F, Sheldon TA. Cholesterol lowering and mortality: the importance of considering initial level of risk. BMJ 1993;306:1367–1373.
  71. Brand R, Kragt H. Importance of trends in the interpretation of an overall odds ratio in the meta-analysis of clinical trials. Stat Med 1992;11:2077–2082.[Medline]
  72. Zeni F, Freeman B, Natanson C. Anti-inflammatory therapies to treat sepsis and septic shock: a reassessment. Crit Care Med 1997;25:1095–1100.[CrossRef][Medline]
  73. Cox DR, Snell EJ. Analysis of binary data. London: New York: Chapman and Hall, CRC Press; 1989.
  74. Breslow NE, Day NE. Statistical methods in cancer research, volume II: the design and analysis of cohort studies. New York: Oxford University Press; 1994.
  75. Yaish P, Gazit A, Gilon C, Levitzki A. Blocking of EGF-dependent cell proliferation by EGF receptor kinase inhibitors. Science 1988;242:933–935.[Abstract/Free Full Text]
  76. Glaser KB, Asmis R, Dennis EA. Bacterial lipopolysaccharide priming of P388D1 macrophage-like cells for enhanced arachidonic acid metabolism. Platelet-activating factor receptor activation and regulation of phospholipase A2. J Biol Chem 1990;265:8658–8664.[Abstract/Free Full Text]
  77. Dong Z, O'Brian CA, Fidler IJ. Activation of tumoricidal properties in macrophages by lipopolysaccharide requires protein-tyrosine kinase activity. J Leukoc Biol 1993;53:53–60.[Abstract]
  78. Guy GR, Chua SP, Wong NS, Ng SB, Tan YH. Interleukin 1 and tumor necrosis factor activate common multiple protein kinases in human fibroblasts. J Biol Chem 1991;266:14343–14352.[Abstract/Free Full Text]
  79. Novogrodsky A, Vanichkin A, Patya M, Gazit A, Osherov N, Levitzki A. Prevention of lipopolysaccharide-induced lethal toxicity by tyrosine kinase inhibitors. Science 1994;264:1319–1322.[Abstract/Free Full Text]
  80. Vanichkin A, Patya M, Gazit A, Levitzki A, Novogrodsky A. Late administration of a lipophilic tyrosine kinase inhibitor prevents lipopolysaccharide and Escherichia coli-induced lethal toxicity. J Infect Dis 1996; 173:927–933.[Medline]
  81. Sevransky JE, Shaked G, Novogrodsky A, Levitzki A, Gazit A, Hoffman A, Elin RJ, Quezado ZM, Freeman BD, Eichacker PQ, et al. Tyrphostin AG 556 improves survival and reduces multiorgan failure in canine Escherichia coli peritonitis. J Clin Invest 1997;99:1966–1973.[Medline]
  82. Natanson C, Danner RL, Reilly JM, Doerfler ML, Hoffman WD, Akin GL, Hosseini JM, Banks SM, Elin RJ, MacVittie TJ, et al. Antibiotics versus cardiovascular support in a canine model of human septic shock. Am J Physiol 1990;259:H1440–H1447.[Abstract/Free Full Text]
  83. Freeman BD, Correa R, Karzai W, Natanson C, Patterson M, Banks S, Fitz Y, Danner RL, Wilson L, Eichacker PQ. Controlled trials of rG-CSF and CD11b-directed MAb during hyperoxia and E. coli pneumonia in rats. J Appl Physiol 1996;80:2066–2076.[Abstract/Free Full Text]
  84. Hedges LV, Olkin I. Statistical methods for meta-analysis. Orlando: Academic Press; 1985.
  85. Bernard GR, Vincent JL, Laterre PF, LaRosa SP, Dhainaut JF, Lopez-Rodriguez A, Steingrub JS, Garber GE, Helterbrand JD, Ely EW, et al. Efficacy and safety of recombinant human activated protein C for severe sepsis. N Engl J Med 2001;344:699–709.[Abstract/Free Full Text]
  86. Taylor FB, Chang A, Esmon CT, D'Angelo A, Vigano-D'Angelo S, Blick KE. Protein C prevents the coagulopathic and lethal effects of Escherichia coli in the baboon. J Clin Invest 1987;79:918–925.
  87. Anonymous. FDA Briefing document: anti infective advisory committee drotrecogin alfa (activated) [recombinant human activated protein C (rhAPC)]. http://www.fda.gov/ohrms/dockets/ac/01/briefing/3797b1_02_FDAbriefing.doc 1 A.D.



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