Safety and Clinical Activity of a New Anti-PD-L1 Antibody as Monotherapy or Combined with Targeted Therapy in Advanced Solid Tumors: The PACT Phase Ia/Ib Trial

PURPOSE

This phase Ia/Ib PACT study evaluated the safety, pharmacokinetics, pharmacodynamics, and antitumor activity of a new programmed cell death ligand 1 (PD-L1) inhibitor, LY3300054, as monotherapy or in combination with ramucirumab, abemaciclib, or merestinib (a type II MET kinase inhibitor) in patients with advanced, refractory solid tumors (NCT02791334).

PATIENTS AND METHODS

Patients were enrolled into cohorts of escalating LY3300054 dose (phase Ia) as monotherapy (N = 15) or combined with ramucirumab (N = 10), abemaciclib (N = 24), or merestinib (N = 12). The phase Ib dose expansion enrolled 8 patients with melanoma in the monotherapy arm and 12 patients with pancreatic cancer in the merestinib combination arm. Combination treatments were administered concurrently from day 1 of each cycle. A 14-day lead-in abemaciclib arm was also explored. Primary endpoints were dose-limiting toxicity (DLT) and safety.

RESULTS

Treatment-related adverse events included fatigue and nausea in the monotherapy arm (13% for each), hypothyroidism (30%) in the ramucirumab arm, diarrhea (54%) in the abemaciclib arm, and nausea (25%) in the merestinib arm. DLTs associated with hepatoxicity were observed in 3 of 4 patients in the abemaciclib lead-in cohorts. No DLTs or grade 3 or 4 hepatoxicity were reported in the concurrent abemaciclib arm. Pharmacokinetic characteristics were comparable with other PD-L1 inhibitors. One patient in each arm experienced a partial response per RECIST v1.1 lasting ≥7 months.

CONCLUSIONS

LY3300054 was well tolerated without unexpected safety concerns when administered alone or concurrently with ramucirumab, abemaciclib, or merestinib. Lead-in abemaciclib before combining with LY3300054 was not feasible due to hepatotoxicity. Durable clinical benefits were seen in all regimens.

Safety and Pharmacokinetics of CXCR4 Peptide Antagonist, LY2510924, in Combination with Durvalumab in Advanced Refractory Solid Tumors

Purpose: This was an open-label phase 1a study assessing the maximum tolerated dose (MTD), safety, and tolerability of CXCR4 peptide antagonist, LY2510924, administered in combination with durvalumab in patients with advanced refractory solid tumors.

Methods: Patients received LY2510924 at 20, 30, or 40 mg subcutaneous (SC) once daily in combination with durvalumab at 1500 mg intravenously (IV) on day 1 of each 28-day cycle. The primary objective was to assess the MTD and safety of LY2510924 SC daily in combination with durvalumab in patients with advanced (metastatic and/or unresectable) solid tumors. Secondary objectives included pharmacokinetics (PK) and the antitumor activity of LY2510924 in combination with durvalumab. Exploratory objectives were biomarker analysis, including pharmacodynamic markers, relevant to LY2510924 and durvalumab, including immune functioning, drug targets, cancer-related pathways, and the disease state.

Results: Nine patients (three each at 20, 30, and 40 mg) were enrolled in the study (eight patients with pancreatic cancer and one patient with rectal cancer). The majority of patients completed one or two cycles (100.0% ≥ 1 cycle; 88.9% ≥ 2 cycles) of LY2510924 and durvalumab. No dose limiting toxicities were reported. Most common (>10%) treatment-emergent adverse events were injection-site reaction (44.4%), fatigue (33.3%), and increased white blood cell count (33.3%). PK parameters for combination were similar to those reported in previous studies when given as monotherapy. Best overall response of stable disease was observed in four (44.4%) patients and one patient had unconfirmed partial response.

Conclusion: The recommended phase 2 dose is 40 mg SC once-daily LY2510924 in combination with durvalumab 1500 mg IV and showed acceptable safety and tolerability in patients with advanced refractory tumors.

A phase Ia/b study of TIM-3/PD-L1 bispecific antibody in patients with advanced solid tumors

TPS2654

Background: Programmed cell death 1 immune checkpoint inhibitors (anti-PD-1, anti-PD-L1) have demonstrated clinical benefit in a subset of patients with manageable safety across a variety of tumor types. T-cell immunoglobulin and mucin-domain-containing molecule-3 (TIM-3) can be co-expressed with PD-1 on exhausted T-cells and may be upregulated in tumors refractory to anti-PD-1 therapy (Koyama et al. 2016). Pre-clinical studies demonstrated that blockade of both PD-1 and TIM-3 improved survival of tumor-bearing mice compared to blocking anti-PD-1 only (Koyama et al. 2016). LY3415244 is a TIM-3/PD-L1 bispecific antibody that has the ability to target and inhibit both TIM-3 and PD-L1 and the potential to overcome primary and acquired anti-PD-(L)1 resistance by a novel mechanism to bridge TIM-3- and PD-L1-expressing cells. Methods: Study JZDA is a multicenter, nonrandomized, open-label, Phase 1a/1b study of LY3415244 in patients with advanced solid tumors. In Phase 1a, subjects with any tumor type who are either PD-(L)1 inhibitor-naïve or exposed are eligible. In Phase 1b, expansion cohorts are planned in subjects with PD-(L)1-experienced NSCLC, urothelial carcinoma, and melanoma. Patients with malignant mesothelioma are not required to have received prior anti-PD-(L)1 therapy. The primary objective is to assess safety and tolerability of LY3415244 and identify the recommended Phase 2 dose (RP2D) in Phase 1a (dose escalation). Safety and tolerability of the RP2D will be assessed in Phase 1b (dose expansion). The secondary objectives are to assess the pharmacokinetics of LY3415244 in Phase 1a/1b and assess early antitumor activity of LY3415244 in Phase 1b cohorts. Pre- and on-treatment biopsies will be obtained to explore potential biomarkers of response. During Phase 1a, dose escalation cohorts will proceed via a modified toxicity probability interval-2 (mTPI-2) design with a 1-cycle (28-day) dose-limiting toxicity (DLT) observation period. LY3415244 will be dosed intravenously every 2 weeks. Data from Phase 1a will determine the RP2D, which will be used for all cohorts in Phase 1b. The study is currently open to enrollment. Clinical trial information: NCT03752177.

Abstract CT018: Interim safety and clinical activity in patients (pts) with advanced refractory solid tumors from a phase Ia/b study investigating the novel anti-PD-L1 antibody (LY3300054) administered alone or in combination with other agents

Background: PD-L1 expression is associated with reduced survival and an unfavorable prognosis in a wide range of cancers. LY3300054 (LY) is a PD-L1 inhibitor that blocks the interaction between PD-L1 and its receptors. The added benefit of combining a second therapeutic agent is an area of active interest. This study (NCT02791334) will assess the safety, tolerability and efficacy of LY as monotherapy and in combination with ramucirumab (R), abemaciclib (A) and merestinib (M). Here we report phase 1a safety and preliminary efficacy results from completed LY, LY+R and LY+M cohorts.

Methods: This ongoing, phase 1a/b, multi-center, dose escalation and expansion study enrolled pts with histologically or cytologically confirmed advanced solid tumor having ECOG PS 0-1 and with measurable disease. Primary objective for Phase 1a was to assess safety and tolerability. Secondary objectives include assessment of pharmacokinetics, efficacy and biomarkers (exploratory). Pts received intravenous infusions of LY: Q2W at 70, 200, 700 mg; Q3W at 1000 mg; Q4W at 1800 mg; LY+R: LY (Q2W 200, 700 mg; Q3W 1400 mg) + R (Q2W, Q3W 8 mg/kg); LY+M: LY (Q2W 200, 700 mg) + M (QD 120 mg oral). Adverse events (AEs) were assessed per NCI CTCAE v4.0. Tumor assessments were performed using RECIST v1.1.

Results: As of 4 September 2017, 38 pts ([LY: Q2W, n=10; Q3W, n=3; Q4W, n=3]; LY+R [(Q2W, n=7; Q3W, n=3)]; LY+M Q2W, n=12) were treated. No DLTs were observed and there were no deaths due to AEs while on treatment. Pts with Gr3 treatment-related AEs (TRAEs) were: LY Q3W (n=1) with nausea, vomiting and fatigue; LY+R Q2W (n=2) with decreased appetite, pulmonary embolism and hypertension; Q3W (n=1) with lipase and amylase increase; no Gr 4/5 TRAEs were reported. Serious adverse events possibly related to study treatment were LY Q3W (n=1) Gr3 nausea and vomiting, and LY+R (n=1) Gr3 pulmonary embolism. There were no TRAEs leading to discontinuation of study treatment. The pharmacokinetics of LY was linear in the dose range tested, with a half-life of approximately 3 weeks, which did not appear to be affected by concomitant doses of M or R. Tumor tissue and blood were collected for biomarker analysis, including but not limited to, PD-L1 and CD8 expression by IHC and whole blood immunophenotyping; preliminary biomarker data will be presented. Preliminary efficacy data showed confirmed partial response in LY +R Q2W: 1pt (esophageal cancer), LY +M Q2W: 1pt (pancreatic cancer) and stable disease in LY Q2W: 3pts, LY+R: Q2W 4pts, Q3W 2pts as their best response. As of the data cut-off, 11 pts (29%) remain on treatment.

Conclusions: LY alone or in combination with R or M appears to be well tolerated and demonstrated preliminary antitumor activity in pts with advanced solid tumors. The PK characteristics of LY support Q2W, Q3W, and possibly the Q4W dosing regimens.

Citation Format: Amita Patnaik, Yung-Jue Bang, Hyun C. Chung, María José de Miguel Luken, Timothy A. Yap, Leijun Hu, Anna M. Szpurka, Danni Yu, Anindya Chatterjee, Shivani Nanda, Burkhard Vangerow, Mythili Koneru, Johanna Bendell. Interim safety and clinical activity in patients (pts) with advanced refractory solid tumors from a phase Ia/b study investigating the novel anti-PD-L1 antibody (LY3300054) administered alone or in combination with other agents [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT018.

Clinical characteristics, patterns of lipid-lowering medication use, and health care resource utilization and costs among patients with atherosclerotic cardiovascular disease

Purpose

The aim of this study was to investigate real-world patient characteristics, medication use, and health care resource utilization (HCRU) and costs among patients with clinical atherosclerotic cardiovascular disease (ASCVD) as defined by 2013 American College of Cardiology/American Heart Association (ACC/AHA) guidelines, to examine burden of disease and unmet needs, such as potential undertreatment.

Patients and methods

This retrospective cohort study utilized a nationally representative managed care database to identify newly diagnosed ASCVD patients between January 1, 2007, and November 30, 2012 (index = first ASCVD diagnosis date) in the USA. Patients had ≥12-month pre-index (baseline) and ≥12-month post-index (follow-up) health plan enrollment and no baseline lipid-lowering medication (LLM). Patient characteristics, LLM utilization patterns, HCRU, and costs were examined for all patients and by subgroups based on LLM use pattern and/or follow-up low-density lipoprotein cholesterol (LDL-C) levels.

Results

A total of 128,017 ASCVD patients were identified with a mean (SD) age of 59 (13) years, 43.1% female, and 48.8% with ≥36-month follow-up. Within 12-month follow-up, 10.6% had high-intensity statins and 56.9% had no LLM fills. Baseline mean (SD) all-cause costs were $8,852 ($25,608). At 12-month follow-up, mean (SD) all-cause and ASCVD-related costs were $31,443 ($54,040) and $20,289 ($45,159), respectively. The 36-month analyses showed similar distributions. Multivariable analyses showed that age, gender, region, health insurance type, baseline comorbidities, baseline use of specific medications, baseline lipid profiles, and index ASCVD type were significantly associated with all-cause and ASCVD-related health care costs.

Conclusion

Patients have nonoptimal treatment for ASCVD and substantial HCRU and costs associated with residual risk. Unmet needs and cost burdens of ASCVD patients merit additional investigation.

Evacetrapib and Cardiovascular Outcomes in High-Risk Vascular Disease

BACKGROUND

The cholesteryl ester transfer protein inhibitor evacetrapib substantially raises the high-density lipoprotein (HDL) cholesterol level, reduces the low-density lipoprotein (LDL) cholesterol level, and enhances cellular cholesterol efflux capacity. We sought to determine the effect of evacetrapib on major adverse cardiovascular outcomes in patients with high-risk vascular disease.

METHODS

In a multicenter, randomized, double-blind, placebo-controlled phase 3 trial, we enrolled 12,092 patients who had at least one of the following conditions: an acute coronary syndrome within the previous 30 to 365 days, cerebrovascular atherosclerotic disease, peripheral vascular arterial disease, or diabetes mellitus with coronary artery disease. Patients were randomly assigned to receive either evacetrapib at a dose of 130 mg or matching placebo, administered daily, in addition to standard medical therapy. The primary efficacy end point was the first occurrence of any component of the composite of death from cardiovascular causes, myocardial infarction, stroke, coronary revascularization, or hospitalization for unstable angina.

RESULTS

At 3 months, a 31.1% decrease in the mean LDL cholesterol level was observed with evacetrapib versus a 6.0% increase with placebo, and a 133.2% increase in the mean HDL cholesterol level was seen with evacetrapib versus a 1.6% increase with placebo. After 1363 of the planned 1670 primary end-point events had occurred, the data and safety monitoring board recommended that the trial be terminated early because of a lack of efficacy. After a median of 26 months of evacetrapib or placebo, a primary end-point event occurred in 12.9% of the patients in the evacetrapib group and in 12.8% of those in the placebo group (hazard ratio, 1.01; 95% confidence interval, 0.91 to 1.11; P=0.91).

CONCLUSIONS

Although the cholesteryl ester transfer protein inhibitor evacetrapib had favorable effects on established lipid biomarkers, treatment with evacetrapib did not result in a lower rate of cardiovascular events than placebo among patients with high-risk vascular disease. (Funded by Eli Lilly; ACCELERATE ClinicalTrials.gov number, NCT01687998 .).

Assessment of the clinical effects of cholesteryl ester transfer protein inhibition with evacetrapib in patients at high-risk for vascular outcomes: Rationale and design of the ACCELERATE trial

BACKGROUND

Potent pharmacologic inhibition of cholesteryl ester transferase protein by the investigational agent evacetrapib increases high-density lipoprotein cholesterol by 54% to 129%, reduces low-density lipoprotein cholesterol by 14% to 36%, and enhances cellular cholesterol efflux capacity. The ACCELERATE trial examines whether the addition of evacetrapib to standard medical therapy reduces the risk of cardiovascular (CV) morbidity and mortality in patients with high-risk vascular disease.

STUDY DESIGN

ACCELERATE is a phase 3, multicenter, randomized, double-blind, placebo-controlled trial. Patients qualified for enrollment if they have experienced an acute coronary syndrome within the prior 30 to 365 days, cerebrovascular accident, or transient ischemic attack; if they have peripheral vascular disease; or they have diabetes with coronary artery disease. A total of 12,092 patients were randomized to evacetrapib 130 mg or placebo daily in addition to standard medical therapy. The primary efficacy end point is time to first event of CV death, myocardial infarction, stroke, hospitalization for unstable angina, or coronary revascularization. Treatment will continue until 1,670 patients reached the primary end point; at least 700 patients reach the key secondary efficacy end point of CV death, myocardial infarction, and stroke, and the last patient randomized has been followed up for at least 1.5 years.

CONCLUSIONS

ACCELERATE will establish whether the cholesteryl ester transfer protein inhibition by evacetrapib improves CV outcomes in patients with high-risk vascular disease.

Abstract 338: Patterns of Lipid Lowering Medication Use among Patients with Atherosclerotic Cardiovascular Disease

Background: The 2013 American College of Cardiology/American Heart Association (ACC/AHA) guidelines for the treatment of hypercholesterolemia marked a departure from previously established guidelines in regards to pharmacologic therapy. This study identified patients with atherosclerotic cardiovascular disease (ASCVD) using the new guidelines, and examined their patterns of lipid lowering medication (LLM) use in a real-world environment.

Methods: This retrospective cohort study utilized claims data from the HealthCore Integrated Research Database (HIRD SM ). Newly diagnosed ASCVD patients aged ≥18 years were identified between 1/1/2007 and 11/30/2012 (index date=first ASCVD diagnosis date). Patients had both ≥ 12 months pre- and post- index health plan enrollment and no LLM use at baseline. Index LLM was identified based on earliest fill of LLM within 6 months after the index date. Index LLM dose titration, discontinuation, switch, and augmentation were examined among monotherapy initiators only. Descriptive statistics were used to examine patterns of LLM use at 12 and 36 months follow-up among all patients and those with ≥36 months post-index health plan enrollment respectively.

Results: The study identified 128,017 ASCVD patients with a mean age of 59 years, 43.1% (55,136 of 128,017) female, and 48.8% (62,493 of 128,017) with ≥36 months follow-up. Within 6 months after the index date, 7.8% (9,929 of 128,017) initiated high-intensity statin monotherapy; 27.8% (35,634 of 128,017) moderate/low-intensity statin monotherapy; 1.6% (2,024 of 128,017) non-statin monotherapy; 1.4% (1,770 of 128,017) combination therapy; and 61.4% (78,660 of 128,017) had no fills for any LLM. Among monotherapy initiators over 12 and 36 months follow-up, 8.8% (4,180 of 47,587) and 12.4% (2,635 of 21,198) had up-titration of index LLM, 54.5% (25,938 of 47,587) and 77.8% (16,488 of 21,198) discontinued index LLM, 9.6% (4,579 of 47,587) and 13.9% (2,935 of 21,198) switched their index LLM, and 3.0% (1,403 of 47,587) and 2.8% (586 of 21,198) augmented index LLM. Among all patients over 12 and 36 months follow-up, 41.4% (53,049 of 128,017) and 49.7% (31,057 of 62,493) had statins, 10.6% (13,522 of 128,017) and 13.0% (8,134 of 62,493) had high-intensity statins, 5.8% (7,361of 128,017) and 12.8% (7,989 of 62,493) had ≥2 types of statins, 4.9% (6,253 of 128,017) and 9.3% (5,798 of 62,493) had both statins and non-statin LLMs, and 56.9% (72,897 of 128,017) and 47.9% (29,923 of 62,493) had no LLM.

Conclusions: Few patients initiated a high-intensity statin within 6 months of ASCVD diagnosis and at 12 months and 36 months follow-up. Our findings suggest that treatment for ASCVD patients was not optimal in relation to the recent ACC/AHA guideline recommendations and significant modifications in prescribing patterns should be made towards use of high-intensity statins to improve treatment outcomes.

Drotrecogin alfa (activated) in adults with septic shock

BACKGROUND

There have been conflicting reports on the efficacy of recombinant human activated protein C, or drotrecogin alfa (activated) (DrotAA), for the treatment of patients with septic shock.

METHODS

In this randomized, double-blind, placebo-controlled, multicenter trial, we assigned 1697 patients with infection, systemic inflammation, and shock who were receiving fluids and vasopressors above a threshold dose for 4 hours to receive either DrotAA (at a dose of 24 μg per kilogram of body weight per hour) or placebo for 96 hours. The primary outcome was death from any cause 28 days after randomization.

RESULTS

At 28 days, 223 of 846 patients (26.4%) in the DrotAA group and 202 of 834 (24.2%) in the placebo group had died (relative risk in the DrotAA group, 1.09; 95% confidence interval [CI], 0.92 to 1.28; P=0.31). At 90 days, 287 of 842 patients (34.1%) in the DrotAA group and 269 of 822 (32.7%) in the placebo group had died (relative risk, 1.04; 95% CI, 0.90 to 1.19; P=0.56). Among patients with severe protein C deficiency at baseline, 98 of 342 (28.7%) in the DrotAA group had died at 28 days, as compared with 102 of 331 (30.8%) in the placebo group (risk ratio, 0.93; 95% CI, 0.74 to 1.17; P=0.54). Similarly, rates of death at 28 and 90 days were not significantly different in other predefined subgroups, including patients at increased risk for death. Serious bleeding during the treatment period occurred in 10 patients in the DrotAA group and 8 in the placebo group (P=0.81).

CONCLUSIONS

DrotAA did not significantly reduce mortality at 28 or 90 days, as compared with placebo, in patients with septic shock. (Funded by Eli Lilly; PROWESS-SHOCK ClinicalTrials.gov number, NCT00604214.).

Randomized trial evaluating serial protein C levels in severe sepsis patients treated with variable doses of drotrecogin alfa (activated)

Introduction

Serial alterations in protein C levels appear to correlate with disease severity in patients with severe sepsis, and it may be possible to tailor severe sepsis therapy with the use of this biomarker. The purpose of this study was to evaluate the dose and duration of drotrecogin alfa (activated) treatment using serial measurements of protein C compared to standard therapy in patients with severe sepsis.

Methods

This was a phase 2 multicenter, randomized, double-blind, controlled study. Adult patients with two or more sepsis-induced organ dysfunctions were enrolled. Protein C deficient patients were randomized to standard therapy (24 μg/kg/hr infusion for 96 hours) or alternative therapy (higher dose and/or variable duration; 24/30/36 μg/kg/hr for 48 to 168 hours). The primary outcome was a change in protein C level in the alternative therapy group, between study Day 1 and Day 7, compared to standard therapy.

Results

Of 557 patients enrolled, 433 patients received randomized therapy; 206 alternative, and 227 standard. Baseline characteristics of the groups were largely similar. The difference in absolute change in protein C from Day 1 to Day 7 between the two therapy groups was 7% (P = 0.011). Higher doses and longer infusions were associated with a more pronounced increase in protein C level, with no serious bleeding events. The same doses and longer infusions were associated with a larger increase in protein C level; higher rates of serious bleeding when groups received the same treatment; but no clear increased risk of bleeding during the longer infusion. This group also experienced a higher mortality rate; however, there was no clear link to infusion duration.

Conclusions

The study met its primary objective of increased protein C levels in patients receiving alternative therapy demonstrating that variable doses and/or duration of drotrecogin alfa (activated) can improve protein C levels, and also provides valuable information for incorporation into potential future studies.

Trial registration

ClinicalTrials.gov identifier: NCT00386425.

Terminal complement complex in septic shock with capillary leakage: marker of complement activation?

BACKGROUND AND OBJECTIVE

The aim of this study was to evaluate the value of terminal complement complex (C5b-9) plasma levels as a marker for complement activation in septic shock with concomitant capillary leak syndrome.

METHODS

In a prospective animal study 10 fasted, anaesthetized, mechanically ventilated and multi-catheterized pigs (20.6 +/- 1.3 kg) were investigated over a period of 8 h. Sepsis was induced by faecal peritonitis (1 g kg(-1) body weight faeces, n = 5) and compared to controls (n = 5). The animals received 6% hydroxyethyl starch 200/0.5 to maintain a central venous pressure of 12 mmHg. To quantify capillary leak syndrome, albumin escape rate was measured using 99mTc-labelled human serum albumin. Plasma levels of terminal complement complex were measured in a double antibody immunoassay (neoepitope-specific MoAb aE 11 as catching antibody). Immunohistological studies of renal specimens were performed to detect terminal complement complex deposition.

RESULTS

Albumen escape rate increased in septic animals (+ 52%) compared to controls (+ 3%, P < 0.05). Plasma levels of terminal complement complex decreased during the study period in both groups. In septic animals this finding was accompanied by a significant deposition of terminal complement complex in renal specimens (P < 0.05).

CONCLUSION

We found an activation of the complement system proven by marked deposition of terminal complement complex in renal specimen, while its plasma levels decreased during the study period in septic and control animals. These results suggest that in septic shock with capillary leak syndrome plasma level of terminal complement complex may not be a reliable marker of complement activation.

[Aseptic central venous catheter exchange with a guide wire]

Central venous catheters are exchanged in cases of malfunction, suspected infections, or when another catheter type is required. It can be replaced by new venipuncture or using a guide wire. The guide wire technique should be used with a defective catheter or when the catheter type is to be changed. It is contraindicated at exit site infections or proven or suspected catheter infections. Due to possible cross contamination of new by old catheter material meticulous aseptic technique is required. A detailed description of the process of catheter exchange using a guide wire with special regard to the aseptic technique is given.

Hydroxyethyl starch and modified fluid gelatin maintain plasma volume in a porcine model of septic shock with capillary leakage

OBJECTIVE

To compare the effects of different volume replacement therapies on maintenance of plasma volume in septic shock and capillary leakage syndrome.

DESIGN AND SETTING

Prospective randomized, controlled animal laboratory study in a university animal laboratory.

MEASUREMENTS AND RESULTS

Twenty-five fasted, anaesthetized, mechanically ventilated and multi-catheterized pigs (20.8+/-1.8 kg) received 1 g/kg body weight faeces into abdominal cavity to induce sepsis and were observed over 8 h. Five animals each received volume replacement therapy with modified fluid gelatin 4% or 8% (MFG4%, MFG8%), 6% HES 200/0.5, or Ringer's solution and were compared to controls receiving 6% HES 200/0.5. Infusion rate was titrated to maintain a central venous pressure of 12 mmHg. Plasma volume was determined using (51)Cr-labelled erythrocytes and standard formulae. Albumin escape rate was calculated using technetium (99m)Tc-labelled albumin. Colloid osmotic pressure, systemic haemodynamics and oxygenation were obtained before and 4 and 8 h after induction of sepsis. Plasma volume was reduced in the Ringer's solution group (-46%) but was maintained in HES (+/-0%), MFG4% (+4%), MFG8% (+23%) groups. Albumin escape rate increased in HES (+52%), MFG4% (+47%), MFG8% (+54%) and the Ringer's solution group (+41%) compared to controls.

CONCLUSION

In this porcine septic shock model with concomitant capillary leakage syndrome, confirmed by an increased albumin escape rate, the artificial colloids HES, MFG4%, and MFG8% maintained plasma volume and colloid osmotic pressure. These results suggest the intravascular persistency of artificial colloids in the presence of albumin leakage. An editorial regarding this article can be found in the same issue (http://dx.doi.org/10.1007/s00134-002-1283-9)

C1-inhibitor for prophylaxis of xenograft rejection after pig to cynomolgus monkey kidney transplantation

BACKGROUND

Early rejection of discordant porcine xenografts in primate recipients is initiated by the intragraft binding of either preformed (hyperacute xenograft rejection) or induced (acute vascular rejection) antiporcine recipient antibodies with subsequent complement activation via the classical pathway. We have investigated the efficacy of the supplemental administration of C1-inhibitor (C1-INH), a specific inhibitor of the classical complement activation pathway, for prophylaxis of xenograft rejection in a pig to primate kidney xenotransplantation setting.

METHODS

Based on the results of pharmacokinetic studies performed in two nontransplanted monkeys, supplemental C1-INH therapy was administered daily to three Cynomolgus monkeys receiving a life-supporting porcine kidney transplant together with cyclophosphamide-induction/cyclosporine A/mycophenolat-mofetil/steroid immunosuppressive therapy.

RESULTS

In the three monkeys receiving porcine kidney xenografts and continuous C1-INH treatment none of the grafts underwent hyperacute rejection; all xenografts showed initial function. Recipient survival was 13, 15, and 5 days. No graft was lost due to acute vascular rejection. All animals died with a functioning graft (latest creatinine 96, 112, and 96 micromol/liter) due to bacterial septicemia.

CONCLUSION

We conclude that, in our model, supplemental C1-INH therapy together with a standard immunosuppressive regimen can be helpful for prevention of xenograft rejection in a pig to primate kidney xenotransplantation setting. The optimal dose and duration of C1-INH treatment, however, has yet to be determined.

C1-Inhibitor for treatment of acute vascular xenograft rejection in cynomolgus recipients of h-DAF transgenic porcine kidneys

At present, the major barrier to successful discordant xenotransplantation of unmodified or complement regulator transgenic porcine xenografts is acute vascular xenograft rejection (AVR). AVR is associated with the intragraft deposition of induced recipient xenoreactive antibodies and subsequent complement activation. In a life-supporting pig to primate kidney xenotransplantation setting using h-DAF transgenic donor organs and postoperative immunosuppression, episodes of AVR were either treated with boluses of cyclophosphamide and steroids or with the same regimen supplemented by a three-day course of C1-Inhibitor, a multifunctional complement regulator. In 8 out of 10 animals stable initial graft function was achieved; in all animals one or more episodes of AVR were observed. When, in 4 animals, C1-Inhibitor was added to the standard anti-rejection treatment regimen, AVR was successfully reversed in 6 out of 7 episodes, while in another group of 4 animals receiving the standard anti-rejection treatment 0 out of 4 episodes of AVR responded to treatment. Response to anti-rejection treatment was associated with a significant increase in recipient survival time. We conclude that AVR of h-DAF transgenic porcine kidneys can be successfully treated by additional short-term fluid phase complement inhibition.

Effects of C1 inhibitor and r-SP-C surfactant on oxygenation and histology in rats with lavage-induced acute lung injury

OBJECTIVE

To assess the effects of C1 inhibitor (INH) administration and r-SP-C surfactant application on oxygenation and lung histology in an acute respiratory distress syndrome model.

DESIGN AND SETTING

Randomized, controlled experimental study in an animal research laboratory.

MATERIAL

36 adult male Sprague-Dawley rats.

INTERVENTIONS

Animals were subjected to repetitive lung lavage. Four experimental groups and two control groups were studied: groups 1 and 2 served as controls. Animals of groups 3-6 received 200 U/kg body weight C1-INH (group 3), 25 mg/kg r-SP-C surfactant (group 4) or both (group 5) at 60 min postlavage (pl). Animals of group 6 were treated with 200 U/kg C1-INH1 at 10 min pl. Animals of group 1 were killed 60 min (min) pl, animals of groups 2-6 were killed at 210 min pl. Thereafter the lungs were excised for histological examination.

MEASUREMENTS AND RESULTS

Hyaline membrane formation, intra-alveolar neutrophil (PMN) accumulation and intra-alveolar/perivascular haemorrhage were graded semiquantitatively (0-4). Blood gases were determined 120, 150, 180 and 210 min pl. At 210 min pl pO(2) in group 4 (456+/-74 mmHg) and group 5 (387+/-155 mmHg) was significantly higher than in controls (72+/-29 mmHg) or after C1-INH monotherapy (group 3: 120+/-103, group 6: 63+/-12 mmHg). PMN infiltration after C1-INH monotherapy was significantly less severe than in controls. The combination of r-SP-C surfactant and C1-INH led to significantly lower PMN infiltration than surfactant monotherapy.

CONCLUSION

In this lavage-induced acute respiratory distress syndrome model the administration of C1-INH might be followed by a higher clinical efficacy of exogenously supplied recombinant SP-C surfactant.

Hemodynamic consequences of porcine kidney xenograft reperfusion in cynomolgus monkeys

BACKGROUND

After xenograft reperfusion, complement activation may lead to generation of anaphylatoxins and cardiocirculatory instability of the recipient.

METHODS

In 13 cynomolgus recipients of either unmodified or human decay accelerating factor transgenic porcine kidneys cardiocirculatory parameters were measured by single indicator transpulmonary thermodilution.

RESULTS

After graft reperfusion, recipient cardiac output decreased by 25.4% (P<0.05), intrathoracic blood volume by 22.8% (P<0.05), extravascular lung water increased slightly (P=n.s.). The impairment in cardiac output was neither influenced by the graft's weight or human decay accelerating factor transgenicity. sC3a and sC5b-9 complement levels in the recipient monkeys showed a sharp peak upon reperfusion.

CONCLUSIONS

After reperfusion a marked and significant cardiodepression accompanied by relative volume depletion were observed. Analysis of volume status ruled out a mere volume shift as the underlying reason for the observed drop in cardiac output. These data may be relevant for the perioperative management of human recipients of discordant xenografts in the future.

Evaluation of noninvasive determinants for capillary leakage syndrome in septic shock patients

OBJECTIVE

Capillary leakage syndrome (CLS) is a frequent complication in sepsis, characterized by loss of intravasal fluids leading to generalized edema and hemodynamic instability despite massive fluid therapy. In spite of its importance no standardized diagnostic criteria are available for CLS.

DESIGN

Prospective clinical study.

SETTING

1,800-bed university hospital

PATIENTS

Six septic shock patients with CLS were compared to six control patients.

MEASUREMENTS AND RESULTS

CLS was clinically determined by generalized edema, positive fluid balance, and weight gain. Plasma volume was measured by indocyanine green, red blood cell volume by chromium-51 labeled erythrocytes, and colloid osmotic pressure before and 90 min after the administration of 300 ml 20% albumin. Extracellular water (ECW) was measured using the inulin distribution volume and bioelectrical impedance analysis. Red blood cells averaged 20.2 +/- 1.0 ml/ kg body weight in CLS patients and 23.3 +/- 4.1 in controls. ECW was higher in CLS patients than in controls (40.0 +/- 6.9 vs. 21.7 +/- 3.71; p< 0.05). ECW of inulin was correlated with that measured by bioelectrical impedance analysis (r = 0.74, p< 0.01). The increase in colloid osmotic pressure over the 90 min was less in CLS patients than in controls (1.1 +/- 0.3 vs. 2.8 +/- 1.3 mmHg;p< 0.05).

CONCLUSION

These results suggest that measurements of an increased ECW using bioelectrical impedance analysis combined with a different response of colloid osmotic pressure to administration of albumin can discriminate noninvasively between patients with and those without CLS.

Acute vascular rejection is associated with systemic complement activation in a pig-to-primate kidney xenograft model

The introduction of h-DAF transgenic porcine organs into pre-clinical pig-to-primate discordant xenotransplantation has led to complete and reliable abrogation of hyperacute xenograft rejection (HAR). Despite additional heavy immunosuppression however, most xenografts are still lost due to acute vascular rejection (AVR), with current treatment protocols being of only limited value. In a life-supporting model of pig-to-primate kidney transplantation, unmodified (n=8) or h-DAF-transgenic (n=9) porcine kidneys were transplanted into cynomolgus monkeys under cyclophosphamide (CyP), cyclosporine and low-dose steroid immunosuppression. Longest recipient survival was 11 days in the control group and 68 days in the h-DAF transgenic group. Stable initial graft function with recipient survival >4 days was generated in eight animals (two controls and six transgenics). In these animals, plasma complement levels were analyzed during ongoing AVR. Compared with baseline levels, a two-fold increase in C3a levels and a four-fold increase in sC5b-9 levels were measured. In parallel to systemic complement activation, increased deposition of C3 and C5b-9 along with massive staining for recipient IgM immunoglobulins was detected in the xenografts on immunohistochemistry. We conclude that acute vascular xenograft rejection of porcine kidneys in cynomolgus monkeys is associated with classical pathway complement activation following binding of induced recipient anti-porcine antibodies. This complement activation can be observed despite membrane bound expression of human complement regulators in the porcine xenografts. Therefore, additional short-term fluid phase complement inhibition seems necessary for the future development of protocols designed for treatment of AVR in the pig-to-primate combination.

Low-dose dopexamine in patients undergoing hemihepatectomy: an evaluation of effects on reduction of hepatic dysfunction and ischaemic liver injury

BACKGROUND

Hepatic dysfunction is a common problem in patients after hemihepatectomy. Treatment with low-dose dopamine has been shown to be beneficial in hemihepatectomy patients. We hypothesized that dopexamine, a synthetic vasoactive catecholamine, due to its specific pharmocodynamic profile may be more effective in reducing hidden ischaemic episodes in the hepato-splanchnic region during and after temporary total cross-clamping of hepatic inflow in these patients.

METHODS

The effects of low-dose dopexamine on hepatic venous haemoglobin oxygen saturation (ShvO2), hepatic venous lactate level, monoethylglycinxylid (MEGX) formation, hepatic synthetic function and indicators for hepatic cell damage were studied during hemihepatectomy and for 16 h postoperatively in hemihepatectomy patients and compared to those of low-dose dopamine. In a prospective, double-blind clinical study 20 patients received randomly either dopexamine (DPX) 0.5 microg kg(-1) min(-1) (n=10) or dopamine (DO) 2.5 microg kg(-1) min(-1) (n= 10). Infusions were started after induction of anaesthesia and continued 16 h postoperatively. Hepatic vein, radial and pulmonary artery were catheterized. Measurements were carried out after induction of anaesthesia, after total cross-clamping of hepatic inflow, and at 2 h and 16 h postoperatively.

RESULTS

There were no differences in systemic haemodynamics, oxygenation, ShvO2, serum aminotransferases or MEGX levels between the groups. At 16 h postoperatively prothrombin and antithrombin III levels were significantly lower while hepatic venous lactate was significantly higher in the DPX group compared to the DO group.

CONCLUSION

In patients undergoing hemihepatectomy, we could not reveal superior hepatoprotective effects of low-dose dopexamine compared to low-dose dopamine.

Xenon inhalation increases airway pressure in ventilated patients

BACKGROUND

The inert gas xenon, known as an anaesthetic for nearly 50 years, is also used as a contrast agent during computerised tomography (CT)-scanning. As xenon has a higher density and viscosity than air, xenon inhalation may increase airway resistance.

METHODS

In a retrospective study we investigated the effects of 33% xenon/67% oxygen on airway pressure and cardio-respiratory parameters in 37 long-term mechanically ventilated patients undergoing cerebral blood flow (rCBF) measurements by means of stable xenon-enhanced CT.

RESULTS

Xenon administration caused a significant increase in peak airway pressure from 31.6+/-8.0 cm H2O to 42.7+/-16.9 cm H2O. This effect was reproducible, did not occur after reduction of inspiratory flow rate by 50% from 0.56+/-0.15 L x s(-1) to 0.28+/-0.08 L x s(-1), and vanished immediately after termination of xenon delivery.

CONCLUSION

Due to the higher density and viscosity of this gas mixture, ventilation with xenon/oxygen produces a higher Reynolds' number than oxygen/air when given at the same flow rate. This means that during xenon ventilation the zone of transition from turbulent to laminar gas flow may be located more peripherally (in smaller airways) than during oxygen/air ventilation with a subsequent increase in airway resistance. Our results indicate that xenon inhalation may cause a clinically relevant increase of peak airway pressure in mechanically ventilated patients.

Septic shock after liver transplantation for Caroli's disease: clinical improvement after treatment with C1-esterase inhibitor

The extent of complement and contact activation is related to outcome in sepsis. A low functional index of their main blocker C1-esterase inhibitor (C1-INH) is considered as a relative deficiency of C1-INH and might contribute to the development of fatal complications in the intensive care unit. The first results of therapeutic intervention with C1-INH concentrate in septic shock are promising. We report on our experience of C1-INH concentrate administration in a young woman with Caroli's disease as ultimate rescue therapy for septic shock with capillary leakage syndrome after combined liver and kidney transplantation. No focus of infection was detectable and thus surgical intervention was not indicated. Antibiotic therapy at that time included vancomycin, tobramycin, meropenem and fluconazol. Hemodynamic stabilization occurred within hours after administration of C1-INH concentrate. Simultaneously a reduction in vasopressor medication was possible and negative fluid balance was achieved.

Compositional, structural, and functional alterations in pulmonary surfactant in surgical patients after the early onset of systemic inflammatory response syndrome or sepsis

OBJECTIVES

Sepsis is one of the most important predisposing factors for the development of the acute respiratory distress syndrome (ARDS). Alterations of pulmonary surfactant contribute in the pathogenesis of ARDS. However, little is known about surfactant in patients with less severe grades of lung injury related to sepsis or systemic inflammatory response syndrome (SIRS). Therefore, the purpose of this study was to characterize endogenous surfactant in surgical intensive care patients with sepsis or SIRS.

DESIGN

Prospective, observational study.

SETTING

University-affiliated, interdisciplinary intensive care unit.

PATIENTS

Eleven patients after major surgery with SIRS or sepsis included within 12 hrs of onset and 11 controls without infection or lung disease.

INTERVENTIONS

Operating room and standard intensive care unit management.

MEASUREMENTS AND MAIN RESULTS

Four serial bronchoalveolar lavage samples (BAL) were recovered over 7 days from the patients and single BAL samples were obtained from controls. BAL cells, total protein, surfactant-associated protein A (SP-A), surfactant alveolar transition forms, and surface activity were analyzed. Two of 11 patients met criteria for acute lung injury and six of the 11 patients met ARDS consensus conference criteria but acute lung injury or ARDS was not persistent. The mean Pao2/F(IO)2 for the patients over 7 days was 253.2+/-15.1 (SEM) and Murray's lung injury score was 1.12+/-0.12, indicating mild-to-moderate lung injury. BAL neutrophil counts were increased (p< .01), and the ratio of poorly functioning light aggregate surfactant to superiorly functioning heavy aggregate surfactant was increased compared with controls (0.32+/-0.06 vs. 0.09+/-0.01, p < .05). SP-A was decreased (1.9+/-0.4 vs. 3.5+/-0.6 microg/mL of BAL, p< .05) and there were increases in the ratios of phospholipid to SP-A (p < .05), protein to SP.A (p < .01), and protein to phospholipid (p < .05). The surface tension-lowering ability of purified heavy aggregate surfactant was significantly impaired (15.6+/-1.6 vs. 2.8+/-0.6 milliNewtons/m, p< .05).

CONCLUSIONS

These observations show that surgical patients with SIRS or sepsis who have mild-to-moderate lung injury develop surfactant dysfunction detectable within 7 days of onset. We propose, therefore, that therapeutic strategies to modulate these severe surfactant abnormalities should be considered, as these strategies may have the potential to reduce lung injury, which is associated with a high mortality in sepsis.

Predictors of respiratory function deterioration after transfer of critically ill patients

OBJECTIVES

Critically ill patients are often transferred due to the growing number of diagnostic procedures required to be performed outside the intensive care unit. These transfers have proved to be very critical. The aim of this study was to evaluate predictors for the deterioration of respiratory function in critically ill patients after transfer.

DESIGN

Prospective, clinical, observational study.

SETTING

1800-bed university teaching hospital.

SUBJECTS

98 mechanically ventilated patients were investigated during transfer.

MEASUREMENT AND MAIN RESULTS

Before transfer, all patients were classified according to the Acute Physiology and Chronic Health Evaluation (APACHE) II score and the Therapeutic Intervention Scoring System (TISS). Haemodynamics and arterial blood gases were measured at 11 different times. Arterial oxygen tension (PaO2), fractional inspired oxygen (FIO2), PaO2/FIO2 ratio, lowest PaO2/FIO2 ratio, minimal PaO2 and maximal FIO2, APACHE II score, TISS before transfer, age and duration of transfer were analysed as potential predictors for deterioration of respiratory function after transfer. Variables were analysed using Classification and Regression Trees and Clustering by Response. In 54 transports (55%) there was a decrease in the PaO2/FIO2 ratio, and a decrease of more than 20% from baseline was noted in 23 of the transferred patients (24%). Age > 43 years and FIO2 > 0.5 were identified as predictors for respiratory deterioration.

CONCLUSIONS

Our predictors were able to indicate deterioration after transfer correctly in 20 of 22 patients (91%), combined with a false-positive rate in 17 of 49 (35%).