Keratinocyte growth factor in acute lung injury to reduce pulmonary dysfunction – a randomised placebo-controlled trial (KARE): study protocol

Background Acute lung injury is a common, devastating clinical syndrome associated with substantial mortality and morbidity with currently no proven therapeutic interventional strategy to improve patient outcomes. The objectives of this study are to test the potential therapeutic effects of keratinocyte growth factor for patients with acute lung injury on oxygenation and biological indicators of acute inflammation, lung epithelial and endothelial function, protease:antiprotease balance, and lung extracellular matrix degradation and turnover. Methods/design This will be a prospective, randomised, double-blind, allocation-concealed, placebo-controlled, phase 2, multicentre trial. Randomisation will be stratified by presence of severe sepsis requiring vasopressors. Patients in an ICU fulfilling the American–European Consensus Conference Definition of acute lung injury will be randomised in a 1:1 ratio to receive an intravenous bolus of either keratinocyte growth factor (palifermin, 60 μg/kg) or placebo (0.9% sodium chloride solution) daily for a maximum of 6 days. The primary endpoint of this clinical study is to evaluate the efficacy of palifermin to improve the oxygenation index at day 7 or the last available oxygenation index prior to patient discontinuation from the study. A formal statistical analysis plan has been constructed. Analyses will be carried out on an intention-to-treat basis. A single analysis is planned at the end of the trial. P = 0.05 will be considered statistically significant and all tests will be two-sided. For continuously distributed outcomes, differences between groups will be tested using independent-sample t tests, analysis of variance and analysis of covariance with transformation of variables to normality or nonparametric equivalents. The trial will be reported in line with the Consolidated Standards of Reporting Trials (Consort 2010 guidelines). Trial registration http://ISRCTN95690673


BACKGROUND AND DESIGN
The trial hypothesis under investigation is that treatment with palifermin will improve surrogate clinical outcomes in adult patients with ALI and is safe.
The objectives of this trial are 1) To conduct a randomised, double-blind, placebo-controlled phase 2 trial of palifermin for the treatment of ALI and 2) To study the biological mechanisms of palifermin on pulmonary and systemic neutrophil function and inflammation; alveolar epithelial and endothelial function protease:antiprotease balance and lung extracellular matrix degradation and turnover The trial is a prospective, randomised, double-blind, placebo-controlled phase 2, clinical study of palifermin in patients with ALI.
Patients will be randomised to Palifermin 60 µg/kg or normal saline placebo daily as a bolus intravenous injection for up to 6 days. Administration will not occur through an intravenous line that has been flushed with heparin. The intravenous line will be flushed with normal saline prior to and after study drug administration. The first dose of study drug will be administered within 4 hours of randomisation and subsequent doses will be at 10 am daily starting on the following calendar day.
Patients will be eligible to participate in the study if they fulfil the following criteria: Inclusion criteria: ALI as defined by acute onset of: a. hypoxic respiratory failure (PaO2/FiO2 ≤ 40 kPa) b.
bilateral infiltrates on chest X-ray consistent with pulmonary oedema. c.
no clinical evidence of left atrial hypertension or if measured, a pulmonary arterial occlusion pressure (PAOP) less than or equal to 18 mmHg. d. requirement for positive pressure mechanical ventilation via an endotracheal tube or tracheostomy.
All ALI criteria (a-d above) must occur within the same 24-hour period. The onset of ALI is when the last ALI criterion is met. Patients must be enrolled within 72 hours of ALI onset The trial is summarised in Figure 1.

Within 72hours of onset of ALI
Full details of the background to the trial and its design are presented in the protocol.
Daily screening in ICU Does the patient have a diagnosis of ALI?
(Acute onset AND PaO2/FiO2 ratio ≤ 40kPa AND bilateral infiltrates on CXR AND no evidence of left atrial hypertension AND ventilated)

Failure to fulfil inclusion and exclusion criteria
Patients with ALI assessed for eligibility

Data collection
Pulmonary and non-pulmonary organ function ICU and hospital outcomes Safety Blood, BAL and urine samples When patient has regained capacity they will be asked for consent to continue follow-up Patients who refuse to continue will be withdrawn 2. OUTCOME MEASURES

Primary outcome measure
The primary endpoint of this clinical study is to evaluate the efficacy of palifermin to improve oxygenation index (OI) at day 7 or the last available OI prior to patient discontinuation from the study.
Physiological indices of acute lung injury, as measured by respiratory compliance (Crs) and P/F ratio at days 3, 7 and 14 3.
Change in sequential organ failure assessment (SOFA) score from baseline to day 7 and 14 4.
Safety and tolerability as assessed by the occurrence of AEs and Suspected Unexpected Serious Reactions (SUSARs).
Although the duration of ventilation and ICU stay as well as ICU and hospital mortality and 28-day mortality will also be documented, these important clinical outcomes are not included as major outcome measures as the study is not adequately powered to assess these outcomes.
The secondary objective of the study is to measure the biological effects of KGF on: 1. Systemic and pulmonary neutrophil function 2.
Systemic and pulmonary inflammatory response 3.
Systemic and pulmonary epithelial and endothelial function 4.
Systemic and pulmonary protease and anti-protease balance 5.
Pulmonary extracellular matrix (ECM) degradation and turnover 3. DATA

CRF Forms and variables
Full details of data collection and timing are described in the trial protocol (version 3.0 30 Nov 2012). A copy of the CRF is presented in the Trial Master File.

Management of datasets
Below is the standard policy for management of data in the CRSC as given in the CTU SOPs.
At the time of analysis (including DMEC reports/Interim analysis (if required)): The trial database will be stored in MACRO:  In collaboration with the Statistician, the Data Manager will file out from MACRO a dataset of all data stored in the database. This will act as the frozen dataset. It is the responsibility of the statistician to accurately record the date of freezing and ensure all data is retrieved.  New data can continue to be entered onto MACRO database.  If any outstanding data queries are resolved during the analysis that relate to data in the frozen dataset (e.g. problems that are found during analysis or amended CRFs that are returned to the CRSC), the main MACRO database should be changed under the oversight of the Trial Data Manager.

Data completion schedule
The following

Data verification
Data verification, consistency and range checks will have been performed at the data entry stage by the CRSC, as well as checks for missing data (copies can be found in the Trial Master File). Additional range, consistency and missing data checks will be performed, as appropriate, when the analysis is performed (and when the datasets for analysis are constructed). All variables will be examined for unusual, outlying, unlabelled or inconsistent values.
Given the thorough nature of our follow-up procedure we expect the issue of missing data to be relatively minimal. We anticipate high compliance with initial data collection as this is close to the time of patient registration. If any data is missing imputation will not be done.
Any problems with trial data will be queried with the Trial Managers, Data Managers, or statisticians, as appropriate. If possible, data queries will be resolved, although it is accepted that due to administrative reasons and data availability a small number of problems will continue to exist. This will be minimised.

Data coding
The variable codings will be as specified on the CRF.

DEFINITION OF TERMS
Give definition of any terms that require explanation.

SAMPLE SIZE CALCULATIONS
The primary outcome measure will be the difference in OI between the palifermin and placebo treated groups at day 7. Day 7 is chosen as it is expected this time interval will minimise the competing effects of death and extubation, while at the same time allowing a sufficient time interval for a biological effect to occur. Based on the data from a recently completed clinical trial in ALI, the mean (standard deviation; SD) OI at day 7 in patients with ALI is 62 (51) cmH2O/kPa. A sample size of 56 subjects (28 in each group) will have 80% power at a twotailed significance level of 0.05 to detect a clinically significant difference of 39 cmH2O/kPa in OI between groups. In a previous phase 2 study of similar size, it was found that an intervention can demonstrate a change in OI of a similar magnitude confirming a treatment effect of this size can be achieved.
In a previous single centre study of simvastatin in ALI there were no withdrawals. In a multicentre UK study of pulmonary artery catheters in ICU patients (PAC-Man), no patients were lost to follow up, and only 2.4% withdrew consent after recovering competency. Therefore a drop-out rate of 5% has been estimated and the study will require a total of 60 patients (30 in each group).
Using the sample size of 60 patients determined from the primary outcome measure, the differences in the secondary outcomes at day 7 that can be detected between the groups are presented in table 3. Data are mean (SD). All calculations assume 80% power at a two-tailed significance level of 0.05.

ANALYSIS PRINCIPLES
Standard approaches will be used to detect patterns in missing data. Analyses will be on an intention-to-treat basis. A single analysis is planned at the end of the trial. A P value of 0.05 will be considered as statistically significant and all tests will be two-sided. For continuously distributed outcomes, differences between groups will be tested using independent samples t-tests, analysis of variance (ANOVA) and analysis of covariance (ANCOVA) with transformations of variables to Normality if appropriate, or non-parametric equivalents. Chi-squared tests (or Fisher's Exact tests) will be used for categorical variables.

N.I Clinical Research Support Centre
Correlations between changes in the biological markers measured and physiological and clinical outcomes will assessed by appropriate graphical and statistical methods including Chisquare and Pearson's correlation coefficient.
Important time points for clinical outcomes such as OI are days 3 and 14, respiratory compliance (Crs) and P/F ratio at days 3, 7 and 14 and change from baseline in SOFA at days 7 and 14.
The randomisation is stratified by vasopressor requirement.

ANALYSIS DETAILS
 Change in sequential organ failure assessment (SOFA) score from baseline to day 7 and 14, mean (sd) by treatment arm

Trial management group (TMG)
The TMG will consist of the Chief Investigator, co-investigators and staff from the CTU. The Chief Investigator will have overall responsibility for the conduct of the study. Dr Mark Cross will be responsible on a day-to-day basis for the trial. Regular meetings of the TMG will be held to discuss and solve problems and monitor progress. The Chairman of CritPaL (Barry Williams) will advise the TMG and will represent the patient's perspective ensuring that the trial remains considerate of the needs of the patients and their families. The Chief Investigator will take responsibility for the need to change the protocol for any reason, reviewing relevant information from other sources and considering recommendations from the DMEC.

Data Monitoring and Ethics Committee (DMEC)
A DMEC will be appointed. The committee will be independent of the study team and will comprise an intensive care clinician and a clinician with experience in undertaking clinical trial. The DMEC will meet to agree conduct and remit. The DMEC will meet after the first 5 patients have been enrolled into the study and meet every 6 months thereafter. In the event of an occurrence of an unexpected severe adverse reaction an additional unplanned DMEC meeting will be convened. As this is a phase 2 trial, an interim analysis of efficacy is not planned although this issue can be discussed by the DMEC as required. The DMEC will function primarily as a check for safety, reviewing adverse events. They will report any issues pertaining to safety to the Chief Investigator. It will be the responsibility of the Chief Investigator to inform the sponsor who will take appropriate action to halt the trial if concerns exist about patient safety.
Include in the appendix any additional information that is relevant to the analyses such as: