Final Report Summary - MON4STRAT (Therapeutic Beta-Lactam Monitoring for Stratified Treatment of hospital-acquired pneumonia, improved dose-dependent efficacy, decreased treatment duration, and prevention of emergence of resistance)
Executive Summary:
Antibacterial drugs are facing increasing limitations in terms of effectiveness not only due to emergence of high-level resistance but also due to a moderate but significant decrease in bacterial susceptibility. These expose the patients to a risk of sub-therapeutic dosages that explains treatment failures and further emergence of drug resistance (EDR). To mitigate these risks, clinicians tend to increase drug dosages and/or to combine antibiotics, which then expose the patients to potential toxicity while not necessarily minimizing efficiently EDR.
This is of main concern in Hospital-Acquired Pneumonia [HAP] (including Ventilator-Associated Pneumonia [VAP]). Despite recent advances in antimicrobial therapy, better supportive care and a wide range of prevention measures, HAP/VAP remains a significant cause of patient morbidity and mortality as well as health care costs. beta-lactams remain at the cornerstone of the current treatments in HAP/VAP patients. However, the underlying illnesses have a marked impact on beta-lactam distribution properties and on patient's excretory function, which creates much variability in their pharmacokinetics and the corresponding blood levels. Thus within the specific HAP/VAP patients groups, there is a need for patient stratification and for individualized treatment with beta-lactams. Failure to achieve this at an early stage of the treatment is probably a main cause of further failure with important consequences in terms of duration of treatment and emergence of resistance.
Paediatric patients, and especially new-borns, represent another group of patients where pharmacokinetics /pharmacodynamics (PK/PD) are highly variable and where the applicability of adult PK/PD targets is still not well established. There is a need in dose adaptation based on patient's weight, body surface area and clinical maturation and developmental pharmacology. Systematic monitoring is also complicated since collecting sufficient volume/number of samples is difficult in paediatric patients.
The main objective of the MON4STRAT Project is to improve beta-lactam-based antibiotic therapy of critically ill patients for moving towards individualized treatments meeting efficacy as well as reduced EDR and adverse effects.
The Project aims to develop and demonstrate at the clinical level (by performing two exploratory clinical trials), an innovative approach usable directly at the patient bed-side allowing the care-giver to correct and adapt its initial beta-lactam treatment regimen (dosage, dose interval, and duration) to the patient-specific needs as soon as there is a quantitative evidence that the initial treatment is no longer appropriate and is likely to lead to poor clinical outcomes (lack of efficacy) as well as risks of EDR and/or adverse effects. Rapid determination of actual beta-lactam blood levels is the key to the success of this approach. To this end, the applicants of this Project already own encouraging preliminary results regarding a highly specific, cost-effective, rapid and accurate method for determining free beta-lactam blood levels within a microbiologic, therapeutic and toxicologic meaningful range.
The major progress beyond the state-of-the-art expected from the successful achievement of the MON4STRAT objectives is:
The evidence and demonstration, for the first time, that a rapid and quasi real-time measure of beta-lactams blood levels regularly recorded at the bed-side of critically-ill (HAP/VAP) patients and immediately translated into drug dosage adjustments leads to rapidly reaching and maintaining PK-PD targets optimized in terms of efficacy, EDR reduction and avoidance of adverse effects and ultimately results in a better treatment.
To achieve its objectives, the MON4STRAT consortium brings together experts in complementary disciplines and fields. Thus, biochemists and experimental pharmacologists closely collaborate with PK-PD experts, antimicrobial resistance experts and clinicians to launch an integrated program.
Project Context and Objectives:
THE GENERAL CONTEXT
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Improving treatment approaches with beta-lactams is particularly needed in nosocomial infections where decreased susceptibility of the etiological organisms is observed worldwide. This is of main concern in Hospital-Acquired Pneumonia [HAP] (including Ventilator-Associated Pneumonia [VAP]), defined as an infection contracted by a patient in a hospital at least 48–72 hours after being admitted. Despite recent advances in antimicrobial therapy, better supportive care and a wide range of prevention measures, HAP/VAP remains a significant cause of patient morbidity and mortality as well as health care costs. Together with Staphylococcus aureus, Gram (-) bacilli such as Enterobacteriaceae and Pseudomonas aeruginosa are the predominant organisms responsible for this infection. beta-lactams (penicillins, cephalosporins, and carbapenems) used alone or in combination with other antibiotics remain at the cornerstone of the current treatments in HAP/VAP patients. However, the underlying illnesses have a marked impact on beta-lactams distribution properties and on patient's excretory function that creates much variability in their pharmacokinetics and the corresponding blood levels.
Several libraries of beta-lactams pharmacokinetics (population-based PK-PD targets) are available in the literature as well as from the data submitted for registration by the suppliers of the beta-lactams. These population-based PK-PD target mainly efficacy. Dosage adjustment based on the population-based PK-PD principles is the current "best approach" for optimizing therapy and is now used in Intensive Care Units (ICU) (eg. Bayesian-based dosing software; non-linear regression approaches; monograms based dosing ...). However, they do not really allow tailoring beta-lactam regimens to the need of individual patients especially if their physiopathological situations change rapidly as it is the case in severe infections. Thus, within the specific HAP/VAP patients groups, there is a need for patient stratification and for individualized treatment with beta-lactams. Failure to achieve this at an early stage of the treatment is probably a main cause of further failure with important consequences in terms of duration of treatment and emergence of resistance.
The problem is still more complex in paediatric populations, especially in prematures and neonates, where dose adaptations are currently made based on weight/size because of lack of data integrating other physiological co-variables. In this group of patients pharmacokinetics are highly variable and the applicability of adult PK/PD targets is still not well established. Systematic monitoring is also complicated since collecting sufficient volume/number of samples is difficult in paediatric patients.
As a matter of fact, dosage adjustment based on population-based PK-PD targets does not address the issues related to actual variability of free (unbound to proteins) beta-lactam blood concentrations beyond what can be predicted from PK-PD models. Adjusting treatment dosages and schedules to the specific patient's conditions using pharmacokinetic models requires knowing both the drug volume of distribution (VD) and its total (renal and non-renal) clearance. But those are markedly perturbed in severely-ill patients and subject to rapid changes, which makes predictions based on population models imprecise.
Beta-lactam antibiotics show a "time-dependent pattern" of antibacterial efficacy. Thus, the time during which the free drug concentration (unbound fraction) of the drug remains above the MIC (Minimum Inhibitory Concentration) is the dominant PK/PD index associated with bacterial killing (fT>MIC). Knowledge of actual blood levels is therefore critical to ensure efficacy. Optimal dosing is also a key parameter concerning emergence of drug resistance (EDR) and prevention of adverse side effects. With respect to EDR, effective antimicrobial therapy cannot be solely relied upon drug potency or pathogen susceptibility but is a complex interplay of both factors.
With respect to prevention of side effects, beta-lactams have long been known to cause neurological disturbances (mainly convulsions) associated with their penetration in the central nervous system (CNS). While variable amongst beta-lactams, and critically dependent on the permeability of the blood-brain barrier of individual patients, these effects have been clearly associated with elevated blood levels.
The implementation of beta-lactams TDM is expected to represent an innovative clinical approach compared to both the empirical practices and the current “best-in-class” population-based PK-PD, none of them being able to meet specific needs of individual patients.
Actually, what is still missing today for really implementing beta-lactam TDM is the possibility for the clinicians to obtain a rapid assessment of drug levels. To this end, there is a clear unmet need to provide the clinicians with a direct, rapid (real-time) information about free beta-lactam actual blood levels both at initiation and during therapy. All methods available so far rely on complex technologies (mainly HPLC and LC-MS-MS) that take several hours before results can be communicated. Since the patient's situation is quickly changing over time, results that come late tend to be ignored.
The concept of the MON4STRAT Project is to develop a novel and more rational approach to the treatment of HAP/VAP patients that combines (a) the knowledge of the beta-lactam blood levels acquired on a real-time basis for individual patients, with (b) best-in-class PK-PD and EDR models gained from population studies and optimized for minimizing EDR and adverse effects. Rapid determination of actual beta-lactam blood levels is key to the success of this approach. ULG, in collaboration with UCL, have developed a colorimetric assay, based on the hydrolysis of a reporter substrate by an enzyme (the biosensor), to determine the concentration of free beta-lactam antibiotics in a complex biological sample. This method, conceptually simpler and faster than HPLC methods, has demonstrated the accurate determination of beta-lactam concentrations in laboratory conditions.
To be useful in the clinical practice, especially for critically-ill patients such as HAP/VAPs, and for offering dose readjustment options tailored to the patient, the MON4STRAT concept still requires additional efforts in terms of the following developments (non clinical objectives):
i : Final customization of assay procedures to the actual conditions of bed-side use as
encountered in daily practice within hospital units caring for HAP/VAP patients;
ii : Monitoring and managing the deviations between the actual blood levels that will
be observed in patients and the PK/PD targets related to efficacy, minimization of
EDR and prevention of toxicity (fT>MIC, Cmax, Ctrough, schedule of administration)
and their corresponding thresholds;
iii : Using this information as evidence-based data together with algorithmic models
for deciding how to optimize dosages and schedules during the treatment.
These development will allow to reach the main objective of the MON4STRAT Project that is to improve beta-lactam-based antibiotic therapy of critically-ill patients for moving towards individualized treatments meeting efficacy as well as reduced EDR and adverse effects.
The Project aims to demonstrate at the clinical level (by performing exploratory clinical trials), an innovative approach usable directly at the patient bed-side allowing the care-giver to correct and adapt its initial beta-lactam treatment regimen (dosage, dose interval, and duration) to the patient-specific needs as soon as there is a quantitative evidence that the initial treatment is no longer appropriate and is likely to lead to poor clinical outcomes (lack of efficacy) as well as risks of EDR and/or adverse effects.
To reach the main objective, two exploratory, open, randomized multicentric clinical trials involving critically-ill patients suffering from nosocomial pneumonia (HAP/VAP) will be conducted: one in adult patients (n=150) and one in paediatric population (n=70).
In STUDY #1 (adults), the objectives are:
i : at the level of the individual patient :to demonstrate that the application of the
MON4STRAT approach will allow maintaining the free beta-lactam blood levels at PK
PD targets optimized for leading to reduction of EDR and toxicity;
ii : at the population level: to demonstrate how this will address the situation of
specific subpopulations (stratification) within the adult population (based on age,
weight, severity of disease, underlying pathologies, alterations of excretory
functions).
In STUDY #2 (paediatric population), the objectives are
i : at the level of the individual patient: to assess the ability to perform real-time
monitoring taking into account the specific issues of this population (small amounts
of blood; sparse sampling) and to compare measured free beta-lactam blood levels
with those predicted from the best available population data;
ii : at the population level: to document how the MON4STRAT approach could help to
stratify this population into specific subpopulations (prematures, neonates,
children) known to show major differences in drug pharmacokinetics.
Project Results:
SPECIFIC S&T OBJECTIVES AND RESULTS
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To reach the overall objectives, both non-clinical and clinical specific objectives were proposed.
1. Non-clinical objectives
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Demonstration of the assets of the MON4STRAT approach at the clinical level imposed beforehand to further develop and validate the beta-lactam dosing methodology, to prepare and to make available the experimental devices usable at the patient bed-side including the necessary models and software for translating the measured beta-lactam blood levels into optimized dosage regimens and duration.
1.1. Specific objective 1:
"TO DEVELOP AND VALIDATE THE MON4STRAT BETA-LACTAM DOSING
METHODOLOGY"
The aim was here to customize the patented methodology (Patent EP2766735A1, US968902B2, WO20130553953/A1 et CA2851984A1) for monitoring free beta-lactam concentrations in blood when using the specific beta-lactams of this Project.
RESULTS
The M0N4STRAT method (M4S-M) is based on the hydrolysis of a reporter substrate by an enzyme (the biosensor). The beta-lactam to be assayed acts as competitive inhibitor and can be quantified by the measurement of the apparent loss of enzyme activity. The colorimetric assay uses the competition between a reporter substrate and a beta-lactam antibiotic towards the catalytic site of the beta-lactamase. In the absence of beta-lactam antibiotic, the beta-lactamase rapidly hydrolyses the reporter substrate (nitrocefin, a commercially available chromogenic cephalosporin) and this reaction produces a deep red colour (maximum of absorbance at 482 nm). In the presence of the beta-lactam antibiotic to be assayed, the beta-lactamase catalytic activity is less available and thus less able to hydrolyse the reporter substrate. Accordingly, the higher the concentration of beta-lactam antibiotic, the lower the coloration of the medium. In this enzymatic competitive kinetic assay, the UV-Visible absorbance is inversely proportional to the concentration of beta-lactam antibiotic (see figure 1).
Three different methods were validated:
• M0N4STRAT Method 1 (M4S-M1), where the biosensor is a class C beta-lactamase.
This biosensor (M4S-Biosensor-1) allows the determination of concentrations of
meropenem (M4S-M1/M) or piperacillin-tazobactam (M4S-M1/PT) or ceftazidime
(M4S-M1/CZ) in ultrafiltrated sera and in absence of another beta-lactam antibiotic.
• M0N4STRAT Method 2 (M4S-M2) was developed during this project to determine meropemen
concentrations in presence of another beta-lactam antibiotics often used in ICUs. The selected
biosensor (M4S-Biosensor-2) is an optimized beta-lactamase that has been patented to specifically
monitor meropenem.
• M0N4STRAT Method 3 (M4S-M3), results obtained for ceftazidime dosage by M4S-M1/CZ
indicate that the biosensor 1, is not sensitive enough because the quantification range was
established between 25 to 100 mg/L of ceftazidime. This range is not acceptable for the paediatric
test, since it does not cover the expected concentration values in children. Thus, a new optimized
beta-lactamase biosensor (M4S-Biosensor 3) was selected and validated to specifically quantify
this antibiotic in a range consistent with the values normally found in children’s population.
Extensive data sets regarding selectivity, lower limits of quantification, calibration, accuracy, precision, dilution integrity, matrix effect and stability in ultrafiltrated sera (the patients’ matrix that will be used in the clinical trials) were collected for the beta-lactams contemplated in this project i.e. meropenem, piperacillin-tazobactam and ceftazidime and for the three M4S-methods. These methods were validated in compliance with the expectations of the EMA (Guideline on bioanalytical method validation, July 2011) and FDA. Furthermore, methods were cross-validated against HPLC/MS-MS (reference method) by analysing a large number of quality control (QC) and study samples, prepared as preconized by the sample preparation method developed in the project. It should be noted that contrary to HPLC/MS-MS method, M4S methods do not exhibit matrix effect.
THE MEASURABLE ACHIEVEMENTS RELATED TO THIS OBJECTIVE ARE:
• Well documented experimental conditions for performing accurate concentration measurements
of each of the beta-lactams of the Project present in the same matrix that the one foreseen for the
project.
• The new M4S-M2 method, developed in the frame of this project, was submitted for an European
patent application (European Patent application no. EP19193190.6
1.2. Specific objective 2:
"TO INTEGRATE THE BETA-LACTAM DOSING METHODOLOGY WITHIN
A BETA-LACTAM TDM APPROACH "
The aim here was to develop an approach for managing the deviation between experimentally observed beta-lactam blood levels and PK-PD targets optimized for leading to high efficacy while minimizing EDR and controlling adverse effects and, subsequently, to translate said observed deviations into dosage corrections. For this, realistic PK-PD targets susceptible to combine optimal efficacy, mitigation of EDR and control of toxic effects should be established.
RESULTS
The presented results are limited to meropenem, the beta-lactam that was used in the adults’ trial. Decisions taken to build the algorithm for dosage corrections are listed below:
• After exhaustive revision of bibliography, it was concluded that clinical data are insufficient to
support a clearly defined PK/PD target for meropenem in critically-ill patients. Thus, a severe
PK/PD target of 100% of the curative time above four times the MIC value of the targeted
pathogenic bacteria (100% fT>4xMIC) that would ensure maximal killing (4xMIC) and maxi-
mal efficacy, and prevent the emergence of resistance was selected. Because the MIC of the
offending organisms may not be known, PK/PD target based on the R [clinically resistant] or
the S [clinically susceptible] breakpoints of EUCAST was selected for meropenem. Thus,
selection is therefore summarized as: PK/PD target will be 100% fT>4x “S” breakpoint for
meropenem, i.e. a target Cmin of 8 mg/L.
• No personalization of the first dosing regimen will be performed during the clinical study. The main
reason for this choice is the difficulty to obtain an informed consent from the patients during the
first hours of antibiotic therapy (which MUST be started without delay as survival is inversely
proportional to the delay before therapy is initiated). Sampling after administration will take place
1h after the end of the infusion and 1h before the next administration.
• Therapeutic modalities were evaluated for both safety (probability that predicted Cmax < target
Cmax) and efficacy (probability that Cmin > 4x the “S” breakpoint), thus:
i : If the standard dosing regimen is considered correct (i.e. sufficient safety and efficacy), it will be
preferred to other optimal dosing regimens for nursing facilities and will be kept for the next
dosing.
ii : The interval between administrations can be modified as follows:
- from 8h downward to 6h
- upward to 12h or 24 h.
If multiple dosing intervals allow safe and effective dosing, the shortest dosing interval will be
selected.
iii : The unit dose will be a maximum of 2g per administration for meropenen. Any changes over the
initial unit dose will be made by 0.5-g steps. This will make the antibiotic administration as
simple aspossible for the nursing staff. If multiple doses allow safe and effective dosing, the
lower dose will be selected in order to avoid high cost of therapy and toxicity risk
iv : Considering results from the MON4STRAT concentrations monitoring and PK calculations, the
unit dose will be given in a 0.5-h or 3-h infusion. If multiple durations of infusion allow safe and
effective dosing, the shortest infusion time will be selected in order to maximize practicality for
the nursing staff and for the patient.
- In patients with proven hyperfiltration, the administration interval will be reduced to 6h. In
patients with abnormally low elimination and, if the optimal interval should be longer than
24h (e.g. patients with major elimination defects), the interval between administrations
will be kept at 24h but the unit dose of beta-lactam may be reduced. Indeed, a longer
interval (> 24h) is not acceptable for beta-lactams, especially meropenem, in view of
their instability
- In patients for whom the targets cannot be reached due to (a) abnormally large drug
distribution (and for whom Cmax will therefore be lower than in average patients) or (b)
major hyperfiltration that cannot be compensated by decreasing the interval between two
successive administrations, the unit dose may be increased to over 2g for meropenem but
care will be taken to avoid toxicity.
- Patients with organism(s) for which meropenem MIC is > 4x the “S” breakpoint will be not
eligible or will be withdrawn from the study.
- Patients with organisms for which MIC is very low in the study (e.g. < 0.25 mg/L) will be
included and the target will not be modified (i.e. 4x the “S” breakpoint).
- Regarding the control of adverse events, a target Cmax equal to the percentile 90 of the
Cmax calculated in the target population of patients (critically-ill patients with HAP/VAP),
after administration of the highest standard registered dose is proposed. Thus, target
meropenem will be Cmax = 140 mg/L after a 2-g dose infused over 30 minutes
To estimate PK parameters so that future predictions can be made for patients, both a straight-forward Bayesian feedback algorithm and an Expectation Maximization (EM) algorithm were implemented. Between both, the EM- algorithm was selected, because it was able to provide good estimates on the Confidence Interval for PK parameters. This allowed a Monte Carlo sampling of the parameters, to provide a prediction of future plasma concentrations under a hypothetical dosing. The prediction is not a single point estimate, but provides a confidence interval. This allows us to account for uncertainty, taking better decisions by adding a safety margin.
Finally, a software for deciding dosing regimen corrections was built for MON4STRAT project, linking data known on the patient that are stored into the database of the clinical study, and the PK/PD model that computes the optimal dosage based on these patient’ data. The recommendation software uses:
i : The antibiotic and the MIC (minimum inhibitory concentration) associated.
ii : The treatment schedule:
- date and time of administration;
- dose (g);
- infusion duration (h).
iii: The patient characteristics:
- body weight (kg);
- creatinine clearance (L/h). It can be measured or, if the measure is not available, estimated by
using the Cockcroft-Gault formula. If needed, the estimation of the creatinine clearance will
be performed in the database.
iv : The observations:
- date and time of the blood test;
- antibiotic concentrations (mg/L) measured by the MON4STRAT device.
v : The stability state of the patient.
The results of simulation tests indicate that the algorithm can accurately estimate individual PK parameters of beta-lactam based on sparse concentrations measured in patients after first or repeated administrations, as well as the confidence interval on these PK parameters.
Results also indicate that the algorithm can select the best dosing regimen for almost all patients. Uncertainty in parameter estimation is taken into account, but residual variability is not. There is a high probability that the patient, using the new individualized dosing regimen, will attain the intended PK targets.
On the other hand, an in vitro hollow-fiber infection model was used to evaluate the impact of different dosing exposures on the emergence of drug resistance (EDR). Results about drug exposures needed to suppress resistance development have been consistent between meropenem and cefepime, when the PK/PD exposures were adjusted to the corresponding MIC of the pathogen but were less clear for piperacillin / tazobactam where deviation from standard clinical practice was needed to enhance bactericidal activity.
THE MEASURABLE ACHIEVEMENTS RELATED TO THIS OBJECTIVE ARE:
• Confirmed PK-PD targets and models usable for meropenem in the clinical study and optimized for
combining optimum efficacy, suppression of EDR and avoidance of adverse effects
• The software that translates deviation between experiment and targets into dose/schedule
corrections.
1.3. Specific objective 3:
"TO PREPARE THE EXPERIMENTAL MONITORING DEVICES (HARDWARE AND
SOFTWARE) ANDMAKE THEM AVAILABLE TO THE CLINICAL SITES INVOLVED
IN THE EXPLORATORY CLINICAL TRIAL"
RESULTS
The original objective was to customize 11 Ellipse instruments. Ellipse is a medical analyzer marketed by Analyzer Medical System (AMS) (Italy) (+/-50kg). This is the device previously used in the laboratory by P1-ULg for the development and validation of the MON4STRAT method, and is the only one commercially available and compatible with MON4STRAT test requirements. This automate has most of the functionalities and performance required for the assays but keeps samples and reagents at room temperature, has no possibility for reagents and samples traceability by barcode and its interface is not user-friendly. Most of these drawbacks could be solved by a specific customization, handled by P3-WOW. However, at the beginning of the project, we were faced with the problem that the manufacturer protected source codes needed to modify the software, so that the device customization became overly complex. Therefore, P3-WOW proposed to develop a new autoanalyzer from scratch, including functionalities of the AMS instrument in addition to all the functionalities that could improve the use of this automate by not specialised staff. P3-WOW, in collaboration with P1-ULg, worked in the development of this new “MON4STRAT machine”, which includes, besides, a software to run the MON4STRAT dosages and an algorithm to calculate antibiotic concentration, with minimal intervention of the clinical staff in user-friendly interface. The decision of building a machine from scratch, tailor-made for the project specific application, even if it represents a clear advantage for the consortium in terms of remarkable ease of use, maintenance and supplies of the device, took longer than originally expected. The first version of the MON4STRAT machine was available at month 24 (see Figure 2) This instrument differs functionally from the previously mentioned commercial device, thus the analytical method needed to be adapted consequently. It is worth noting that the device is a handmade prototype, not an industrially made one, so that slight differences could be present between devices. To address this problem, P1-ULg and P2-UCL validated each device that will be sent to the clinical sites, to be in compliance with EMA regulatory requirements for biochemical tests used to adjust the dose of a drug.
A restricted access website, hosting MON4STRAT assays database (calibration curves and assays) with flexible access from any computer connected to the Internet was built by P1-ULg. This database stores raw data and calculated dosage values, obtained after application of reliable statistical methods. It allows to evaluate remotely and in real time the performance of the different machines and the reagents, and to intervene if problems would arise. At the same time, data about the dosage could be accumulated for further analysis.
The health care attendants in charge of running the clinical trial received the training for (a) fully understanding the PK/PD basis of the trial and (b) allowing them to be comfortable with the manipulation of both hardware, reagents and software.
THE MEASURABLE ACHIEVEMENTS RELATED TO THIS OBJECTIVE ARE:
• 6 machines (experimental prototypes) transferred to the partners who will use them in clinical
trials In addition, 4 machines are available for enabling further improvements away from the
clinical settings (of which, two spare devices are foreseen in case of failure of ones sent to the
hospitals
• Trained health-care attendants for using the MON4STRAT machine and understand the importance
of TDM for dose optimisation.
2. Clinical objectives
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The first clinical objective was to validate the MON4STRAT assay methodology against a best-in-class benchmark method in real clinical settings and to confirm its usability at bed-side. The second clinical objective was to perform a prospective, randomized, open, controlled, multicentre clinical trial in adults for demonstrating the appropriateness of the MON4STRAT approach for improving the meropenem-based treatment of HAP/VAP patients. The third clinical objective was to explore how and to what extent the approach is also feasible in paediatric populations.
2.1. Specific objective 4:
"TO CONFIRM THE SPECIFICATIONS OF THE MON4STRAT METHOD IN THE
ACTUAL CONDITIONS OF ICU AND TO SET THE BEST PROTOCOL FOR USING
IT AT BED-SIDE"
RESULTS
Originally, the first clinical objective aimed to validate the M0N4STRAT assay methodology against the best-in-class benchmark method, including the blood collection and preparation prior to perform the MON4STRAT assay, in a real clinical setting (P7-ULB) and to confirm its suitability at bedside (dry run prior to start the clinical trial).
However, after extensive discussion, clinicians expressed their concern to test practical feasibility of the MON4STRAT method before starting the clinical trial. The deviation from the initial pilot study towards the clinical pre-study was motivated by the need to clinically validate the MON4STRAT approach (i.e. dosage and algorithms) before starting the clinical study. The maim objectives of the clinical pre-study were (a) to ensure the point of care’s feasibility of the MON4STRAT algorithm implementation and (b) to verify the accuracy of the device for determining free-meropenem concentrations. The pre-study was observational, open-label, controlled and multicentre (P7-ULB, P4-ICAN), conducted on 50 adult patients with microbiologically-confirmed or suspected Gram-negative infection to assess the accuracy of the MON4STRAT mathematical algorithm for reaching and maintaining pre-determined PK/PD targets (meropenem Cmin ≥ 8 mg/L and Cmax < 140 mg/L) in ICU patients treated with meropenem and requiring mechanical ventilation. The total study duration was estimated in approximately 6 months (enrolling approximately 9 subjects per month). Each subject shall participate for the duration of their prescribed antibiotic treatment (approximately 7-14 days) and for a test of cure (TOC) follow-up evaluation performed 5 to 7 days after completion of all antibiotic therapy. The pre-test should allow to test practical feasibility, to assess unanticipated problems in sample preparation, dosing-machine and dose adaptation and to address solutions before the real trial. Clinical protocols, case report form (CRF), electronic case report form (eCRF) and database (DB) were constructed, and ethical committee’s authorizations were obtained. This work was not planned in the original project.
The pre-test started when the first version of the device was available. The two first pre-validated prototypes were installed in P4-ICAN and P7-ULB centres, staffs were trained and a pre-test started at the end of 2015. The pre-test highlighted several weaknesses of the device, some of these constraints could be eliminated by P3-WOW intervention, but others emerged, giving rise to inaccurate results. The pre-test was suspended until a reliable version of the device was available. At the same time, several modifications were introduced in the algorithm for dose recommendation, as result of observations made with the first patients enrolled.
An improved version 3 of the device, previously validated against the reference HPLC/MS-MS method, was installed in both centers; the staff was trained again and pre-test resumed. Analysis of results of the clinical pre-study highlighted the need for TDM practice for meropenem in critically-ill patients (interindividual variability in meropenem PK was large, around 48.2 to 109%). In addition, when the meropenem dosage was individually guided using the MON4STRAT device, a significant improvement in the PK/PD target was clearly observed with, as a result, an improved clinical efficacy and reduced risk of resistance emergence
THE MEASURABLE ACHIEVEMENTS RELATED TO THIS OBJECTIVE ARE:
• Practical evidence that MON4STRAT methodology is applicable in ICUs.
• Practical evidence that the dosing algorithm and the MON4STRAT test work in clinical practice
2.2. Specific objective 5 :
"TO PERFORM A PHASE IIB-TYPE CLINICAL TRIAL TO ASSESS THE MERITS OF THE
MON4STRAT APPROACH FOR OPTIMIZING BETA-LACTAM TREATMENTS (DOSES
AND SCHEDULES) IN HAP/VAP ADULT PATIENTS"
RESULTS
When pre-test ended, several modifications were introduced to the algorithm and the devices and related software were modified accordingly. The eCRF and DB was also updated. The protocol for adult’s trial incorporated minor modifications in the endpoints, taking into account the results of the pre-test.
The inclusion of the new-partner P12-APHP as study sponsor was consolidated. The protocol, “Prospective, Randomized, Open, Controlled, Multicenter Study to Evaluate the Safety and Efficacy of the MON4STRAT Approach for Optimizing Meropenem Therapy in Intubated and Mechanically-Ventilated, Adult Patients with severe Gram-Negative lower respiratory tract infection », in adults, was sent to competent authorities and ethical committees in each of the 3 countries, Spain, Belgium and France as a clinical trial with an investigational medicinal product (IMP)
The three centers (Madrid, Brussels and Paris) were progressively opened in 2019, but more slowly than expected because of the inherent administrative constraints.
Because of the end of funding, the project and the trial were closed on July 31, 2019. Data base was closed and data was sent to Principal Investigators for analysis. The clinical characteristics of recruited patients at time of admission to ICU and of randomization were in accordance with the inclusion/exclusion criteria specified in the protocol. Informed consent was obtained for all of them. All data were monitored in accordance with the protocol, with no deviation detected. The only adverse events reported were those expected in such a population of ICU patients, and none were related to meropenem or the Mon4Strat device.
Unfortunately, the low number of patients included into the study precludes any meaningful statistical comparison of the two groups, even if numerical data seems favoring the Mon4Strat strategy. We are therefore not able to draw significant conclusions concerning the MON4STRAT approach. Nevertheless, we can provide a list of positive points presented in the next paragraph.
Future clinical studies using the MON4STRAT approach should be pursued since the MON4STRAT approach appears to have permitted patients to rapidly reach adequate antibiotic concentrations to treat pulmonary infections. The MON4STRAT approach was able to do so, despite the fact that the PK of antibiotics are very unpredictable in the ICU setting. Indeed, reaching antibiotic target concentrations very rapidly may have a significant impact on patient morbidity, and/or mortality.
THE MEASURABLE ACHIEVEMENTS RELATED TO THIS OBJECTIVE ARE:
• The protocol was consistent with the objectives of the study
• The measurement of meropenem concentrations using the hospital’s MON4STRAT devices
produced reproducible and robust results.
• The algorithm was able to recommend dosage regimens to rapidly obtain meropenem
concentrations within target values, most of the time.
• No serious adverse events related to the MON4STRAT approach were reported.
2.3. Specific objective 6 :
"MON4STRAT APPROACH FOR MEASURING BETA-LACTAM FREE SERUM LEVELS
IN CRITICALLY-ILL PAEDIATRIC PATIENTS"
The main objective of the paediatric study was to demonstrate the interest and the feasibility of the MON4STRAT approach in children, prematures and neonates where blood sampling is limited. The paediatric study was observational, and aimed to prepare the grounds for a more complete phase IIb clinical trial to be performed after the completion of the present project.
RESULTS
Altogether, 37 paediatric patients were included: 23 in Estonia and 14 in France. There were in total 23 neonates and 14 outside of neonatal age. 15 patients received meropenem, 20 piperacillin/tazobactam and 2 ceftazidime at doses that are recommended in local guidelines. All patients were severely ill and received antibiotics treatment for confirmed or suspected acute bacterial infection.
PK samples were taken prior to and after the antibiotic dose, at day 3 after inclusion in the study. In total 8 patients provided one evaluable sample, 27 gave two and 2 patients provided more than 2 samples. Antibiotic concentrations were measured at participating hospitals and then ultrafiltrate were stored at -80°C and sent to UCL for further analysis. The clinicians were not aware of measured concentrations (concentration results were encrypted by the M4S device) and thus no action was taken as a result of antibiotic concentration measurement.
Altogether 69 samples (27 for meropenem, 38 for piperacillin/tazobactam and 4 for ceftazidime) were successfully assayed with M4S device on sites. The concentrations were variable and are undergoing further analysis and PK modelling. The median predose and postdose concentrations for meropenem in neonates were 4.9 mg/l and 41.04 mg/l, respectively. For piperacillin/tazobactam respective values for neonates were 7.7 mg/l and 27 mg/l and for non-neonates 5 mg/l and 108 mg/l. These values are largely in ranges that have been reported in other studies where concentrations have been determined with the HPLC/MS-MS method, outside the ICUs. The differences between neonates and non-neonates in piperacillin/tazobactam post-dose concentration requires further analysis but is probably due to differences in infused doses between neonates (~200 mg/kg/day) and children (~300-400 mg/kg/day).
We have collected data from 23 neonates and 14 non-neonatal children. These data are likely sufficient to correlate PK concentrations measured by M4S device with clinical data and laboratory deviations. As database was locked very recently then the detailed analysis will be completed in coming months.
The number of recruited patients was lower than expected. The reasons for this lower recruitement are listed below:
i : The device became available late in the porject, thus the recruitment period remained shorter
than initially forecasted.
ii : In Tartu, a screening log was maintained. It showed that , among the screened patients, the
recruitement is smaller than we have seen in previous studies. The reasons for not recruiting
patients were: participation in other interventional studies, patients with extreme prematurity or
critical medical condition, parental refusal and also because study antibiotic was stopped prior
to signing the informed consent.
iii : In Lille, the reasons for non-inclusion were mainly a unit too busy to proceed or the absence
of consent by some parents (mainly parents of critically ill highly premature babies).
iv : Study staff was not used to work with the device, it is not current practice and because there was
no direct benefit for the patient they may have had low motivation especially during the times of
high work load.
The calculation of patients needed was initially based on the analysis of dosages of 4 antibiotics. But dosages for 2 antibiotics were not possible: (a) cefepime was withdrawn before starting the inclusions for technical reasons and (b) data for ceftazidime were too small (n=2) to allow any analysis. Despite smaller recruitment we have enough data for meropenem and piperacillin-tazobactam and still believe that the study provided valuable data of using M4S device in neonatal and paediatric intensive care units for these antibiotics.
THE MEASURABLE ACHIEVEMENTS RELATED TO THIS OBJECTIVE ARE:
• Practical evidence that MON4STRAT methodology is applicable in paediatric ICUs.
Potential Impact:
The main outcome of the MON4STRAT Project would have been a new clinically validated therapeutic approach to treat HAP/VAP patients suffering of Pseudomonas aeruginosa bacterial infection. The MONSTRAT approach integrates a rapid, simple and cost-effective device for monitoring free beta-lactam blood levels performed at the patient’s bed-side and, accordingly, offers to the clinician, for the first time, (i) rapid indications on the possible patient-specific deviation of the point-of-care beta-lactam blood levels compared to the theoretical PK-PD targets and, accordingly, (ii) rapid dosage adjustement/corrective means.
However, due to the limitations encountered to clinically validate the approach, the impact of the project is limited. Indeed, all the Key Performance Indicators that have been described in the MON4STRAT grant to measure the impact at the end of the Project were strictly related with the results of the trial.
With respect to the paediatric study, the objectives are being met since the study will continue after the end of the project. Theses results will contribute to a best knowledge of PK-PD values for neonates and children. These data will deliver health benefits to children suffering from bacterial infections.
We would like, however, to stress that:
• The clinical partners of the MON4STRAT are key-opinion leaders in the field of infectious diseases, especially dealing with antimicrobial resistance issues. They are all convinced, from the results of pre-test and from the adults' trial that the MON4STRAT approach is able to “track” from the very beginning of the treatment patient-specific “abnormalities” compared to the PK-PD targets and, by correcting the dosage, improve efficacy (the faster the targeted PK-PD index is reached, the faster the conditions for efficient bacterial killing are met, which is an essential requirement in successful treatment). Thus, as all the tools needed to test the approach are now ready, additional clinical studies are possible and are needed to confirm the assets of the MON4STRAT approach at an individual level.
• There is still a clear unmet need of a rapid method to determine antibiotics concentration at bed side, or, at least within the ICUs. Each of the essential constitutive parts of the MON4STRAT approach (concentration determination method, device, algorithm) were conceived in compliance with regulatory (EMA and FDA) and GCP guidelines, we consider that this, together with preliminary results, would accelerate the adoption of the methodology by the medical community, even in absence of effective clinical validation, to support a broad clinical trial (meta-analysis) that would allow to consolidate the MON4STRAT concept (large number of ICUs). Furthermore, this could be applicable also In other infectious indications using beta-lactam(s): to support the clinical validation of the approach for performing an antibiotherapy in the case of non-critically-ill patients (outside the ICUs), since none of the current beta-lactam-based treatments used in clinics enable to make a patient “signature” in terms of individual exposure-response relationship, certainly not at the early stage of the treatment (classical methods are too slow).
• Broad implementation of the MON4STRAT approach relies also on the replication of device enabling rapid (real-time), accurate free beta-lactam blood level monitoring. To this end, the consortium developed a prototype device, user-friendly, that could still be improved and completed for translating into an smaller and faster industrial commercial device. An European SME has already signed, with the patent applicants (ULG and UCL), an option for an exclusive, worldwide license for exploiting the technology and this will, of course, strongly accelerate the overall process of market uptake of the methodology. Industrial production of a customized device is expected in the coming years. All results achieved (biochemistry, reagents formulation, robotic, software, plasmids, enzymes production, PK-PD tables, ...) during MON4STRAT project will transferred to the European SME after the signature of the license agreement.
• In parallel to the scaling-up and commercialization of the apparatus customized for monitoring the b-lactams contemplated during the Project, additional steps are already foreseen for widening the scope of application to the monitoring of other antimicrobials (Preliminary results already exist within the consortium in that direction). One may thus expect a rapid and widespread valorization of the acquired knowledge and expertise in the field of human health as well as animal health.
List of Websites:
http://www.mon4strat.ulg.ac.be/
PROJECT COORDINATOR
Prof. Bernard Joris,
Center for Protein Engineering.
Univ. of Liège. Liège. BELGIUM
Tel: + 32 4 366 2954
Fax:+ 32 4 366 3364
E-mail: bjoris@ulg.ac.be
Antibacterial drugs are facing increasing limitations in terms of effectiveness not only due to emergence of high-level resistance but also due to a moderate but significant decrease in bacterial susceptibility. These expose the patients to a risk of sub-therapeutic dosages that explains treatment failures and further emergence of drug resistance (EDR). To mitigate these risks, clinicians tend to increase drug dosages and/or to combine antibiotics, which then expose the patients to potential toxicity while not necessarily minimizing efficiently EDR.
This is of main concern in Hospital-Acquired Pneumonia [HAP] (including Ventilator-Associated Pneumonia [VAP]). Despite recent advances in antimicrobial therapy, better supportive care and a wide range of prevention measures, HAP/VAP remains a significant cause of patient morbidity and mortality as well as health care costs. beta-lactams remain at the cornerstone of the current treatments in HAP/VAP patients. However, the underlying illnesses have a marked impact on beta-lactam distribution properties and on patient's excretory function, which creates much variability in their pharmacokinetics and the corresponding blood levels. Thus within the specific HAP/VAP patients groups, there is a need for patient stratification and for individualized treatment with beta-lactams. Failure to achieve this at an early stage of the treatment is probably a main cause of further failure with important consequences in terms of duration of treatment and emergence of resistance.
Paediatric patients, and especially new-borns, represent another group of patients where pharmacokinetics /pharmacodynamics (PK/PD) are highly variable and where the applicability of adult PK/PD targets is still not well established. There is a need in dose adaptation based on patient's weight, body surface area and clinical maturation and developmental pharmacology. Systematic monitoring is also complicated since collecting sufficient volume/number of samples is difficult in paediatric patients.
The main objective of the MON4STRAT Project is to improve beta-lactam-based antibiotic therapy of critically ill patients for moving towards individualized treatments meeting efficacy as well as reduced EDR and adverse effects.
The Project aims to develop and demonstrate at the clinical level (by performing two exploratory clinical trials), an innovative approach usable directly at the patient bed-side allowing the care-giver to correct and adapt its initial beta-lactam treatment regimen (dosage, dose interval, and duration) to the patient-specific needs as soon as there is a quantitative evidence that the initial treatment is no longer appropriate and is likely to lead to poor clinical outcomes (lack of efficacy) as well as risks of EDR and/or adverse effects. Rapid determination of actual beta-lactam blood levels is the key to the success of this approach. To this end, the applicants of this Project already own encouraging preliminary results regarding a highly specific, cost-effective, rapid and accurate method for determining free beta-lactam blood levels within a microbiologic, therapeutic and toxicologic meaningful range.
The major progress beyond the state-of-the-art expected from the successful achievement of the MON4STRAT objectives is:
The evidence and demonstration, for the first time, that a rapid and quasi real-time measure of beta-lactams blood levels regularly recorded at the bed-side of critically-ill (HAP/VAP) patients and immediately translated into drug dosage adjustments leads to rapidly reaching and maintaining PK-PD targets optimized in terms of efficacy, EDR reduction and avoidance of adverse effects and ultimately results in a better treatment.
To achieve its objectives, the MON4STRAT consortium brings together experts in complementary disciplines and fields. Thus, biochemists and experimental pharmacologists closely collaborate with PK-PD experts, antimicrobial resistance experts and clinicians to launch an integrated program.
Project Context and Objectives:
THE GENERAL CONTEXT
=====================
Improving treatment approaches with beta-lactams is particularly needed in nosocomial infections where decreased susceptibility of the etiological organisms is observed worldwide. This is of main concern in Hospital-Acquired Pneumonia [HAP] (including Ventilator-Associated Pneumonia [VAP]), defined as an infection contracted by a patient in a hospital at least 48–72 hours after being admitted. Despite recent advances in antimicrobial therapy, better supportive care and a wide range of prevention measures, HAP/VAP remains a significant cause of patient morbidity and mortality as well as health care costs. Together with Staphylococcus aureus, Gram (-) bacilli such as Enterobacteriaceae and Pseudomonas aeruginosa are the predominant organisms responsible for this infection. beta-lactams (penicillins, cephalosporins, and carbapenems) used alone or in combination with other antibiotics remain at the cornerstone of the current treatments in HAP/VAP patients. However, the underlying illnesses have a marked impact on beta-lactams distribution properties and on patient's excretory function that creates much variability in their pharmacokinetics and the corresponding blood levels.
Several libraries of beta-lactams pharmacokinetics (population-based PK-PD targets) are available in the literature as well as from the data submitted for registration by the suppliers of the beta-lactams. These population-based PK-PD target mainly efficacy. Dosage adjustment based on the population-based PK-PD principles is the current "best approach" for optimizing therapy and is now used in Intensive Care Units (ICU) (eg. Bayesian-based dosing software; non-linear regression approaches; monograms based dosing ...). However, they do not really allow tailoring beta-lactam regimens to the need of individual patients especially if their physiopathological situations change rapidly as it is the case in severe infections. Thus, within the specific HAP/VAP patients groups, there is a need for patient stratification and for individualized treatment with beta-lactams. Failure to achieve this at an early stage of the treatment is probably a main cause of further failure with important consequences in terms of duration of treatment and emergence of resistance.
The problem is still more complex in paediatric populations, especially in prematures and neonates, where dose adaptations are currently made based on weight/size because of lack of data integrating other physiological co-variables. In this group of patients pharmacokinetics are highly variable and the applicability of adult PK/PD targets is still not well established. Systematic monitoring is also complicated since collecting sufficient volume/number of samples is difficult in paediatric patients.
As a matter of fact, dosage adjustment based on population-based PK-PD targets does not address the issues related to actual variability of free (unbound to proteins) beta-lactam blood concentrations beyond what can be predicted from PK-PD models. Adjusting treatment dosages and schedules to the specific patient's conditions using pharmacokinetic models requires knowing both the drug volume of distribution (VD) and its total (renal and non-renal) clearance. But those are markedly perturbed in severely-ill patients and subject to rapid changes, which makes predictions based on population models imprecise.
Beta-lactam antibiotics show a "time-dependent pattern" of antibacterial efficacy. Thus, the time during which the free drug concentration (unbound fraction) of the drug remains above the MIC (Minimum Inhibitory Concentration) is the dominant PK/PD index associated with bacterial killing (fT>MIC). Knowledge of actual blood levels is therefore critical to ensure efficacy. Optimal dosing is also a key parameter concerning emergence of drug resistance (EDR) and prevention of adverse side effects. With respect to EDR, effective antimicrobial therapy cannot be solely relied upon drug potency or pathogen susceptibility but is a complex interplay of both factors.
With respect to prevention of side effects, beta-lactams have long been known to cause neurological disturbances (mainly convulsions) associated with their penetration in the central nervous system (CNS). While variable amongst beta-lactams, and critically dependent on the permeability of the blood-brain barrier of individual patients, these effects have been clearly associated with elevated blood levels.
The implementation of beta-lactams TDM is expected to represent an innovative clinical approach compared to both the empirical practices and the current “best-in-class” population-based PK-PD, none of them being able to meet specific needs of individual patients.
Actually, what is still missing today for really implementing beta-lactam TDM is the possibility for the clinicians to obtain a rapid assessment of drug levels. To this end, there is a clear unmet need to provide the clinicians with a direct, rapid (real-time) information about free beta-lactam actual blood levels both at initiation and during therapy. All methods available so far rely on complex technologies (mainly HPLC and LC-MS-MS) that take several hours before results can be communicated. Since the patient's situation is quickly changing over time, results that come late tend to be ignored.
The concept of the MON4STRAT Project is to develop a novel and more rational approach to the treatment of HAP/VAP patients that combines (a) the knowledge of the beta-lactam blood levels acquired on a real-time basis for individual patients, with (b) best-in-class PK-PD and EDR models gained from population studies and optimized for minimizing EDR and adverse effects. Rapid determination of actual beta-lactam blood levels is key to the success of this approach. ULG, in collaboration with UCL, have developed a colorimetric assay, based on the hydrolysis of a reporter substrate by an enzyme (the biosensor), to determine the concentration of free beta-lactam antibiotics in a complex biological sample. This method, conceptually simpler and faster than HPLC methods, has demonstrated the accurate determination of beta-lactam concentrations in laboratory conditions.
To be useful in the clinical practice, especially for critically-ill patients such as HAP/VAPs, and for offering dose readjustment options tailored to the patient, the MON4STRAT concept still requires additional efforts in terms of the following developments (non clinical objectives):
i : Final customization of assay procedures to the actual conditions of bed-side use as
encountered in daily practice within hospital units caring for HAP/VAP patients;
ii : Monitoring and managing the deviations between the actual blood levels that will
be observed in patients and the PK/PD targets related to efficacy, minimization of
EDR and prevention of toxicity (fT>MIC, Cmax, Ctrough, schedule of administration)
and their corresponding thresholds;
iii : Using this information as evidence-based data together with algorithmic models
for deciding how to optimize dosages and schedules during the treatment.
These development will allow to reach the main objective of the MON4STRAT Project that is to improve beta-lactam-based antibiotic therapy of critically-ill patients for moving towards individualized treatments meeting efficacy as well as reduced EDR and adverse effects.
The Project aims to demonstrate at the clinical level (by performing exploratory clinical trials), an innovative approach usable directly at the patient bed-side allowing the care-giver to correct and adapt its initial beta-lactam treatment regimen (dosage, dose interval, and duration) to the patient-specific needs as soon as there is a quantitative evidence that the initial treatment is no longer appropriate and is likely to lead to poor clinical outcomes (lack of efficacy) as well as risks of EDR and/or adverse effects.
To reach the main objective, two exploratory, open, randomized multicentric clinical trials involving critically-ill patients suffering from nosocomial pneumonia (HAP/VAP) will be conducted: one in adult patients (n=150) and one in paediatric population (n=70).
In STUDY #1 (adults), the objectives are:
i : at the level of the individual patient :to demonstrate that the application of the
MON4STRAT approach will allow maintaining the free beta-lactam blood levels at PK
PD targets optimized for leading to reduction of EDR and toxicity;
ii : at the population level: to demonstrate how this will address the situation of
specific subpopulations (stratification) within the adult population (based on age,
weight, severity of disease, underlying pathologies, alterations of excretory
functions).
In STUDY #2 (paediatric population), the objectives are
i : at the level of the individual patient: to assess the ability to perform real-time
monitoring taking into account the specific issues of this population (small amounts
of blood; sparse sampling) and to compare measured free beta-lactam blood levels
with those predicted from the best available population data;
ii : at the population level: to document how the MON4STRAT approach could help to
stratify this population into specific subpopulations (prematures, neonates,
children) known to show major differences in drug pharmacokinetics.
Project Results:
SPECIFIC S&T OBJECTIVES AND RESULTS
===================================
To reach the overall objectives, both non-clinical and clinical specific objectives were proposed.
1. Non-clinical objectives
°°°°°°°°°°°°°°°°°°°°°°°°
Demonstration of the assets of the MON4STRAT approach at the clinical level imposed beforehand to further develop and validate the beta-lactam dosing methodology, to prepare and to make available the experimental devices usable at the patient bed-side including the necessary models and software for translating the measured beta-lactam blood levels into optimized dosage regimens and duration.
1.1. Specific objective 1:
"TO DEVELOP AND VALIDATE THE MON4STRAT BETA-LACTAM DOSING
METHODOLOGY"
The aim was here to customize the patented methodology (Patent EP2766735A1, US968902B2, WO20130553953/A1 et CA2851984A1) for monitoring free beta-lactam concentrations in blood when using the specific beta-lactams of this Project.
RESULTS
The M0N4STRAT method (M4S-M) is based on the hydrolysis of a reporter substrate by an enzyme (the biosensor). The beta-lactam to be assayed acts as competitive inhibitor and can be quantified by the measurement of the apparent loss of enzyme activity. The colorimetric assay uses the competition between a reporter substrate and a beta-lactam antibiotic towards the catalytic site of the beta-lactamase. In the absence of beta-lactam antibiotic, the beta-lactamase rapidly hydrolyses the reporter substrate (nitrocefin, a commercially available chromogenic cephalosporin) and this reaction produces a deep red colour (maximum of absorbance at 482 nm). In the presence of the beta-lactam antibiotic to be assayed, the beta-lactamase catalytic activity is less available and thus less able to hydrolyse the reporter substrate. Accordingly, the higher the concentration of beta-lactam antibiotic, the lower the coloration of the medium. In this enzymatic competitive kinetic assay, the UV-Visible absorbance is inversely proportional to the concentration of beta-lactam antibiotic (see figure 1).
Three different methods were validated:
• M0N4STRAT Method 1 (M4S-M1), where the biosensor is a class C beta-lactamase.
This biosensor (M4S-Biosensor-1) allows the determination of concentrations of
meropenem (M4S-M1/M) or piperacillin-tazobactam (M4S-M1/PT) or ceftazidime
(M4S-M1/CZ) in ultrafiltrated sera and in absence of another beta-lactam antibiotic.
• M0N4STRAT Method 2 (M4S-M2) was developed during this project to determine meropemen
concentrations in presence of another beta-lactam antibiotics often used in ICUs. The selected
biosensor (M4S-Biosensor-2) is an optimized beta-lactamase that has been patented to specifically
monitor meropenem.
• M0N4STRAT Method 3 (M4S-M3), results obtained for ceftazidime dosage by M4S-M1/CZ
indicate that the biosensor 1, is not sensitive enough because the quantification range was
established between 25 to 100 mg/L of ceftazidime. This range is not acceptable for the paediatric
test, since it does not cover the expected concentration values in children. Thus, a new optimized
beta-lactamase biosensor (M4S-Biosensor 3) was selected and validated to specifically quantify
this antibiotic in a range consistent with the values normally found in children’s population.
Extensive data sets regarding selectivity, lower limits of quantification, calibration, accuracy, precision, dilution integrity, matrix effect and stability in ultrafiltrated sera (the patients’ matrix that will be used in the clinical trials) were collected for the beta-lactams contemplated in this project i.e. meropenem, piperacillin-tazobactam and ceftazidime and for the three M4S-methods. These methods were validated in compliance with the expectations of the EMA (Guideline on bioanalytical method validation, July 2011) and FDA. Furthermore, methods were cross-validated against HPLC/MS-MS (reference method) by analysing a large number of quality control (QC) and study samples, prepared as preconized by the sample preparation method developed in the project. It should be noted that contrary to HPLC/MS-MS method, M4S methods do not exhibit matrix effect.
THE MEASURABLE ACHIEVEMENTS RELATED TO THIS OBJECTIVE ARE:
• Well documented experimental conditions for performing accurate concentration measurements
of each of the beta-lactams of the Project present in the same matrix that the one foreseen for the
project.
• The new M4S-M2 method, developed in the frame of this project, was submitted for an European
patent application (European Patent application no. EP19193190.6
1.2. Specific objective 2:
"TO INTEGRATE THE BETA-LACTAM DOSING METHODOLOGY WITHIN
A BETA-LACTAM TDM APPROACH "
The aim here was to develop an approach for managing the deviation between experimentally observed beta-lactam blood levels and PK-PD targets optimized for leading to high efficacy while minimizing EDR and controlling adverse effects and, subsequently, to translate said observed deviations into dosage corrections. For this, realistic PK-PD targets susceptible to combine optimal efficacy, mitigation of EDR and control of toxic effects should be established.
RESULTS
The presented results are limited to meropenem, the beta-lactam that was used in the adults’ trial. Decisions taken to build the algorithm for dosage corrections are listed below:
• After exhaustive revision of bibliography, it was concluded that clinical data are insufficient to
support a clearly defined PK/PD target for meropenem in critically-ill patients. Thus, a severe
PK/PD target of 100% of the curative time above four times the MIC value of the targeted
pathogenic bacteria (100% fT>4xMIC) that would ensure maximal killing (4xMIC) and maxi-
mal efficacy, and prevent the emergence of resistance was selected. Because the MIC of the
offending organisms may not be known, PK/PD target based on the R [clinically resistant] or
the S [clinically susceptible] breakpoints of EUCAST was selected for meropenem. Thus,
selection is therefore summarized as: PK/PD target will be 100% fT>4x “S” breakpoint for
meropenem, i.e. a target Cmin of 8 mg/L.
• No personalization of the first dosing regimen will be performed during the clinical study. The main
reason for this choice is the difficulty to obtain an informed consent from the patients during the
first hours of antibiotic therapy (which MUST be started without delay as survival is inversely
proportional to the delay before therapy is initiated). Sampling after administration will take place
1h after the end of the infusion and 1h before the next administration.
• Therapeutic modalities were evaluated for both safety (probability that predicted Cmax < target
Cmax) and efficacy (probability that Cmin > 4x the “S” breakpoint), thus:
i : If the standard dosing regimen is considered correct (i.e. sufficient safety and efficacy), it will be
preferred to other optimal dosing regimens for nursing facilities and will be kept for the next
dosing.
ii : The interval between administrations can be modified as follows:
- from 8h downward to 6h
- upward to 12h or 24 h.
If multiple dosing intervals allow safe and effective dosing, the shortest dosing interval will be
selected.
iii : The unit dose will be a maximum of 2g per administration for meropenen. Any changes over the
initial unit dose will be made by 0.5-g steps. This will make the antibiotic administration as
simple aspossible for the nursing staff. If multiple doses allow safe and effective dosing, the
lower dose will be selected in order to avoid high cost of therapy and toxicity risk
iv : Considering results from the MON4STRAT concentrations monitoring and PK calculations, the
unit dose will be given in a 0.5-h or 3-h infusion. If multiple durations of infusion allow safe and
effective dosing, the shortest infusion time will be selected in order to maximize practicality for
the nursing staff and for the patient.
- In patients with proven hyperfiltration, the administration interval will be reduced to 6h. In
patients with abnormally low elimination and, if the optimal interval should be longer than
24h (e.g. patients with major elimination defects), the interval between administrations
will be kept at 24h but the unit dose of beta-lactam may be reduced. Indeed, a longer
interval (> 24h) is not acceptable for beta-lactams, especially meropenem, in view of
their instability
- In patients for whom the targets cannot be reached due to (a) abnormally large drug
distribution (and for whom Cmax will therefore be lower than in average patients) or (b)
major hyperfiltration that cannot be compensated by decreasing the interval between two
successive administrations, the unit dose may be increased to over 2g for meropenem but
care will be taken to avoid toxicity.
- Patients with organism(s) for which meropenem MIC is > 4x the “S” breakpoint will be not
eligible or will be withdrawn from the study.
- Patients with organisms for which MIC is very low in the study (e.g. < 0.25 mg/L) will be
included and the target will not be modified (i.e. 4x the “S” breakpoint).
- Regarding the control of adverse events, a target Cmax equal to the percentile 90 of the
Cmax calculated in the target population of patients (critically-ill patients with HAP/VAP),
after administration of the highest standard registered dose is proposed. Thus, target
meropenem will be Cmax = 140 mg/L after a 2-g dose infused over 30 minutes
To estimate PK parameters so that future predictions can be made for patients, both a straight-forward Bayesian feedback algorithm and an Expectation Maximization (EM) algorithm were implemented. Between both, the EM- algorithm was selected, because it was able to provide good estimates on the Confidence Interval for PK parameters. This allowed a Monte Carlo sampling of the parameters, to provide a prediction of future plasma concentrations under a hypothetical dosing. The prediction is not a single point estimate, but provides a confidence interval. This allows us to account for uncertainty, taking better decisions by adding a safety margin.
Finally, a software for deciding dosing regimen corrections was built for MON4STRAT project, linking data known on the patient that are stored into the database of the clinical study, and the PK/PD model that computes the optimal dosage based on these patient’ data. The recommendation software uses:
i : The antibiotic and the MIC (minimum inhibitory concentration) associated.
ii : The treatment schedule:
- date and time of administration;
- dose (g);
- infusion duration (h).
iii: The patient characteristics:
- body weight (kg);
- creatinine clearance (L/h). It can be measured or, if the measure is not available, estimated by
using the Cockcroft-Gault formula. If needed, the estimation of the creatinine clearance will
be performed in the database.
iv : The observations:
- date and time of the blood test;
- antibiotic concentrations (mg/L) measured by the MON4STRAT device.
v : The stability state of the patient.
The results of simulation tests indicate that the algorithm can accurately estimate individual PK parameters of beta-lactam based on sparse concentrations measured in patients after first or repeated administrations, as well as the confidence interval on these PK parameters.
Results also indicate that the algorithm can select the best dosing regimen for almost all patients. Uncertainty in parameter estimation is taken into account, but residual variability is not. There is a high probability that the patient, using the new individualized dosing regimen, will attain the intended PK targets.
On the other hand, an in vitro hollow-fiber infection model was used to evaluate the impact of different dosing exposures on the emergence of drug resistance (EDR). Results about drug exposures needed to suppress resistance development have been consistent between meropenem and cefepime, when the PK/PD exposures were adjusted to the corresponding MIC of the pathogen but were less clear for piperacillin / tazobactam where deviation from standard clinical practice was needed to enhance bactericidal activity.
THE MEASURABLE ACHIEVEMENTS RELATED TO THIS OBJECTIVE ARE:
• Confirmed PK-PD targets and models usable for meropenem in the clinical study and optimized for
combining optimum efficacy, suppression of EDR and avoidance of adverse effects
• The software that translates deviation between experiment and targets into dose/schedule
corrections.
1.3. Specific objective 3:
"TO PREPARE THE EXPERIMENTAL MONITORING DEVICES (HARDWARE AND
SOFTWARE) ANDMAKE THEM AVAILABLE TO THE CLINICAL SITES INVOLVED
IN THE EXPLORATORY CLINICAL TRIAL"
RESULTS
The original objective was to customize 11 Ellipse instruments. Ellipse is a medical analyzer marketed by Analyzer Medical System (AMS) (Italy) (+/-50kg). This is the device previously used in the laboratory by P1-ULg for the development and validation of the MON4STRAT method, and is the only one commercially available and compatible with MON4STRAT test requirements. This automate has most of the functionalities and performance required for the assays but keeps samples and reagents at room temperature, has no possibility for reagents and samples traceability by barcode and its interface is not user-friendly. Most of these drawbacks could be solved by a specific customization, handled by P3-WOW. However, at the beginning of the project, we were faced with the problem that the manufacturer protected source codes needed to modify the software, so that the device customization became overly complex. Therefore, P3-WOW proposed to develop a new autoanalyzer from scratch, including functionalities of the AMS instrument in addition to all the functionalities that could improve the use of this automate by not specialised staff. P3-WOW, in collaboration with P1-ULg, worked in the development of this new “MON4STRAT machine”, which includes, besides, a software to run the MON4STRAT dosages and an algorithm to calculate antibiotic concentration, with minimal intervention of the clinical staff in user-friendly interface. The decision of building a machine from scratch, tailor-made for the project specific application, even if it represents a clear advantage for the consortium in terms of remarkable ease of use, maintenance and supplies of the device, took longer than originally expected. The first version of the MON4STRAT machine was available at month 24 (see Figure 2) This instrument differs functionally from the previously mentioned commercial device, thus the analytical method needed to be adapted consequently. It is worth noting that the device is a handmade prototype, not an industrially made one, so that slight differences could be present between devices. To address this problem, P1-ULg and P2-UCL validated each device that will be sent to the clinical sites, to be in compliance with EMA regulatory requirements for biochemical tests used to adjust the dose of a drug.
A restricted access website, hosting MON4STRAT assays database (calibration curves and assays) with flexible access from any computer connected to the Internet was built by P1-ULg. This database stores raw data and calculated dosage values, obtained after application of reliable statistical methods. It allows to evaluate remotely and in real time the performance of the different machines and the reagents, and to intervene if problems would arise. At the same time, data about the dosage could be accumulated for further analysis.
The health care attendants in charge of running the clinical trial received the training for (a) fully understanding the PK/PD basis of the trial and (b) allowing them to be comfortable with the manipulation of both hardware, reagents and software.
THE MEASURABLE ACHIEVEMENTS RELATED TO THIS OBJECTIVE ARE:
• 6 machines (experimental prototypes) transferred to the partners who will use them in clinical
trials In addition, 4 machines are available for enabling further improvements away from the
clinical settings (of which, two spare devices are foreseen in case of failure of ones sent to the
hospitals
• Trained health-care attendants for using the MON4STRAT machine and understand the importance
of TDM for dose optimisation.
2. Clinical objectives
°°°°°°°°°°°°°°°°°°
The first clinical objective was to validate the MON4STRAT assay methodology against a best-in-class benchmark method in real clinical settings and to confirm its usability at bed-side. The second clinical objective was to perform a prospective, randomized, open, controlled, multicentre clinical trial in adults for demonstrating the appropriateness of the MON4STRAT approach for improving the meropenem-based treatment of HAP/VAP patients. The third clinical objective was to explore how and to what extent the approach is also feasible in paediatric populations.
2.1. Specific objective 4:
"TO CONFIRM THE SPECIFICATIONS OF THE MON4STRAT METHOD IN THE
ACTUAL CONDITIONS OF ICU AND TO SET THE BEST PROTOCOL FOR USING
IT AT BED-SIDE"
RESULTS
Originally, the first clinical objective aimed to validate the M0N4STRAT assay methodology against the best-in-class benchmark method, including the blood collection and preparation prior to perform the MON4STRAT assay, in a real clinical setting (P7-ULB) and to confirm its suitability at bedside (dry run prior to start the clinical trial).
However, after extensive discussion, clinicians expressed their concern to test practical feasibility of the MON4STRAT method before starting the clinical trial. The deviation from the initial pilot study towards the clinical pre-study was motivated by the need to clinically validate the MON4STRAT approach (i.e. dosage and algorithms) before starting the clinical study. The maim objectives of the clinical pre-study were (a) to ensure the point of care’s feasibility of the MON4STRAT algorithm implementation and (b) to verify the accuracy of the device for determining free-meropenem concentrations. The pre-study was observational, open-label, controlled and multicentre (P7-ULB, P4-ICAN), conducted on 50 adult patients with microbiologically-confirmed or suspected Gram-negative infection to assess the accuracy of the MON4STRAT mathematical algorithm for reaching and maintaining pre-determined PK/PD targets (meropenem Cmin ≥ 8 mg/L and Cmax < 140 mg/L) in ICU patients treated with meropenem and requiring mechanical ventilation. The total study duration was estimated in approximately 6 months (enrolling approximately 9 subjects per month). Each subject shall participate for the duration of their prescribed antibiotic treatment (approximately 7-14 days) and for a test of cure (TOC) follow-up evaluation performed 5 to 7 days after completion of all antibiotic therapy. The pre-test should allow to test practical feasibility, to assess unanticipated problems in sample preparation, dosing-machine and dose adaptation and to address solutions before the real trial. Clinical protocols, case report form (CRF), electronic case report form (eCRF) and database (DB) were constructed, and ethical committee’s authorizations were obtained. This work was not planned in the original project.
The pre-test started when the first version of the device was available. The two first pre-validated prototypes were installed in P4-ICAN and P7-ULB centres, staffs were trained and a pre-test started at the end of 2015. The pre-test highlighted several weaknesses of the device, some of these constraints could be eliminated by P3-WOW intervention, but others emerged, giving rise to inaccurate results. The pre-test was suspended until a reliable version of the device was available. At the same time, several modifications were introduced in the algorithm for dose recommendation, as result of observations made with the first patients enrolled.
An improved version 3 of the device, previously validated against the reference HPLC/MS-MS method, was installed in both centers; the staff was trained again and pre-test resumed. Analysis of results of the clinical pre-study highlighted the need for TDM practice for meropenem in critically-ill patients (interindividual variability in meropenem PK was large, around 48.2 to 109%). In addition, when the meropenem dosage was individually guided using the MON4STRAT device, a significant improvement in the PK/PD target was clearly observed with, as a result, an improved clinical efficacy and reduced risk of resistance emergence
THE MEASURABLE ACHIEVEMENTS RELATED TO THIS OBJECTIVE ARE:
• Practical evidence that MON4STRAT methodology is applicable in ICUs.
• Practical evidence that the dosing algorithm and the MON4STRAT test work in clinical practice
2.2. Specific objective 5 :
"TO PERFORM A PHASE IIB-TYPE CLINICAL TRIAL TO ASSESS THE MERITS OF THE
MON4STRAT APPROACH FOR OPTIMIZING BETA-LACTAM TREATMENTS (DOSES
AND SCHEDULES) IN HAP/VAP ADULT PATIENTS"
RESULTS
When pre-test ended, several modifications were introduced to the algorithm and the devices and related software were modified accordingly. The eCRF and DB was also updated. The protocol for adult’s trial incorporated minor modifications in the endpoints, taking into account the results of the pre-test.
The inclusion of the new-partner P12-APHP as study sponsor was consolidated. The protocol, “Prospective, Randomized, Open, Controlled, Multicenter Study to Evaluate the Safety and Efficacy of the MON4STRAT Approach for Optimizing Meropenem Therapy in Intubated and Mechanically-Ventilated, Adult Patients with severe Gram-Negative lower respiratory tract infection », in adults, was sent to competent authorities and ethical committees in each of the 3 countries, Spain, Belgium and France as a clinical trial with an investigational medicinal product (IMP)
The three centers (Madrid, Brussels and Paris) were progressively opened in 2019, but more slowly than expected because of the inherent administrative constraints.
Because of the end of funding, the project and the trial were closed on July 31, 2019. Data base was closed and data was sent to Principal Investigators for analysis. The clinical characteristics of recruited patients at time of admission to ICU and of randomization were in accordance with the inclusion/exclusion criteria specified in the protocol. Informed consent was obtained for all of them. All data were monitored in accordance with the protocol, with no deviation detected. The only adverse events reported were those expected in such a population of ICU patients, and none were related to meropenem or the Mon4Strat device.
Unfortunately, the low number of patients included into the study precludes any meaningful statistical comparison of the two groups, even if numerical data seems favoring the Mon4Strat strategy. We are therefore not able to draw significant conclusions concerning the MON4STRAT approach. Nevertheless, we can provide a list of positive points presented in the next paragraph.
Future clinical studies using the MON4STRAT approach should be pursued since the MON4STRAT approach appears to have permitted patients to rapidly reach adequate antibiotic concentrations to treat pulmonary infections. The MON4STRAT approach was able to do so, despite the fact that the PK of antibiotics are very unpredictable in the ICU setting. Indeed, reaching antibiotic target concentrations very rapidly may have a significant impact on patient morbidity, and/or mortality.
THE MEASURABLE ACHIEVEMENTS RELATED TO THIS OBJECTIVE ARE:
• The protocol was consistent with the objectives of the study
• The measurement of meropenem concentrations using the hospital’s MON4STRAT devices
produced reproducible and robust results.
• The algorithm was able to recommend dosage regimens to rapidly obtain meropenem
concentrations within target values, most of the time.
• No serious adverse events related to the MON4STRAT approach were reported.
2.3. Specific objective 6 :
"MON4STRAT APPROACH FOR MEASURING BETA-LACTAM FREE SERUM LEVELS
IN CRITICALLY-ILL PAEDIATRIC PATIENTS"
The main objective of the paediatric study was to demonstrate the interest and the feasibility of the MON4STRAT approach in children, prematures and neonates where blood sampling is limited. The paediatric study was observational, and aimed to prepare the grounds for a more complete phase IIb clinical trial to be performed after the completion of the present project.
RESULTS
Altogether, 37 paediatric patients were included: 23 in Estonia and 14 in France. There were in total 23 neonates and 14 outside of neonatal age. 15 patients received meropenem, 20 piperacillin/tazobactam and 2 ceftazidime at doses that are recommended in local guidelines. All patients were severely ill and received antibiotics treatment for confirmed or suspected acute bacterial infection.
PK samples were taken prior to and after the antibiotic dose, at day 3 after inclusion in the study. In total 8 patients provided one evaluable sample, 27 gave two and 2 patients provided more than 2 samples. Antibiotic concentrations were measured at participating hospitals and then ultrafiltrate were stored at -80°C and sent to UCL for further analysis. The clinicians were not aware of measured concentrations (concentration results were encrypted by the M4S device) and thus no action was taken as a result of antibiotic concentration measurement.
Altogether 69 samples (27 for meropenem, 38 for piperacillin/tazobactam and 4 for ceftazidime) were successfully assayed with M4S device on sites. The concentrations were variable and are undergoing further analysis and PK modelling. The median predose and postdose concentrations for meropenem in neonates were 4.9 mg/l and 41.04 mg/l, respectively. For piperacillin/tazobactam respective values for neonates were 7.7 mg/l and 27 mg/l and for non-neonates 5 mg/l and 108 mg/l. These values are largely in ranges that have been reported in other studies where concentrations have been determined with the HPLC/MS-MS method, outside the ICUs. The differences between neonates and non-neonates in piperacillin/tazobactam post-dose concentration requires further analysis but is probably due to differences in infused doses between neonates (~200 mg/kg/day) and children (~300-400 mg/kg/day).
We have collected data from 23 neonates and 14 non-neonatal children. These data are likely sufficient to correlate PK concentrations measured by M4S device with clinical data and laboratory deviations. As database was locked very recently then the detailed analysis will be completed in coming months.
The number of recruited patients was lower than expected. The reasons for this lower recruitement are listed below:
i : The device became available late in the porject, thus the recruitment period remained shorter
than initially forecasted.
ii : In Tartu, a screening log was maintained. It showed that , among the screened patients, the
recruitement is smaller than we have seen in previous studies. The reasons for not recruiting
patients were: participation in other interventional studies, patients with extreme prematurity or
critical medical condition, parental refusal and also because study antibiotic was stopped prior
to signing the informed consent.
iii : In Lille, the reasons for non-inclusion were mainly a unit too busy to proceed or the absence
of consent by some parents (mainly parents of critically ill highly premature babies).
iv : Study staff was not used to work with the device, it is not current practice and because there was
no direct benefit for the patient they may have had low motivation especially during the times of
high work load.
The calculation of patients needed was initially based on the analysis of dosages of 4 antibiotics. But dosages for 2 antibiotics were not possible: (a) cefepime was withdrawn before starting the inclusions for technical reasons and (b) data for ceftazidime were too small (n=2) to allow any analysis. Despite smaller recruitment we have enough data for meropenem and piperacillin-tazobactam and still believe that the study provided valuable data of using M4S device in neonatal and paediatric intensive care units for these antibiotics.
THE MEASURABLE ACHIEVEMENTS RELATED TO THIS OBJECTIVE ARE:
• Practical evidence that MON4STRAT methodology is applicable in paediatric ICUs.
Potential Impact:
The main outcome of the MON4STRAT Project would have been a new clinically validated therapeutic approach to treat HAP/VAP patients suffering of Pseudomonas aeruginosa bacterial infection. The MONSTRAT approach integrates a rapid, simple and cost-effective device for monitoring free beta-lactam blood levels performed at the patient’s bed-side and, accordingly, offers to the clinician, for the first time, (i) rapid indications on the possible patient-specific deviation of the point-of-care beta-lactam blood levels compared to the theoretical PK-PD targets and, accordingly, (ii) rapid dosage adjustement/corrective means.
However, due to the limitations encountered to clinically validate the approach, the impact of the project is limited. Indeed, all the Key Performance Indicators that have been described in the MON4STRAT grant to measure the impact at the end of the Project were strictly related with the results of the trial.
With respect to the paediatric study, the objectives are being met since the study will continue after the end of the project. Theses results will contribute to a best knowledge of PK-PD values for neonates and children. These data will deliver health benefits to children suffering from bacterial infections.
We would like, however, to stress that:
• The clinical partners of the MON4STRAT are key-opinion leaders in the field of infectious diseases, especially dealing with antimicrobial resistance issues. They are all convinced, from the results of pre-test and from the adults' trial that the MON4STRAT approach is able to “track” from the very beginning of the treatment patient-specific “abnormalities” compared to the PK-PD targets and, by correcting the dosage, improve efficacy (the faster the targeted PK-PD index is reached, the faster the conditions for efficient bacterial killing are met, which is an essential requirement in successful treatment). Thus, as all the tools needed to test the approach are now ready, additional clinical studies are possible and are needed to confirm the assets of the MON4STRAT approach at an individual level.
• There is still a clear unmet need of a rapid method to determine antibiotics concentration at bed side, or, at least within the ICUs. Each of the essential constitutive parts of the MON4STRAT approach (concentration determination method, device, algorithm) were conceived in compliance with regulatory (EMA and FDA) and GCP guidelines, we consider that this, together with preliminary results, would accelerate the adoption of the methodology by the medical community, even in absence of effective clinical validation, to support a broad clinical trial (meta-analysis) that would allow to consolidate the MON4STRAT concept (large number of ICUs). Furthermore, this could be applicable also In other infectious indications using beta-lactam(s): to support the clinical validation of the approach for performing an antibiotherapy in the case of non-critically-ill patients (outside the ICUs), since none of the current beta-lactam-based treatments used in clinics enable to make a patient “signature” in terms of individual exposure-response relationship, certainly not at the early stage of the treatment (classical methods are too slow).
• Broad implementation of the MON4STRAT approach relies also on the replication of device enabling rapid (real-time), accurate free beta-lactam blood level monitoring. To this end, the consortium developed a prototype device, user-friendly, that could still be improved and completed for translating into an smaller and faster industrial commercial device. An European SME has already signed, with the patent applicants (ULG and UCL), an option for an exclusive, worldwide license for exploiting the technology and this will, of course, strongly accelerate the overall process of market uptake of the methodology. Industrial production of a customized device is expected in the coming years. All results achieved (biochemistry, reagents formulation, robotic, software, plasmids, enzymes production, PK-PD tables, ...) during MON4STRAT project will transferred to the European SME after the signature of the license agreement.
• In parallel to the scaling-up and commercialization of the apparatus customized for monitoring the b-lactams contemplated during the Project, additional steps are already foreseen for widening the scope of application to the monitoring of other antimicrobials (Preliminary results already exist within the consortium in that direction). One may thus expect a rapid and widespread valorization of the acquired knowledge and expertise in the field of human health as well as animal health.
List of Websites:
http://www.mon4strat.ulg.ac.be/
PROJECT COORDINATOR
Prof. Bernard Joris,
Center for Protein Engineering.
Univ. of Liège. Liège. BELGIUM
Tel: + 32 4 366 2954
Fax:+ 32 4 366 3364
E-mail: bjoris@ulg.ac.be
