In-Hydrogel Cell-Free Protein Expression System as Biocompatible and Implantable Biomaterial

Biomaterials capable of delivering therapeutic proteins are relevant in biomedicine, yet their manufacturing relies on centralized manufacturing chains that pose challenges to their remote implementation at the point of care. This study explores the viability of confined cell-free protein synthesis within porous hydrogels as biomaterials that dynamically produce and deliver proteins to in vitro and in vivo biological microenvironments. These functional biomaterials have the potential to be assembled as implants at the point of care. To this aim, we first entrap cell-free extracts (CFEs) from Escherichia coli containing the transcription-translation machinery, together with plasmid DNA encoding the super folded green fluorescence protein (sGFP) as a model protein, into hydrogels using various preparation methods. Agarose hydrogels result in the most suitable biomaterials to confine the protein synthesis system, demonstrating efficient sGFP production and diffusion from the core to the surface of the hydrogel. Freeze-drying (FD) of agarose hydrogels still allows for the synthesis and diffusion of sGFP, yielding a more attractive biomaterial for its reconstitution and implementation at the point of care. FD-agarose hydrogels are biocompatible in vitro, allowing for the colonization of cell microenvironments along with cell proliferation. Implantation assays of this biomaterial in a preclinical mouse model proved the feasibility of this protein synthesis approach in an in vivo context and indicated that the physical properties of the biomaterials influence their immune responses. This work introduces a promising avenue for biomaterial fabrication, enabling the in vivo synthesis and targeted delivery of proteins and opening new paths for advanced protein therapeutic approaches based on biocompatible biomaterials.

AB0356 THERAPEUTIC DRUG MONITORING: STANDARDIZATION OF PROMONITOR QUICK IFX AND PROMONITOR QUICK ADL POINT OF CARE TESTS WITH WHO INTERNATIONAL STANDARDS FOR THE QUANTIFICATION OF INFLIXIMAB AND ADALIMUMAB IN WHOLE BLOOD AND SERUM

Background

Promonitor Quick IFX and Promonitor Quick ADL are rapid point of care lateral flow tests (LFT) based on a sandwich immunoassay for the quantification of infliximab (IFX) and adalimumab (ADL), respectively, in human whole blood (finger prick or venous) or serum. These tests are to be used as an aid in Therapeutic Drug Monitoring (TDM) of rheumatic and inflammatory bowel disease patients under anti-TNFα therapy. The international standards (IS) developed by World Health Organization (WHO) for IFX and ADL allow harmonization and comparability among different assays.

Objectives

The aim of this study, was to show that Promonitor Quick IFX and Promonitor Quick ADL can measure either reference or biosimilar drugs, as well as to evaluate the agreement of Promonitor Quick IFX and Promonitor Quick ADL tests and the WHO IS.

Methods

Clinical and Laboratory Standards Institute EP10-A3 guidelines were followed to estimate the bias of Promonitor Quick assays when used to quantify IFX or ADL in samples containing the reference drugs, biosimilars or the WHO IS. Briefly, whole blood was spiked with four known concentrations of IFX or ADL, including current clinical decision levels. Ten replicates were measured of each level along two days.

Promonitor Quick IFX was evaluated using the reference drug, SB2 and CT-P13 biosimilars, and the WHO IS (NIBSC 16/170).

Promonitor Quick ADL was evaluated using the reference drug, ABP501 and SB5 biosimilars, and the WHO IS (NIBSC 17/236).

Results were obtained in combination with the automated portable reader PQreader.

Results

Bias was estimated by comparing the observed concentration of drug spiked whole blood samples. Each biosimilar was compared to the reference at the different drug levels tested. Results showed that Promonitor Quick IFX and Promonitor Quick ADL are able to measure equivalently any molecule (see Table 1).

Table 1.Promonitor Quick IFX bias results in whole blood samples. Each molecule was compared to the reference drug.IFX concentration (μg/mL)Bias (%)CT-P13SB2GP1111WHO IS314%3%4%8%79%0%5%15%101%5%6%8%Promonitor Quick ADL bias results in whole blood samples.Each molecule was compared to the reference drug.ADL concentration (μg/mL)Bias (%)ABP501SB5WHO IS317%2%3%513%3%12%82%2%7%10517%2%

Similar results were obtained when serum matrix was used.

The accuracy or closeness of the agreement between the result provided by Promonitor Quick IFX and Promonitor Quick ADL and the true value of the measurand was assessed by measuring the IS developed by the WHO (see Table 1).

Conclusion

Promonitor Quick IFX and Promonitor Quick ADL allow monitoring of patients treated with IFX and ADL, respectively, with just a finger prick sample. Both tests can quantify reference and biosimilar drugs with equivalent results. Moreover, comparable results were obtained with the WHO IS, and thus, demonstrate that Promonitor Quick tests are suited to accurately determine drug levels at the clinical decision points in both whole blood and serum, proving to be an effective and valuable tool in TDM and immediate decision making in the doctor office or hospitals.

Disclosure of Interests

Amagoia Ametzazurra Employee of: Employee of Progenika Biopharma - Grifols, Javier Pascual Employee of: Employee of Progenika Biopharma - Grifols, Lorena Del Rio Employee of: Employee of Progenika Biopharma - Grifols, Ane Urigoitia Employee of: Employee of Progenika Biopharma - Grifols, Daniel Nagore Employee of: Employee of Progenika Biopharma - Grifols, M. Begoña Ruiz-Argüello Employee of: Employee of Progenika Biopharma - Grifols

AB0369 CORRELATION OF THE FIRST LATERAL FLOW-BASED POINT OF CARE TEST TO QUANTIFY INFLIXIMAB AND ANTI-INFLIXIMAB ANTIBODIES IN A FINGER PRICK SAMPLE WITH THE REFERENCE ELISA TECHNIQUE

Background

Current techniques to monitor clinical response may require several days and centralised facilities, which may cause delays in effective therapeutic decisions. Therefore, the use of a rapid decentralized test will facilitate patient management and improve patient care.

Objectives

The goal of this study was to validate the use of capillary blood in a real point-of-care (POC) setting for rheumatic patients under infliximab treatment by using Promonitor Quick lateral flow (LF) tests. Results were compared to the Promonitor ELISA reference technique in serum samples used by centralised laboratories.

Methods

A prospective, observational study was designed to evaluate the performance of a rapid LF test (Promonitor Quick IFX, Progenika, Spain). 160 infliximab treated rheumatology consecutive patients (400 samples) were recruited in two hospitals in Galicia, Spain. Prior to the infusion, a finger prick sample was obtained and analysed. Anti-infliximab antibodies were also determined with Promonitor Quick ANTI-IFX1-4. Results were read with the automated portable PQreader instrument. Additionally, a serum sample was collected for subsequent comparative analysis with either LF or ELISA tests.

Qualitative (positive (PPA) and negative (NPA) agreements) and quantitative (Pearson correlation and bias) performance of the LF test was compared to ELISA, as well as between different specimens following CLSI EP09-A3.

Results

Overall agreement between Promonitor Quick IFX finger prick and ELISA test was 91% (88% PPA; 100% NPA). The quantitative comparison showed a good correlation (Pearson correlation coefficient: 0.85 and observed bias: 25%) (Table 1).

Table 1.Performance results: infliximab drugQualitative ComparisonN*PPANPAoverallPOC finger prick vs ELISA27488%100%91%POC serum vs ELISA28198%100%98%Quantitative ComparisonN*Pearson correlationBiasPOC finger prick vs ELISA1650.8525%POC serum vs ELISA1810.916%*Only samples in the common measurement range for both methods considered.Performance results: anti-infliximab anti-drug antibodiesQualitative ComparisonN*PPANPAoverallPOC finger prick visual vs. PQreader396100%99%99%POC serum visual vs PQreader398100%100%100%POC finger prick PQreader vs ELISA39390%99%98%POC serum PQreader vs ELISA39589%100%99%

Similar results were also observed when serum was used with either the LF or the ELISA tests (98% overall agreement, 0.91 correlation coefficient; 6% bias) (Table 1).

Overall agreements for visual and automated (PQreader) interpretations with Promonitor Quick ANTI-IFX were 99% and 100% for finger prick and serum specimens, respectively (Table 1).

Conclusion

Promonitor Quick can be used to reliably quantify infliximab in capillary blood samples and results are comparable to those obtained with the reference ELISA technique. The use of the rapid POC test with finger prick will allow clinicians to monitor their patients in a fully decentralized mode to aid in the decision making process. PQreader is a sensitive portable equipment to report drug as well as antibody levels in the patient samples.

References

[1]Atreya, R. et al. J Crohns Colitis. 2019;13:S391

[2]Ametzazurra, A. et al. J Crohns Colitis. 2017;11:S335-S336

[3]Fiorino, G. et al. J Crohns Colitis. 2017;11:S388

[4]Facchin, A. et al. J Crohns Colitis. 2019;13:S349- S350

Disclosure of Interests

M. Begoña Ruiz-Argüello Employee of: Employee of Progenika Biopharma - Grifols, Javier Pascual Employee of: Employee of Progenika Biopharma - Grifols, Lorena Del Rio Employee of: Employee of Progenika Biopharma - Grifols, Ane Urigoitia Employee of: Employee of Progenika Biopharma - Grifols, Cristina Balo-Farto: None declared, Carlos Fernández-López: None declared, ANTONIO MERA VARELA: None declared, Francisco Javier de-Toro-Santos: None declared, Daniel Nagore Employee of: Employee of Progenika Biopharma - Grifols, Amagoia Ametzazurra Employee of: Employee of Progenika Biopharma - Grifols