A personalised approach to manage adverse reactions to CFTR modulator therapy in patients with cystic fibrosis

Lead Research Organisation: University of Liverpool
Department Name: Pharmacology & Therapeutics

Abstract

Adverse drug reactions are a major health concern and an impediment to the development of new medicines. Approximately 1 in 16 hospital admissions in the UK are due to some form of adverse drug reaction. One of the best known, but least understood drug side-effects is T-lymphocyte-mediated hypersensitivity. Such reactions are unpredictable with respect to the chemistry of the drug and the biology of the patient. CFTR modulator therapies are now widely available as dual or triple therapy and these have transformed cystic fibrosis (CF) into a much milder disease. However, adverse reactions to CFTR modulator therapy such as cutaneous drug hypersensitivity and liver injury can result in drug discontinuation and deleterious clinical outcome. The objective of this proposal is to relate drug exposure, HLA allele expression and drug-specific immune responses to clinical outcome in patients exposed to CFTR modulator therapies. Our approach will provide a framework to more effectively assess patients hypersensitive to this important class of drug. By collecting blood samples during reintroduction of CFTR modulator therapies, we will then define how the drug-specific T-cell response develops during treatment and the pathways that regulate effector T-cell responses.

T-cells are involved in the decision process that determines whether drug exposure will lead to a hypersensitivity reaction. Thus, using PBMC and drug-responsive cloned T-cells from patients with skin and liver reactions, we will define a hypersensitivity phenotype and identify pathways of drug-specific T-cell activation. These data will identify the drug(s) associated with adverse events and provide valuable information on the disease pathogenesis. Resulted will be compared with de-novo priming experiments and used to stratify patients with adverse events.

Analysis of patient cells, although important, provides no information about the primary T-cell response. Thus, we will utilize our healthy donor HLA genotyped PBMC bank to study the origin of drug-specific T-cells. Our assessment will involve characterization of CFTR modulator drug-specific stimulation of naïve/memory T-cells with assessment of the pre-curser T-cell frequency and the phenotype and function of drug-specific T-cells.

Access to a repository of PBMC from patients with CF (with and without CFTR modulator therapy hypersensitivity) will allow us to conduct HLA sequence-based genotyping. Any associations will allow us to define of the role of specific HLA molecules in CFTR modulator drug presentation to T-cells and may pave the way to genetic testing prior to drug use.

We have recently utilized mass spectrometry to characterize drugs, drug metabolites and drug protein adducts and relate exposure to the activation of a drug-specific T-cell response. We will now use these methods to quantify CFTR modulator drug and metabolite levels in human plasma and relate exposure to patient outcome (health benefit or adverse event). Similar methods will be used to assess CFTR modulator drug metabolism by CYP3A4 expressing HepG2 cells in an immune cell co-culture system to relate metabolite formation to the activation of human T-cells.

Several patients with immunologically confirmed adverse events will be offered alternative therapies or the same therapy at reduced dose or through drug provocation or drug desensitisation. Blood sampling will be undertaken prior to, during and after treatment to explore: (i) how the drug-specific effector T-cell response develops; (ii) expression of effector and regulatory cytokines, and (iii) suppression through the function of Tregs and co-inhibitory molecules. Once we have developed a robust assessment that will risk stratify individual patients with CFTR modulator therapy adverse events it could be applied to other patient groups, including those receiving novel medicines.

Technical Summary

Background: Drug hypersensitivity is one of the best known, but least understood drug side-effects. Recently, we have shown that CFTR modulator drugs can activate T-cells in hypersensitive patients. We have also confirmed that desensitisation is an important tool in the treatment of hypersensitive patients with cystic fibrosis. Despite this, knowledge of the pathways through which sensitisation is acquired, and how drug re-exposure serves to modify those mechanisms, have not been defined.
Objectives: We propose to relate drug exposure, HLA expression and drug-specific immune responses to clinical outcome in patients exposed to CFTR modulator therapy. Our experiments will provide a framework to more effectively assess hypersensitive patients and design personalized treatment strategies. By collecting blood during re-exposure, we will define how the drug-specific and regulatory immune response develops.
Methods: Patient drug-specific T-cell responses, HLA genotyping and the priming of naïve T-cells will be measured using established methods. HLA-restriction, cellular phenotype/function, and cross reactivity will be assessed with T-cell clones. Access to a CYP3A4 expressing liver cell line will allow us to explore drug metabolite T-cell responses. Mass spectrometry will be used to quantify drug exposure in vitro and in plasma. When drug re-exposure is offered to hypersensitive patients blood will be collected to measure attenuation of the effector T-cell response and regulatory parameters.
Impact: A better understanding of drug hypersensitivity will support personalised management strategies that determine whether a patient should be re-exposed to the drug and the need for desensitisation. By relating immune responses to clinical outcome, we will define a clear hypersensitivity phenotype, paving the way for the development of diagnostic tests. New insights into drug exposure levels may indicate that lower doses will reduce the chances of hypersensitivity.

Publications

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Gardner J (2024) Glycolysis: An early marker for vancomycin-specific T-cell activation in Clinical & Experimental Allergy

 
Title Isolation of T-cells from human liver biopsies. 
Description Protocols have now been developed by researchers at the University of Liverpool to enable to isolation of T-cells from small punch biopsies taken from cystic fibrosis patients with suspected liver injury. 
Type Of Material Biological samples 
Year Produced 2023 
Provided To Others? No  
Impact Resulting from this research method, T-cells can now be isolated and characterised for cellular phenotype and function from small punch biopsies. Together with diagnostics undertaken by clincal teams as part of rountine patient care, this can provide greater insight into the mechanisms of CFTR-modulator induced liver injury in addtion to potentially identifying the causative drugs. 
 
Description Liverpool Leeds collaboration 
Organisation St James's University Hospital (Jimmy's)
Country United Kingdom 
Sector Hospitals 
PI Contribution We are working together to recruit UK patients with adverse reactions to CFTR modulator drugs in the UK. The collaboration has allowed the transfer of viable PBMC between research groups. We have also established protocols for the effective transfer of tissue samples (liver and skin) between the 2 teams.
Collaborator Contribution The collaboration has allowed the transfer of viable PBMC between research groups. We have also established protocols for the effective transfer of tissue samples (liver and skin) between the 2 teams.
Impact In process
Start Year 2023
 
Description Naisbitt Roehmel collaboration 
Organisation Charité - University of Medicine Berlin
Country Germany 
Sector Academic/University 
PI Contribution The research team in Liverpool are working closely with the clinical cystic fibrosis team in Berlin, Germany. Liverpool researcher have visited the team in berlin to provide lab training and to discuss collaborative research. A protocol is established for the effective transfer of viable human cells between labs.
Collaborator Contribution Networks have been established to recruit patients with most severe adverse reactions to CFTR modulator drugs. A survey supported by the European cystic fibrosis society is complete and will be published shortly describing the nature and frequency of adverse reactions to these drugs.
Impact Outputs are in preparation
Start Year 2023
 
Description Cystic Fibrosis Clincal Research workshop 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Cystic Fibrosis Clincal Research workshop attended in November 2023 at Leeds St James Hospital to update clincal teams on the progess of the study. This research day was held at the CF unit at Leeds St James Hospital and involved all clinical research teams studying CF. The presentation given from the Liverpool team sparked discussions about the data and findings relating to specific CF patients and plans were made with collaborators directly involved in the treatment of these patients for future sampling to contribute towards the active study.
Year(s) Of Engagement Activity 2023
 
Description Lab visit to Berlin to teach collaborators techniques 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Study participants or study members
Results and Impact Researchers from the University of Liverpool travelled to the Charite Hospital in Berlin. During this visit, knowlege exchange took place and assays/procedures relating to the collection of CF patient samples perfomed in order to ensure immune cells could be successfully collected from severe patients throughout the European cohort.
Year(s) Of Engagement Activity 2023