Lecture 25 - Biological Therapy for Respiratory Diseases

Question 1

Define biological therapy

List a few examples

Answer 1

Use of:
• Living organisms
• Living organism-derived products
• Lab produced versions

Examples:
• Immunotherapy: vaccines, bacteria
• mAbs

Question 2

Describe the use of nucleotide sequences in biological therapy

Answer 2

Used as: Antisense oligonucleotides

e.g. Formvirisen
• Marketed for CMV and ApoB

Question 3

What are exosomes?

Answer 3

Vesicles released by a cell via exocytosis

Question 4

How can exosomes be used therapeutically?

Answer 4

Exosomes can be engineered to contain desired components for delivery to cells:
• Introduction of nucleic acids via Exoporesis
• Small molecule loading

Particularly useful in administration of highly charged molecules that normally cannot cross plasma membranes

Question 5

Outline the generation of mAbs

Answer 5

1. Spleen cells from antigen challenged mice + myeloma cells
2. Membranes forced to fuse with PEG
3. HAT kills off myeloma cells that did not fuse
4. Spleen cells are now immortal hybridomas
5. Screening to look for the mAb specificity of interest

Question 6

When was the generation of mAbs discovered?

Who designed this process?

Answer 6

Milstein & Köhler, 1975

Question 7

When were mAbs first humanised?

Answer 7

1997

Question 8

When were human mAbs first produced?

Describe how they were produced

Answer 8

2002 - Adalimumab (anti-TNF)

Generated from spleen cells of transgenic mice (have complete human Ig genes)

Question 9

Describe therapeutic use of novel protein scaffold technology

Answer 9

*

Question 10

What are recombinant proteins?

Give an example of therapeutic use of R.P.s

Answer 10

Recombinant proteins:
• Proteins derived from recombinant DNA

Recombinant DNA:
• DNA formed by laboratory methods of genetic recombination (such as molecular cloning) to bring together genetic material from multiple sources
• Creates sequences that would not otherwise be found in biological organisms

Therapeutic use:
• Recombinant GM-CSF in PAP (pulmonary alveolar proteinosis)

Question 11

What is pulmonary alveolar proteinosis (PAP)?

Describe the mechanism, pathology, symptoms and murine model

Answer 11

Accumulation of surfactant in the alveoli

Mechanism:
• Loss of GM-CSF activity
• Reduced macrophage and PMN clearance of surfactant in the alveoli

Pathology:
• Alveolar oedema
• Impaired gas exchange

Symptoms:
• Dyspnoea and cough

GM-CSF -/- mice:
• Exhibit PAP like disease

Observation in PAP individuals:
• Anti-GMCSF autoantibodies
• Can PAP in mice with infusion of these Abs

Question 12

How has PAP been treated in the past?

How could it be treated now?

Answer 12

Past:
• Lung lavage

Novel therapy:
• Administration of recombinant GM-CSF

Question 13

Outline cell therapy for respiratory disease

Answer 13

Mesenchymal stem cells

Action:
• Tissue repair
• Anti-inflammatory effects

Release:
• IL-10
• TGF-β
• IL-6

Question 14

Outline vaccine / adjuvant therapy for respiratory disease

What is the rationale?

Give examples and challenges

Answer 14

Vaccination against viruses that exacerbate COPD and asthma

Vaccines:
• Influenza vaccine
• RSV
• Rhinovirus

NB There are many serotypes for these viruses, so vaccination is challenging

Question 15

Describe cytokine targeting of respiratory disease

Answer 15

e.g. In severe asthma
• Not controlled by LABA/ICS

Lebrikizumab
• anti-IL-13 mAb
• Prevents IL-13 from binding to receptor subunit IL-4Rα

IL-13 role in asthma:
 • IgE class switching
 • Macrophage stimulation
 • Smooth muscle stimulation
 • Differentiation of respiratory epithelium into goblet cells
 • Activation of fibroblasts

Question 16

Describe how Lebrikizumab was trialled

Answer 16

Serum periostin is a marker of IL-13 activity:
• When IL-13 acts on respiratory epithelium, periostin is release and detectable in the serum

Design:
• Individuals with high or low periostin
• Control + Lebrikizumab groups

Primary outcome measure:
• Change in FEV1

Results:
• Asthma control not complete, but probably improved
• Primary outcome was met (there was improvement in FEV1 in treatment group)

Question 17

Describe the IL-13 receptor

Answer 17

Subunits:
• IL-4Rα
• IL-13Rα

Question 18

What is Dupilumab?

Answer 18

Dupilumab: anti-IL4Rα mAb

Question 19

What are the benefits of Dupilumab over Lebrikizumab?

Answer 19

Lebrikizumab prevent IL-13 from binding IL-4Rα subunit of the IL-13R, but also prevented IL-4 binding to IL-4Rα of IL-4R

Question 20

Describe trials of Dupilumab

Answer 20

Design:
• Individuals with asthma
• Two groups: treatment + placebo groups

Primary outcome measure:
• Frequency of exacerbations
Other measures:
• FEV1 increase

Results:
• Increased FEV1 on Dupilumab
• 87% reduction in exacerbations on drug

Question 21

What are the advantages and disadvantages of cytokine targeting therapy over ICS for the treatment of asthma?

Answer 21

Advantages:
• Selective: decreased burden of adverse effects
• Long half life

Disadvantages:
• Expensive production costs
• Parenteral administration
• Many targets are intracellular

Question 22

Describe use of vectors in gene therapy of cystic fibrosis

Answer 22

It has proven very difficult to deliver genes to the respiratory epithelium due to the protective mucus coat

Adenovirus administration was only marginally effective

Pseudo-typed lentiviruses: do not have to infect rapidly turning over cells to incorporate its genome into the host cell, thus the gene of interest can be introduced into cells that aren’t rapidly proliferating