Sample Answer
Monoclonal Antibodies: Inflectra (Infliximab / Remicade Biosimilar)
Introduction
Infliximab is a monoclonal antibody (mAb) used widely in the treatment of autoimmune and inflammatory diseases. The original reference product, Remicade, was developed by Janssen Biotech, while Inflectra is a biosimilar version developed by Celltrion and commercialised globally through partnerships such as Pfizer and Hospira. These biologics target tumour necrosis factor alpha (TNF-α), a key inflammatory cytokine involved in chronic immune-mediated diseases.
Monoclonal antibodies like infliximab represent a major advancement in biotechnology due to their ability to selectively target disease mechanisms at the molecular level.
Mechanism of Action
Infliximab is a chimeric IgG1 monoclonal antibody that binds with high affinity to tumour necrosis factor alpha (TNF-α). TNF-α is a cytokine involved in systemic inflammation and is overproduced in autoimmune diseases.
The mechanism of action includes:
- Binding to both soluble and transmembrane TNF-α
- Preventing TNF-α from interacting with TNF receptors
- Reducing inflammatory signalling cascades
- Suppressing immune-mediated tissue damage
This leads to reduced inflammation in conditions such as:
- Rheumatoid arthritis
- Crohn’s disease
- Ulcerative colitis
- Psoriasis
- Ankylosing spondylitis
Infliximab does not cure these diseases but helps control symptoms and slow disease progression.
Commercialisation
The original antibody, Remicade, is marketed by Janssen Biotech (Johnson & Johnson group). Inflectra (infliximab-dyyb) is a biosimilar version developed by Celltrion (South Korea) and commercialised in different regions through partnerships.
In the United States, Pfizer holds exclusive commercialisation rights for Inflectra following agreements with Celltrion and Hospira.
Key development status:
- Remicade: fully approved biologic (originator product)
- Inflectra: FDA-approved biosimilar (2016)
- Development stage: commercial stage product (post-market biosimilar)
Other biosimilars competing in the same market include:
- Renflexis (Samsung Bioepis)
- Avsola (Amgen)
Intellectual Property (IP)
Remicade was protected by extensive patents covering:
- Antibody structure and production process
- Manufacturing methods
- Therapeutic use indications
These patents delayed biosimilar entry for years. After expiry, biosimilars like Inflectra entered the market under regulatory biosimilar pathways rather than full clinical development programmes.
