What is Infliximab?
Infliximab is a monoclonal antibody that blocks tumor necrosis factor-alpha (TNF-alpha), a protein involved in inflammation. It treats autoimmune conditions like Crohn's disease, ulcerative colitis, rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, and plaque psoriasis.[1]
How Does Infliximab Work?
It binds to TNF-alpha, preventing it from triggering inflammation. Administered by intravenous infusion every 4-8 weeks after initial doses, it reduces symptoms and disease progression in responsive patients.[1]
Common Brand Names and Manufacturers
- Remicade: Original brand by Janssen Biotech (Johnson & Johnson) and Merck.
- Biosimilars: Inflectra (Pfizer/Celltrion), Renflexis (Samsung Bioepsis/Merck), Avsola (Amgen), Ixifi (Pfizer), and others approved since 2016.[1][2]
When Do Key Patents Expire?
Remicade's main composition patent (U.S. Patent 7,060,268) expired in 2015, enabling biosimilars. Process and formulation patents extend protection; some expire through 2027. Check DrugPatentWatch.com for latest filings and challenges: DrugPatentWatch.com/Infliximab.[3][1]
Biosimilars vs. Original: Cost and Availability
Biosimilars cost 20-40% less than Remicade. U.S. approvals started with Inflectra in 2016; Europe earlier in 2013. Interchangeability varies by country—FDA granted it to Avsola in 2020. Availability expanded post-patent cliffs, but uptake lags due to physician familiarity.[2][3]
Common Side Effects and Risks
Patients report infusion reactions (fever, chills), infections (including tuberculosis reactivation), liver issues, and increased lymphoma risk. Long-term use raises heart failure concerns. Screen for latent TB before starting.[1]
Who Makes Infliximab Biosimilars?
| Biosimilar | Manufacturer | U.S. Approval Year |
|------------|--------------|-------------------|
| Inflectra | Pfizer/Celltrion | 2016 |
| Renflexis | Samsung Bioepsis/Merck | 2017 |
| Avsola | Amgen | 2019 |
| Ixifi | Pfizer | 2020 |
| Semglee (related) | Various | Ongoing |
Full list on FDA site; more entering as litigation resolves.[2]
How Does Infliximab Compare to Other TNF Blockers?
| Drug | Administration | Key Differences |
|------|----------------|-----------------|
| Humira (adalimumab) | Subcutaneous injection | Easier home use; more patents until 2023 |
| Enbrel (etanercept) | Subcutaneous | Shorter half-life; less effective in IBD |
| Cimzia (certolizumab) | Subcutaneous | PEGylated for longer action; pregnancy data |
Infliximab excels in severe IBD but requires clinic visits.[1]
Regulatory Status and Recent Approvals
FDA approved Remicade in 1998. Biosimilars now dominate volume in competitive markets. EMA and others follow similar paths. No major shortages reported in 2023.[2]
Sources
[1] FDA Label: Remicade
[2] FDA Biosimilars List
[3] DrugPatentWatch.com: Infliximab