Renflexis - Drug Monograph

Introduction

Renflexis (infliximab-abda) is a biosimilar to Remicade (infliximab), a chimeric monoclonal antibody that binds to tumor necrosis factor-alpha (TNF-α). It is a TNF-blocking agent indicated for the treatment of various autoimmune and inflammatory conditions. As a biosimilar, Renflexis has demonstrated no clinically meaningful differences from the reference product in terms of safety, purity, and potency.

Mechanism of Action

Renflexis binds with high affinity to both soluble and transmembrane forms of TNF-α, a proinflammatory cytokine that plays a central role in inflammatory pathways. By neutralizing TNF-α, Renflexis inhibits its binding with TNF receptors, thereby preventing TNF-mediated cellular responses including:

• Inhibition of cytokine production (IL-1, IL-6)
• Reduction of neutrophil and endothelial cell activation
• Decreased adhesion molecule expression
• Attenuation of acute phase reactants and tissue-degrading enzymes

This mechanism results in reduced inflammation and tissue damage in affected organs.

Indications

Renflexis is FDA-approved for the following indications:

• Rheumatoid arthritis (in combination with methotrexate)
• Crohn's disease in adults and pediatric patients (≥6 years)
• Fistulizing Crohn's disease
• Ulcerative colitis in adults and pediatric patients (≥6 years)
• Ankylosing spondylitis
• Psoriatic arthritis
• Plaque psoriasis

Dosage and Administration

• Rheumatoid arthritis: 3 mg/kg IV at 0, 2, and 6 weeks, then every 8 weeks
• Crohn's disease: 5 mg/kg IV at 0, 2, and 6 weeks, then every 8 weeks
• Ulcerative colitis: 5 mg/kg IV at 0, 2, and 6 weeks, then every 8 weeks
• Ankylosing spondylitis: 5 mg/kg IV at 0, 2, and 6 weeks, then every 6-8 weeks
• Psoriatic arthritis/plaque psoriasis: 5 mg/kg IV at 0, 2, and 6 weeks, then every 8 weeks

• Administer as IV infusion over at least 2 hours
• Premedicate with antihistamines, acetaminophen, and/or corticosteroids to prevent infusion reactions
• Do not administer as IV push or bolus

• Hepatic impairment: No dosage adjustment recommended
• Renal impairment: No dosage adjustment recommended
• Elderly: Use with caution due to increased infection risk
• Pediatrics: Dosing based on weight (≥6 years old)

Pharmacokinetics

Contraindications

• Hypersensitivity to infliximab products or any excipients
• Patients with moderate to severe heart failure (NYHA Class III/IV)
• Active tuberculosis or other serious infections
• Known malignancy

Warnings and Precautions

Drug Interactions

Adverse Effects

Monitoring Parameters

• Tuberculosis screening (PPD/IGRA and chest X-ray)
• Hepatitis B and C serology
• Complete blood count
• Liver function tests
• Renal function
• Heart failure assessment

• Signs and symptoms of infection
• Infusion reactions during and after administration
• CBC and LFTs periodically
• Lipid panel (may improve with therapy)
• Disease-specific activity markers (CRP, ESR)
• Clinical response assessment
• Malignancy screening per guidelines

• Annual tuberculosis screening in endemic areas
• Regular skin examinations for melanoma
• Cardiovascular assessment

Patient Education

• Report any signs of infection (fever, cough, fatigue) immediately
• Inform all healthcare providers about Renflexis therapy
• Avoid live vaccines during treatment
• Seek immediate medical attention for signs of allergic reaction
• Understand the increased malignancy risk and report unusual symptoms
• Do not stop concomitant medications unless directed by physician
• Report new or worsening neurological symptoms
• Inform physician if pregnant, planning pregnancy, or breastfeeding
• Keep all scheduled appointments for infusions and monitoring

References

1. FDA Prescribing Information: Renflexis (infliximab-abda) 2. Sands BE, Anderson FH, Bernstein CN, et al. Infliximab maintenance therapy for fistulizing Crohn's disease. N Engl J Med. 2004;350(9):876-885. 3. Hanauer SB, Feagan BG, Lichtenstein GR, et al. Maintenance infliximab for Crohn's disease: the ACCENT I randomised trial. Lancet. 2002;359(9317):1541-1549. 4. Rutgeerts P, Sandborn WJ, Feagan BG, et al. Infliximab for induction and maintenance therapy for ulcerative colitis. N Engl J Med. 2005;353(23):2462-2476. 5. Maini R, St Clair EW, Breedveld F, et al. Infliximab (chimeric anti-tumour necrosis factor alpha monoclonal antibody) versus placebo in rheumatoid arthritis patients receiving concomitant methotrexate: a randomised phase III trial. Lancet. 1999;354(9194):1932-1939. 6. Reich K, Nestle FO, Papp K, et al. Infliximab induction and maintenance therapy for moderate-to-severe psoriasis: a phase III, multicentre, double-blind trial. Lancet. 2005;366(9494):1367-1374. 7. Keystone EC, Kavanaugh AF, Sharp JT, et al. Radiographic, clinical, and functional outcomes of treatment with adalimumab (a human anti-tumor necrosis factor monoclonal antibody) in patients with active rheumatoid arthritis receiving concomitant methotrexate therapy: a randomized, placebo-controlled, 52-week trial. Arthritis Rheum. 2004;50(5):1400-1411.