What is the function of Relizorb (enzyme cartridge)?

What is Relizorb?

Relizorb is an FDA-approved in-line lipase cartridge that connects to enteral feeding tube sets and hydrolyzes fats in enteral nutrition formulas into absorbable fatty acids and monoglycerides for patients with exocrine pancreatic insufficiency (EPI) who cannot take oral pancreatic enzyme replacement therapy (PERT) with their tube feedings. 1

Mechanism of Action

• Relizorb contains immobilized lipase enzymes that break down long-chain triglycerides in enteral formulas as they pass through the cartridge 2
• The device hydrolyzes greater than 90% of fats in most polymeric and semielemental enteral formulas into absorbable fatty acids and monoglycerides 2
• It works continuously during the feeding, eliminating the need to mix oral PERT capsules into enteral formulas (which is not supported by guidelines and carries risks) 2

Clinical Indications

Relizorb is specifically designed for patients receiving enteral nutrition who have EPI and cannot effectively use standard oral PERT products. 1 This includes:

• Patients with cystic fibrosis receiving supplemental enteral tube feedings 3, 4
• Patients with short bowel syndrome dependent on parenteral nutrition 5
• Any patient requiring enteral nutrition support who has pancreatic insufficiency 2

Clinical Evidence for Efficacy

Fat Absorption Improvements

• In patients with cystic fibrosis, Relizorb use resulted in a statistically significant 2.8-fold increase in plasma omega-3 fatty acid concentrations compared to placebo 4
• Red blood cell levels of DHA+EPA significantly improved, along with improved omega-6/omega-3 ratios, demonstrating enhanced long-term fatty acid absorption 3
• The device efficiently addresses the malabsorption of complex long-chain triglycerides that severely pancreatic insufficient patients cannot absorb despite oral PERT 2

Anthropometric Outcomes

• Pediatric patients with cystic fibrosis using Relizorb for 12 months showed significantly higher mean height z-scores at 6 months (adjusted mean difference = 0.2540; P = 0.0153) and 12 months (adjusted mean difference = 0.2684; P = 0.0340) post-initiation 6
• Mean weight z-score improvements approached statistical significance at 12 months when excluding patients with advanced lung disease 6

Safety Profile

• Relizorb use was not associated with any unanticipated adverse events in clinical trials 3
• The device was safe and well tolerated across multiple studies 3, 4
• Patients reported decreased frequency and severity of malabsorption symptoms with cartridge use 4
• Participants noted increased preservation of appetite and breakfast consumption compared to their pre-study regimen 4

Position Among PERT Options

Relizorb is the only FDA-approved PERT formulation specifically indicated for use with enteral nutrition. 1 The 2023 AGA guidelines list it alongside other PERT products (Creon, Zenpep, Pancreaze, Pertzye, Viokace) but specifically designate it as "for enteral feeding formulas" rather than oral administration. 1

Key Clinical Advantages

• Provides continuous enzyme delivery throughout the feeding period, ensuring optimal enzyme-nutrient mixing 2
• Eliminates the impractical requirement of waking patients to administer oral PERT capsules during overnight tube feedings 6
• Avoids the risks associated with crushing PERT capsules or mixing enzymes directly into enteral formulas 2
• Compatible with a wide range of commercially available polymeric and semielemental formulas with varying nutrient content and triglyceride chain lengths 2

Important Caveats

• This is the first prospective study demonstrating that enteral nutrition can improve fatty acid abnormalities in cystic fibrosis when combined with appropriate enzyme therapy 3
• The improvement in omega-3 levels may have important long-term therapeutic benefits for pulmonary and inflammatory status in patients with cystic fibrosis 3
• Patients with cystic fibrosis receiving enteral nutrition for an average of 6.6 years still had omega-3 fatty acid plasma concentrations at only 60% of normal healthy subjects before Relizorb use, highlighting the inadequacy of standard approaches 4