Omiganan

Omiganan (MBI 226) is a 12-amino-acid synthetic cationic antimicrobial peptide (sequence: ILRWPWWPWRRK-NH2, MW ~1779 g/mol) derived from indolicidin, a natural antimicrobial peptide from bovine neutrophils. It has been investigated in Phase III clinical trials for prevention of catheter-related infections and topical treatment of rosacea (as CLS001), but has not received regulatory approval for either indication.

Category: Antimicrobial / Immune. Evidence rating: C (early/mixed human evidence).

Clinical status: Phase III completed for catheter infections (not approved, 2003). Phase III for rosacea (CLS001 by Cutanea Life Sciences, results ~2018). No regulatory approval.

Omiganan is a tryptophan- and arginine-rich cationic peptide that disrupts microbial cell membranes through electrostatic and hydrophobic interactions. Unlike purely alpha-helical antimicrobial peptides, omiganan adopts an extended polyproline-type structure enriched in tryptophan residues that…

Safety considerations: Topical formulation generally well-tolerated in clinical trials; Application site reactions (burning, erythema) reported as most common adverse events; Systemic absorption from topical application is minimal.

Reviewed by the PeptideAtlas Editorial Team.

Omiganan — measured properties

Amino-acid sequenceILRWPWWPWRRK-NH2
Molecular weight~1779 g/mol
CAS number232941-39-0
Production methodsynthetic
Anti-doping statusnot-listed
US regulatory statusNot FDA-approved. Phase III catheter infection trial did not meet primary endpoint. Rosacea trials completed but NDA not filed.

Related peptides: LL-37, Beta-Defensins, Alpha-Defensins.

Frequently asked questions

Why was omiganan not approved for catheter infections?

The Phase III trial showed omiganan reduced catheter colonization compared to povidone-iodine but did not meet the primary endpoint of reducing catheter-related bloodstream infections, which is the clinically meaningful outcome.

Is omiganan available for rosacea?

No. Although Phase III trials showed efficacy for papulopustular rosacea, the developer (Cutanea Life Sciences) did not pursue regulatory approval, and omiganan is not commercially available for any indication.

What is indolicidin?

Indolicidin is a 13-amino-acid tryptophan-rich antimicrobial peptide isolated from bovine neutrophil cytoplasmic granules. Omiganan is a synthetic derivative of indolicidin with modified sequence for improved antimicrobial activity and reduced toxicity.