Discontinued Healing & Recovery

Omiganan

also known as: MBI-226, MX-594AN, CLS001, Omiganan pentahydrochloride

An indolicidin-derived cationic antimicrobial peptide (Micrologix / BioWest / Cutanea Life Sciences / Cellect Biotechnology / Maruho) developed across roughly two decades for several dermatologic and catheter-prevention indications. Failed its pivotal Phase 3 for central venous catheter exit-site infection prevention (2002), then pivoted to rosacea where it also failed Phase 3 (2015). Not FDA-approved.

A 12-residue synthetic analog of bovine indolicidin (a tryptophan-rich cathelicidin first isolated from bovine neutrophils). Developed initially by Micrologix Biotech (later BioWest Therapeutics, then Cutanea Life Sciences and subsequently Cellect Biotechnology and Maruho) for topical prevention of exit-site infection and catheter-related bloodstream infection in patients with central venous catheters. The Phase 3 trial for this indication (MX-594AN, n=1859) was reported in 2002 as failing to show statistically significant benefit over standard povidone-iodine. The asset was subsequently repositioned for inflammatory dermatologic conditions — most prominently rosacea, where the Phase 3 "OMNI" trial of a 1% gel (Cutanea Life Sciences, 2015) failed to show superiority over vehicle. Continued exploratory development in atopic dermatitis and vulvar intraepithelial neoplasia has not yielded an approval. Not FDA- or EMA-approved as of early 2026.

Mechanism of action

Cationic amphipathic antimicrobial peptide. The unusually tryptophan-rich sequence (three tryptophans clustered in the central region) supports strong membrane insertion via indole-ring interactions with membrane lipid interfaces. Binds negatively charged bacterial outer membrane and causes rapid membrane permeabilization. Broad-spectrum bactericidal activity against Gram-positive and Gram-negative bacteria and fungi. In rosacea, proposed additional mechanism involves modulation of Demodex folliculorum colonization and of TLR-2/cathelicidin innate-immune signaling in facial skin.

Primary uses

Central venous catheter exit-site infection prevention (Phase 3 failure 2002)
Rosacea (Phase 3 failure 2015)
Atopic dermatitis (exploratory development)
Antimicrobial peptide drug-development case study

Typical dosing

Not established (investigational only) (topical)

Rosacea Phase 3: 1% topical gel applied twice daily. Catheter-site Phase 3: 1% topical gel applied to exit site after catheter placement and at each dressing change. Not an approved product.

Regulatory status

Not FDA-approved. Phase 3 CLIRS trial for central venous catheter exit-site infection prevention failed in 2002 (MBI-226, Micrologix / BioWest Therapeutics). Phase 3 OMNI trial in rosacea failed in 2015 (CLS001, Cutanea Life Sciences). Subsequent exploratory development in atopic dermatitis (Cellect Biotechnology) and vulvar intraepithelial neoplasia (Maruho) has not produced an approval. Development status as of early 2026 is effectively terminated for the major originally-pursued indications; some academic and investigator-initiated studies continue.

References

[pubmed] Fritsche TR, et al. "Antimicrobial activity of omiganan pentahydrochloride against contemporary fungal pathogens responsible for catheter-associated infections." Antimicrob Agents Chemother, 2008;52:1187-1189.
[pubmed] Melo MN, Castanho MARB. "Omiganan interaction with bacterial membranes and cell wall: assessing the importance of lipid A interaction." Biochim Biophys Acta, 2007;1768:1277-1290.
[news-release] Cutanea Life Sciences. "Cutanea Life Sciences Announces Phase 3 OMNI Trial Results of Omiganan 1% Gel in Rosacea." September 2015 (Phase 3 failure).

Related peptides

LL-37

The only human cathelicidin — an antimicrobial peptide with direct activity against bacteria, fungi, viruses, and biofilms, with additional roles in wound healing and immune signaling.

Pexiganan

A Xenopus-magainin-derived antimicrobial peptide (Locilex; Dipexium Pharmaceuticals / later acquired by PLx Pharma) developed for topical treatment of mildly infected diabetic foot ulcers. Twice rejected by the FDA — once in 1999 (Magainin Pharmaceuticals) and again in 2017 (Dipexium) after the OneStep-1 and OneStep-2 Phase 3 trials failed to show superiority over placebo cream. Instructive regulatory case study in antimicrobial peptide drug development.

Disclaimer

This entry is for educational purposes only and does not constitute medical advice. Dosing information reflects published regulatory or research data and is not a recommendation. Many compounds described here are not approved for human use in the United States. Consult a licensed medical professional before considering any peptide therapy.