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FDA Approved Immune & Anti-Inflammatory

Daptomycin

also known as: Cubicin, LY146032

A last-resort lipopeptide antibiotic — the first-in-class cyclic peptide that kills MRSA and VRE by depolarizing bacterial membranes, without resistance through traditional mechanisms.

A 13-amino-acid cyclic lipopeptide antibiotic with a decanoyl fatty acid tail, FDA-approved for complicated skin infections and S. aureus bacteremia, acting by calcium-dependent insertion into bacterial cell membranes causing rapid depolarization.

Mechanism of action

In the presence of calcium ions, daptomycin oligomerizes and inserts into the gram-positive bacterial cell membrane, forming ion-conducting channels that cause rapid depolarization. Loss of membrane potential halts DNA, RNA, and protein synthesis simultaneously, producing rapid bactericidal activity. The mechanism is distinct from all other antibiotic classes.

Primary uses

  • MRSA skin and soft tissue infections
  • S. aureus bacteremia
  • Right-sided endocarditis
  • Vancomycin-resistant Enterococcus (VRE) infections (off-label)

Typical dosing

4–10 mg/kg once daily (intravenous)

4 mg/kg for skin infections; 6 mg/kg for bacteremia. Higher doses (8–10 mg/kg) used off-label for VRE and deep-seated infections.

Regulatory status

FDA-approved in 2003 (Cubicin, Cubist/Merck) for complicated skin and skin-structure infections and S. aureus bacteremia including right-sided endocarditis. Generics available.

References

  1. [fda-pi] Cubicin (daptomycin) Prescribing Information. Merck.
  2. [clinical-trial] Fowler VG, et al. "Daptomycin versus standard therapy for bacteremia and endocarditis caused by Staphylococcus aureus." N Engl J Med, 2006;355:653-665.

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.

Omiganan

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.
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.