Bestatin (Ubenimex) vs LL-37
Natural dipeptide analogue aminopeptidase inhibitor with dual immunostimulatory and antitumor activity, approved in Japan as adjuvant cancer therapy
Human cathelicidin-derived antimicrobial peptide (37 amino acids) that disrupts bacterial membranes at MIC 0.62 μM against S. aureus, neutralizes endotoxin (LPS) to prevent septic shock, and has reached Phase II clinical trials as Ropocamptide for wound healing — achieving 6-fold accelerated healing at 0.5 mg/mL in venous leg ulcers
Written by Michael Carroll — Owner, Director of Research · Reviewed by the Peptide Initiative Research Team · Editorial standards
Quick comparison
Dose range
Bestatin (Ubenimex)
30–30 mg
LL-37
1.6–1.6 mg/mL
Frequency
Bestatin (Ubenimex)
Once daily
LL-37
Once daily
Administration
Bestatin (Ubenimex)
Oral (capsule)
LL-37
Topical application (wound healing)
Cycle length
Bestatin (Ubenimex)
12+ weeks
LL-37
12+ weeks
Onset speed
Bestatin (Ubenimex)
Moderate (1-2 weeks)
LL-37
Moderate (1-2 weeks)
Evidence level
Bestatin (Ubenimex)
Moderate human trials (Phase 1-2)
LL-37
Moderate human trials (Phase 1-2)
Benefit ratings
Immune
Healing & Recovery
Anti-Aging
Wound Healing
Fighting Infections
Immune Boost
Compound specifications
Bestatin (Ubenimex)
Molecular formula
C16H24N2O4
Molecular weight
308.37 g/mol
Half-life
Approximately 2-3 hours (oral administration)
Bioavailability
Well absorbed orally; peak plasma concentration reached within 1-2 hours
CAS number
58970-76-6
LL-37
Molecular formula
C205H340N60O53
Molecular weight
4,493.26 Da
Half-life
Short systemic half-life (minutes) due to protease susceptibility; local tissue persistence at wound sites is longer due to binding to extracellular matrix components and lipid membranes
Bioavailability
Topical application achieves high local wound-bed concentrations; systemic bioavailability limited by rapid proteolytic degradation and serum protein binding; not intended for oral delivery
CAS number
154947-66-7
Dosing compared
Bestatin (Ubenimex)
Oral
30 mg
Once daily · Long-term, alongside maintenance chemotherapy
30 mg by mouth once daily is the approved Japanese dose used as add-on therapy after leukemia remission. It helped patients, especially older adults, stay in remission longer [4][1].
LL-37
Topical
0.5 mg/mL gel
Twice weekly · 4 weeks
Lowest dose in the LL-37 (ropocamptide) Phase I/IIa venous leg-ulcer trial and the most effective: ~6-fold faster healing and ~68% ulcer-area reduction vs placebo, applied to the wound twice weekly [4].
1.6 mg/mL gel
Twice weekly · 4 weeks
Mid dose in the same trial; ~3-fold improvement and ~50% area reduction vs placebo. The highest tested concentration (3.2 mg/mL) showed no benefit over placebo, so dose escalation above this is not supported [4].
Best suited for
Bestatin (Ubenimex)
Adjunctive AML Immunotherapy
Bestatin is specifically approved in Japan for patients with acute non-lymphocytic leukemia who have achieved complete remission after induction chemotherapy. [10] Clinical trials demonstrated significant prolongation of disease-free survival when bestatin was added to standard maintenance therapy [3][4].
Post-Chemotherapy Immune Recovery
By stimulating bone marrow stem cell proliferation and enhancing T-lymphocyte and macrophage function, bestatin supports immune system recovery in patients whose immune function has been suppressed by cytotoxic chemotherapy [1][3].
Pulmonary Arterial Hypertension (Investigational)
Through inhibition of LTA4 hydrolase and reduction of pro-inflammatory leukotriene B4, [5] bestatin is being investigated as a novel approach to PAH. Eiger BioPharmaceuticals conducted Phase 2 trials (NCT02664558) [7] and received FDA orphan drug designation for this indication [9].
Lymphedema Management (Investigational)
The anti-inflammatory properties of bestatin via LTB4 pathway inhibition have led to Phase 2 investigation (NCT02700529) [8] for lymphedema, a condition with limited treatment options where inflammation plays a key role in disease progression.
LL-37
Treatment of chronic non-healing wounds including venous leg ulcers and diabetic ulcers
LL-37 is particularly well-suited for individuals focused on treatment of chronic non-healing wounds including venous leg ulcers and diabetic ulcers. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Immune defense against antibiotic-resistant bacterial infections (MRSA, Pseudomonas)
LL-37 is particularly well-suited for individuals focused on immune defense against antibiotic-resistant bacterial infections (mrsa, pseudomonas). Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Anti-biofilm strategies for chronic wound infections and medical device-associated infections
LL-37 is particularly well-suited for individuals focused on anti-biofilm strategies for chronic wound infections and medical device-associated infections. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Boosting innate immune defense in immunocompromised or aging individuals
LL-37 is particularly well-suited for individuals focused on boosting innate immune defense in immunocompromised or aging individuals. Research and clinical experience suggest meaningful benefits in this area when used as part of a comprehensive treatment approach.
Side effects
Bestatin (Ubenimex)
Common
- Gastrointestinal discomfort
- Skin rash or pruritus
- Facial flushing
- Fatigue
Uncommon
- Elevated liver enzymes
- Mild leukopenia
Serious
- Severe allergic reaction
LL-37
Common
- Local site irritation
- Transient stinging or burning
- Mild perilesional erythema
- Increased wound exudate
Uncommon
- Allergic contact reaction
Serious
- Hemolytic activity at systemic concentrations
Safety & evidence
Bestatin (Ubenimex)
Evidence level
Moderate human trials (Phase 1-2)
FDA status
Research compound
Safety overview
Bestatin (ubenimex) has an established safety profile based on decades of clinical use in Japan for AML maintenance therapy at 30 mg daily. [3][10] The compound is generally well-tolerated, with the most common side effects being mild gastrointestinal symptoms and skin reactions. [10] Japanese post-marketing surveillance and long-term clinical studies have not identified major safety concerns at standard doses. Phase 2 trials in the US for PAH and lymphedema [7][8] also demonstrated acceptable safety profiles at higher doses.
Contraindications
- Known hypersensitivity to bestatin or any component of the formulation
- Pregnancy and breastfeeding (insufficient safety data)
- Severe hepatic impairment
- Active autoimmune diseases in flare
LL-37
Evidence level
Moderate human trials (Phase 1-2)
FDA status
Research compound
Safety overview
LL-37 is an endogenous cathelicidin antimicrobial peptide naturally produced by immune cells and epithelial tissues, conferring inherent biocompatibility and low toxicity at physiological concentrations. Synthetic LL-37 shows excellent safety in in vitro immune assays and animal models with no hepatotoxicity, nephrotoxicity, or genotoxicity at relevant doses. At elevated concentrations, the cationic amphipathic structure can cause hemolysis and cell membrane damage, but therapeutic doses are far below these thresholds. Injection site reactions are minimal in research applications.
Contraindications
- Known hypersensitivity to cathelicidin peptides or formulation components
- Active hemolytic conditions — LL-37 demonstrates concentration-dependent hemolytic activity
- Pregnancy and breastfeeding — insufficient reproductive safety data from clinical trials
- Severe renal impairment — peptide clearance may be altered
Which is right for you?
Choose Bestatin (Ubenimex) if...
- Adjunctive immunotherapy following chemotherapy for acute leukemia
- Restoring immune function during and after cancer treatment
- Supporting bone marrow recovery post-chemotherapy
- Emerging treatment for pulmonary arterial hypertension (PAH)
Choose LL-37 if...
- Treatment of chronic non-healing wounds including venous leg ulcers and diabetic ulcers
- Immune defense against antibiotic-resistant bacterial infections (MRSA, Pseudomonas)
- Anti-biofilm strategies for chronic wound infections and medical device-associated infections
- Boosting innate immune defense in immunocompromised or aging individuals