CB-06-01 is our topical antibiotic under development for the treatment of moderate to severe acne. According to in vitro MIC (Minimum Inhibitory Concentration) tests, it is highly effective on bacterial strains of P. acnes, the most important microbe implicated in acne, including strains resistant to some other antibiotics. Up to 70% of P. acnes strains are resistant against erythromycin, a commonly-prescribed antibiotic. Most erythromycin-resistant bacteria are cross-resistant against clindamycin, another antibiotic that is commonly used against acne.
Because it is not active against non-disease-specific bacterial strains, CB-06-01 probability to contribute to the development of general microbial resistance is very low.
CB-06-01 can be complementary to Winlevi™ in a multiprescription typical of dermatologists. Currently, CB-06-01 is in Phase II trials.
The API of CB-06-01 (previous codes: NAI-003, BIK-0376, NAI-Acne) is an amide derivative of GE2270, a natural antibiotic belonging to the polyenic cyclic thiazolyl-petides class. GE2270 is a novel antibiotic obtained from fermentation of a Planobispora rosea strain. It is active against Gram-positive bacteria and anaerobes. Its chemical formula is C60H60N14O8S6 and its molecular weight is 1297.63.
Figure 11: Chemical Structure of the API of CB-06-01
CB-06-01 is a PEG400-based gel formulation at 3%.
Mechanism of Action
The API of CB-06-01 is a novel antibiotic. We believe that its profile makes it a potential breakthrough for the topical treatment of acne infections. CB-06-01 demonstrated high selectivity and potent activity in vitro against P. acnes, including strains resistant to erythromycin and clindamycin, two commonly-used used antibiotics. CB-06-01 acts against susceptible bacteria by a novel mechanism of action. It inhibits the protein synthesis elongation factor Tu (Ef-Tu) at a site different from that of other protein synthesis inhibitors. This explains the lack of cross-resistance with some other known antibiotics and its activity against strains of P. acnes that are poorly susceptible or resistant to erythromycin and clindamycin.
Figure 12: MIC activity against bacterial strains
Notes: data from Naicons pre-clinical study; based on tests so far.
The low frequency of naturally occurring resistant mutants further supports the potential of CB-06-01 for the topical treatment of antibiotic resistant acne.
To date, no systemic side effects have been discovered. A Phase I clinical POC study has shown that CB-06-01 did not cause LSR and is well tolerated. The cutaneous penetration has been minimal.
CB-06-01 is currently undergoing Phase II POC clinical trials with expected completion in first half of 2016.