Tetracycline; protein synthesis of bacteria

With MIC90s of 1.0, 0.25, 0.5, 0.25, and 2.0 μg/mL, respectively, omadacycline shows activity against methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), beta-hemolytic streptococci, penicillin-resistant Streptococcus pneumonia (PRSP), and Haemophilus influenzae (H. influenzae)[2]. Through ribosomal protection and active tetracycline efflux, omadacycline effectively combats strains that express resistance to tetracycline and other antibiotics[2].

In a mouse systemic infection model, omadacycline (0.11–18 mg/kg; a single intravenous dose) shows effectiveness against Streptococcus pneumonia, Escherichia coli, and Staphylococcus aureus, with ED50s ranging from 0.30 mg/kg to 3.39 mg/kg[2].

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In vivo efficacy of omadacycline was demonstrated using an intraperitoneal infection model in mice. A single intravenous dose of omadacycline exhibited efficacy against Streptococcus pneumoniae, Escherichia coli, and Staphylococcus aureus, including tet(M) and tet(K) efflux-containing strains and MRSA strains. The 50% effective doses (ED50s) for Streptococcus pneumoniae obtained ranged from 0.45 mg/kg to 3.39 mg/kg, the ED50s for Staphylococcus aureus obtained ranged from 0.30 mg/kg to 1.74 mg/kg, and the ED50 for Escherichia coli was 2.02 mg/kg. These results demonstrate potent in vivo efficacy including activity against strains containing common resistance determinants. Omadacycline demonstrated in vitro activity against a broad range of Gram-positive and select Gram-negative pathogens, including resistance determinant-containing strains, and this activity translated to potent efficacy in vivo[2].

In vitro stability and drug–drug interaction potential of omadacycline[2] The stability of omadacycline (4.8 and 48 μM) was assessed in human microsomes and hepatocytes. After 30 min incubation of omadacycline in human microsomes, >90% of omadacycline was recovered intact. Similarly, after incubation of omadacycline up to 24 h in human hepatocytes, >86% was recovered intact. These results indicate that omadacycline is not metabolized to any significant extent.The potential for drug-drug-interactions with omadacycline was assessed using either pooled human liver microsome preparations, S9, liver cytosol, or recombinant flavin monooxygenases (FMO1, FMO3, FMO5). Induction of CYP450 isozymes was evaluated in primary human hepatocytes incubated with omadacycline 1–100 μM and a substrate probe for 24 and 48 h. Inhibition of CYP450 isozymes was evaluated with pooled human microsomes at omadacycline concentrations of 1–50 μM and isozyme specific substrates at concentrations approximating the Km of each substrate. Isozymes evaluated included CYP 1A1, 1A2, 1B1, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, 2J2, and 3A4/5.Omadacycline did not induce CYP isozymes, and no or minimal (<40% of maximal positive control response) induction of their mRNAs was observed. Omadacycline demonstrated no significant inhibition of CYP isozyme activity. In addition, there was no time-dependent inhibition of omadacycline or its possible metabolites for CYP1A2 2C9, 2D6 or 3A4/5.Bioorg Med Chem.2016 Dec 15;24(24):6409-6419.

The omadacycline MIC90s for MRSA, VRE, and beta-hemolytic streptococci are 1.0 μg/mL, 0.25 μg/mL, and 0.5 μg/mL, respectively, and the omadacycline MIC90s for PRSP and H. influenzae are 0.25 μg/ml and 2.0 μg/mL, respectively. Omadacycline is active against organisms demonstrating the two major mechanisms of resistance, ribosomal protection and active tetracycline efflux. Omadacycline inhibits protein synthesis while having no significant effect on RNA, DNA and peptidoglycan synthesis. Further, omadacycline binds to the tetracycline binding site on the 30S subunit of the bacterial ribosome with enhanced binding similar to tigecycline based on additional molecular interactions.

Mice: Sterile saline is used to dissolve omadacycline. A 3-mL lock-top sterile syringe with a sterile 25-gauge, 5/8-in. needle is used to infect mice. Mice are given an intravenous (i.v.) dose of omadacycline or relevant comparator compounds at a volume of 10 ml/kg at one hour post-infection (p.i.). Each experiment involves testing a minimum of four dose levels on five mice per group. With a few notable exceptions, the usual dose range tested is 0.11 to 18 mg/kg of body weight[1]. Significantly higher or lower doses are needed for comparators to achieve 50% efficacy.

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Systemic i.p. challenge model. Six-week-old, specific-pathogen-free, male CD-1 mice, weighing 18 to 30 g were used for all experiments. At 1 h postinfection (p.i.), mice were dosed intravenously (i.v.) with omadacycline or comparator compounds of interest, dissolved in sterile saline for injection at a volume of 10 ml/kg. All drug doses were formulated fresh immediately prior to administration and adjusted to account for percent activity. A minimum of four dose levels were tested per experiment with 5 mice/group. The typical doses tested ranged from 0.11 to 18 mg/kg of body weight, with exceptions for comparators that required significantly higher or lower doses to achieve 50% efficacy (dose range minimum-maximum, 0.08 to 54 mg/kg). Each study also included an untreated control group. Mice were housed in filter-topped cages in an isolated room and monitored for morbidity at least every 24 h for 7 days. Efficacy was determined by calculating the 50% effective dose (ED50) for all drugs tested. The ED50 is defined as the dose required to achieve 50% survival at 7 days p.i. and was estimated when possible using the formula y = 1/[1 + 10(log(k)-log(x)× 4.2)], where k = 0.5, by nonlinear regression analysis with Prism, version 3.0 software. [2]

The pharmacokinetics of omadacycline are best described by a linear, three-compartment model following a zero-order intravenous infusion or first-order oral administration with transit compartments to account for delayed absorption. Omadacycline has a volume of distribution (Vd) ranging from 190 to 204 L, a terminal elimination half-life (t½) of 13.5-17.1 h, total clearance (CLT) of 8.8-10.6 L/h, and protein binding of 21.3% in healthy subjects. Oral bioavailability of omadacycline is estimated to be 34.5%. A single oral dose of 300 mg (bioequivalent to 100 mg IV) of omadacycline administered to fasted subjects achieved a maximum plasma concentration (Cmax) of 0.5-0.6 mg/L and an area under the plasma concentration-time curve from 0 to infinity (AUC0-∞) of 9.6-11.9 mg h/L. The free plasma area under concentration-time curve divided by the minimum inhibitory concentration (i.e., fAUC24h/MIC), has been established as the pharmacodynamic parameter predictive of omadacycline antibacterial efficacy. Several animal models including neutropenic murine lung infection, thigh infection, and intraperitoneal challenge model have documented the in vivo antibacterial efficacy of omadacycline. A phase II clinical trial on complicated skin and skin structure infection (cSSSI) and three phase III clinical trials on ABSSSI and CABP demonstrated the safety and efficacy of omadacycline. The phase III trials, OASIS-1 (ABSSSI), OASIS-2 (ABSSSI), and OPTIC (CABP), established non-inferiority of omadacycline to linezolid (OASIS-1, OASIS-2) and moxifloxacin (OPTIC), respectively. Omadacycline is currently approved by the FDA for use in treatment of ABSSSI and CABP. Phase II clinical trials involving patients with acute cystitis and acute pyelonephritis are in progress. Mild, transient gastrointestinal events are the predominant adverse effects associated with use of omadacycline. Based on clinical trial data to date, the adverse effect profile of omadacycline is similar to studied comparators, linezolid and moxifloxacin. Unlike tigecycline and eravacycline, omadacycline has an oral formulation that allows for step-down therapy from the intravenous formulation, potentially facilitating earlier hospital discharge, outpatient therapy, and cost savings. Omadacycline has a potential role as part of an antimicrobial stewardship program in the treatment of patients with infections caused by antibiotic-resistant and multidrug-resistant Gram-positive [including methicillin-resistant Staphylococcus aureus (MRSA)] and Gram-negative pathogens. [https://pubmed.ncbi.nlm.nih.gov/31970713/]

Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
No information is available on the use of omadacycline during breastfeeding. It is unknown how much omadacycline is excreted into breastmilk, but the drug is only about 35% absorbed orally under optimal circumstances, and is probably less from milk because of its calcium content. The manufacturer states that breastfeeding is not recommended during treatment and for 4 days after the last dose. If an infant is breastfed, monitor the infant for possible effects on the gastrointestinal flora, such as diarrhea, candidiasis (e.g., thrush, diaper rash) or rarely, blood in the stool indicating possible antibiotic-associated colitis. As a theoretical precaution, avoid prolonged or repeat courses during nursing.
◉ Effects in Breastfed Infants
Relevant published information was not found as of the revision date.
◉ Effects on Lactation and Breastmilk
Relevant published information was not found as of the revision date.

[1]. Pharmaceuticals (Basel). 2019 Apr 21;12(2):63.

[2]. Antimicrob Agents Chemother. 2014;58(2):1127-35.

[3]. Drugs. 2020 Feb;80(3):285-313.

[4]. Drugs. 2018 Dec;78(18):1931-1937.

Omadacycline (Nuzyra®) is a new aminomethylcycline, approved by the U. S. Food and Drug Administration in 2018, as a tetracycline antibacterial. It can be used in community-acquired pneumonia and in acute bacterial skin and skin-structure infections. It was developed and is commercialized by Paratek Pharmaceuticals. It is a semisynthetic compound, derived from minocycline, capable of evading widely distributed efflux and target protection antibacterial resistance mechanisms and has demonstrated activity in a broad spectrum of bacteria.[1]

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Omadacycline is the first intravenous and oral 9-aminomethylcycline in clinical development for use against multiple infectious diseases including acute bacterial skin and skin structure infections (ABSSSI), community-acquired bacterial pneumonia (CABP), and urinary tract infections (UTI). The comparative in vitro activity of omadacycline was determined against a broad panel of Gram-positive clinical isolates, including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), Lancefield groups A and B beta-hemolytic streptococci, penicillin-resistant Streptococcus pneumoniae (PRSP), and Haemophilus influenzae (H. influenzae). The omadacycline MIC90s for MRSA, VRE, and beta-hemolytic streptococci were 1.0 μg/ml, 0.25 μg/ml, and 0.5 μg/ml, respectively, and the omadacycline MIC90s for PRSP and H. influenzae were 0.25 μg/ml and 2.0 μg/ml, respectively. Omadacycline was active against organisms demonstrating the two major mechanisms of resistance, ribosomal protection and active tetracycline efflux. In vivo efficacy of omadacycline was demonstrated using an intraperitoneal infection model in mice. A single intravenous dose of omadacycline exhibited efficacy against Streptococcus pneumoniae, Escherichia coli, and Staphylococcus aureus, including tet(M) and tet(K) efflux-containing strains and MRSA strains. The 50% effective doses (ED50s) for Streptococcus pneumoniae obtained ranged from 0.45 mg/kg to 3.39 mg/kg, the ED50s for Staphylococcus aureus obtained ranged from 0.30 mg/kg to 1.74 mg/kg, and the ED50 for Escherichia coli was 2.02 mg/kg. These results demonstrate potent in vivo efficacy including activity against strains containing common resistance determinants. Omadacycline demonstrated in vitro activity against a broad range of Gram-positive and select Gram-negative pathogens, including resistance determinant-containing strains, and this activity translated to potent efficacy in vivo.[2]

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Omadacycline is a novel aminomethylcycline antibiotic developed as a once-daily, intravenous and oral treatment for acute bacterial skin and skin structure infection (ABSSSI) and community-acquired bacterial pneumonia (CABP). Omadacycline, a derivative of minocycline, has a chemical structure similar to tigecycline with an alkylaminomethyl group replacing the glycylamido group at the C-9 position of the D-ring of the tetracycline core. Similar to other tetracyclines, omadacycline inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit. Omadacycline possesses broad-spectrum antibacterial activity against Gram-positive and Gram-negative aerobic, anaerobic, and atypical bacteria. Omadacycline remains active against bacterial isolates possessing common tetracycline resistance mechanisms such as efflux pumps (e.g., TetK) and ribosomal protection proteins (e.g., TetM) as well as in the presence of resistance mechanisms to other antibiotic classes.[3]

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Paratek Pharmaceuticals are developing omadacycline (NUZYRA™), a first-in-class orally active aminomethylcycline antibacterial, as a treatment for various bacterial infections. The drug, which is available in intravenous and oral formulations, has a broad spectrum of antibacterial activity and was recently approved in the USA as a treatment for the treatment of community acquired bacterial pneumonia (CABP) and acute bacterial skin and skin structure infections (ABSSSI) in adults. This article summarizes the milestones in the development of omadacycline leading to this first global approval for the treatment of CABP and ABSSSI.[4]

C29H41CLN4O7

593.1114

592.266

C, 58.73; H, 6.97; Cl, 5.98; N, 9.45; O, 18.88

1196800-39-1

Omadacycline;389139-89-3;Omadacycline tosylate;1075240-43-5;Omadacycline-d9;2272886-41-4;Omadacycline mesylate;1196800-40-4

54746487

Brown to black solid powder

7

10

7

41

1140

4

CC(C)(C)CNCC1=CC(=C2C[C@H]3C[C@H]4[C@@H](C(=O)C(=C([C@]4(C(=O)C3=C(C2=C1O)O)O)O)C(=O)N)N(C)C)N(C)C.Cl

HXMCZSICOWSBRX-XGLFQKEBSA-N

InChI=1S/C29H40N4O7.ClH/c1-28(2,3)12-31-11-14-10-17(32(4)5)15-8-13-9-16-21(33(6)7)24(36)20(27(30)39)26(38)29(16,40)25(37)18(13)23(35)19(15)22(14)34;/h10,13,16,21,31,34,36-37,40H,8-9,11-12H2,1-7H3,(H2,30,39);1H/t13-,16-,21-,29-;/m0./s1

(4S,4aS,5aR,12aS)-4,7-bis(dimethylamino)-3,10,12,12a-tetrahydroxy-9-((neopentylamino)methyl)-1,11-dioxo-1,4,4a,5,5a,6,11,12a-octahydrotetracene-2-carboxamide hydrochloride

Omadacycline HCl; Omadacycline hydrochloride; PTK 0796; PTK-0796; PTK0796; Amadacyclin; Omadacycline (hydrochloride); (4S,4aS,5aR,12aR)-4,7-bis(dimethylamino)-9-[(2,2-dimethylpropylamino)methyl]-1,10,11,12a-tetrahydroxy-3,12-dioxo-4a,5,5a,6-tetrahydro-4H-tetracene-2-carboxamide;hydrochloride; PTK0796 hydrochloride; CHEMBL3942449; Omadacycline; Nuzyra.

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

H2O : 200 mg/mL (~!337.21 mM)
DMSO : 50 mg/mL (~84.30 mM)

Solubility in Formulation 1: ≥ 2.62 mg/mL (4.42 mM) (saturation unknown) in 5% DMSO + 95% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 2: 50 mg/mL (84.30 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with ultrasonication.

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 (Please use freshly prepared in vivo formulations for optimal results.)