Nemonoxacin, a novel nonfluorinated quinolone, exhibits potent in vitro and in vivo activities against community-acquired pneumonia (CAP) pathogens, including multidrug-resistant Streptococcus pneumoniae. Patients with mild to moderate CAP (n ‫؍‬ 265) were randomized to receive oral nemonoxacin (750 mg or 500 mg) or levofloxacin (500 mg) once daily for 7 days. Clinical responses were determined at the test-of-cure visit in intent-to-treat (ITT), clinical per protocol (PPc), evaluable-ITT, and evaluable-PPc populations. The clinical cure rates for 750 mg nemonoxacin, 500 mg nemonoxacin, and levofloxacin were 89.9%, 87.0%, and 91.1%, respectively, in the evaluable-ITT population; 91.7%, 87.7%, and 90.3%, respectively, in the evaluable-PPc population; 82.6%, 75.3%, and 80.0%, respectively, in the ITT population; and 83.5%, 78.0%, and 82.3%, respectively, in the PPc population. Noninferiority to levofloxacin was demonstrated in both the 750-mg and 500-mg nemonoxacin groups for the evaluable-ITT and evaluable-PPc populations, and also in the 750 mg nemonoxacin group for the ITT and PPc populations. Overall bacteriological success rates were high for all treatment groups in the evaluable-bacteriological ITT population (90.2% in the 750 mg nemonoxacin group, 84.8% in the 500 mg nemonoxacin group, and 92.0% in the levofloxacin group). All three treatments were well tolerated, and no drug-related serious adverse events were observed. Overall, oral nemonoxacin (both 750 mg and 500 mg) administered for 7 days resulted in high clinical and bacteriological success rates in CAP patients. Further, good tolerability and excellent activity against common causative pathogens were demonstrated. Nemonoxacin (750 mg and 500 mg) once daily is as effective and safe as levofloxacin (500 mg) once daily for the treatment of CAP.

Nemonoxacin (TG-873870) is a novel nonfluorinated quinolone with potent broad-spectrum activity against Gram-positive and Gram-negative pathogens, including methicillin-resistant Staphylococcus aureus, penicillinand quinolone-resistant Streptococcus pneumoniae, and vancomycin-intermediate and vancomycin-resistant Staphylococcus aureus. The safety, tolerability, and pharmacokinetics of nemonoxacin were investigated in a double-blind, ascending-single-dose study involving 56 healthy subjects (48 males and 8 females) who were randomly assigned to 1 of 7 dose cohorts. In each successive cohort, two subjects received a placebo and six received single oral doses of 25, 50, 125, 250, 500, 1,000, or 1,500 mg nemonoxacin. Nemonoxacin was well tolerated up to the maximum dose of 1,500 mg. No severe or serious adverse events were observed. The most frequent adverse events were contact dermatitis, pruritus, and erythema. No clinically significant abnormalities were noted in the electrocardiograms, vital signs, or laboratory tests. The plasma concentrations increased over the dose range, and at 500 mg, the free area under the plasma concentration-time curve/MIC 90 ratios and free maximum nemonoxacin concentration/MIC 90 ratios against drug-sensitive/drug-resistant S. pneumoniae and S. aureus were greater than 227 and 24, respectively. The peak time and elimination half-life of nemonoxacin were 1 to 2 h and 9 to 16 h, respectively. The oral clearance was approximately 0.22 liter/h/kg. The plasma protein binding was approximately 16%. The results of this study support further evaluation of the multiple-dose safety, tolerability, and pharmacokinetics of nemonoxacin.Newer-generation quinolones are largely fluoroquinolones (FQs); they are characterized by the presence of a fluorine at the R6 position of the quinolone nucleus (2, 9, 19). Owing to their improved activity against Gram-positive and atypical pathogens, they have been widely used for the treatment and prophylaxis of bacterial infections. However, the use of FQs has been compromised by the emergence of bacterial resistance (3,8,14,18,22,30) and the potential for adverse side effects (15, 21), including ECG QTc interval prolongation, hepatotoxicity, and phototoxicity. Thus, there is an unmet need for newer compounds that are broad-spectrum agents effective against existing bacterial resistance and that have the potential to minimize the risk of use-limiting adverse effects.Nemonoxacin (TG-873870) (36), a novel nonfluorinated quinolone, has recently been developed from a series of 8-methoxy nonfluorinated quinolones (29) as a malate salt. It differs from FQs in that it lacks the fluorine at the R6 position (Fig. 1); this was formerly believed to be important for the antibacterial potency of FQs. Nemonoxacin has demonstrated broadspectrum activity (4, 20, 28) against Gram-positive, Gramnegative, and atypical pathogens. Furthermore, nemonoxacin appears to be more potent than several FQs, including ciprofloxacin, levofloxacin, and moxifloxacin (20). In preclinical studies, ...

Nemonoxacin (TG-873870) is a novel nonfluorinated quinolone with broad-spectrum activities againstGram-positive and Gram-negative aerobic, anaerobic, and atypical pathogens, as well as against methicillinresistant Staphylococcus aureus, vancomycin-resistant S. aureus, and multiple-resistant bacterial pathogens. We conducted a randomized, double-blind, placebo-controlled, dose-escalating study to ascertain the safety, tolerability, and pharmacokinetics of nemonoxacin. We enrolled 46 healthy volunteers and used a once-daily oral-dosing range of 75 to 1,000 mg for 10 days. Additionally, the food effect was evaluated in subjects in the 500-mg cohort. Nemonoxacin was generally safe and well tolerated, with no significant changes in the clinical laboratory tests or electrocardiograms. Adverse effects, including headache, contact dermatitis, and rash, were mild and resolved spontaneously. Nemonoxacin was rapidly absorbed within 2 h postdosing, and generally, a steady state was reached after 3 days. The maximum plasma concentration and the area under the plasma concentration-time curve were dose proportional over the dosing range. The elimination half-life was approximately 7.5 h and 19.7 h on days 1 and 10, respectively. Approximately 37 to 58% of the drug was excreted in the urine. Food affected the pharmacokinetics, with decreases in the maximum plasma concentration and area under the plasma concentration-time curve of 46% and 27%, respectively. However, the free AUC/MIC 90 of nemonoxacin was more than 100 under both the fasting and fed conditions, predicting the efficacy of nemonoxacin against most of the tested pathogens. In conclusion, the results support further clinical investigation of once-daily nemonoxacin administration for antibiotic-sensitive and antibiotic-resistant bacterial infections.Nemonoxacin (TG-873870) (31) is a novel nonfluorinated quinolone developed from a series of 8-methoxy nonfluorinated quinolones (25). It lacks the characteristic fluorine at the sixth position in fluoroquinolones (FQs) (Fig. 1). Nemonoxacin is a potent antibacterial agent with broad-spectrum activity against clinical isolates and reference strains in both in vitro studies and experimental infections in animals. It is active against Gram-positive, Gram-negative, and atypical pathogens, including penicillin-and quinolone-resistant Streptococcus pneumoniae (PRSP and QRSP), methicillin-resistant Staphylococcus aureus (MRSA), quinolone-resistant MRSA (QR-MRSA), and vancomycin-resistant enterococci (4, 17). The nemonoxacin MIC 90 range is 0.06 to 1 g/ml for MRSA clinical isolates and 0.03 to 1 g/ml for PRSP clinical isolates from North America and Taiwan (17, 24, 33). For QR-MRSA clinical isolates, the MIC 90 range is 1 to 2 g/ml; this is 4-to 64-fold lower than the MIC 90 s of FQs in parallel testing, including ciprofloxacin, levofloxacin, and moxifloxacin (17, 24). There is increasing concern about vancomycin-intermediate S. aureus (VISA) among clinical isolates. Nemonoxacin showed an MIC 90 of 2 g/ml against heterogeneous VIS...

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866 Background: Stem cells are retained in the bone marrow via the trophic effects of the binding of chemokine stromal cell-derived factor-1α (SDF-1α) to its receptor, CXC chemokine receptor 4 (CXCR4). TG-0054 inhibits SDF-1α/CXCR4 binding and therefore mobilizes stem cells into peripheral blood. Animal studies in mice showed rapid and effective mobilization of CD34+ hematopoietic stem cells (HSCs) and CD133+ endothelial progenitor cells (EPCs) into peripheral blood after TG-0054 administration. A Phase I study was conducted in healthy volunteers to assess safety, tolerability, pharmacokinetics (PK) and stem cell mobilization of TG-0054. Materials and Methods: This is a phase I, randomized, double-blind, placebo-controlled, single ascending dose study. In each cohort, 2 volunteers received placebo and 6 received 0.10, 0.14, 0.28, 0.56, 1.12, 2.24, 3.14, or 4.40 mg/kg of TG-0054 (dose was calculated based on TG-0054 free base) via 15 minutes single IV infusion. All subjects underwent PK sampling at pre-dose, 5 and 15 minutes during infusion, and at 1, 2.5, 5, 10, 30 minutes and 1, 2, 4, 6, 9, 12, 24, 36 hours after infusion. The pharmacodynamics (PD) sampling time points were at pre-dose, 1, 2, 4, 6, 9, 24, and 36 hours after infusion. General tolerability, adverse events (AEs), electrocardiogram (ECG), vital signs and laboratory tests were recorded. Results: In this study, the maximum tolerated dose (MTD) was not reached in TG-0054 doses up to 4.40 mg/kg in healthy volunteers. Dose escalation was stopped due to plateau of mobilized CD34+ and CD133+ cell numbers. TG-0054 was well tolerated up to 4.40 mg/kg. The majority of AEs were mild in severity (53 out of 55 events), and all AEs resolved by the end of the study without medical treatment. The number of subjects reporting the most common AEs included: abdominal pain (7/64, 11%), diarrhea/loose stools (5/64, 8%), dizziness (3/64, 5%), nausea (3/64, 5%), and diaphoresis (3/64, 5%). No significant abnormalities were noted in vital signs, ECG, holter monitoring, telemetry, pulse oximetry, physical examination, or laboratory tests. The area under the plasma concentration vs. time curve (AUC0-t) and maximum plasma concentration (Cmax) showed dose proportionality over the dose range studied. The mean of terminal elimination half-life (t1/2) was approximately 2.5 to 5 hrs. Single-dose administration of 1.12 - 4.40 mg/kg of TG-0054 significantly increased CD34+ cell counts in peripheral blood. At peak time, TG-0054 caused a 3 - 14 fold increase in circulating CD34+ cells from baseline. The mean CD34+ cell counts at peak time were 27.1 ± 9.3 cells/μL (1.12 mg/kg TG-0054), 35.9 ± 27.3 cells/μL (2.24 mg/kg), 32.5 ± 27.7 cells/μL (3.14 mg/kg), and 29.2 ± 12.9 cells/μL (4.40 mg/kg). The increase in circulating CD34+ cell counts was evident within 2 hours of TG-0054 administration, peaked at 4 - 6 hours after TG-0054 administration, followed by a gradual decline to baseline at 24 hours post-dosing. Similarly, increases in WBC and CD133+ cell counts were observed in all subjects. No AEs were deemed to be associated with WBC increases. Conclusion: TG-0054 exhibited a favorable safety and PK profile in healthy subjects in this Phase I study. PD analysis also displayed potent mobilization of CD34+ HSCs and CD133+ EPCs from TG-0054 dose levels of 1.12 - 4.40 mg/kg. These results support subsequent clinical investigations. Disclosures: Chung: TaiGen Biotechnology, Inc.: Employment. Chang:TaiGen Biotechnology, Inc.: Employment. Huang:TaiGen Biotechnology, Inc.: Employment. Tsai:TaiGen Biotechnology, Inc.: Employment. Hsu:TaiGen Biotechnology, Inc.: Employment. King:TaiGen Biotechnology, Inc.: Employment. Yuan:TaiGen Biotechnology, Inc.: Employment. Yen:TaiGen Biotechnology, Inc.: Employment. Chen:TaiGen Biotechnology, Inc.: Employment. Lu:TaiGen Biotechnology, Inc.: Employment. Hsu:TaiGen Biotechnology, Inc.: Membership on an entity's Board of Directors or advisory committees.