Oxazolidinone-quinolone hybrid antibacterial for the parenteral treatment of prophylaxis of bacterial diseases

Abstract

The present invention relates to the use of oxazolidinone-quinolone hybrids for the parenteral (especially intravenous) treatment or prophylaxis of bacterial diseases. The present invention relates moreover to improved methods of administering oxazolidinone-quinolone hybrid antibacterials.

Claims

1. A method for treating a bacterial infection caused by Clostridium difficile, comprising administering to a patient in need thereof a compound, which is 7-(4-{4-[(5S)-5-(acetylamino-methyl)-2-oxo-oxazolidin-3-yl]-2-fluoro-phenoxymethyl}-4-phosphonooxy-piperidin-1-yl)-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid: ##STR00020## or a pharmacologically acceptable salt thereof.

2. The method according to claim 1, wherein the compound, or a pharmacologically acceptable salt thereof, is administered by an infusion.

3. The method according to claim 2, wherein the compound, or a pharmacologically acceptable salt thereof, is administered at an infusion rate of from 0.4 to 3 mg/(kg body weight×h).

4. The method according to claim 3, wherein the compound, or a pharmacologically acceptable salt thereof, is administered at an infusion rate of from 0.4 to 1.5 mg/(kg body weight×h).

5. The method according to claim 4, wherein the compound, or a pharmacologically acceptable salt thereof, is administered at an infusion rate of from 0.4 to 0.75 mg/(kg body weight×h).

6. The method according to claim 5, wherein the compound, or a pharmacologically acceptable salt thereof, is administered at an infusion rate of 0.5 mg/(kg body weight×h).

7. The method according to claim 1, wherein the compound, or a pharmacologically acceptable salt thereof, is administered over a period of from 20 min to 24 h per day.

8. The method according to claim 7, wherein the compound, or a pharmacologically acceptable salt thereof, is administered over a period of from 4 h to 12 h per day.

9. The method according to claim 8, wherein the compound, or a pharmacologically acceptable salt thereof, is administered over a period of 12 h per day.

10. The method according to claim 1, wherein the compound, or a pharmacologically acceptable salt thereof, is administered daily for a period of up to 10 days.

11. The method according to claim 10, wherein the compound, or a pharmacologically acceptable salt thereof, is administered daily for a period of 10 days.

12. The method according to claim 1, wherein the compound, or a pharmacologically acceptable salt thereof, is administered daily at a dose of 6 mg/kg.

13. The method according to claim 1, wherein the compound, or a pharmacologically acceptable salt thereof, is a sodium salt of the compound.

14. The method according to claim 1, wherein the bacterial infection caused by Clostridium difficile is an intestinal disease caused by Clostridium difficile.

15. The method according to claim 14, wherein the intestinal disease caused by Clostridium difficile is diarrhea, colitis, or pseudomembranous colitis.

16. The method according to claim 1, wherein the bacterial infection caused by Clostridium difficile is ileus, toxic megacolon, fulminant colitis, colonic perforation or need for colectomy.

17. A method for treating an intestinal disease caused by Clostridium difficile, comprising administering to a patient in need thereof a compound, which is 7-(4-{4-[(5S)-5-(acetylamino-methyl)-2-oxo-oxazolidin-3-yl]-2-fluoro-phenoxymethyl}-4-phosphonooxy-piperidin-1-yl)-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid: ##STR00021## or a pharmacologically acceptable salt thereof, wherein the compound, or a pharmacologically acceptable salt thereof, is administered daily at an infusion rate of 0.5 mg/(kg body weight×h) over a period of 12 h per day for a period of 10 days.

18. The method according to claim 17, wherein the intestinal disease caused by Clostridium difficile is diarrhea, colitis, or pseudomembranous colitis.

19. The method according to claim 17, wherein the intestinal disease caused by Clostridium difficile is ileus, toxic megacolon, fulminant colitis, colonic perforation or need for colectomy.

20. The method according to claim 17, wherein the compound, or a pharmacologically acceptable salt thereof, is a sodium salt of the compound.

Description

EXAMPLES

Example 1 (Infusion Rate)

(1) Compound 1 has been administered to animals of different species (among them mice and rats) by intravenous (iv.) bolus injection. The duration of this bolus injection had been set to 2 minutes to ensure that the exposure to the Prodrug (Compound 1) as well as to the Drug (Compound 2) is as high as possible for a given dose.

(2) According to the principles of the distribution of a drug within the blood circulation during and after its iv. bolus injection, the maximum plasma concentration (Cmax) of the Prodrug (Compound 1) has been observed at the end of the bolus injection. Moreover, according to the results derived from all the respective studies in animals it was concluded that the Drug (Compound 2) is very rapidly generated from the Prodrug (Compound 1): In all studies Cmax of the Drug (Compound 2) was observed at the very first sampling time (i.e. <5 min after the end of the iv. bolus injection).

(3) To establish the highest exposure possible also in humans, a study with Compound 1 has been designed. Therefore, ascending Prodrug (Compound 1) doses considered safe have been administered to 38 healthy Caucasian male volunteers by 2 min iv. bolus injections in the First-in-Man study.

(4) Volunteers were administered doses of up to 3.0 mg/kg body weight (BW) of Compound 1 given as iv. bolus injection of 2 min duration. Additionally, doses of 1.5 and 3.0 mg/kg BW of Compound 1 were administered as a short-term infusion of 20 min duration, resulting in infusion rates of 4.5 and 9.0 mg/(kg BW×h), respectively.

(5) As observed in all animal species investigated, also in humans there was very rapid conversion of the Prodrug (Compound 1) to the Drug (Compound 2) at all doses applied; Cmax of the Drug (Compound 2) was already observed 10 min after iv. bolus administration of the Prodrug.

(6) These observations led to the assumption that a prolongation of the duration of the iv. administration from the 2 min bolus to a short-term infusion of 20 min cannot result in any further improvement of the conversion of the Prodrug (Compound 1) into the Drug (Compound 2).

(7) However, surprisingly, the exposure to the Drug (Compound 2) was much higher after the 20-min infusion (infusion rate 9 mg/(kg BW×h)) than after bolus administration of 3.0 mg/kg BW, i.e. 149% and 130% for the area under the curve (AUC) and the maximum concentration (Cmax), respectively (see table 1). For the 1.5 mg/kg BW dose infused over 20 min (infusion rate 4.5 mg/(kg BW×h)), the dose-normalized exposure data of the Drug (Compound 2) are even higher than those measured following the dose of 3 mg/kg BW regardless if administered as iv. bolus or 20 min infusion (see table 1).

(8) TABLE-US-00002 TABLE 1 Mean exposure data of the Drug (Compound 2) after intravenous administration of 3.0 mg/kg BW Prodrug (Compound 1) as bolus, or after 20 min infusions of 3.0 or 1.5 mg/kg BW at an infusion rate of 9.0 and 4.5 mg/(kg BW × h), respectively. Infusion Dose Rate Ratio Ratio [mg/kg [mg/(kg AUC infusion/ Cmax infusion/ BW] BW .Math. h)] [μg .Math. h/L] bolus [%] [μg/L] bolus [%] 3.0 bolus 2174 2449 3.0 9.0 3234 149 3175 130 1.5 4.5  5622* 259  4924* 201 *value normalized to a dose of 3.0 mg/kg BW

(9) Accordingly, a dose of 1.5 mg/kg BW infused at a rate of 4.5 mg/(kg BW×h) resulted in a similar exposure compared to a dose of 3.0 mg/kg BW infused at a rate of 9.0 mg/(kg BW×h).

(10) For the Prodrug (Compound 1), the prolongation of the administration of 3.0 mg/kg BW to 20 min infusion resulted in a lower AUC compared to bolus administration, because of the more efficient conversion to the Drug (Compound 2).

(11) Considering the results of the First-in-Man study the effect of the infusion rate on the efficacy of the conversion of the Prodrug (Compound 1) into the Drug (Compound 2) has been investigated in a systematic manner.

(12) In this clinical study the Prodrug (Compound 1) was administered to 30 healthy Caucasian male volunteers at infusion rates ranging between 0.4 and 3.0 mg/(kg BW×h). This range of infusion rates has been realised by combining different doses (1-6 mg/kg BW) with different durations of infusion (20-720 min).

(13) Accordingly, it was possible to evaluate 3 Cohorts (groups) of volunteers each of which were infused at a range of infusion rates resulting from the different doses and infusion durations applied to this group.

(14) The ratio of the AUC-values of the Drug vs. the Prodrug (Compound 2/Compound 1) was used as a measure of the conversion efficacy. The infusion rates of the respective Cohort and the resulting ratios are given in table 2; the higher the ratio, the more efficient the conversion of the Prodrug (Compound 1) into the Drug (Compound 2).

(15) TABLE-US-00003 TABLE 2 Infusion rates applied to the Cohorts of volunteers and resulting AUC ratios Compound 2/Compound 1 Infusion Rate [mg/(kg BW .Math. h)] Mean ratio Cohort 1 3.00 0.65 1.50 0.72 0.75 0.86 Cohort 2 1.50 0.75 0.75 0.83 0.40 0.62 Cohort 3 0.50 0.65 0.50 0.60 0.50 0.63

(16) In general, the mean ratios of AUC Compound 2/Compound 1 ranged between 0.86 and 0.60. It has been observed that the ratios were similar at identical infusion rates even if the doses administered are different.

(17) Within Cohort 1 there was a steady increase of the mean ratio from 0.65 to 0.86 with decreasing infusion rate from 3 to 0.75 mg/(kg BW×h). Within Cohort 2 there was an increase of the mean ratio from 0.75 to 0.83 while the infusion rate decreased from 1.5 to 0.75 mg/(kg BW×h). The lowest infusion rate of 0.4 mg/(kg BW×h) in Cohort 2 showed a ratio of 0.62 and did not differ from the ratios observed in Cohort 3 at the infusion rate of 0.5 mg/(kg BW×h), ranging very consistently between 0.60 and 0.65.

(18) Accordingly, by means of a systematic pharmacokinetic study performed in humans it was found that an infusion rate between 0.4 and 3 mg/(kg BW×h) is a preferred range with respect to the maximum amount of the Drug (Compound 2) generated from the infused Prodrug (Compound 1).

(19) Moreover, for a given dose infused, the safety and tolerability improves with decreasing infusion rate.

(20) Accordingly, an infusion rate between 0.4 and 0.75 mg/(kg BW×h) is especially preferred.

Example 2 (Treatment of Intestinal Diseases)

(21) Healthy human volunteers received i.v. infusions of Compound 1 at a dose of 6 mg/kg body weight over 12 hours for 5 consecutive days. On Day 5, all volunteers had fecal concentrations of Compound 2, ranging between 98 and 226 mg/kg feces. These fecal concentrations of Compound 2 translated into marked effects on the Gram-positive aerobic and anaerobic microflora. The reduction of viable counts of Clostridium spp. from predose to Day 5 was 3.0 log 10 CFU/g, and viable counts were reduced below the limit of detection until Day 3 postdose in all except one of the volunteers. Viable counts of lactobacilli were reduced from predose to Day 5 by 4.0 log 10 CFU/g. The effect of Compound 2 on bifidobacteria was most pronounced: Viable counts were reduced from predose to Day 5 by 7.9 log 10 CFU/g. Likewise, enterococci were reduced from predose to Day 5 by 3.8 log 10 CFU/g on average. Exposure of the fecal flora to MCB3681 did not affect the Gram-negative species.

(22) Evaluation of the Activity of Compound 2 Against Clostridium difficile:

(23) One hundred fourteen Clostridium difficile strains were collected from 67 patients and analyzed for the presence of C. difficile toxin B by the cell cytotoxicity neutralization assay, genes for toxin A, toxin B, binary toxin and TcdC deletion by PCR. All strains were also PCR-ribotyped. The MICs of the isolates were determined against Compound 2 by the agar dilution method. All isolates were positive for toxin B. One hundred thirteen isolates were positive for toxin A and B genes. In addition, 13 isolates were positive for the binary toxin genes. Thirty-two different ribotypes were identified. No strain of ribotype 027 was found. All 114 isolates were sensitive to Compound 2 (MIC range 0.008-0.5 mg/1). Accordingly, Compound 2 has a potent in vitro activity against C. difficile.

(24) 1. Materials and Methods:

(25) 1.1. Collection and Typing of Strains

(26) One hundred fourteen C. difficile strains were selected from patients (26 males and 41 females) with primary and/or recurrent CDI. The mean age of the patients was 74 years (age range 19-97 years). The strains (67 primary and 47 recurrent isolates) were identified by characteristic colony morphology, typical smell and Gram staining. Gas chromatography was used to detect volatile, short chain fatty acids production by the C. difficile strains for the final identification.

(27) 1.2. Toxin and Toxin Gene Detection

(28) The production of toxin B was determined by the cell cytotoxicity neutralization assay. The gene for toxin A was detected by conventional PCR [Kato H, Kato N, Watanabe K, Iwai N, Nakamura H, Yamamoto T, et al. Identification of toxin A-negative, toxin B-positive Clostridium difficile by PCR. J Clin Microbiol 1998; 36:2178-82]. The genes for toxin B, the binary toxin and TcdC deletion were detected by real time PCR using the GeneXpert® System (Cepheid, Sunnyvale, Calif., USA) assay [Huang H, Weintraub A, Fang H, Nord C E. Comparison of a commercial multiplex real-time PCR to the cell cytotoxicity neutralization assay for diagnosis of Clostridium difficile infections. J Clin Microbiol 2009; 47:3729-31].

(29) 1.3. Ribotyping

(30) PCR ribotyping and electrophoresis of the gels were performed with a method described previously [Stubbs S L, Brazier J S, O'Neill G L, Duerden B I. PCR targeted to the 16S-23S rRNA gene intergenic spacer region of Clostridium difficile and construction of a library consisting of 116 different PCR ribotypes. J Clin Microbiol 1999; 37:461-3; Rashid M U, Lozano H M, Weintraub A, Nord C E. In vitro activity of cadazolid against Clostridium difficile strains isolated from primary and recurrent infections in Stockholm, Sweden. Anaerobe 2013; 20:32-5]. The gels were scanned and analyzed by Bionumerics software version 6.6. (Applied Maths, Kortrijk, Belgium). A molecular size standard (100 bp; GE Healthcare, Little Chalfont, Buckinghamshire, UK) was run at four to five lane intervals in all gels to enable normalization of the gel patterns. In every gel two known PCR ribotypes (005 and 012) were run as controls. The banding patterns were compared to a database including C. difficile reference strains. The stability, reliability and homogeneity of the database banding patterns constituting each type was tested with the cluster correlation algorithm with the unweighted pair group method by using arithmetic averages and fine alignment.

(31) 1.4. Antimicrobial Susceptibility

(32) The antimicrobial susceptibility of the C. difficile strains was determined according to CLSI guidelines by the agar dilution method using Bacteroides fragilis ATCC 25285 and C. difficile ATCC 700057 as reference strains [CLSI. Methods for Antimicrobial Susceptibility Testing of Anaerobic Bacteria; Approved Standard-Eighth Edition. 2012]. Compound 2 was prepared as described in WO 2005/058888.

(33) MIC was defined as the lowest concentration of the drug that inhibited growth completely. MIC.sub.50/90 corresponds to the concentrations that inhibit the growth of 50% and 90% of the strains tested, respectively.

(34) 1.5. Statistical Methods

(35) PCR ribotype profiles from clinical isolates were compared to those profiles which define the database by maximum matching with Pearson correlation. IBM SPSS Statistics 22 (Armonk, N.Y., USA) software was used to calculate the percentiles 50 and 90 of the MIC results. Descriptive statistics were used to summarize the results.

(36) 2. Results

(37) 2.1. Toxin Detection

(38) The 114 strains were positive for toxin B by cell cytotoxicity neutralization assay. One hundred thirteen strains were positive for the genes of both toxin A and B. In addition, 13 strains were positive for the binary toxin genes. All strains were negative for TcdC deletion.

(39) 2.2. Ribotypes

(40) Thirty-two different ribotypes were identified (Table 1). The ribotypes for the 13 strains positive for the genes of toxin A, toxin B and binary toxin were 023, 075, 078/126 and 019. One strain did not match with any of the known ribotypes and was a cluster of SE 91. The most common ribotypes were 020 (14.9%), 014/077 (8.8%), 078/126 (7%), 001 (6.1%) and 026 (6.1%). No ribotype 027 was found among any of the isolates.

(41) TABLE-US-00004 TABLE 1 Thirty two different PCR-ribotypes of the 114 C. difficile strains. Ribotype Number of strains 020 17 014/077 10 078/126 8 001 7 026 7 SE14 6 SE21 6 005 5 SE2 5 023 4 207 4 002 3 231 3  SE23a 3 SE35 3 012 2 017 2 075 2  SE23b 2 SE36 2 SE46 2

(42) One strain each of ribotypes 003, 019, 029, 046, 087, SE14b, SE20d, SE24, SE48, SE49 and SE91 cluster ribotypes were identified.

(43) 2.3. Antimicrobial Susceptibility

(44) The antimicrobial susceptibility patterns are shown in Table 2. All strains were sensitive to Compound 2 with MIC.sub.90 values of 0.064 mg/l. None of the 114 C. difficile strains were resistant against Compound 2.

(45) TABLE-US-00005 TABLE 2 Minimum inhibitory concentrations of 114 C. difficile strains against Compound 2. MIC.sub.50 (mg/l) MIC.sub.90 (mg/l) Range (mg/l) 0.032 0.064 0.008-0.5