14 CLINICAL STUDIES
14.1 Complicated Skin and Skin Structure Infections
TYGACIL was evaluated in adults for the treatment of complicated skin and skin structure infections (cSSSI) in two randomized, double-blind, active-controlled, multinational, multicenter studies (Studies 1 and 2). These studies compared TYGACIL (100 mg intravenous initial dose followed by 50 mg every 12 hours) with vancomycin (1 g intravenous every 12 hours)/aztreonam (2 g intravenous every 12 hours) for 5 to 14 days. Patients with complicated deep soft tissue infections including wound infections and cellulitis (≥10 cm, requiring surgery/drainage or with complicated underlying disease), major abscesses, infected ulcers, and burns were enrolled in the studies. The primary efficacy endpoint was the clinical response at the test of cure (TOC) visit in the co-primary populations of the clinically evaluable (CE) and clinical modified intent-to-treat (c-mITT) patients. See Table 4. Clinical cure rates at TOC by pathogen in the microbiologically evaluable patients are presented in Table 5.
TYGACIL* n/N (%) | Vancomycin/Aztreonam† n/N (%) | |
---|---|---|
Study 1 | ||
CE | 165/199 (82.9) | 163/198 (82.3) |
c-mITT | 209/277 (75.5) | 200/260 (76.9) |
Study 2 | ||
CE | 200/223 (89.7) | 201/213 (94.4) |
c-mITT | 220/261 (84.3) | 225/259 (86.9) |
Pathogen | TYGACIL n/N (%) | Vancomycin/Aztreonam n/N (%) |
---|---|---|
Escherichia coli | 29/36 (80.6) | 26/30 (86.7) |
Enterobacter cloacae | 10/12 (83.3) | 15/15 (100) |
Enterococcus faecalis (vancomycin-susceptible only) | 15/21 (71.4) | 19/24 (79.2) |
Klebsiella pneumoniae | 12/14 (85.7) | 15/16 (93.8) |
Methicillin-susceptible Staphylococcus aureus (MSSA) | 124/137 (90.5) | 113/120 (94.2) |
Methicillin-resistant Staphylococcus aureus (MRSA) | 79/95 (83.2) | 46/57 (80.7) |
Streptococcus agalactiae | 8/8 (100) | 11/14 (78.6) |
Streptococcus anginosus grp.† | 17/21 (81.0) | 9/10 (90.0) |
Streptococcus pyogenes | 31/32 (96.9) | 24/27 (88.9) |
Bacteroides fragilis | 7/9 (77.8) | 4/5 (80.0) |
14.2 Complicated Intra-abdominal Infections
TYGACIL was evaluated in adults for the treatment of complicated intra-abdominal infections (cIAI) in two randomized, double-blind, active-controlled, multinational, multicenter studies (Studies 1 and 2). These studies compared TYGACIL (100 mg intravenous initial dose followed by 50 mg every 12 hours) with imipenem/cilastatin (500 mg intravenous every 6 hours) for 5 to 14 days. Patients with complicated diagnoses including appendicitis, cholecystitis, diverticulitis, gastric/duodenal perforation, intra-abdominal abscess, perforation of intestine, and peritonitis were enrolled in the studies. The primary efficacy endpoint was the clinical response at the TOC visit for the co-primary populations of the microbiologically evaluable (ME) and the microbiologic modified intent-to-treat (m-mITT) patients. See Table 6. Clinical cure rates at TOC by pathogen in the microbiologically evaluable patients are presented in Table 7.
TYGACIL* n/N (%) | Imipenem/Cilastatin† n/N (%) | |
---|---|---|
Study 1 | ||
ME | 199/247 (80.6) | 210/255 (82.4) |
m-mITT | 227/309 (73.5) | 244/312 (78.2) |
Study 2 | ||
ME | 242/265 (91.3) | 232/258 (89.9) |
m-mITT | 279/322 (86.6) | 270/319 (84.6) |
Pathogen | TYGACIL n/N (%) | Imipenem/Cilastatin n/N (%) |
---|---|---|
Citrobacter freundii | 12/16 (75.0) | 3/4 (75.0) |
Enterobacter cloacae | 15/17 (88.2) | 16/17 (94.1) |
Escherichia coli | 284/336 (84.5) | 297/342 (86.8) |
Klebsiella oxytoca | 19/20 (95.0) | 17/19 (89.5) |
Klebsiella pneumoniae | 42/47 (89.4) | 46/53 (86.8) |
Enterococcus faecalis | 29/38 (76.3) | 35/47 (74.5) |
Methicillin-susceptible Staphylococcus aureus (MSSA) | 26/28 (92.9) | 22/24 (91.7) |
Methicillin-resistant Staphylococcus aureus (MRSA) | 16/18 (88.9) | 1/3 (33.3) |
Streptococcus anginosus grp.† | 101/119 (84.9) | 60/79 (75.9) |
Bacteroides fragilis | 68/88 (77.3) | 59/73 (80.8) |
Bacteroides thetaiotaomicron | 36/41 (87.8) | 31/36 (86.1) |
Bacteroides uniformis | 12/17 (70.6) | 14/16 (87.5) |
Bacteroides vulgatus | 14/16 (87.5) | 4/6 (66.7) |
Clostridium perfringens | 18/19 (94.7) | 20/22 (90.9) |
Peptostreptococcus micros | 13/17 (76.5) | 8/11 (72.7) |
14.3 Community-Acquired Bacterial Pneumonia
TYGACIL was evaluated in adults for the treatment of community-acquired bacterial pneumonia (CABP) in two randomized, double-blind, active-controlled, multinational, multicenter studies (Studies 1 and 2). These studies compared TYGACIL (100 mg intravenous initial dose followed by 50 mg every 12 hours) with levofloxacin (500 mg intravenous every 12 or 24 hours). In Study 1, after at least 3 days of intravenous therapy, a switch to oral levofloxacin (500 mg daily) was permitted for both treatment arms. Total therapy was 7 to 14 days. Patients with community-acquired bacterial pneumonia who required hospitalization and intravenous therapy were enrolled in the studies. The primary efficacy endpoint was the clinical response at the test of cure (TOC) visit in the co-primary populations of the clinically evaluable (CE) and clinical modified intent-to-treat (c-mITT) patients. See Table 8. Clinical cure rates at TOC by pathogen in the microbiologically evaluable patients are presented in Table 9.
TYGACIL* n/N (%) | Levofloxacin† n/N (%) | 95% CI‡ | |
---|---|---|---|
| |||
Study 1§ | |||
CE | 125/138 (90.6) | 136/156 (87.2) | (-4.4, 11.2) |
c-mITT | 149/191 (78) | 158/203 (77.8) | (-8.5, 8.9) |
Study 2 | |||
CE | 128/144 (88.9) | 116/136 (85.3) | (-5.0, 12.2) |
c-mITT | 170/203 (83.7) | 163/200 (81.5) | (-5.6, 10.1) |
Pathogen | TYGACIL n/N (%) | Levofloxacin n/N (%) |
---|---|---|
Haemophilus influenzae | 14/17 (82.4) | 13/16 (81.3) |
Legionella pneumophila | 10/10 (100.0) | 6/6 (100.0) |
Streptococcus pneumoniae (penicillin-susceptible only)† | 44/46 (95.7) | 39/44 (88.6) |
To further evaluate the treatment effect of tigecycline, a post-hoc analysis was conducted in CABP patients with a higher risk of mortality, for whom the treatment effect of antibacterial drugs is supported by historical evidence. The higher-risk group included CABP patients from the two studies with any of the following factors:
- Age ≥50 years
- PSI score ≥3
- Streptococcus pneumoniae bacteremia
The results of this analysis are shown in Table 10. Age ≥50 was the most common risk factor in the higher-risk group.
TYGACIL n/N (%) | Levofloxacin n/N (%) | 95% CI† | |
---|---|---|---|
| |||
Study 1‡ | |||
CE | |||
Higher risk | |||
Yes | 93/103 (90.3) | 84/102 (82.4) | (-2.3, 18.2) |
No | 32/35 (91.4) | 52/54 (96.3) | (-20.8, 7.1) |
c-mITT | |||
Higher risk | |||
Yes | 111/142 (78.2) | 100/134 (74.6) | (-6.9, 14) |
No | 38/49 (77.6) | 58/69 (84.1) | (-22.8, 8.7) |
Study 2 | |||
CE | |||
Higher risk | |||
Yes | 95/107 (88.8) | 68/85 (80) | (-2.2, 20.3) |
No | 33/37 (89.2) | 48/51 (94.1) | (-21.1, 8.6) |
c-mITT | |||
Higher risk | |||
Yes | 112/134 (83.6) | 93/120 (77.5) | (-4.2, 16.4) |
No | 58/69 (84.1) | 70/80 (87.5) | (-16.2, 8.8) |