Clinical Pharmacology for Zevtera
Mechanism Of Action
ZEVTERA is an antibacterial drug [see Microbiology]
Pharmacodynamics
Ceftobiprole exposure-response relationships and the time course of pharmacodynamic response are unknown.
Time Above The Minimum Inhibitory Concentration (MIC)
The time that the unbound plasma concentration of ceftobiprole exceeds the MIC of Staphylococcus aureus , Streptococcus pneumoniae, and species of Enterobacterales correlates with efficacy in a neutropenic murine thigh infection model [see CLINICAL PHARMACOLOGY].
Cardiac Electrophysiology
At a dose 1 to 2 times the maximum recommended dose, ZEVTERA does not prolong the QT interval to any clinically relevant extent.
Pharmacokinetics
Ceftobiprole medocaril is the prodrug of the active moiety ceftobiprole. No clinically significant differences in the pharmacokinetics of ceftobiprole were observed with ZEVTERA following single or multiple dose administration. Ceftobiprole exhibits linear and time-independent pharmacokinetics. The Cmax and AUC increase proportionally with the dose over a range of 125 to 1000 mg (0.25 to 2 times the highest approved recommended adult dosage).
The pharmacokinetic properties of ceftobiprole are summarized in Table 11.
The mean pharmacokinetic parameters of ceftobiprole in healthy adults with normal renal function after single and multiple 2-hour IV infusions of ZEVTERA 667 mg (equivalent to 500 mg of ceftobiprole) administered every 8 hours are summarized in Table 11. Pharmacokinetic parameters were similar for single and multiple dose administrations.
Table 11 : Mean (Standard Deviation) Pharmacokinetic Parameters of ZEVTERA in Healthy Adults
| Parameter |
Multiple doses administered every 8 hours as a 2-hour infusion
(n = 27) |
| Cmax (μg/mL) |
33.0 (4.83) |
| AUC0-8h (μg•h/mL) |
102 (11.9) |
| Distribution |
| % Bound to human plasma protein |
16 |
| % ELF/unbound plasma |
15-19 |
| Vss (L) |
18 |
| Metabolism |
|
Minimally Metabolized |
| t½ (h) |
3.3 (0.3) |
| CL (L/h) |
4.98 (0.582) |
| Excretion |
| Major route of elimination |
Renal |
| % excreted unchanged in urine |
83 |
| Cmax = Maximum plasma concentration; AUC0-8h = Area under the plasma concentration-time curve from 0 to 8 h; Vss = Volume of distribution at steady state; CL = Clearance. |
Specific Populations
No clinically significant differences in the pharmacokinetics of ceftobiprole were observed in adults based on age (18 to 91 years), gender (36% female), or race/ethnicity (88% white, 3% Black, 5% Asian). The effect of hepatic impairment on ceftobiprole pharmacokinetics is unknown.
Patients With Renal Impairment
No clinically significant differences in the pharmacokinetics of ceftobiprole were observed in adult subjects and subjects with mild renal impairment (CLCR 50 to 80 mL/min). Ceftobiprole AUC increased 2.5-fold in adult subjects with moderate renal impairment (CLCR 30 to < 50 mL/min) and 3.3-fold in severe renal impairment (CLCR < 30 mL/min). The effect of any degree of renal impairment in pediatric patients less than 2 years of age or in pediatric patients with CLCR < 15 mL/min/1.73 m² on ceftobiprole pharmacokinetics is unknown.
End-stage Renal Disease Requiring Dialysis
No clinically significant difference in the pharmacokinetics of ceftobiprole were observed in adult patients with ESRD (CLCR < 15 mL/min) compared to healthy adult subjects based on limited PK data and pharmacokinetic modeling and simulation. Ceftobiprole was demonstrated to be removed by hemodialysis in patients receiving ZEVTERA.
Patients With Augmented Renal Clearance
A clinically significant reduction in ceftobiprole exposure is predicted in adult patients with augmented renal clearance (CLCR > 150 mL/min) based upon a mechanistic understanding of this drug. The effect of augmented renal clearance (CLCR > 150 mL/min) on ceftobiprole pharmacokinetics in pediatric patients is unknown.
Pediatric Use
No clinically significant differences in the pharmacokinetics of ceftobiprole were observed between pediatric patients from birth to < 18 years with normal renal function following administration of an intravenous dose of ZEVTERA. ZEVTERA is not approved for use in pediatric patients less than 3 months of age [see Use In Specific Populations].
Drug Interaction Studies
In Vitro Studies
Ceftobiprole does inhibit or induce CYP450 1A2, 2B6, 2C8, 2C9, 2C19, 2D6, or 3A4/5.
Transporter Systems: Ceftobiprole is an inhibitor of OATP1B1, OATP1B3, MRP2 and BSEP but is not an inhibitor of P-glycoprotein, BCRP, OAT1, OAT3, OCT1, OCT2, or MATE1.
Microbiology
Mechanism Of Action
Ceftobiprole is a cephalosporin with bactericidal activity by inhibition of bacterial cell wall synthesis. Ceftobiprole has in vitro activity against gram-positive and gram-negative bacteria, including methicillin-resistant and susceptible Staphylococcus aureus. Bactericidal activity is mediated through binding to essential penicillin-binding proteins (PBPs) and inhibiting their transpeptidase activity, which is essential for the synthesis of the peptidoglycan layer of the bacterial cell wall. Ceftobiprole has a high affinity for S. aureus PBPs 1 – 4, including PBP2a in methicillin-resistant Staphylococcus aureus, and PBP2x and PBP2b in penicillin-resistant Streptococcus pneumoniae.
Resistance
Ceftobiprole is not active against gram-negative bacteria producing extended-spectrum β-lactamases (ESBLs) from the TEM, SHV or CTX-M families, serine carbapenemases (such as KPC), class B metallo-β-lactamases, class C (AmpC cephalosporinases) if expressed at high levels), and Ambler class D β-lactamases including carbapenemases.
No cross-resistance with other classes of antimicrobials has been identified. Although cross-resistance may occur, some isolates resistant to other cephalosporins may be susceptible to ceftobiprole.
Interaction With Other Antimicrobials
In vitro studies have not demonstrated any antagonism between ceftobiprole and other commonly-used antibacterial agents (e.g., gentamicin, vancomycin, daptomycin, rifampicin) against strains of Staphylococcus aureus. Against Escherchia coli, no antagonism was observed between ceftobiprole and doripenem or levofloxacin.
Activity Against Bacteria In Animal Infection Models
Ceftobiprole demonstrated activity in a neutropenic murine thigh infection model reducing tissue counts of MRSA. Ceftobiprole was effective in treating experimental murine septicemia for strains of MSSA, MRSA, S. pneumoniae (including strains of penicillin-resistant S. pneumoniae [PRSP]), E. coli expressing TEM-1 and Act-1 AmpC cephalosporinase, K. pneumoniae, C. freundii, S. marcescens, and P. mirabilis. In an acute mouse model of pneumonia ceftobiprole was effective against S. pneumoniae (ceftobiprole MICs < 0.5 μg/mL)including a strain of PRSP ). In a rabbit model of meningitis ceftobiprole was effective at clearing strains of E. coli, K. pneumoniae and β-lactamase positive and negative H. influenzae. In both a rat and rabbit model of endocarditis, ceftobiprole did not sterilize but was effective in reducing cardiac vegetations of MRSA including a vancomycin intermediate strain (ceftobiprole MIC ≤ 2 μg/mL). Similarly in both a rat and rabbit model of osteomyelitis, ceftobiprole was effective in clearing MRSA infection (ceftobiprole MIC ≤ 1μg/mL). The clinical significance of the above findings in animal infection models is not known.
Antimicrobial Activity
ZEVTERA has been shown to be active against most isolates of the following bacteria, both in vitro and in clinical infections [see INDICATIONS AND USAGE].
SAB
Gram-positive Bacteria
- Staphylococcus aureus (including methicillin-susceptible and methicillin-resistant isolates)
ABSSSI
Gram-positive Bacteria
- Staphylococcus aureus (including methicillin-susceptible and methicillin-resistant isolates)
- Streptococcus pyogenes
Gram-negative Bacteria
CABP
Gram-positive Bacteria
- Staphylococcus aureus (including methicillin-susceptible isolates)
- Streptococcus pneumoniae
Gram-negative Bacteria
- Escherichia coli
- Klebsiella pneumoniae
- Haemophilus influenzae
- Haemophilus parainfluenzae
The following in vitro data are available, but their clinical significance is unknown. At least 90 percent of the following bacteria exhibit an in vitro minimum inhibitory concentration (MIC) less than or equal to the susceptible breakpoint for ZEVTERA against isolates of similar genus or organism group. However, the efficacy of ZEVTERA in treating clinical infections caused by these bacteria has not been established in adequate and well-controlled clinical trials.
Gram-positive bacteria
- Staphylococcus epidermidis
- Staphylococcus hominis
- Staphylococcus lugdunensis
- Streptococcus agalactiae
- Streptococcus mitis group
- Streptococcus dysgalactiae
- Streptococcus anginosus group
Gram-negative bacteria
- Citrobacter koseri
- Enterobacter cloacae
- Klebsiella aerogenes
- Moraxella catarrhalis
- Morganella morganii
- Proteus mirabilis
Susceptibility Test Methods
For specific information regarding susceptibility testing methods, interpretive criteria, and associated test methods and quality control standards recognized by FDA for ZEVTERA, see: https://www.fda.gov/STIC.
Animal Toxicology And/Or Pharmacology
Both rats and marmosets showed convulsions and thrombi and/or emboli with dosing durations greater than one month. In the 13-week intravenous rat study, clonic convulsions were noted at 500 mg/kg/day (2 times the MRHD based on BSA comparisons) with early deaths seen at 250 mg/kg in the males (1 time the MRHD based on BSA comparison). In the 13-week intravenous marmoset study, convulsions and thrombi were noted at multiple sites distal to the injection site (i.e., lung, and heart) at doses ≥ 50 mg/kg/day (0.1 times the MRHD, based on BSA comparisons). While dogs did not show convulsions in a 13-week toxicology study, catheter patency could only be maintained between 4 to 11 weeks in most animals at doses up to 32 mg/kg/day (0.4 times the MRHD based on BSA comparisons). Fibrin, erythrocytes and inflammatory cells within the lumens of the catheters were noted in the 13-week dog study, while thrombi were observed at the injection site in all species tested. Kidney findings were also noted in the 13-week studies in rats (tubular/duct eosinophilic bodies and presence of foreign material) at 1 times the MRHD.
Clinical Studies
Staphylococcus Aureus Bloodstream Infection (Bacteremia)
Adult Patients
Trial Design
The efficacy of ZEVTERA in the treatment of adult patients with SAB, including right-sided infective endocarditis, was demonstrated in a randomized, controlled, double-blind, multinational, multicenter trial (Trial 1) (NCT03138733). In this trial, adult patients were randomized to either ZEVTERA 667 mg (equivalent to 500 mg of ceftobiprole) IV every 6 hours from study Day 1 to Day 8, and 667 mg IV every 8 hours from study Day 9 onwards) or daptomycin (6 mg/kg up to 10 mg/kg IV every 24 hours) plus optional aztreonam for coverage of gram-negative co-infections (the comparator). Randomization was stratified by study site, dialysis status, and use of prior antibacterial drugs.The study was performed in two cohorts based on findings in animal studies [see Nonclinical Toxicology]. The initial cohort was enrolled to receive a maximum treatment duration of 28 days. Based on a safety evaluation of cohort 1, patients could be enrolled in cohort 2 to receive a treatment duration of up to 42 days. The duration of study treatment was based on the investigator’s clinical evaluation.
Study patients were required to have at least one positive blood culture for S. aureus obtained within 72 hours prior to randomization, signs and symptoms of bacteremia (fever, elevated white blood cell count or immature neutrophils, tachycardia, or hypotension), and at least one of the following conditions of complicated S. aureus bacteremia: chronic dialysis, persistent SAB, acute bacterial skin and skin structure infection, metastatic infections of native tissue, osteomyelitis, epidural or cerebral abscess, or definite native-valve right-sided infective endocarditis by Modified Duke’s Criteria. Patients with uncomplicated S. aureus bacteremia, left-sided infective endocarditis, prosthetic heart valves, foreign body material that could not be removed, severe neutropenia, or pneumonia, were excluded from the study.
Upon entry, patients were classified for likelihood of endocarditis using the modified Duke’s criteria (definite, possible, or rejected). Echocardiography, including a transesophageal echocardiogram, was to be performed during screening or within 7 days following study enrollment. Final diagnoses were to be made by the study investigators within 7 days of randomization. The final diagnosis for persistent S. aureus bacteremia was made by an independent treatment-blinded Data Review Committee (DRC).
Baseline Demographic And Disease Characteristics
A total of 390 patients (192 ZEVTERA, 198 daptomycin) with SAB were randomized from 60 centers in the USA, Europe, Latin America, and South Africa. The modified ITT (mITT) population was used for the primary efficacy analysis, comprising 387 patients (189 ZEVTERA, 198 daptomycin ± aztreonam) who received study drugs and had a baseline blood culture positive for S. aureus.
Patient demographic and baseline characteristics were balanced between the treatment groups. The median age among the 387 patients in the mITT population was 58 years, ranging from 19 to91 years), with 31% aged ≥ 65 years, 69% of patients were male, and 96% were White.
Frequent conditions of complicated SAB included acute bacterial skin and skin structure infections (61%), intra-abdominal abscesses (14%), osteoarticular infections (13%), and patients on chronic dialysis (13%). A total of 6.5% of patients had definite right-sided infective endocarditis. A total of 24% had bacteremia caused by methicillin-resistant S. aureus (MRSA).
Efficacy Results
The primary efficacy outcome in the study was overall success at the post-treatment evaluation (PTE) visit at 70 days post-randomization in the mITT population, as assessed by the independent DRC.
Overall success required survival, symptom improvement, S. aureus bacteremia bloodstream clearance, no new S. aureus bacteremia complications, and no use of other potentially effective antibacterial drugs.
Overall success rates at the PTE visit in the mITT population were 69.8% (132/189) in patients treated with ZEVTERA and 68.7% (136/198) in patients treated withthe comparator. The overall primary study outcome and in pre-defined subgroups in the mITT population is shown in Table 12.
Table 12 : Data Review Committee Overall Success Rate at the PTE Visit in the mITT Population from the Adult SAB Patients in Trial 1
| Group/Subgroup |
ZEVTERA n/N (%) |
Daptomycin ± aztreonam n/N (%) |
Between-group Difference (%) (2-sided 95% CI)* |
| Overall |
132/189
(69.8) |
136/198
(68.7) |
2.0
(-7.1, 11.1) |
MSSA
(methicillin-susceptible) |
100/141
(70.9) |
97/146
(66.4) |
4.8
(-5.9, 15.5) |
MRSA
(methicillin-resistant) |
31/45
(68.9) |
38/49
(77.6) |
-8.3
(-25.3, 8.6) |
| ABSSSI |
81/116
(69.8) |
80/121
(66.1) |
4.5
(-7.3, 16.3) |
| Definite right-sided infective endocarditis |
10/15
(66.7) |
7/10
(70.0) |
-6.6
(-40.1, 27.0) |
| * Between-group difference of ceftobiprole minus daptomycin ± aztreonam using Cochran-Mantel-Haenszel weights method adjusted for actual stratum (dialysis status and prior antibacterial treatment use). |
For patients enrolled in Ukraine, overall success rates at the PTE visit in the mITT population were 77/84 (84.1%) in patients treated with ZEVTERA and 82/92 (89.1%) in patients treated with the comparator. For patients enrolled outside Ukraine, overall success rates at the PTE visit in the mITT population were 58/101 (57.4%) in patients treated with ZEVTERA and 54/106 (50.9%) in patients treated with the comparator.
All-cause mortality between randomization and the PTE visit was observed in 17/189 (9.0%) patients treated with ZEVTERA, and 18/198 (9.1%) patients treated with the comparator. Other key secondary efficacy outcomes included microbiological eradication at the PTE visit in the mITT population, which was achieved in 82% of patients treated with ZEVTERA and 77% of patients treated with the comparator, and the development of new S. aureus bacteremia complications, which occurred in 6% of patients treated with ZEVTERA and 6% of patients treated with the comparator. S. aureus bloodstream clearance, defined as 2 consecutive study days with negative blood cultures for S. aureus with no subsequent S. aureus relapse or reinfection, was achieved after a median of 4 days in each treatment group.
S. aureus bloodstream clearance in patients with MSSA was achieved after a median of 3 days in patients treated with ZEVTERA and after a median of 4 days in patients treated with the comparator.
S. aureus bloodstream clearance in patients with MRSA was achieved after a median of 5 days in each treatment group.
Failure of treatment due to relapse of S. aureus bacteremia was assessed by the DRC in two patients (1%) treated with ZEVTERA, and in four patients (2%) treated in the comparator arm. No increase in ceftobiprole MIC was observed for the two isolates from the ZEVTERA treated patients.
Acute Bacterial Skin And Skin Structure Infections (ABSSSI)
Adult Patients
Trial Design
The efficacy of ZEVTERA in the treatment of adult patients with ABSSSI was demonstrated in a randomized, controlled, double-blind, multinational, multicenter trial (Trial 2) (NCT03137173). Patients were randomized to either ZEVTERA 667 mg (equivalent to 500 mg of ceftobiprole) IV every 8 hours or vancomycin plus aztreonam (vancomycin 1 gram or 15 mg/kg IV every 12 hours, aztreonam 1 gram IV every 12 hours). Randomization was stratified by study site and type of ABSSSI. Treatment duration was 5 to 14 days. Patients could receive concomitant metronidazole for suspected anaerobic infection. A switch to oral therapy was not allowed.
The study enrolled adult patients with ABSSSI (cellulitis/erysipelas, major cutaneous abscess, wound infection) with a lesion area of at least 75 cm², systemic or regional signs of infection, and a requirement for IV antibiotic treatment. Patients with other forms of ABSSSI, uncomplicated skin and skin structure infections, or infections related to prosthetic devices, were excluded.
The ITT primary analysis population comprised all patients randomized.
The primary endpoint, assessed in the ITT population, was early clinical response 48–72 hours after start of treatment. Early clinical response required a reduction of the primary skin lesion by at least 20%, survival for at least 72 hours, and the absence of concomitant antibacterial treatment or additional unplanned surgery.
The main secondary endpoint was investigator-assessed clinical success at the test-of-cure (TOC) visit 15 to 22 days after randomization and at least 5 days after the end-of-treatment.
A total of 679 patients (335 ZEVTERA, 344 vancomycin plus aztreonam) were randomized from 32 centers in the USA and Europe. The microbiological ITT (mITT) population included 506 patients with at least one valid baseline pathogen.
Baseline Demographic And Disease Characteristics
Patient demographic and baseline characteristics in the ITT population were balanced between the treatment groups. Approximately 95% of patients were classified as White, 59% were male, the median age was 50 years (range: 18 to 89), and the mean body mass index was 28 kg/m², 62% of patients were enrolled in the USA, and 38% in Europe. A history of diabetes was present in 11% of patients and current injection drug use was reported in 33% of patients. The types of ABSSSI included cellulitis/erysipelas (33%), wound infection (39%), and major cutaneous abscesses (28%). The median area of the primary skin infection was 259 cm².
Efficacy Results
The primary and main secondary outcomes are shown in Table 13.
Table 13 : Primary and Main Secondary Efficacy Outcomes from the Adult Patients with ABSSSI in Trial 2
|
ZEVTERA
n/N (%) |
Vancomycin plus aztreonam
n/N (%) |
Between-group Difference (%) (2-sided 95% CI)* |
| Primary endpoint analyses† |
| Early clinical response at 48-72 hours after start of treatment (ITT) |
306/335 (91.3) |
303/344 (88.1) |
3.3 (-1.2, 7.8) |
| Main secondary endpoint analysis‡ |
| Investigator-assessed clinical success at the TOC visit (ITT) |
302/335 (90.1) |
306/344 (89.0) |
1.0 (-3.5, 5.6) |
* Between-group difference of ceftobiprole minus vancomycin plus aztreonam, using Cochran-Mantel-Haenszel weights method adjusted for geographical region and actual type of ABSSSI.
† Early clinical response based on at least 20% reduction from baseline in the area of the primary lesion, survival for ≥ 72 hours from the time of administration of the first dose of study drug, no use of concomitant systemic antibacterial treatments or topical antibacterial administration on the primary lesion, and no additional unplanned surgical procedure for the ABSSSI after the start of study treatment.
‡ Clinical success was defined as complete (cured) or nearly complete (improved) resolution of baseline signs and symptoms of the primary infection, such that no further antibacterial treatment was needed. |
Clinical response rates at TOC by the most common baseline pathogens in the microbiological ITT (mITT) population, defined as all randomized patients with a baseline pathogen, are presented in Table 14.
Table 14 : Primary Efficacy Outcome by Pathogen from the Adult Patients with ABSSSI in Trial 2
| Pathogen |
Early clinical response at 48-72 hours after start of treatment* (mITT) |
Investigator-assessed clinical success at the TOC visit† (mITT) |
ZEVTERA
n/N (%) |
Vancomycin plus aztreonam
n/N (%) |
ZEVTERA
n/N (%) |
Vancomycin plus aztreonam
n/N (%) |
| Any gram-positive pathogen |
213/228
(93.4) |
220/244
(90.2) |
203/228
(89.0) |
217/244
(88.9) |
| Staphylococcus aureus |
186/197
(94.4) |
185/205
(90.2) |
174/197
(88.3) |
180/205
(87.8) |
| Methicillin-susceptible |
102/108
(94.4) |
112/124
(90.3) |
95/108
(88.0) |
107/124
(86.3) |
| Methicillin-resistant |
81/86
(94.2) |
67/73
(91.8) |
76/86
(88.4) |
66/73
(90.4) |
| Streptococcus pyogenes |
17/20
(85.0) |
23/24
(95.8) |
17/20
(85.0) |
22/24
(91.7) |
| Any gram-negative pathogen |
26/27
(96.3) |
33/37
(89.2) |
24/27
(88.9) |
34/37
(91.9) |
| Enterobacterales |
16/16
(100.0) |
24/27
(88.9) |
15/16
(93.8) |
25/27
(92.6) |
| Klebsiella pneumoniae |
8/8
(100.0) |
5/5
(100.0) |
7/8
(87.5) |
5/5
(100.0) |
* Early clinical response based on at least a 20% reduction from baseline in the area of the primary lesion, survival for ≥ 72 hours from the time of administration of the first dose of study drug, no use of concomitant systemic antibacterial treatments, or topical antibacterial administration on the primary lesion and no additional unplanned surgical procedure for the ABSSSI after the start of study treatment.
† Clinical success was defined as complete (cured) or nearly complete (improved) resolution of baseline signs and symptoms of the primary infection such that no further antibacterial treatment was needed. |
Community-Acquired Bacterial Pneumonia
Adult Patients
Trial Design
The efficacy of ZEVTERA in the treatment of adult patients with community-acquired bacterial pneumonia (CABP) was demonstrated in a randomized, controlled, double-blind, multinational, multicenter study (Trial 3) (NCT00326287). 638 adults hospitalized with CABP and requiring IV antibacterial treatment for at least 3 days were included in the intent-to-treat (ITT) population, comparing ZEVTERA 667 mg (equivalent to 500 mg of ceftobiprole) IV every 8 hours to ceftriaxone (2 grams IV every 24 hours) with optional linezolid (600 mg IV every 12 hours) for the coverage of resistant gram-positive pathogens, including methicillin-resistant S. aureus (MRSA). Randomization was stratified by Pneumonia Outcomes Research Team (PORT) classification I to III versus IV to V, and by the need for adjunctive treatment with linezolid or matching placebo. The treatment duration was 5–14 days. No adjunctive macrolide therapy was allowed. A switch to oral cefuroxime (500 mg every 12 hours) was allowed after at least 72 hours of IV study treatment for patients who met stringent protocol-specified criteria for improvement and were candidates for hospital discharge.
The study enrolled adult patients hospitalized with CABP based on clinical signs and symptoms, fever and/or leukocytosis/leukopenia, and new radiographic evidence of pulmonary infiltrates. Patients with known bronchial obstruction, pulmonary malignancies, cystic fibrosis, lung abscess, pleural effusion as the primary source of infection, active tuberculosis, or pneumonia known or suspected to be caused by atypical bacteria, were excluded from study participation, as were patients with known or suspected extrapulmonary complications such as concomitant meningitis, endocarditis, septic arthritis, or osteomyelitis.
The ITT primary analysis population comprised all patients randomized. The clinically evaluable (CE) population comprised patients in the ITT population who received at least 48 hours of study medication and met protocol-defined criteria regarding clinical evaluability.
The protocol-specified primary efficacy analyses included clinical cure rates at TOC visit, 7 to 14 days after the end-of-treatment (EOT) in the co-primary ITT and CE populations. The ITT population comprised 638 patients (314 ZEVTERA, 324 ceftriaxone ± linezolid), in 103 centers in the USA, Asia, Europe, and Latin America. The CE population comprised 469 patients, and the microbiological ITT (mITT) population comprised 184 patients with at least one valid baseline pathogen.
Baseline Demographic And Disease Characteristics
Patient demographic and baseline characteristics in the ITT population were balanced between the treatment groups. Approximately 62% of patients were classified as White, and 57% were male. The median age was 56 years (range 18–94). 48% of patients were categorized at baseline as PORT classification III to V, and 22% of patients as PORT classification IV or V. 40% of patients did not receive any prior antibacterial drugs within 30 days of randomization. 12% of patients in the ceftriaxone arm received adjunctive linezolid, and 52% of patients in the ITT population switched to oral antibacterial therapy after at least 72 hours of IV study treatment.
Efficacy Results
The results for clinical cure at the test-of-cure visit at Day 7 to 14 after end of treatment are shown in Table 15.
Table 15 : Clinical Cure at Test of Cure visit, 7 to 14 days After End-of-Treatment, in Adult Patients with CABP in Trial 3
|
ZEVTERA
n/N (%) |
Ceftriaxone ± Linezolid
n/N (%) |
Between-group Difference (%) (two-sided 95% CI)* |
| Clinical cure† at TOC visit (ITT) |
240/314
(76.4) |
257/324
(79.3) |
-2.9
(-9.3, 3.6) |
| Clinical cure† at TOC visit (CE) |
200/231
(86.6) |
208/238
(87.4) |
-0.8
(-6.9, 5.3) |
*Between-group difference of ceftobiprole minus ceftriaxone ± linezolid. Two-sided 95% CI is based on the Normal approximation to the difference of the two proportions.
† Clinical cure was defined as survival with resolution of signs and symptoms of the infection or improvement to such an extent that no further antimicrobial therapy was necessary; improvement or stabilization of chest X-ray findings and no receipt of non-study antibacterial treatment for CABP. |
The 30-day all-cause mortality rates in the ITT population were 5/314 (1.6%) for patients treated with ZEVTERA, and 8/324 (2.5%) for patients treated with ceftriaxone ± linezolid group.
As this study was designed prior to the current regulatory guidelines, post-hoc re-analyses were conducted to determine the consistency of study results with these guidelines. These post-hoc analyses considered an earlier timepoint of clinical success at Day 3 in patients in the ITT population, based on survival and the improvement in at least two, and no worsening in any, of the following symptoms: pleuritic chest pain, cough, purulent sputum production or respiratory secretion, tachypnea.
Clinical success at Day 3 was also evaluated in the following analysis populations which were also defined post-hoc:
The Day 3-ITT population included 97% (618 of 638) of ITT patients who had at least two of the following symptoms at baseline: difficulty breathing, cough, production of purulent sputum, or chest pain.
The Day 3-modified ITT population included Day 3-ITT patients with baseline PORT classification of PORT Risk Class ≥ III, at least two of fever, hypothermia, hypotension, tachycardia, and tachypnea, as well as, at least one of new-onset hypoxemia, rales or pulmonary consolidation, and leukocytosis or leukopenia and new radiographic infiltrates (not related to another disease process) consistent with the diagnosis of bacterial pneumonia.
The Day 3-micro ITT population was the subset of the Day 3-ITT patients who had a valid pathogen at baseline.
Results of early clinical success at Day 3 in the Day 3-ITT and Day 3- modified ITT populations are shown in Table 16 below:
Table 16 : Early Clinical Success at Day 3 in Adult Patients with CABP Based on a Post-hoc Analysis of Trial 3
|
ZEVTERA
n/N (%) |
Ceftriaxone ± linezolid
n/N (%) |
Between-group Difference (%) (two-sided 95% CI)* |
| Day-3 ITT Population |
| Clinical Success at Day 3† |
218/307
(71.0) |
221/311
(71.1) |
-0.1%
(-7.2, 7.1) |
| Day-3 modified ITT Population |
| Clinical Success at Day 3 |
69/97
(71.1) |
60/90
(66.7)) |
4.5%
(-8.8, 17.7)) |
*Between-group difference of ceftobiprole minus ceftriaxone ± linezolid. Two-sided 95% CI is based on the Normal approximation to the difference of the two proportions.
† Clinical success based on improvement in at least two, with no worsening in any, of the following symptoms: pleuritic chest pain, cough, purulent sputum production or respiratory secretion, tachypnea. Seven patients in the ZEVTERA arm and 13 patients in the comparator arm did not report any of these symptoms, and were therefore not included in the ITT population for the analysis evaluating early clinical success at Day 3. |
Clinical response rates at TOC by most common baseline pathogen in the mITT population, defined as all randomized patients with a baseline pathogen, are presented in Table 17.
Table 17 : Clinical Cure at Test of Cure Visit and Post-hoc Outcome of Early Clinical Success at Day 3 by Pathogen in Adult CABP Patients in Trial 3
| Pathogen |
Clinical Cure at the TOC visit* (micro-ITT) |
Early Clinical Success at Day 3† (Day 3 micro-ITT) |
ZEVTERA
n/N (%) |
Ceftriaxone ± linezolid
n/N (%) |
ZEVTERA
n/N (%) |
Ceftriaxone ± linezolid
n/N (%) |
| Any gram-positive pathogen |
37/48 (77.1) |
40/53 (75.5) |
36/46 (78.3) |
35/52 (67.3) |
| Staphylococcus aureus |
10/14 (71.4) |
6/10 (60.0) |
10/14 (71.4) |
7/10 (70.0) |
| Methicillin-susceptible |
9/12 (75.0) |
6/10 (60.0) |
8/12 (66.7) |
7/10 (70.0) |
| Streptococcus pneumoniae |
29/35 (82.9) |
33/41 (80.5) |
27/33 (81.8) |
27/41 (65.9) |
| Any gram-negative pathogen |
39/49 (79.6) |
43/51 (84.3) |
35/49 (71.4) |
40/51 (78.4) |
| Enterobacterales spp. |
14/18 (77.8) |
11/16 (68.8) |
14/18 (77.8) |
13/16 (81.3) |
| Escherichia coli |
6/6 (100.0) |
1/4 (25.0) |
6/6 (100.0) |
2/4 (50.0) |
| Klebsiella pneumoniae |
6/8 (75.0) |
7/8 (87.5) |
7/8 (87.5) |
7/8 (87.5) |
| Haemophilus influenzae |
9/10 (90.0) |
15/16 (93.8) |
4/10 (40.0) |
11/16 (68.8) |
| Haemophilus parainfluenzae |
6/9 (66.7) |
7/8 (87.5) |
8/9 (88.9) |
8/8 (100.0) |
* Clinical cure was defined as resolution of signs and symptoms of the infection or improvement to such an extent that no further antimicrobial therapy was necessary; and improvement or stabilization of chest X-ray findings.
† Clinical success based on improvement in at least two, with no worsening in any, of the following symptoms: pleuritic chest pain, cough, purulent sputum production or respiratory secretion, tachypnea. |
Pediatric Patients (3 months to < 18 Years of Age) With CABP
The pediatric pneumonia phase 3 study was a randomized, investigator-blind, active-controlled study in pediatric patients 3 months to < 18 years of age with CABP or hospital-acquired bacterial pneumonia (HABP) requiring IV antibacterial drug treatment (Trial 5) (NCT03439124). Although patients with HABP were included in the study, the safety and effectiveness of ZEVTERA for the treatment of HABP have not been established and ZEVTERA is not approved for the treatment of HABP.
138 pediatric patients were randomized in a 2:1 ratio to ZEVTERA 13.3 mg/kg (equivalent to 10 mg/kg of ceftobiprole) to 26.7 mg/kg (equivalent to 20 mg/kg of ceftobiprole - higher than the recommended approved dose) [see DOSAGE AND ADMINISTRATION]. ZEVTERA was administered by intravenous infusion every 8 hours based on age with a maximum dose of ZEVTERA 667 mg (equivalent to 500 mg of ceftobiprole) (n = 94) or a standard-of-care cephalosporin antibacterial drug (n = 44) for a treatment duration of 7 to 14 days. A switch to an age-appropriate oral antibacterial drug after study Day 3 was allowed.
The primary objective of this study was to evaluate the safety of ZEVTERA. The study was not powered for comparative inferential efficacy analysis, and no efficacy endpoint was identified as primary.
The numbers of patients in the age groups evaluated in the ZEVTERA arm were as follows: 18 pediatric patients aged 12 to < 18 years, 27 pediatric patients aged 6 to < 12 years, 37 pediatric patients aged 2 to < 6 years, and 12 pediatric patients (infants) aged 3 months to < 2 years.
Of the 138 pediatric patients enrolled in the ITT/Safety population, 94% had CABP requiring hospitalization, and 6% had HABP. Patients with ventilator-associated HABP were excluded from the study.
The median treatment duration with ZEVTERA was 6.0 days; 88% of patients treated with ZEVTERA switched to oral antibacterial drugs to complete treatment.
The clinical response was determined at study Day 4, the EOT visit, and at the TOC visit 7 to 14 days after the EOT visit. The ITT population included all patients randomized.
In the ITT population, the clinical response rates in the ZEVTERA and comparator arms were, respectively, 95.7% and 93.2% on Day 4 (between-group difference 2.6% [95% confidence interval (CI): -5.5, 14.7]), 96.8% and 100% at the EOT visit (between-group difference -3.2% [95% CI: -9.1, 5.5]), and 90.4% and 97.7% at the TOC visit (between-group difference -7.3% [95% CI: -15.7, 3.6]).