CLINICAL PHARMACOLOGY
Mechanism Of Action
Eravacycline is an antibacterial drug [see Microbiology].
Pharmacodynamics
The AUC divided by the MIC of eravacycline has been shown to be the best predictor of activity.
Based on the flat exposure-response relationship observed in clinical studies, eravacycline
exposure achieved with the recommended dosage regimen appears to be on the plateau of the
exposure-response curve.
Cardiac Electrophysiology
The effect of XERAVA on the QTc interval was evaluated in a Phase 1 randomized, placebo and
positive controlled, double-blind, single-dose, crossover thorough QTc study in 60 healthy adult
subjects. At the 1.5 mg/kg single dose (1.5 times the maximum approved recommended dose),
XERAVA did not prolong the QTc interval to any clinically relevant extent.
Pharmacokinetics
Following single-dose intravenous administration, eravacycline AUC and Cmax increase
approximately dose-proportionally over doses from 1 mg/kg to 3 mg/kg (3 times the approved
dose).
The mean exposure of eravacycline after single and multiple intravenous infusions
(approximately 60 minutes) of 1 mg/kg administered to healthy adults every 12 hours is
presented in Table 2.
There is approximately 45% accumulation following intravenous dosing of 1 mg/kg every
12 hours.
Table 2: Mean (%CV) Plasma Exposure of Eravacycline After Single and Multiple
Intravenous Dose in Healthy Adults
Exposure [Arithmetic Mean (%CV)] |
Cmax (ng/mL) |
AUC0-12 (ng·h/mL) |
Day 1 |
2125 (15) |
4305 (14)a |
Day 10 |
1825 (16) |
6309 (15)b |
Abbreviations: Cmax = maximum observed plasma concentration, CV = coefficient of variation;
AUC0-12 = area under the plasma concentration-time curve from time 0 to 12 hours.
aAUC of day 1 equals AUC0-12 after the first dose of eravacycline.
bAUC of day 10 equals steady state AUC0-12. |
Distribution
Protein binding of eravacycline to human plasma proteins increases with increasing plasma
concentrations, with 79% to 90% (bound) at plasma concentrations ranging from 100 to
10,000 ng/mL. The volume of distribution at steady-state is approximately 321 L.
Elimination
The mean elimination half-life is 20 hours.
Metabolism
Eravacycline is metabolized primarily by CYP3A4- and FMO-mediated oxidation.
Excretion
Following a single intravenous dose of radiolabeled eravacycline 60 mg, approximately 34% of
the dose is excreted in urine and 47% in feces as unchanged eravacycline (20% in urine and 17%
in feces) and metabolites.
Specific Populations
No clinically significant differences in the pharmacokinetics of eravacycline were observed
based on age (18-86 years), sex, and race.
Patients With Renal Impairment
The geometric least square mean Cmax for eravacycline was increased by 8.8% for subjects with
end stage renal disease (ESRD) versus healthy subjects with 90% CI -19.4, 45.2. The geometric
least square mean AUC0-inf for eravacycline was decreased by 4.0% for subjects with ESRD
versus healthy subjects with 90% CI -14.0, 12.3 [see Use In Specific Populations].
Patients With Hepatic Impairment
Eravacycline Cmax was 13.9%, 16.3%, and 19.7% higher in subjects with mild (Child-Pugh Class
A), moderate (Child-Pugh Class B), and severe (Child-Pugh Class C) hepatic impairment versus
healthy subjects, respectively. Eravacycline AUC0-inf was 22.9%, 37.9%, and 110.3% higher in
subjects with mild, moderate, and severe hepatic impairment versus healthy subjects,
respectively [see DOSAGE AND ADMINISTRATION and Use In Specific Populations].
Drug Interaction Studies
Clinical Studies
Concomitant use of rifampin (strong CYP3A4/3A5 inducer) decreased eravacycline AUC by
35% and increased eravacycline clearance by 54% [see DOSAGE AND ADMINISTRATION and DRUG INTERACTIONS].
Concomitant use of itraconazole (strong CYP3A inhibitor) increased eravacycline Cmax by 5%
and AUC by 32%, and decreased eravacycline clearance by 32%.
In Vitro Studies
Eravacycline is not an inhibitor of CYP1A2, 2B6, 2C8, 2C9, 2C19, 2D6, or 3A4/5. Eravacycline
is not an inducer of CYP1A2, 2B6, or 3A4.
Eravacycline is not a substrate for P-glycoprotein (P-gp), breast cancer resistance protein
(BCRP), bile salt export pump (BSEP), organic anion transporter peptide (OATP)1B1,
OATP1B3, organic ion transporter (OAT)1, OAT3, OCT1, OCT2, multidrug and toxin extrusion
(protein) (MATE)1, or MATE2-K transporters.
Eravacycline is not an inhibitor of BCRP, BSEP, OATP1B1, OATP1B3, OAT1, OAT3, OCT1,
OCT2, MATE1, or MATE2-K transporters.
Microbiology
Mechanism Of Action
Eravacycline is a fluorocycline antibacterial within the tetracycline class of antibacterial drugs.
Eravacycline disrupts bacterial protein synthesis by binding to the 30S ribosomal subunit thus
preventing the incorporation of amino acid residues into elongating peptide chains.
In general, eravacycline is bacteriostatic against gram-positive bacteria (e.g., Staphylococcus
aureus and Enterococcus faecalis); however, in vitro bactericidal activity has been demonstrated
against certain strains of Escherichia coli and Klebsiella pneumoniae.
Resistance
Eravacycline resistance in some bacteria is associated with upregulated, non-specific intrinsic
multidrug-resistant (MDR) efflux, and target-site modifications such as to the 16s rRNA or
certain 30S ribosomal proteins (e.g., S10).
The C7 and C9 substitutions in eravacycline are not present in any naturally occurring or
semisynthetic tetracyclines and the substitution pattern imparts microbiological activities
including in vitro activity against gram-positive and gram-negative strains expressing certain
tetracycline-specific resistance mechanism(s) [i.e., efflux mediated by tet(A), tet(B), and tet(K);
ribosomal protection as encoded by tet(M) and tet(Q)].
Activity of eravacycline was demonstrated in vitro against Enterobacteriaceae in the presence of
certain beta-lactamases, including extended spectrum β-lactamases, and AmpC. However, some
beta-lactamase-producing isolates may confer resistance to eravacycline via other resistance
mechanisms.
The overall frequency of spontaneous mutants in the gram-positive organisms tested was in the
range of 10-9 to 10-10 at 4 times the eravacycline Minimum Inhibitory Concentration (MIC).
Multistep selection of gram-negative strains resulted in a 16- to 32-times increase in eravacycline
MIC for one isolate of Escherichia coli and Klebsiella pneumoniae, respectively. The frequency
of spontaneous mutations in K. pneumoniae was 10-7 to 10-8 at 4 times the eravacycline MIC.
Interaction With Other Antimicrobials
In vitro studies have not demonstrated antagonism between XERAVA and other commonly used
antibacterial drugs for the indicated pathogens.
Antimicrobial Activity
XERAVA has been shown to be active against most isolates of the following microorganisms,
both in vitro and in clinical infections [see INDICATIONS]:
Aerobic bacteria
Gram-positive Bacteria
Enterococcus faecalis
Enterococcus faecium
Staphylococcus aureus
Streptococcus anginosusgroup
Gram-negative Bacteria
Citrobacter freundii
Enterobacter cloacae
Escherichia coli
Klebsiella oxytoca
Klebsiella pneumoniae
Anaerobic bacteria
Gram-positive Bacteria
Clostridium perfringens
Gram-negative Bacteria
Bacteroides caccae
Bacteroides fragilis
Bacteroides ovatus
Bacteroides thetaiotaomicron
Bacteroides uniformis
Bacteroides vulgatus
Parabacteroides distasonis
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 eravacycline against isolates of similar genus or
organism group. However, the efficacy of eravacycline in treating clinical infections caused by these
bacteria has not been established in adequate and well-controlled clinical trials.
Aerobic bacteria
Gram-positive Bacteria
Streptococcus salivarius group
Gram-negative Bacteria
Citrobacter koseri
Enterobacter aerogenes
Susceptibility Test Methods
For specific information regarding susceptibility test interpretive criteria, and associated test methods
and quality control standards recognized by FDA for this drug, please see https://www.fda.gov/STIC.
Animal Toxicology And/Or Pharmacology
In repeated dose toxicity studies in rats, dogs and monkeys, lymphoid depletion/atrophy of
lymph nodes, spleen and thymus, decreased erythrocytes, reticulocytes, leukocytes, and platelets
(dog and monkey), in association with bone marrow hypocellularity, and adverse gastrointestinal
effects (dog and monkey) were observed with eravacycline. These findings were reversible or
partially reversible during recovery periods of 3 to 7 weeks.
Bone discoloration, which was not fully reversible over recovery periods of up to 7 weeks, was
observed in rats and monkeys after 13 weeks of dosing and in the juvenile rat study after dosing
over Post-Natal Days 21-70.
Intravenous administration of eravacycline has been associated with a histamine response in rat
and dog studies.
Clinical Studies
Complicated Intra-Abdominal Infections In Adults
A total of 1,041 adults hospitalized with cIAI were enrolled in two Phase 3, randomized, doubleblind,
active-controlled, multinational, multicenter trials (Trials 1, NCT01844856, and Trial 2,
NCT02784704). These studies compared XERAVA (1 mg/kg intravenous every 12 hours) with
either ertapenem (1 g every 24 hours) or meropenem (1 g every 8 hours) as the active comparator
for 4 to 14 days of therapy. Complicated intra-abdominal infections included appendicitis,
cholecystitis, diverticulitis, gastric/duodenal perforation, intra-abdominal abscess, perforation of
intestine, and peritonitis.
The microbiologic intent-to-treat (micro-ITT) population, which included all patients who had at
least one baseline intra-abdominal pathogen, consisted of 846 patients in the two trials.
Populations in Trial 1 and Trial 2 were similar. The median age was 56 years and 56% were
male. The majority of patients (95%) were from Europe; 5% were from the United States. The
most common primary cIAI diagnosis was intra-abdominal abscess(es), occurring in 60% of
patients. Bacteremia at baseline was present in 8% of patients.
Clinical cure was defined as complete resolution or significant improvement of signs or
symptoms of the index infection at the Test of Cure (TOC) visit which occurred 25 to 31 days
after randomization. Selected clinical responses were reviewed by a Surgical Adjudication
Committee. Table 3 presents the clinical cure rates in the micro-ITT population. Clinical cure
rates at the TOC visit for selected pathogens are presented in Table 4.
Table 3: Clinical Cure Rates at TOC in the Phase 3 cIAI Trials, Micro-ITT
Population
|
Trial 1 |
Trial 2 |
XERAVAa
N=220
n (%) |
Ertapenemb
N=226
n (%) |
XERAVAa
N=195
n (%) |
Meropenemc
N=205
n (%) |
Clinical cure |
191 (86.8) |
198 (87.6) |
177 (90.8) |
187 (91.2) |
Difference (95% CI)d |
-0.80
(-7.1, 5.5) |
-0.5
(-6.3, 5.3) |
Abbreviations: CI = confidence interval; IV = intravenous; micro-ITT = all randomized subjects who had baseline bacterial
pathogens that caused cIAI and against at least one of which the investigational drug has in vitro antibacterial activity; N =
number of subjects in the micro-ITT population; n = number within a specific category with a clinical cure based on the Surgical
Adjudication Committee assessment (if available); TOC=Test of Cure.
a XERAVA dose equals 1 mg/kg every 12 hours IV.
b Ertapenem dose equals1 g every 24 hours IV
c Meropenem dose equals 1 g every 8 hours IV.
d Treatment Difference = Difference in clinical cure rates (eravacycline minus ertapenem or meropenem). Confidence intervals
are calculated using the unadjusted Miettinen-Nurminen method |
Table 4: Clinical Cure Rates at TOC by Selected Baseline Pathogens in Pooled Phase
3 cIAI Trials, Micro-ITT Population
Pathogen |
XERAVAa
N=415
n/N1 (%) |
Comparatorsb
N=431
n/N1 (%) |
Enterobacteriaceae |
271/314 (86.3) |
289/325 (88.9) |
Citrobacter freundii |
19/22 (86.4) |
8/10 (80.0) |
Enterobacter cloacae complex |
17/21 (81.0) |
23/24 (95.8) |
Escherichia coli |
220/253 (87.0) |
237/266 (89.1) |
Klebsiella oxytoca |
14/15 (93.3) |
16/19 (84.2) |
Klebsiella pneumoniae |
37/39 (94.9) |
42/50 (84.0) |
Enterococcus faecalis |
45/54 (83.3) |
47/54 (87.0) |
Enterococcus faecium |
38/45 (84.4) |
48/53 (90.6) |
Staphylococcus aureus |
24/24 (100.0) |
12/14 (85.7) |
Streptococcus anginosus groupc |
79/92 (85.9) |
50/59 (84.7) |
Anaerobesd |
186/215 (86.5) |
194/214 (90.7) |
Abbreviations: IV = intravenous; N = Number of subjects in the micro-ITT Population; N1 = Number of subjects with a specific
pathogen; n = Number of subjects with a clinical cure at the TOC visit. Percentages are calculated as 100 × (n/N1); TOC = Test
of Cure
a XERAVA dose equals 1 mg/kg every 12 hours IV.
b Comparators include Ertapenem 1 g every 24 hours IV and Meropenem 1 g every 8 hours IV.
c Includes Streptococcus anginosus, Streptococcus constellatus, and Streptococcus intermedius
d Includes Bacteroides caccae, Bacteroides fragilis, Bacteroides ovatus, Bacteroides thetaiotaomicron, Bacteroides uniformis,
Bacteroides vulgatus, Clostridium perfringens, and Parabacteroides distasonis. |
Complicated Urinary Tract Infections (cUTI) In Adults
Two randomized, double-blind, active-controlled, clinical trials (Trial 4, NCT01978938, and
Trial 5, NCT03032510) evaluated the efficacy and safety of once-daily intravenous eravacycline
for the treatment of patients with complicated urinary tract infections (cUTI). Trial 4 included an
optional switch from IV to oral therapy with eravacycline. The trials did not demonstrate the
efficacy of XERAVA for the combined endpoints of clinical cure and microbiological success in
the microbiological intent-to-treat (micro-ITT) population at the test-of-cure visit [see INDICATIONS].