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Plazomicin Injection

TABLE OF CONTENTS

1. DESCRIPTION 8. USE IN SPECIFIC POPULATIONS
2. INDICATIONS AND USAGE 9. OVERDOSAGE
3. DOSAGE AND ADMINISTRATION 10. MECHANISM OF ACTION
4. CONTRAINDICATIONS 11. PHARMACODYNAMICS
5. WARNINGS AND PRECAUTIONS 12. PHARMACOKINETICS
6. ADVERSE REACTIONS 13. HOW SUPPLIED/STORAGE AND HANDLING

 


WARNING: NEPHROTOXICITY, OTOTOXICITY, NEUROMUSCULAR BLOCKADE and FETAL HARM

 Nephrotoxicity has been reported with plazomicin. The risk of nephrotoxicity is greater in patients with impaired renal function, the elderly, and in those receiving concomitant nephrotoxic medications. Assess creatinine clearance in all patients prior to initiating therapy and daily during therapy [see Dosage and Administration (2.2) and Warnings and Precautions (5.1)]. Therapeutic Drug Monitoring (TDM) is recommended for complicated urinary tract infection (cUTI) patients with CLcr less than 90 mL/min to avoid potentially toxic levels [see Dosage and Administration (3.3, 3.4)].

 Ototoxicity, manifested as hearing loss, tinnitus, and/or vertigo, has been reported with plazomicin. Symptoms of aminoglycoside-associated ototoxicity may be irreversible and may not become evident until after completion of therapy. Aminoglycoside-associated ototoxicity has been observed primarily in patients with a family history of hearing loss, patients with renal impairment, and in patients receiving higher doses and/or longer durations of therapy than recommended [see Warnings and Precautions (5.2)].

 Aminoglycosides have been associated with neuromuscular blockade. During therapy with plazomicin, monitor for adverse reactions associated with neuromuscular blockade, particularly in high-risk patients, such as patients with underlying neuromuscular disorders (including myasthenia gravis) or in patients concomitantly receiving neuromuscular blocking agents [see Warning and Precautions (5.3)].

 Aminoglycosides, including plazomicin, can cause fetal harm when administered to a pregnant woman [see Warnings and Precautions (5.4), Use in Specific Populations (8.1)].


 

1. DESCRIPTION

Plazomicin sulfate is a semi-synthetic aminoglycoside antibacterial derived from sisomicin. The chemical name of plazomicin sulfate is (2"R,3"R,4"R,5"R)-2"- [(1S,2S,3R,4S,6R)-4-amino-6-[(2'"S)-4'"-amino-2'"-hydroxybutanamido)amino]-3-[(2'S,3'R)-3'- amino-6'-((2-hydroxyethylamino)methyl)-3',4'-dihydro-2H-pyran-2'-yloxy]-2- hydroxycyclohexyloxy]-5''-methyl-4''-(methylamino)tetrahydro-2H-pyran-3'',5''-diol sulfate. Plazomicin sulfate contains a theoretical 2.5 molar equivalents of sulfate relative to the freebase, based on complete protonation. The molecular weight of plazomicin sulfate is calculated based on 1:2.5 stoichiometry.

Figure 1: Chemical Structure of Plazomicin Sulfate

Empirical formula: C25H48N6O10∙2.5 H2SO4

Molecular weight: 837.89 g/mol (plazomicin sulfate salt)

592.69 g/mol (free base)

Plazomicin injection 500 mg/10 mL is a sterile, clear, colorless-to-yellow liquid for intravenous administration supplied in 10-mL single-dose Type 1 glass vials. Each vial contains plazomicin sulfate equivalent to 500 mg plazomicin freebase at a concentration of 50 mg/mL adjusted to pH 6.5. Each vial also contains Water for Injection and sodium hydroxide for pH adjustment. This sterile, nonpyrogenic solution is formulated without preservatives.

2. INDICATIONS AND USAGE

2.1 Complicated Urinary Tract Infections (cUTI), including Pyelonephritis

Plazomicin is indicated in patients 18 years of age or older for the treatment of complicated urinary tract infections (cUTI), including pyelonephritis caused by the following susceptible microorganism(s): Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Enterobacter cloacae.

As only limited clinical safety and efficacy data for plazomicin are currently available, reserve plazomicin for use in cUTI patients who have limited or no alternative treatment options [see Clinical Studies].

2.2 Usage

To reduce the development of drug-resistant bacteria and maintain the effectiveness of plazomicin and other antibacterial drugs, plazomicin should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

3. DOSAGE AND ADMINISTRATION

3.1 Recommended Dosage

The recommended dosage regimen of plazomicin is 15 mg/kg administered every 24 hours by intravenous (IV) infusion over 30 minutes in patients 18 years of age or older and with creatinine clearance (CLcr) greater than or equal to 90 mL/min (Table 1). The duration of therapy should be guided by the severity of infection and the patient’s clinical status for up to 7 days. During treatment, dosage adjustments may be required based on change in renal function [see Dosage and Administration (3.3, 3.4)].

Table 1: Dosage Regimen of Plazomicin in Adults With CLcr a Greater Than or Equal to 90 mL/min

a CLcr estimated by the Cockcroft-Gault formula using total body weight (TBW). For patients with TBW greater than ideal body weight (IBW) by 25% or more, use IBW.

b Calculate dosage using TBW. For patients with TBW greater than IBW by 25% or more, use adjusted body weight based on the equation: Adjusted body weight = IBW + 0.4 × [TBW – IBW].

c An appropriate oral therapy may be considered after 4 to 7 days of plazomicin therapy to complete a total duration of 7 to 10 days (IV plus oral). The maximum duration of plazomicin for cUTI is 7 days.

3.2 Monitoring of Renal Function

Assess creatinine clearance in all patients prior to initiating therapy and daily during therapy with plazomicin [see Dosage and Administration (3.3),Warnings and Precautions (5.1) and Use in Specific Populations (8.6)].

3.3 Dosage in Adult Patients With Renal Impairment

The recommended initial dosage regimen of plazomicin in adult patients with CLcr greater than or equal to 15 and less than 90 mL/min, estimated by the Cockcroft-Gault formula, is described in Table 2.

Patients with CLcr greater than or equal to 15 and less than 90 mL/min receiving plazomicin may require subsequent dosage adjustments based on change in renal function and/or Therapeutic Drug Monitoring (TDM) as appropriate [see Dosage and Administration (3.4)].

Table 2: Dosage Regimen of Plazomicin in Adults With CLcr Less Than 90 mL/min

a CLcr estimated by the Cockcroft-Gault formula using total body weight (TBW). For patients with TBW greater than ideal body weight (IBW) by 25% or more, use IBW.

b Calculate dosage using TBW. For patients with TBW greater than IBW by 25% or more, use adjusted body weight based on the equation: Adjusted body weight = IBW + 0.4 × [TBW – IBW].

There is insufficient information to recommend a dosage regimen in patients with CLcr less than 15 mL/min or on renal replacement therapy, including hemodialysis or continuous renal replacement therapy.

3.4 TDM in cUTI Patients With Renal Impairment

For cUTI patients with CLcr greater than or equal to 15 mL/min and less than 90 mL/min, TDM is recommended to maintain plasma trough concentrations below 3 mcg/mL. Measure plazomicin plasma trough concentration within approximately 30 minutes before administration of the second dose of plazomicin. Adjustment of the plazomicin dosage regimen based on TDM involves extending plazomicin dosing interval by 1.5 fold (i.e., from every 24 hours to every 36 hours or from every 48 hours to every 72 hours) for patients with plasma trough concentrations greater than or equal to 3 mcg/mL [see Warnings and Precautions (5.1) and Clinical Pharmacology].

3.5 Preparation of Diluted Solutions of Plazomicin

Plazomicin is supplied as a single-dose fliptop 10-mL vial that contains plazomicin sulfate equivalent to 500 mg plazomicin freebase in 10 mL Water for Injection (concentration of 50 mg/mL). The appropriate volume of plazomicin solution (50 mg/mL) for the required dose should be diluted in 0.9% Sodium Chloride Injection, USP or Lactated Ringer’s Injection, USP to achieve a final volume of 50 mL for intravenous infusion. The stability of plazomicin solution in the compatible diluents is described below [see Dosage and Administration (3.7)].

Plazomicin does not contain preservatives. Aseptic technique must be followed in preparing the infusion solution. Discard unused portion of the plazomicin vial.

Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.

3.6 Stability of Plazomicin Solution in Intravenous Fluids

After dilution, plazomicin solution for administration is stable for 24 hours at room temperature at concentrations of 2.5 mg/mL to 45 mg/mL in the following solutions:

 0.9% Sodium Chloride Injection, USP

 Lactated Ringer’s Injection, USP

3.7 Drug Compatibility

Compatibility of plazomicin for administration with other drugs has not been established. Plazomicin should not be mixed with other drugs or physically added to solutions containing other drugs. Other medications should not be infused simultaneously with plazomicin through the same IV line.

4. CONTRAINDICATIONS

Plazomicin is contraindicated in patients with known hypersensitivity to any aminoglycoside [see Warnings and Precautions (5.5)].

5. WARNINGS AND PRECAUTIONS

5.1 Nephrotoxicity

Nephrotoxicity has been reported with the use of plazomicin [see Adverse Reactions (6.1)]. Most serum creatinine increases were ≤ 1 mg/dL above baseline and reversible.

In Trial 1, the incidence of adverse reactions associated with renal function (acute kidney injury, serum creatinine increased, chronic kidney disease, creatinine clearance decreased, renal failure, renal impairment) was 3.6% (11/303) in plazomicin-treated patients compared with 1.3% (4/301) in meropenem-treated patients [see Adverse Reactions (6.1)].

Serum creatinine increases of 0.5 mg/dL or greater above baseline occurred in 7% (21/300) of plazomicin-treated patients compared with 4% (12/297) of meropenem-treated patients. These increases mainly occurred in patients with CLcr ≤ 90 mL/min and were associated with a plazomicin trough level (Cmin) greater than or equal to 3 mcg/mL [see Adverse Reactions (6.1) and Clinical Pharmacology].

Assess CLcr in all patients prior to initiating therapy and daily during therapy with plazomicin, particularly in those at increased risk of nephrotoxicity, such as those with renal impairment, the elderly, and those receiving concomitant potentially nephrotoxic medications. In the setting of worsening renal function, the benefit of continuing plazomicin should be assessed [see Dosage and Administration (3.2, 3.4), Adverse Reactions (6.1) and Use in Specific Populations (8.5, 8.6)].

Adjust the initial dosage regimen in cUTI patients with CLcr ≥ 15 mL/min and < 60 mL/min [see Dosage and Administration (3.3)]. For subsequent doses, TDM is recommended for patients with CLcr ≥15 mL/min and < 90 mL/min [see Dosage and Administration (3.4)].

5.2 Ototoxicity

Ototoxicity, manifested as hearing loss, tinnitus, and/or vertigo, has been reported with plazomicin. Symptoms of aminoglycoside-associated ototoxicity may be irreversible and may not become evident until after completion of therapy.

Regarding the incidence of adverse reactions associated with cochlear or vestibular function, in Trial 1, there was one case of reversible hypoacusis (1/303;0.3%) in plazomicin-treated patients and one case of tinnitus (1/301;0.3%) in meropenem-treated patients [see Adverse Reactions (6.1)]. In Trial 2, one case each of irreversible tinnitus and reversible vertigo was reported in plazomicin-treated patients, and one case of an abnormal audiogram occurred in a levofloxacintreated patient [see Adverse Reactions (6.1)].

Aminoglycoside-associated ototoxicity has been observed primarily in patients with a family history of hearing loss (excluding age-related hearing loss), patients with renal impairment, and in patients receiving higher doses and/or for longer periods than recommended. In Trial 1 and Trial 2, patients with a history of hearing loss, with the exception of age-related hearing loss, were excluded. The benefit-risk of plazomicin therapy should be considered in these patients.

5.3 Neuromuscular Blockade

Aminoglycosides have been associated with exacerbation of muscle weakness in patients with underlying neuromuscular disorders, or delay in recovery of neuromuscular function in patients receiving concomitant neuromuscular blocking agents.

During therapy with plazomicin, monitor for adverse reactions associated with neuromuscular blockade, particularly in high-risk patients, such as patients with underlying neuromuscular disorders (including myasthenia gravis) or those patients concomitantly receiving neuromuscular blocking agents.

5.4 Fetal Harm

Aminoglycosides, including plazomicin, can cause fetal harm when administered to a pregnant woman. Aminoglycosides cross the placenta, and streptomycin has been associated with several reports of total, irreversible, bilateral congenital deafness in pediatric patients exposed in utero. Patients who use plazomicin during pregnancy, or become pregnant while taking plazomicin should be apprised of the potential hazard to the fetus [see Use in Specific Populations (8.1)].

5.5 Hypersensitivity Reactions

Serious and occasionally fatal hypersensitivity (anaphylactic) reactions have been reported in patients receiving aminoglycoside antibacterial drugs. Before therapy with plazomicin is instituted, careful inquiry about previous hypersensitivity reactions to other aminoglycosides should be made. A history of hypersensitivity to other aminoglycosides is a contraindication to the use of plazomicin, because cross-sensitivity among aminoglycoside antibacterial drugs has been established. Discontinue plazomicin if an allergic reaction occurs.

5.6 Clostridium difficile-Associated Diarrhea

Clostridium difficile-associated diarrhea (CDAD) has been reported for nearly all systemic antibacterial drugs and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial drugs alters the normal flora of the colon and may permit overgrowth of C. difficile.

C. difficile produces toxins A and B that contribute to the development of CDAD. Hypertoxin-producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibacterial use. Careful medical history is necessary because CDAD has been reported to occur more than 2 months after the administration of antibacterial drugs.

If CDAD is suspected or confirmed, antibacterial drugs not directed against C. difficile may need to be discontinued. Manage fluid and electrolyte levels as appropriate, supplement protein intake, monitor antibacterial treatment of C. difficile, and institute surgical evaluation as clinically indicated.

5.7 Development of Drug-Resistant Bacteria

Prescribing plazomicin in the absence of a proven or strongly suspected bacterial infection is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.

6. ADVERSE REACTIONS

The following important adverse reactions are discussed in greater detail in the Warnings and Precautions section:

 Nephrotoxicity [see Warnings and Precautions (5.1)]

 Ototoxicity [see Warnings and Precautions (5.2)]

 Neuromuscular Blockade [see Warnings and Precautions (5.3)]

 Fetal Harm [see Warnings and Precautions (5.4)]

 Hypersensitivity Reactions [see Warnings and Precautions (5.5)]

 Clostridium difficile-Associated Diarrhea [see Warnings and Precautions (5.6)]

6.1 Clinical Trial Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be compared directly to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Plazomicin was evaluated in two comparator-controlled clinical trials (Trial 1, NCT02486627 and Trial 2, NCT01096849) in patients with cUTI, including pyelonephritis. In both trials, patients with CLcr greater than 60 mL/min received plazomicin 15 mg/kg IV once daily as a 30-minute infusion [see Clinical Studies].

Trial 1 included 303 patients treated with plazomicin and 301 patients treated with meropenem. Patients were to receive 4 to 7 days of plazomicin (mean duration of 5.1 days). In some patients, parenteral therapy was followed by a switch to an oral antibacterial drug.

The median age of patients treated with plazomicin in Trial 1 was 62 years (range 18 to 90 years) and 45.2% of patients were 65 years of age or older. Patients treated with plazomicin were predominantly female (56.1%) and White (99.3%). A majority of patients (68.0%) had mild or moderate renal impairment (CLcr >30 to 90 mL/min) at baseline. Patients with CLcr of 30 mL/min or less were excluded.

Adverse Reactions Leading to Treatment Discontinuations in Trial 1

In Trial 1, treatment discontinuation from IV study drug due to an adverse reaction occurred in 2.0% of patients receiving plazomicin (6/303) and meropenem (6/301), respectively.

Common Adverse Reactions in Trial 1

Table 3 lists adverse reactions occurring in 1% or more of patients receiving plazomicin in Trial 1.

Table 3: Incidence (%) of Adverse Reactions Occurring in 1% or More of cUTI Adult Patients Treated With Plazomicin in Trial 1

a 1 g IV every 8 hours.

b Combined term that corresponds to adverse reactions associated with renal function described in Nephrotoxicity section below.

The adverse reactions profile for the cUTI patients in Trial 2 were similar to those observed in Trial 1.

Nephrotoxicity Reported in Trial 1

In Trial 1, serum creatinine increases of 0.5 mg/dL or greater above baseline occurred in 7.0% (21/300) of plazomicin-treated patients compared with 4.0% (12/297) of meropenem-treated patients. Of these, the incidence during IV therapy was 3.7% (11/300) vs 3.0% (9/297) in plazomicin- and meropenem-treated patients, respectively. By the last follow-up visit (between 8 to 43 days after completion of IV therapy), the majority of plazomicin-treated patients (9/11) and all meropenem treated patients (9/9) with serum creatinine increases while on therapy had fully recovered renal function. Serum creatinine increases of 0.5 mg/dL or greater above baseline were observed following completion of IV therapy. These increases were generally ≤ 1.0 mg/dL above baseline and recovered by the next measurement.

In cUTI patients with CLcr of greater than 30 and less than or equal to 90 mL/min, 9.7% (20/207) plazomicin-treated and 4.1% (9/217) meropenem-treated patients had serum creatinine increases of 0.5 mg/dL or greater above baseline. In cUTI patients with CLcr greater than 90 mL/min, 1.1% (1/93) plazomicin-treated and 3.8% (3/80) of meropenem-treated patients had serum creatinine increases of 0.5 mg/dL or greater above baseline [see Use in Specific Populations (8.6)].

Ototoxicity

Pure tone audiometry was evaluated in Phase 1 trials and in Trial 2. Treatment associated ototoxicity could not be definitively excluded according to the American Speech-Language-Hearing Association criteria1 in 2.2% (4/182) of plazomicin-exposed and 2.0% (1/49) of comparator- or placebo-exposed adults.

Other Adverse Reactions Reported with Plazomicin

The following selected adverse reactions were reported in more than one plazomicin-treated patient in Trials 1 and 2 and are not described elsewhere in the labeling: Gastrointestinal disorders: constipation, gastritis Laboratory Investigations: alanine aminotransferase increased Metabolism and nutrition disorders: hypokalemia Nervous system disorders: dizziness Renal and urinary disorders: hematuria Respiratory, thoracic and mediastinal disorders: dyspnea

8. USE IN SPECIFIC POPULATIONS

8.1 Pregnancy

Risk Summary

Aminoglycosides, including plazomicin, can cause fetal harm when administered to a pregnant woman. There are no available data on the use of plazomicin in pregnant women to inform a drug associated risk of adverse developmental outcomes. Published literature reports of streptomycin, an aminoglycoside, state that it can cause total, irreversible, bilateral congenital deafness in children whose mothers received streptomycin during pregnancy. No drug-related visceral or skeletal malformations were observed in pregnant rats and rabbits administered subcutaneous plazomicin during organogenesis at maternal exposures approximately 0.8-fold (rats) and 2.5-fold (rabbits) of the human AUC at the clinical dose of 15 mg/kg/day. Auditory function of offspring was not measured in animal studies (see Data). Advise pregnant women of the potential risk to a fetus.

The background risk of major birth defects and miscarriage for the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.

Data

Animal Data

In an embryo-fetal development study in rats, plazomicin doses of 0, 8, 25, or 50 mg/kg/day administered subcutaneously during organogenesis did not cause drug-related visceral or skeletal malformations, or reduce survival of fetuses. The mid and high doses caused maternal toxicity (reductions in food consumption and body weight gain; increased kidney weight). The high dose resulted in maternal exposure (AUC) approximately 0.8-fold the human AUC at the clinical dose of 15 mg/kg once daily.

In an embryo-fetal development study in rabbits, plazomicin administered subcutaneously at doses of 0, 10, 30, or 50 mg/kg/day did not cause visceral or skeletal malformations or reduced fetal survival. At the high dose, significant maternal toxicity was observed (including renal injury and lethality) and exposure was approximately 2.5-fold the human AUC at the recommended clinical dose.

In a pre- and postnatal development study in rats, maternal animals received subcutaneous plazomicin at 0, 3, 8, or 30 mg/kg/day from the start of organogenesis through lactation. There were no adverse effects on maternal function or pre- and postnatal survival, development, behavior, or reproductive function of the offspring at up to 30 mg/kg/day (0.32-fold human AUC at the clinical daily dose of 15 mg/kg).

8.2 Lactation

Risk Summary

There are no data on the presence of plazomicin in human milk, the effects on the breastfed infant, or the effects on milk production. Plazomicin was detected in rat milk (see Data). The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for plazomicin and any potential adverse effects on the breastfed infant from plazomicin or from the underlying maternal condition.

Data

In a pre- and postnatal development study in rats, low concentrations of plazomicin in maternal milk were detected, with mean concentrations representing 2% to 4% of maternal plasma concentrations. In nursing pups, the systemic exposure (AUC) to plazomicin through lactational exposure was approximately 0.04% of maternal systemic exposure.

8.4. Pediatric Use

The safety and effectiveness of plazomicin in patients less than 18 years of age have not been established.

8.5 Geriatric Use

Of the 425 patients treated with plazomicin in Trials 1 and 2, 40% (170/425) were 65 years of age and older, including 17.2% (73/425) patients 75 years of age and older. In Trial 1, for plazomicin-treated patients ≥ 65 years old, the incidence rate of adverse reactions was 27% (37/137) versus 18.9% (27/143) in the meropenem-treated patients ≥ 65 years old. For plazomicin- treated patients < 65 years old, the incidence rate of adverse reactions was 13.3% (22/166) versus 24.1% (38/158) in the meropenem-treated patients < 65 years old.

The rate of adverse reactions associated with renal function for the plazomicin-treated patients ≥ 65 years old was 6.6% (9/137) versus 2.8% (4/143) in the meropenem-treated patients. For plazomicin- treated patients < 65 years old, the incidence rate of adverse reactions associated with renal function was 1.2% (2/166), versus 0% (0/158) in the meropenem-treated patients [see Clinical Studies and Adverse Reactions (6.1)].

Plazomicin is substantially excreted by the kidneys, and the risk of adverse reactions to plazomicin may be greater in patients with renal impairment. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and renal function should be monitored. Dosage adjustment in elderly patients should take into account renal function and plazomicin concentrations as appropriate [see Dosage and Administration (3.2, 3.3, 3.4) and Clinical Pharmacology].

8.6 Renal Impairment

Plazomicin total body clearance was significantly decreased in patients with CLcr greater than or equal to 15 to less than 60 mL/min compared to patients with CLcr greater than or equal to 60 mL/min [see Clinical Pharmacology]. Monitor CLcr daily and adjust plazomicin dosage accordingly [see Dosage and Administration (3.2)]. There is insufficient information to recommend a dosage regimen in patients with CLcr less than 15 mL/min or on renal replacement therapy, including hemodialysis or continuous renal replacement therapy.

For patients with CLcr greater than or equal to 15 mL/min and less than 90 mL/min, TDM is recommended. Monitor plazomicin trough concentrations and adjust plazomicin dosage accordingly [see Dosage and Administration (3.3, 3.4)].

9. OVERDOSAGE

In the event of overdosage, plazomicin should be discontinued and supportive care is advised. Maintenance of glomerular filtration and careful monitoring of renal function is recommended. Hemodialysis may aid in the removal of plazomicin from the blood, especially if renal function is, or becomes, compromised. No clinical information is available on the use of hemodialysis to treat plazomicin overdosage.

10. MECHANISM OF ACTION

Plazomicin is an antibacterial drug.

Mechanism of Action

Plazomicin is an aminoglycoside that acts by binding to bacterial 30S ribosomal subunit, thereby inhibiting protein synthesis. Plazomicin has concentration-dependent bactericidal activity as measured by time kill studies. In vitro studies demonstrated a plazomicin post-antibiotic effect ranging from 0.2 to 2.6 hours at 2X MIC against Enterobacteriaceae.

Resistance

Resistance to aminoglycosides includes production of aminoglycoside modifying enzymes (AMEs), alteration of the ribosomal target through production of 16S rRNA methyltransferases, up-regulation of efflux pumps and reduced permeability into bacterial cell due to loss of outer membrane porins.

Plazomicin is not inhibited by most AMEs known to affect gentamicin, amikacin and tobramycin, including acetyltransferases (AACs), phosphotransferases (APHs) and nucleotidyltransferases (ANTs). Plazomicin, like other aminoglycosides, is inactive against bacterial isolates that produce 16S rRNA methyltransferases. Plazomicin may have reduced activity against Enterobacteriaceae that overexpress certain efflux pumps (e.g., acrAB-tolC) or lower expression of porins (e.g., ompF or ompK36).

Plazomicin has no in vitro activity against streptococci (including Streptococcus pneumoniae), enterococci (including Enterococcus faecalis, E. faecium), anaerobes, Stenotrophomonas maltophilia and Acinetobacter spp and variable activity against Pseudomonas aeruginosa.

Activity of plazomicin was demonstrated in vitro against Enterobacteriaceae in the presence of certain beta-lactamases, including extended-spectrum beta-lactamases (TEM, SHV, CTX-M, AmpC), serine carbapenemases (KPC-2, KPC-3), and oxacillinase (OXA-48). Bacteria producing metallo-beta-lactamases often co-express 16S rRNA methyltransferase, conferring resistance to plazomicin.

Interaction With Other Antimicrobials

In vitro studies have demonstrated that against Enterobacteriaceae isolates, no antagonism was observed for plazomicin in combination with clindamycin, colistin, daptomycin, fosfomycin, levofloxacin, linezolid, rifampin, tigecycline and vancomycin; few isolates showed synergy with ceftazidime, meropenem and piperacillin-tazobactam. The clinical significance of these findings is unknown.

Animal Infection Models

Plazomicin demonstrated activity in animal models of infection (e.g., thigh infection, lung infection, and septicemia) caused by either amikacin-non-susceptible, gentamicin-non-susceptible, or beta-lactamase producing Enterobacteriaceae.

Antimicrobial Activity

Plazomicin has been shown to be active against most isolates of the following bacteria, both in vitro and in clinical infections [see Indications and Usage (3)]

Aerobic Bacteria

Gram-negative Bacteria

o Escherichia coli

o Klebsiella pneumoniae

o Proteus mirabilis

o Enterobacter cloacae

The following in vitro data are available, but their clinical significance is unknown. At least 90 percent of the following bacteria exhibit in vitro minimum inhibitory concentration (MIC) less than or equal to the susceptible breakpoint for plazomicin against isolates of similar genus or organism group. However, the efficacy of plazomicin in treating clinical infections caused by these bacteria has not been established in adequate and well-controlled clinical trials.

Aerobic Bacteria

Gram-negative Bacteria

o Citrobacter freundii

o Citrobacter koseri

o Enterobacter aerogenes

o Klebsiella oxytoca

o Morganella morganii

o Proteus vulgaris

o Providencia stuartii

o Serratia marcescens

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

11. PHARMACODYNAMICS

The ratio of area under the plasma concentration-time curve to the minimum inhibitory concentration (AUC:MIC) for plazomicin has been shown to best correlate with efficacy in animal and in vitro models of infection against Enterobacteriaceae.

Exposure-Response Relationship for Nephrotoxicity in cUTI Patients

Based on exposure-response analysis for nephrotoxicity, defined as serum creatinine increases greater than or equal to 0.5 mg/dL from baseline, using the data from two cUTI clinical trials (Trial 1 and Trial 2), development of nephrotoxicity was associated with estimated plazomicin exposure (i.e., the plasma trough concentration [Cmin]) in patients with CLcr greater than 30 mL/min and less than or equal to 90 mL/min (N=243). The incidence of nephrotoxicity was higher in patients with plazomicin Cmin greater than or equal to 3 mcg/mL (36%, 10/28) compared to patients with plazomicin Cmin less than 3 mcg/mL (5%, 11/215).

Cardiac Electrophysiology

The effect of plazomicin on the QTc interval was evaluated in a Phase 1 randomized, placebo and positive controlled, double-blind, single-dose, crossover thorough QTc study in 56 healthy adult subjects. At a single dose of 20 mg/kg (1.3 times the maximum recommended dose), plazomicin did not prolong the QTc interval to any clinically relevant extent.

12. PHARMACOKINETICS

The pharmacokinetic (PK) parameters of plazomicin are similar for single- and multiple-dose administration of plazomicin in healthy subjects. No appreciable accumulation of plazomicin was observed following multiple IV infusions of 15 mg/kg administered every 24 hours in subjects with normal renal function. The AUC, maximum plasma concentration (Cmax), and Cmin increased in proportion to the dose over the dose range of 4 to 15 mg/kg. The plazomicin AUC, Cmax, and Cmin are summarized in Table 4.

Table 4: Pharmacokinetic Parameters (Geometric Mean [±SD]) of Plazomicin Following Administration of Plazomicin 15 mg/kg by 30-Minute IV Infusion in Healthy Subjects and cUTI Patients with CLcr Greater than or Equal to 90 mL/min

a PK parameters following a single dose of 15 mg/kg; Based on non-compartmental analysis of PK data; AUC0-inf is reported; Cmin is concentration at 24 hours.

b Day 1 PK parameters following administration of 15 mg/kg; Derived based on population PK model; AUC0-24h is reported.

Distribution

The mean (±SD) volume of distribution of plazomicin in healthy adults and cUTI patients is 17.9 (±4.8) and 30.8 (±12.1) L, respectively. The average binding of plazomicin to human plasma proteins is approximately 20%. The degree of protein binding was concentrationindependent across the range tested in vitro (5 to 100 mcg/mL).

Elimination

The mean (±SD) total body clearance of plazomicin in healthy adults and cUTI patients is 4.5 (±0.9) and 5.1 (±2.01) L/h, respectively. The mean (±SD) half-life of plazomicin was 3.5 h (±0.5) in healthy adults with normal renal function (n=54).

Metabolism

Plazomicin does not appear to be metabolized to any appreciable extent.

Excretion

Plazomicin is primarily excreted by the kidneys. Following a single 15 mg/kg IV dose of radiolabeled plazomicin in healthy subjects, 56% of the total administered radioactivity was recovered in urine within 4 hours, 89.1% was recovered within 168 hours, with less than 0.2% in feces. In total, 97.5% of the dose was recovered in the urine as unchanged plazomicin. The mean renal clearance (±SD) of plazomicin (4.6 [±1.2] L/h) was similar to total body clearance, suggesting that plazomicin is eliminated by the kidneys.

Specific Populations

No clinically significant differences in the pharmacokinetics of plazomicin were observed based on age (18 to 90 years of age), sex, or race/ethnicity. The pharmacokinetics of plazomicin in patients with hepatic impairment is unknown.

Patients with Renal Impairment

Following a single 7.5 mg/kg IV dose (0.5 times the recommended dose) of plazomicin as a 30-minute infusion, the geometric mean AUC0-inf of plazomicin in subjects with mild (CLcr 60 to <90 mL/min, n=6), moderate (CLcr 30 to <60 mL/min, n=6), and severe (CLcr 15 to <30 mL/min, n=6) renal impairment was 1.01-fold, 1.98-fold, and 4.42-fold higher, respectively, compared to subjects with normal renal function (CLcr ≥90 mL/min, n=6) [see Dosage and Administration (3.2) and Use in Specific Populations (8.6)].

Based on the population PK model, the recommended dosage of plazomicin was associated with a mean (±SD) Cmin of 1.0 (±1.3) and 1.7 (±1.4) mcg/mL in cUTI patients with mild (CLcr 60 to <90 mL/min, n=104) and moderate (CLcr 30 to <60 mL/min, n=89) renal impairment, respectively. The mean (±SD) area under the curve from time zero to 24 hours (AUC0-24h) was 261 (±102) and 224 (±147) mcgꞏh/mL in cUTI patients with mild (CLcr 60 to <90 mL/min, n=104) and moderate (CLcr 30 to <60 mL/min, n=89) renal impairment, respectively. There were insufficient data to calculate Cmin and AUC0-24h for patients with severe renal impairment (CLcr 15 to <30 mL/min).

Geriatric Patients

No clinically relevant trend in plazomicin exposure (Cmax and AUC0-24h) was observed with regard to age alone. Higher Cmin in elderly subjects (65 to 90 years of age) as compared to nonelderly adult subjects (18 to 64 years of age) was mainly attributable to age-related changes in renal function [see Dosage and Administration (3.2) and Use in Specific Populations (8.5)].

Drug Interaction Studies

Clinical Studies

Based on the results of a clinical drug-drug interaction (DDI) study that evaluated the effect of a single dose of plazomicin (15 mg/kg) on the single dose plasma PK of metformin, plazomicin did not affect the PK of metformin, which is a substrate of OCT and MATE transporters.

In Vitro Studies

Drug-Metabolizing Enzymes

Plazomicin does not inhibit the following cytochrome P450 isoforms: CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A4/5. Plazomicin does not induce CYP1A2, CYP2B6, and CYP3A4.

Membrane Transporters

Plazomicin is not a substrate of P-gp or BCRP transporters. Plazomicin does not inhibit the following hepatic and renal transporters in vitro at clinically relevant concentrations: P-gp, BCRP, BSEP, MRP2, OATP1B1, OATP1B3, OAT1, OAT3, OCT1, and OCT2. Plazomicin selectively inhibited the MATE1 and MATE2-K renal transporter in vitro with an IC50 value of 1300 and 338 mcg/mL, respectively.

13. HOW SUPPLIED/STORAGE AND HANDLING

How Supplied:

ZEMDRI injection 500 mg/10 mL (50 mg/mL) is supplied in single-dose, 10-mL vials fitted with flip-off seals with royal blue polypropylene buttons as a clear, colorless to yellow, sterile solution. Each vial contains plazomicin sulfate equivalent to 500 mg plazomicin freebase at a concentration of 50 mg/mL plazomicin in Water for Injection. Each vial contains sodium hydroxide for pH adjustment to 6.5. The solution may become yellow in color; this does not indicate a decrease in potency.

Storage and Handling:

Store refrigerated at 2°C to 8°C (36°F to 46°F).

Rx only

Rev 06/18