Sivextro tedizolid phosphate 200 mg Tablet, Film Coated, 6-count — NDC 67919-041-05 (Billing 67919-0041-05)

12 CLINICAL PHARMACOLOGY

12.1Mechanism of Action Tedizolid is an antibacterial drug [see Microbiology (12.4) ] .

12.2Pharmacodynamics The AUC/minimum inhibitory concentration (MIC) was shown to best correlate with tedizolid activity in animal infection models. In the mouse thigh infection model of S. aureus , antistaphylococcal killing activity was impacted by the presence of granulocytes. In granulocytopenic mice (neutrophil count <100 cells/mL), bacterial stasis was achieved at a human-equivalent dose of approximately 2000 mg/day; whereas, in non-granulocytopenic animals, stasis was achieved at a human-equivalent dose of approximately 100 mg/day.

The safety and efficacy of SIVEXTRO for the treatment of neutropenic patients (neutrophil counts <1000 cells/mm 3 ) have not been evaluated. Cardiac Electrophysiology In a randomized, positive- and placebo-controlled crossover thorough QTc study, 48 enrolled subjects were administered a single oral dose of SIVEXTRO at a therapeutic dose of 200 mg, SIVEXTRO at a supratherapeutic dose of 1200 mg, placebo, and a positive control; no significant effects of SIVEXTRO on heart rate, electrocardiogram morphology, PR, QRS, or QT interval were detected.

Therefore, SIVEXTRO does not affect cardiac repolarization.

12.3Pharmacokinetics Tedizolid phosphate is a prodrug that is converted by phosphatases to tedizolid, the microbiologically active moiety, following oral and intravenous administration. Only the pharmacokinetic profile of tedizolid is discussed further due to negligible systemic exposure of tedizolid phosphate following oral and intravenous administration. Following multiple once-daily oral or intravenous administration, steady-state concentrations are achieved within approximately three days with tedizolid accumulation of approximately 30% (tedizolid half-life of approximately 12 hours).

Pharmacokinetic (PK) parameters of tedizolid following oral and intravenous administration of 200 mg once daily tedizolid phosphate in adults are shown in Table 8 . Table 8: Mean (Standard Deviation) Tedizolid Pharmacokinetic Parameters Following Single and Multiple Oral and Intravenous Administration of 200 mg Once-Daily Tedizolid Phosphate in Adults Pharmacokinetic Parameters of Tedizolid C max , maximum concentration; T max , time to reach C max ; AUC, area under the concentration-time curve; CL, systemic clearance; CL/F, apparent oral clearance Oral Intravenous Single Dose Steady State Single Dose Steady State C max (mcg/mL) 2.0 (0.7) 2.2 (0.6) 2.3 (0.6) 3.0 (0.7) T max (hr) Median (range) 2.5 (1.0 - 8.0) 3.5 (1.0 - 6.0) 1.1 (0.9 - 1.5) 1.2 (0.9 - 1.5) AUC (mcg ∙ hr/mL) AUC is AUC 0- ∞ (AUC from time 0 to infinity) for single-dose administration and AUC 0-24 (AUC from time 0 to 24 hours) for multiple-dose administration 23.8 (6.8) 25.6 (8.5) 26.6 (5.2) 29.2 (6.2) CL or CL/F (L/hr) 7.5 (2.3) 6.9 (1.7) 6.4 (1.2) 5.9 (1.4) Absorption Peak plasma tedizolid concentrations are achieved within approximately 3 hours following oral administration of the oral tablet under fasting conditions or at the end of the 1 hour intravenous infusion of tedizolid phosphate.

The absolute bioavailability of the oral tablet is approximately 91% and no dosage adjustment is necessary between intravenous and oral administration. Tedizolid phosphate (oral tablet) may be administered with or without food as total systemic exposure (AUC 0-∞ ) is unchanged between fasted and fed (high-fat, high-calorie) conditions. Distribution Protein binding of tedizolid to human plasma proteins is approximately 70 to 90%.

The mean steady state volume of distribution of tedizolid in healthy adults following a single intravenous dose of tedizolid phosphate 200 mg ranged from 67 to 80 L (approximately twice total body water). Tedizolid penetrates into the interstitial space fluid of adipose and skeletal muscle tissue with exposure similar to free drug exposure in plasma. Elimination Metabolism Other than tedizolid, which accounts for approxi… [Excerpted — this section continues on DailyMed.]

12.1Mechanism of Action Tedizolid is an antibacterial drug [see Microbiology (12.4) ] .

12.3Pharmacokinetics Tedizolid phosphate is a prodrug that is converted by phosphatases to tedizolid, the microbiologically active moiety, following oral and intravenous administration. Only the pharmacokinetic profile of tedizolid is discussed further due to negligible systemic exposure of tedizolid phosphate following oral and intravenous administration. Following multiple once-daily oral or intravenous administration, steady-state concentrations are achieved within approximately three days with tedizolid accumulation of approximately 30% (tedizolid half-life of approximately 12 hours).

Pharmacokinetic (PK) parameters of tedizolid following oral and intravenous administration of 200 mg once daily tedizolid phosphate in adults are shown in Table 8 . Table 8: Mean (Standard Deviation) Tedizolid Pharmacokinetic Parameters Following Single and Multiple Oral and Intravenous Administration of 200 mg Once-Daily Tedizolid Phosphate in Adults Pharmacokinetic Parameters of Tedizolid C max , maximum concentration; T max , time to reach C max ; AUC, area under the concentration-time curve; CL, systemic clearance; CL/F, apparent oral clearance Oral Intravenous Single Dose Steady State Single Dose Steady State C max (mcg/mL) 2.0 (0.7) 2.2 (0.6) 2.3 (0.6) 3.0 (0.7) T max (hr) Median (range) 2.5 (1.0 - 8.0) 3.5 (1.0 - 6.0) 1.1 (0.9 - 1.5) 1.2 (0.9 - 1.5) AUC (mcg ∙ hr/mL) AUC is AUC 0- ∞ (AUC from time 0 to infinity) for single-dose administration and AUC 0-24 (AUC from time 0 to 24 hours) for multiple-dose administration 23.8 (6.8) 25.6 (8.5) 26.6 (5.2) 29.2 (6.2) CL or CL/F (L/hr) 7.5 (2.3) 6.9 (1.7) 6.4 (1.2) 5.9 (1.4) Absorption Peak plasma tedizolid concentrations are achieved within approximately 3 hours following oral administration of the oral tablet under fasting conditions or at the end of the 1 hour intravenous infusion of tedizolid phosphate.

The absolute bioavailability of the oral tablet is approximately 91% and no dosage adjustment is necessary between intravenous and oral administration. Tedizolid phosphate (oral tablet) may be administered with or without food as total systemic exposure (AUC 0-∞ ) is unchanged between fasted and fed (high-fat, high-calorie) conditions. Distribution Protein binding of tedizolid to human plasma proteins is approximately 70 to 90%.

The mean steady state volume of distribution of tedizolid in healthy adults following a single intravenous dose of tedizolid phosphate 200 mg ranged from 67 to 80 L (approximately twice total body water). Tedizolid penetrates into the interstitial space fluid of adipose and skeletal muscle tissue with exposure similar to free drug exposure in plasma. Elimination Metabolism Other than tedizolid, which accounts for approximately 95% of the total radiocarbon AUC in plasma, there are no other significant circulating metabolites in humans.

There was no degradation of tedizolid in human liver microsomes indicating tedizolid is unlikely to be a substrate for hepatic CYP450 enzymes. In vitro studies showed that conjugation of tedizolid is mediated via multiple sulfotransferase (SULT) isoforms (SULT1A1, SULT1A2, and SULT2A1). Excretion Following single oral administration of 14C-labeled tedizolid phosphate under fasted conditions in adult healthy volunteers, the majority of elimination occurred via the liver, with 82% of the radioactive dose recovered in feces and 18% in urine, primarily as a non-circulating and microbiologically inactive sulfate conjugate.

Most of the elimination of tedizolid (>85%) occurs within 96 hours. Less than 3% of the tedizolid phosphate-administered dose is excreted in feces and urine as unchanged tedizolid. Specific Populations Based on the population pharmacokinetic analysis, there are no clinically relevant demographic or clinical patient factors (including age, gender, race, ethnicity, weight, body mass index, and measures of renal or liver function) that impact the pharmacokinetics of tedizolid.

Patients with Hepatic Impairment Following admi… [Excerpted — this section continues on DailyMed.]

12.2Pharmacodynamics The AUC/minimum inhibitory concentration (MIC) was shown to best correlate with tedizolid activity in animal infection models. In the mouse thigh infection model of S. aureus , antistaphylococcal killing activity was impacted by the presence of granulocytes. In granulocytopenic mice (neutrophil count <100 cells/mL), bacterial stasis was achieved at a human-equivalent dose of approximately 2000 mg/day; whereas, in non-granulocytopenic animals, stasis was achieved at a human-equivalent dose of approximately 100 mg/day.

The safety and efficacy of SIVEXTRO for the treatment of neutropenic patients (neutrophil counts <1000 cells/mm 3 ) have not been evaluated. Cardiac Electrophysiology In a randomized, positive- and placebo-controlled crossover thorough QTc study, 48 enrolled subjects were administered a single oral dose of SIVEXTRO at a therapeutic dose of 200 mg, SIVEXTRO at a supratherapeutic dose of 1200 mg, placebo, and a positive control; no significant effects of SIVEXTRO on heart rate, electrocardiogram morphology, PR, QRS, or QT interval were detected.

Therefore, SIVEXTRO does not affect cardiac repolarization.

14 CLINICAL STUDIES

14.1Acute Bacterial Skin and Skin Structure Infections Adults A total of 1333 adults with acute bacterial skin and skin structure infections (ABSSSI) were randomized in two multicenter, multinational, double-blind, non-inferiority trials. Both trials compared SIVEXTRO 200 mg once daily for 6 days versus linezolid 600 mg every 12 hours for 10 days. In Trial 1, patients were treated with oral therapy, while in Trial 2, patients could receive oral therapy after a minimum of one day of intravenous therapy.

Patients with cellulitis/erysipelas, major cutaneous abscess, or wound infection were enrolled in the trials. Patients with wound infections could have received aztreonam and/or metronidazole as adjunctive therapy for gram-negative bacterial coverage, if needed. The intent-to-treat (ITT) patient population included all randomized patients.

In Trial 1, 332 patients with ABSSSI were randomized to SIVEXTRO and 335 patients were randomized to linezolid. The majority (91%) of patients treated with SIVEXTRO in Trial 1 were less than 65 years old with a median age of 43 years (range: 18 to 86 years). Patients treated with SIVEXTRO were predominantly male (61%) and White (84%); 13% had BMI ≥35 kg/m 2 , 8% had diabetes mellitus, 35% were current or recent intravenous drug users, and 2% had moderate to severe renal impairment.

The overall median surface area of infection was 188 cm 2 . The types of ABSSSI included were cellulitis/erysipelas (41%), wound infection (29%), and major cutaneous abscess (30%). In addition to local signs and symptoms of infection, patients were also required to have at least one regional or systemic sign of infection at baseline, defined as lymphadenopathy (87% of patients), temperature 38°C or higher (16% of patients), white blood cell count greater than 10,000 cells/mm 3 or less than 4000 cells/mm 3 (42%), or 10% or more band forms on white blood cell differential (4%).

The primary endpoint in Trial 1 was early clinical response defined as no increase from baseline lesion area at 48-72 hours after the first dose and oral temperature of ≤37.6°C, confirmed by a second temperature measurement within 24 hours in the ITT population. In Trial 2, 332 patients with ABSSSI were randomized to SIVEXTRO and 334 patients were randomized to linezolid. The majority (87%) of patients treated with SIVEXTRO in Trial 2 were less than 65 years old with a median age of 46 years (range: 17 to 86 years).

Patients treated with SIVEXTRO were predominantly male (68%) and White (86%); 16% had BMI ≥35 kg/m 2 , 10% had diabetes mellitus, 20% were current or recent intravenous drug users, and 4% had moderate to severe renal impairment. The overall median surface area of infection was 231 cm 2 . The types of ABSSSI included were cellulitis/erysipelas (50%), wound infection (30%), and major cutaneous abscess (20%).

In addition to local signs and symptoms of infection, patients were also required to have at least one regional or systemic sign of infection at baseline, defined as lymphadenopathy (71% of patients), temperature 38°C or higher (31% of patients), white blood cell count greater than 10,000 cells/mm 3 or less than 4000 cells/mm 3 (53%), or 10% or more band forms on white blood cell differential (16%). The primary endpoint in Trial 2 was early clinical response defined as at least a 20% decrease from baseline lesion area at 48-72 hours after the first dose in the ITT population ( Table 10 ).

Table 10: Early Clinical Response in the ITT Adult Patient Population SIVEXTRO (200 mg) Linezolid (1200 mg) Treatment Difference (2-sided 95% CI) CI=confidence interval No increase in lesion surface area from baseline and oral temperature of ≤37.6°C, confirmed by a second temperature measurement within 24 hours at 48-72 hours Primary endpoint for Trial 1; sensitivity analysis for Trial 2 Trial 1, N 332 335 Responder, n (%) 264 (79.5) 266 (79.4) 0.1 (-6.1, 6.2) Trial 2, N 332 334 Responder, n (%) 286 (86.1) 281 (84.1) 2.0 (-3.… [Excerpted — this section continues on DailyMed.]

13 NONCLINICAL TOXICOLOGY

13.1Carcinogenesis, Mutagenesis, Impairment of Fertility Carcinogenicity Long-term carcinogenicity studies have not been conducted with tedizolid phosphate. Mutagenesis Tedizolid phosphate was negative for genotoxicity in all in vitro assays (bacterial reverse mutation (Ames), Chinese hamster lung (CHL) cell chromosomal aberration) and in all in vivo tests (mouse bone marrow micronucleus, rat liver unscheduled DNA synthesis). Tedizolid, generated from tedizolid phosphate after metabolic activation ( in vitro and in vivo ), was also tested for genotoxicity.

Tedizolid was positive in an in vitro CHL cell chromosomal aberration assay, but negative for genotoxicity in other in vitro assays (Ames, mouse lymphoma mutagenicity) and in vivo in a mouse bone marrow micronucleus assay. Impairment of Fertility In a fertility study, oral tedizolid phosphate administered in doses of 5, 15, and 50 mg/kg/day for 28 days before mating and during mating to male rats had no adverse effects on the fertility or reproductive performance, including spermatogenesis, at the maximum tested dose (50 mg/kg/day) with a plasma tedizolid AUC approximately 5-fold greater than the plasma AUC value in humans at the maximum recommended human dose (MRHD).

Tedizolid phosphate administered in doses of 2.5, 5, and 15 mg/kg/day for 14 days before mating, during mating, and until Gestation Day (GD)7 to female rats also had no adverse effects on the fertility or reproductive performance at doses up to the maximum tested dose of 15 mg/kg/day (approximately 4-fold higher than exposures in humans at the MRHD based on plasma AUC comparison).

13.2Animal Toxicology and/or Pharmacology Repeated-oral and intravenous dosing of tedizolid phosphate in rats in 1 month and 3 month toxicology studies produced dose- and time-dependent bone marrow hypocellularity (myeloid, erythroid, and megakaryocyte), with associated reduction in circulating RBCs, WBCs, and platelets. These effects showed evidence of reversibility and occurred at plasma tedizolid exposure levels (AUC) ≥6-fold greater than the plasma exposure associated with the human therapeutic dose. In a 1-month immunotoxicology study in rats, repeated oral dosing of tedizolid phosphate was shown to significantly reduce splenic B cells and T cells and reduce plasma IgG titers.

These effects occurred at plasma tedizolid exposure levels (AUC) ≥3-fold greater than the expected human plasma exposure associated with the therapeutic dose.