Orbactiv IV

SIDE EFFECTS

The following adverse reactions are also discussed in the Warnings and Precautions section of labeling:

• Hypersensitivity Reactions [see WARNINGS AND PRECAUTIONS]
• Infusion Related Reactions [see WARNINGS AND PRECAUTIONS]
• Clostridioides difficile-associated Diarrhea [see WARNINGS AND PRECAUTIONS]
• Osteomyelitis [see WARNINGS AND PRECAUTIONS]

Clinical Trials Experience

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

ORBACTIV has been evaluated in two, double-blind, controlled ABSSSI clinical trials, which included 976 adult patients treated with a single 1,200 mg intravenous dose of ORBACTIV and 983 patients treated with intravenous vancomycin for 7 to 10 days. The median age of patients treated with ORBACTIV was 45.6 years, ranging between 18 and 89 years of age with 8.8% ≥65 years of age. Patients treated with ORBACTIV were predominantly male (65.4%), 64.4% were Caucasian, 5.8% were African American, and 28.1% were Asian. Safety was evaluated for up to 60 days after dosing.

In the pooled ABSSSI clinical trials, serious adverse reactions were reported in 57/976 (5.8%) patients treated with ORBACTIV and 58/983 (5.9%) treated with vancomycin. The most commonly reported serious adverse reaction was cellulitis in both treatment groups: 11/976 (1.1%) in ORBACTIV and 12/983 (1.2%) in the vancomycin arms, respectively.

The most commonly reported adverse reactions (≥3%) in patients receiving a single 1,200 mg dose of ORBACTIV in the pooled ABSSSI clinical trials were: headache, nausea, vomiting, limb and subcutaneous abscesses, and diarrhea.

In the pooled ABSSSI clinical trials, ORBACTIV was discontinued due to adverse reactions in 36/976 (3.7%) of patients; the most common reported reactions leading to discontinuation were cellulitis (4/976, 0.4%) and osteomyelitis (3/976, 0.3%).

Table 1 provides selected adverse reactions occurring in ≥1.5% of patients receiving ORBACTIV in the pooled ABSSSI clinical trials. There were 540 (55.3%) patients in the ORBACTIV arm and 559 (56.9%) patients in the vancomycin arm, who reported ≥1 adverse reaction.

Table 1: Incidence of Selected Adverse Reactions Occurring in ≥1.5% of Patients Receiving ORBACTIV in the Pooled ABSSSI Clinical Trials

Adverse Reactions	ORBACTIV N=976 (%)	Vancomycin N=983 (%)
Gastrointestinal disorders
Diarrhea	36 (3.7)	32 (3.4)
Nausea	97 (9.9)	103 (10.5)
Vomiting	45 (4.6)	46 (4.7)
Nervous system disorders
Dizziness	26 (2.7)	26 (2.6)
Headache	69 (7.1)	66 (6.7)
General disorders and administration
Infusion site phlebitis	24 (2.5)	15 (1.5)
Infusion site reaction	19 (1.9)	34 (3.5)
Infections and infestations
Abscess (limb and subcutaneous)	37 (3.8)	23 (2.3)
Investigations
Alanine aminotransferase increased	27 (2.8)	15 (1.5)
Aspartate aminotransferase increased	18 (1.8)	15 (1.5)
Cardiac disorders
Tachycardia	24 (2.5)	11 (1.1)

The following selected adverse reactions were reported in ORBACTIV-treated patients at a rate of less than 1.5%:

Blood and lymphatic system disorders: anemia, eosinophilia

General disorders and administration site conditions: infusion site erythema, extravasation, induration, pruritus, rash, edema peripheral

Immune system disorders: hypersensitivity

Infections and infestations: osteomyelitis

Investigations: total bilirubin increased, hyperuricemia

Metabolism and nutrition disorders: hypoglycemia

Musculoskeletal and connective tissue disorders: tenosynovitis, myalgia

Respiratory, thoracic and mediastinal disorders: bronchospasm, wheezing

Skin and subcutaneous tissue disorders: urticaria, angioedema, erythema multiforme, pruritus, leucocytoclastic vasculitis, rash

Immunogenicity

There is potential for immunogenicity following administration of oritavancin products, including ORBACTIV. The detection of antibody formation is highly dependent on the sensitivity and specificity of the assay. Because several factors in an assay may influence the observed incidence of antibody positivity, comparison of the incidence of antibodies to oritavancin in the studies described below with the incidence of antibodies in other studies or to other products may be misleading.

Positive indirect and direct antiglobulin tests (IAT/DAT) were noted with the administration of ORBACTIV and KIMYRSA (hereinafter referred to as another oritavancin product) in studies with healthy subjects and patients with ABSSSI. In a randomized, open-label, multi-center ABSSSI study, positive antiglobulin tests were reported in 9.6% (5/52) of subjects who received ORBACTIV and 2% (1/50) of subjects who received another oritavancin product. Oritavancindependent RBC antibodies were detected when tested in the presence of drug for three subjects in the ORBACTIV group.

In a multiple dose study with ORBACTIV in healthy volunteers, 90% (9/10) of subjects had a positive IAT 14 days after the second infusion.

In a healthy volunteer study, 66% (22/32) of subjects receiving another oritavancin product had a positive IAT 15 days after receiving dosing and one subject had a positive DAT at 8 days after dosing.

There were no reports of hemolysis in subjects who had positive IAT/DAT. If hemolytic anemia develops following treatment with ORBACTIV provide appropriate care. Positive IAT may interfere with cross-matching before blood transfusion [see DRUG INTERACTIONS].

DRUG INTERACTIONS

Effect Of ORBACTIV On CYP Substrates

A screening drug-drug interaction study indicated that ORBACTIV is a nonspecific, weak inhibitor (CYP2C9 and CYP2C19) or inducer (CYP3A4 and CYP2D6) of several CYP isoforms [see CLINICAL PHARMACOLOGY]. A drug-drug interaction study that assessed the interaction potential of a single 1,200 mg dose of ORBACTIV on the pharmacokinetics of S-warfarin (CYP2C9 probe substrate) showed no effect of ORBACTIV on S-warfarin Cmax or AUC.

Avoid administering ORBACTIV concomitantly with drugs that are predominantly metabolized by one of the affected CYP450 enzymes, as co-administration may increase or decrease concentrations of those drugs. Patients should be closely monitored for signs of toxicity or lack of efficacy if they have been given ORBACTIV while on a potentially affected compound (e.g. patients should be monitored for bleeding if concomitantly receiving ORBACTIV and warfarin).

Drug-Laboratory Test Interactions

Prolongation Of Certain Laboratory Coagulation Tests

ORBACTIV may artificially prolong certain laboratory coagulation tests (see Table 2) by binding to and preventing the action of the phospholipid reagents which activate coagulation in commonly used laboratory coagulation tests [see CONTRAINDICATIONS and WARNINGS AND PRECAUTIONS]. For patients who require monitoring of anticoagulation effect within the indicated time after ORBACTIV dosing, a non-phospholipid dependent coagulation test such as a Factor Xa (chromogenic) assay or an alternative anticoagulant not requiring aPTT monitoring may be considered.

ORBACTIV does not interfere with coagulation in vivo. In addition, ORBACTIV does not affect tests that are used for diagnosis of Heparin Induced Thrombocytopenia (HIT).

Table 2: Coagulation Tests Affected and Unaffected by ORBACTIV

Elevated by ORBACTIV	Unaffected by ORBACTIV
Prothrombin time (PT) up to 12 hours	Chromogenic Factor Xa Assay
International normalized ratio (INR) up to 12 hours	Thrombin Time (TT)
Activated partial thromboplastin time (aPTT) up to 120 hours
Activated clotting time (ACT) up to 24 hours
Silica clot time (SCT) up to 18 hours
Dilute Russell’s viper venom time (DRVVT) up to 72 hours
D-dimer up to 72 hours

Positive Indirect And Direct Antiglobulin Tests (IAT/DAT)

Positive IAT/DAT were noted with administration of oritavancin products, including ORBACTIV, in studies with healthy volunteers and patients with ABSSSI. Positive IAT may interfere with cross-matching before blood transfusion [see ADVERSE REACTIONS].

Read the entire FDA prescribing information for Orbactiv IV (Orbactiv Oritavancin Injection)