ZIAGEN

1 INDICATIONS AND USAGE ZIAGEN tablets and oral solution, in combination with other antiretroviral agents, are indicated for the treatment of human immunodeficiency virus (HIV-1) infection. ZIAGEN, a nucleoside analogue human immunodeficiency virus (HIV-1) reverse transcriptase inhibitor, is indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection. ( 1 )

2 DOSAGE AND ADMINISTRATION • Before initiating ZIAGEN, screen for the HLA-B*5701 allele. ( 2.1 ) • Adults: 600 mg daily, administered as either 300 mg twice daily or 600 mg once daily. ( 2.2 ) • Pediatric Patients Aged 3 Months and Older: Administered either once or twice daily. Dose should be calculated on body weight (kg) and should not exceed 600 mg daily. ( 2.3 ) • Patients with Hepatic Impairment: Mild hepatic impairment – 200 mg twice daily. ( 2.4 ) 2.1 Screening for HLA-B*5701 Allele prior to Starting ZIAGEN Screen for the HLA‑B*5701 allele prior to initiating therapy with ZIAGEN [see Boxed Warning, Warnings and Precautions ( 5.1 )]. 2.2 Recommended Dosage for Adult Patients The recommended dosage of ZIAGEN for adults is 600 mg daily, administered orally as either 300 mg twice daily or 600 mg once daily, in combination with other antiretroviral agents. 2.3 Recommended Dosage for Pediatric Patients The recommended dosage of ZIAGEN oral solution in HIV-1–infected pediatric patients aged 3 months and older is 8 mg per kg orally twice daily or 16 mg per kg orally once daily (up to a maximum of 600 mg daily) in combination with other antiretroviral agents. ZIAGEN is also available as a scored tablet for HIV-1–infected pediatric patients weighing greater than or equal to 14 kg for whom a solid dosage form is appropriate. Before prescribing ZIAGEN tablets, children should be assessed for the ability to swallow tablets. If a child is unable to reliably swallow ZIAGEN tablets, the oral solution formulation should be prescribed. The recommended oral dosage of ZIAGEN tablets for HIV-1–infected pediatric patients is presented in Table 1 . Table 1. Dosing Recommendations for ZIAGEN Scored Tablets in Pediatric Patients a Data regarding the efficacy of once-daily dosing is limited to subjects who transitioned from twice-daily dosing to once-daily dosing after 36 weeks of treatment [see Clinical Studies ( 14.2 )]. Weight (kg) Once-Daily Dosing Regimen a Twice-Daily Dosing Regimen AM Dose PM Dose Total Daily Dose 14 to <20 1 tablet (300 mg) ½ tablet (150 mg) ½ tablet (150 mg) 300 mg ≥20 to <25 1½ tablets (450 mg) ½ tablet (150 mg) 1 tablet (300 mg) 450 mg ≥25 2 tablets (600 mg) 1 tablet (300 mg) 1 tablet (300 mg) 600 mg 2.4 Recommended Dosage for Patients with Hepatic Impairment The recommended dose of ZIAGEN in patients with mild hepatic impairment (Child‑Pugh Class A) is 200 mg twice daily. To enable dose reduction, ZIAGEN oral solution (10 mL twice daily) should be used for the treatment of these patients. The safety, efficacy, and pharmacokinetic properties of abacavir have not been established in patients with moderate to severe hepatic impairment; therefore, ZIAGEN is contraindicated in these patients.

5 WARNINGS AND PRECAUTIONS • Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogues. ( 5.2 ) • Immune reconstitution syndrome has been reported in patients treated with combination antiretroviral therapy. ( 5.3 ) 5.1 Hypersensitivity Reactions Serious and sometimes fatal hypersensitivity reactions have occurred with ZIAGEN (abacavir). These hypersensitivity reactions have included multi-organ failure and anaphylaxis and typically occurred within the first 6 weeks of treatment with ZIAGEN (median time to onset was 9 days); although abacavir hypersensitivity reactions have occurred any time during treatment [see Adverse Reactions ( 6.1 ) ]. Patients who carry the HLA-B*5701 allele are at a higher risk of abacavir hypersensitivity reactions; although, patients who do not carry the HLA‑B*5701 allele have developed hypersensitivity reactions. Hypersensitivity to abacavir was reported in approximately 206 (8%) of 2,670 patients in 9 clinical trials with abacavir-containing products where HLA‑B*5701 screening was not performed. The incidence of suspected abacavir hypersensitivity reactions in clinical trials was 1% when subjects carrying the HLA‑B*5701 allele were excluded. In any patient treated with abacavir, the clinical diagnosis of hypersensitivity reaction must remain the basis of clinical decision making. Due to the potential for severe, serious, and possibly fatal hypersensitivity reactions with ZIAGEN: • All patients should be screened for the HLA‑B*5701 allele prior to initiating therapy with ZIAGEN or reinitiation of therapy with ZIAGEN, unless patients have a previously documented HLA‑B*5701 allele assessment. • ZIAGEN is contraindicated in patients with a prior hypersensitivity reaction to abacavir and in HLA‑B*5701-positive patients. • Before starting ZIAGEN, review medical history for prior exposure to any abacavir-containing product. NEVER restart ZIAGEN or any other abacavir‑containing product following a hypersensitivity reaction to abacavir, regardless of HLA‑B*5701 status. • To reduce the risk of a life-threatening hypersensitivity reaction, regardless of HLA-B*5701 status, discontinue ZIAGEN immediately if a hypersensitivity reaction is suspected, even when other diagnoses are possible (e.g., acute onset respiratory diseases such as pneumonia, bronchitis, pharyngitis, or influenza; gastroenteritis; or reactions to other medications). • If a hypersensitivity reaction cannot be ruled out, do not restart ZIAGEN or any other abacavir-containing products because more severe symptoms which may include life-threatening hypotension and death, can occur within hours. • If a hypersensitivity reaction is ruled out, patients may restart ZIAGEN. Rarely, patients who have stopped abacavir for reasons other than symptoms of hypersensitivity have also experienced life-threatening reactions within hours of reinitiating abacavir therapy. Therefore, reintroduction of ZIAGEN or any other abacavir-containing product is recommended only if medical care can be readily accessed. • A Medication Guide and Warning Card that provide information about recognition of hypersensitivity reactions should be dispensed with each new prescription and refill. 5.2 Lactic Acidosis and Severe Hepatomegaly with Steatosis Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogues, including ZIAGEN. A majority of these cases have been in women. Female sex and obesity may be risk factors for the development of lactic acidosis and severe hepatomegaly with steatosis in patients treated with antiretroviral nucleoside analogues. Treatment with ZIAGEN should be suspended in any patient who develops clinical or laboratory findings suggestive of lactic acidosis or pronounced hepatotoxicity, which may include hepatomegaly and steatosis even in the absence of marked transaminase elevations. 5.3 Immune Reconstitut…

4 CONTRAINDICATIONS ZIAGEN is contraindicated in patients: • who have the HLA‑B*5701 allele [see Warnings and Precautions ( 5.1 )]. • with prior hypersensitivity reaction to abacavir [see Warnings and Precautions ( 5.1 )]. • with moderate or severe hepatic impairment [see Use in Specific Populations ( 8.6 )]. • Presence of HLA-B*5701 allele. ( 4 ) • Prior hypersensitivity reaction to abacavir. ( 4 ) • Moderate or severe hepatic impairment. ( 4 )

7 DRUG INTERACTIONS • Methadone: An increased methadone dose may be required in a small number of patients. ( 7.1 ) • Riociguat: The riociguat dose may need to be reduced. ( 7.2 ) 7.1 Methadone In a trial of 11 HIV‑1–infected subjects receiving methadone‑maintenance therapy with 600 mg of ZIAGEN twice daily (twice the currently recommended dose), oral methadone clearance increased [see Clinical Pharmacology ( 12.3 )] . This alteration will not result in a methadone dose modification in the majority of patients; however, an increased methadone dose may be required in a small number of patients. 7.2 Riociguat Coadministration with fixed-dose abacavir/dolutegravir/lamivudine resulted in increased riociguat exposure, which may increase the risk of riociguat adverse reactions [see Clinical Pharmacology ( 12.3 )] . The riociguat dose may need to be reduced. See full prescribing information for ADEMPAS (riociguat).

8.1 Pregnancy Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to ZIAGEN during pregnancy. Healthcare Providers are encouraged to register patients by calling the Antiretroviral Pregnancy Registry (APR) at 1-800-258-4263. Risk Summary Available data from the APR show no difference in the overall risk of birth defects for abacavir compared with the background rate for birth defects of 2.7% in the Metropolitan Atlanta Congenital Defects Program (MACDP) reference population (see Data) . The APR uses the MACDP as the U.S. reference population for birth defects in the general population. The MACDP evaluates women and infants from a limited geographic area and does not include outcomes for births that occurred at less than 20 weeks’ gestation. The rate of miscarriage is not reported in the APR. The estimated background rate of miscarriage in clinically recognized pregnancies in the U.S. general population is 15% to 20%. The background risk for major birth defects and miscarriage for the indicated population is unknown. In animal reproduction studies, oral administration of abacavir to pregnant rats during organogenesis resulted in fetal malformations and other embryonic and fetal toxicities at exposures 35 times the human exposure (AUC) at the recommended clinical daily dose. However, no adverse developmental effects were observed following oral administration of abacavir to pregnant rabbits during organogenesis, at exposures approximately 9 times the human exposure (AUC) at the recommended clinical dose (see Data) . Data Human Data: Based on prospective reports to the APR of exposures to abacavir during pregnancy resulting in live births (including over 1,300 exposed in the first trimester and over 1,300 exposed in the second/third trimester), there was no difference between the overall risk of birth defects for abacavir compared with the background birth defect rate of 2.7% in the U.S. reference population of the MACDP. The prevalence of defects in live births was 3.2% (95% CI: 2.3% to 4.3%) following first trimester exposure to abacavir-containing regimens and 2.9% (95% CI: 2.1% to 4.0%) following second/third trimester exposure to abacavir-containing regimens. Abacavir has been shown to cross the placenta and concentrations in neonatal plasma at birth were essentially equal to those in maternal plasma at delivery [see Clinical Pharmacology ( 12.3 )] . Animal Data: Abacavir was administered orally to pregnant rats (at 100, 300, and 1,000 mg per kg per day) and rabbits (at 125, 350, or 700 mg per kg per day) during organogenesis (on Gestation Days 6 through 17 and 6 through 20, respectively). Fetal malformations (increased incidences of fetal anasarca and skeletal malformations) or developmental toxicity (decreased fetal body weight and crown‑rump length) were observed in rats at doses up to 1,000 mg per kg per day, resulting in exposures approximately 35 times the human exposure (AUC) at the recommended daily dose. No developmental effects were observed in rats at 100 mg per kg per day, resulting in exposures (AUC) 3.5 times the human exposure at the recommended daily dose. In a fertility and early embryo-fetal development study conducted in rats (at 60, 160, or 500 mg per kg per day), embryonic and fetal toxicities (increased resorptions, decreased fetal body weights) or toxicities to the offspring (increased incidence of stillbirth and lower body weights) occurred at doses up to 500 mg per kg per day. No developmental effects were observed in rats at 60 mg per kg per day, resulting in exposures (AUC) approximately 4 times the human exposure at the recommended daily dose. Studies in pregnant rats showed that abacavir is transferred to the fetus through the placenta. In pregnant rabbits, no developmental toxicities and no increases in fetal malformations occurred at up to the highest dose evaluated, resulting in exposures (AUC) approximately 9 times the human exp…

6 ADVERSE REACTIONS The following adverse reactions are discussed in other sections of the labeling: • Serious and sometimes fatal hypersensitivity reactions [see Boxed Warning, Warnings and Precautions ( 5.1 )] . • Lactic acidosis and severe hepatomegaly with steatosis [see Warnings and Precautions ( 5.2 )] . • Immune reconstitution syndrome [see Warnings and Precautions ( 5.3 )] . • Myocardial infarction [see Warnings and Precautions ( 5.4 )] . • The most commonly reported adverse reactions of at least moderate intensity (incidence greater than or equal to 10%) in adult HIV-1 clinical trials were nausea, headache, malaise and fatigue, nausea and vomiting, and dreams/sleep disorders. ( 6.1 ) • The most commonly reported adverse reactions of at least moderate intensity (incidence greater than or equal to 5%) in pediatric HIV-1 clinical trials were fever and/or chills, nausea and vomiting, skin rashes, and ear/nose/throat infections. ( 6.2 ) To report SUSPECTED ADVERSE REACTIONS, contact ViiV Healthcare at 1-877-844-8872 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience in Adult Subjects Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. Serious and Fatal Abacavir-Associated Hypersensitivity Reactions In clinical trials, serious and sometimes fatal hypersensitivity reactions have occurred with abacavir [see Boxed Warning, Warnings and Precautions ( 5.1 )]. These reactions have been characterized by 2 or more of the following signs or symptoms: (1) fever; (2) rash; (3) gastrointestinal symptoms (including nausea, vomiting, diarrhea, or abdominal pain); (4) constitutional symptoms (including generalized malaise, fatigue, or achiness); (5) respiratory symptoms (including dyspnea, cough, or pharyngitis). Almost all abacavir hypersensitivity reactions include fever and/or rash as part of the syndrome. Other signs and symptoms have included lethargy, headache, myalgia, edema, arthralgia, and paresthesia. Anaphylaxis, liver failure, renal failure, hypotension, adult respiratory distress syndrome, respiratory failure, myolysis, and death have occurred in association with these hypersensitivity reactions. Physical findings have included lymphadenopathy, mucous membrane lesions (conjunctivitis and mouth ulcerations), and maculopapular or urticarial rash (although some patients had other types of rashes and others did not have a rash). There were reports of erythema multiforme. Laboratory abnormalities included elevated liver chemistries, elevated creatine phosphokinase, elevated creatinine, and lymphopenia, and abnormal chest x-ray findings (predominantly infiltrates, which were localized). Additional Adverse Reactions with Use of ZIAGEN Therapy-Naive Adults: Treatment-emergent clinical adverse reactions (rated by the investigator as moderate or severe) with a greater than or equal to 5% frequency during therapy with ZIAGEN 300 mg twice daily, lamivudine 150 mg twice daily, and efavirenz 600 mg daily compared with zidovudine 300 mg twice daily, lamivudine 150 mg twice daily, and efavirenz 600 mg daily from CNA30024 are listed in Table 2 . Table 2. Treatment-Emergent (All Causality) Adverse Reactions of at Least Moderate Intensity (Grades 2-4, Greater than or Equal to 5% Frequency) in Therapy-Naive Adults (CNA30024 a ) through 48 Weeks of Treatment a This trial used double-blind ascertainment of suspected hypersensitivity reactions. During the blinded portion of the trial, suspected hypersensitivity to abacavir was reported by investigators in 9% of 324 subjects in the abacavir group and 3% of 325 subjects in the zidovudine group. b Ten (3%) cases of suspected drug hypersensitivity were reclassified as not being due to abacavir following unblinding. Adverse Reaction ZIAGEN plus Lamivudine…