VIREAD is the brand name for tenofovir disoproxil fumarate (TDF) (a prodrug of tenofovir) which is a fumaric acid salt of bis-isopropoxycarbonyloxymethyl ester derivative of tenofovir. TDF is converted in vivo to tenofovir, an acyclic nucleoside phosphonate (nucleotide) analog of adenosine 5'-monophosphate. Tenofovir exhibits activity against HIV-1 reverse transcriptase. The chemical name of TDF is 9-[( R )-2-[[bis[[(isopropoxycarbonyl)oxy]methoxy]phosphinyl]methoxy]propyl]adenine fumarate (1:1). It has a molecular formula of C 19 H 30 N 5 O 10 P ∙ C 4 H 4 O 4 and a molecular weight of 635.52. It has the following structural formula: Tenofovir disoproxil fumarate is a white to off-white crystalline powder with a solubility of 13.4 mg/mL in distilled water at 25 °C. It has an octanol/phosphate buffer (pH 6.5) partition coefficient (log p) of 1.25 at 25 °C. VIREAD is available as tablets or as an oral powder. VIREAD tablets are for oral administration and are available in the following strengths: 150 mg, 200 mg, 250 mg, and 300 mg of TDF (equivalent to 123 mg, 163 mg, 204 mg, and 245 mg of tenofovir disoproxil, respectively). All strengths of VIREAD tablets contain the following inactive ingredients: croscarmellose sodium, lactose monohydrate, magnesium stearate, microcrystalline cellulose, and pregelatinized starch. The 300 mg strength tablets are coated with Opadry II Y-30-10671-A, which contains FD&C blue #2 aluminum lake, hypromellose 2910, lactose monohydrate, titanium dioxide, and triacetin. The 150 mg, 200 mg, and 250 mg strength tablets are coated with Opadry II 32K-18425, which contains hypromellose 2910, lactose monohydrate, titanium dioxide, and triacetin. VIREAD oral powder is available for oral administration as white, taste-masked, coated granules containing 40 mg of TDF per gram of oral powder (equivalent to 33 mg of tenofovir disoproxil). The oral powder contains the following inactive ingredients: mannitol, hydroxypropyl cellulose, ethylcellulose, and silicon dioxide. In this insert, all dosages are expressed in terms of TDF except where otherwise noted. Chemical Structure

VIREAD is a nucleotide analog HIV-1 reverse transcriptase inhibitor and an HBV reverse transcriptase inhibitor and is indicated: in combination with other antiretroviral agents for the treatment of HIV-1 infection in adults and pediatric patients 2 years of age and older weighing at least 10 kg. for the treatment of chronic hepatitis B in adults and pediatric patients 2 years and older weighing at least 10 kg

HIV-1 Infection VIREAD is indicated in combination with other antiretroviral agents for the treatment of human immunodeficiency virus type 1 (HIV-1) infection in adults and pediatric patients 2 years of age and older weighing at least 10 kg

Chronic Hepatitis B VIREAD is indicated for the treatment of chronic hepatitis B virus (HBV) in adults and pediatric patients 2 years of age and older weighing at least 10 kg .

VIREAD is available as tablets in four dose strengths or as an oral powder. 150 mg Tablets: 150 mg of tenofovir disoproxil fumarate (TDF) (equivalent to 123 mg of tenofovir disoproxil): triangle shaped, white, film coated, debossed with "GSI" on one side and with "150" on the other side. 200 mg Tablets: 200 mg of TDF (equivalent to 163 mg of tenofovir disoproxil): round shaped, white, film coated, debossed with "GSI" on one side and with "200" on the other side. 250 mg Tablets: 250 mg of TDF (equivalent to 204 mg of tenofovir disoproxil): capsule shaped, white, film coated, debossed with "GSI" on one side and with "250" on the other side. 300 mg Tablets: 300 mg of TDF (equivalent to 245 mg of tenofovir disoproxil): almond shaped, light blue, film coated, debossed with "GILEAD" and "4331" on one side and with "300" on the other side. Oral Powder: white, taste-masked, coated granules containing 40 mg of TDF (equivalent to 33 mg of tenofovir disoproxil) per level scoop. Each level scoop contains 1 gram of oral powder. Tablets: 150 mg, 200 mg, 250 mg, and 300 mg of tenofovir disoproxil fumarate. Oral Powder: 40 mg per 1 g of oral powder of tenofovir disoproxil fumarate.

Testing: Prior to or when initiating VIREAD test for hepatitis B virus infection and HIV-1 infection. Prior to initiation and during use of VIREAD, on a clinically appropriate schedule, assess serum creatinine, estimated creatinine clearance, urine glucose, and urine protein in all patients. In patients with chronic kidney disease, also assess serum phosphorous. Recommended tablet dosage in adults and pediatric patients weighing at least 35 kg: One VIREAD 300 mg tablet once daily taken orally without regard to food. Recommended dosage in pediatric patients at least 2 years of age and adults: Tablets: For patients weighing at least 17 kg who can swallow an intact tablet, one VIREAD tablet (150 mg, 200 mg, 250 mg, or 300 mg based on body weight) once daily taken orally without regard to food. Oral powder: For patients weighing at least 10 kg and unable to swallow a tablet, 8 mg per kg VIREAD oral powder (up to a maximum of 300 mg) taken once daily with food. Recommended dosage in renally impaired adult patients: Creatinine clearance (CrCl) 30–49 mL/min: 300 mg every 48 hours. CrCl 10–29 mL/min: 300 mg every 72 to 96 hours. Hemodialysis: 300 mg every 7 days or after approximately 12 hours of dialysis

Testing Prior to Initiation of VIREAD for Treatment of HIV-1 Infection or Chronic Hepatitis B Prior to or when initiating VIREAD, test patients for HBV infection and HIV-1 infection. VIREAD alone should not be used in patients with HIV-1 infection . Prior to initiation and during use of VIREAD, on a clinically appropriate schedule, assess serum creatinine, estimated creatinine clearance, urine glucose and urine protein in all patients. In patients with chronic kidney disease, also assess serum phosphorus

Recommended Tablet Dosage in Adults and Pediatric Patients 2 Years and Older Weighing at Least 17 kg The recommended dosage of VIREAD in adults and pediatric patients weighing at least 35 kg is one 300 mg tablet taken orally once daily without regard to food . The dosage for VIREAD is the same for both HIV and HBV indications. The recommended dosage of VIREAD tablet in adults and pediatric patients 2 years and older weighing at least 17 kg is 8 mg of tenofovir disoproxil fumarate (TDF) per kg of body weight (up to a maximum of 300 mg) once daily. Dosage for pediatric patients 2 years and older weighing between 17 kg and 35 kg and able to swallow an intact tablet is provided in Table 1. Weight should be monitored periodically and the VIREAD dose adjusted accordingly. Table 1 Recommended Dosing for Patients 2 Years and Older and Weighing at Least 17 kg Using VIREAD Tablets Body Weight (kg) Dosing of VIREAD Tablets 17 to less than 22 one 150 mg tablet once daily 22 to less than 28 one 200 mg tablet once daily 28 to less than 35 one 250 mg tablet once daily at least 35 one 300 mg tablet once daily 2.3 Recommended Oral Powder Dosage in Adults and Pediatric Patients 2 Years and Older Weighing at Least 10 kg The recommended dosage of VIREAD oral powder in adults and pediatric patients 2 years and older weighing at least 10 kg who are unable to swallow a tablet is 8 mg of TDF per kg of body weight (up to a maximum of 300 mg) once daily administered as oral powder . Weight should be monitored periodically and the VIREAD dose adjusted accordingly. VIREAD oral powder should be measured only with the supplied dosing scoop. One level scoop delivers 1 g of powder, which contains 40 mg of TDF. VIREAD oral powder should be mixed in a container with 2 to 4 ounces of soft food not requiring chewing (e.g., applesauce, baby food, yogurt). The entire mixture should be ingested immediately to avoid a bitter taste. Do not administer VIREAD oral powder in a liquid as the powder may float on top of the liquid even after stirring. Further patient instructions on how to administer VIREAD oral powder with the supplied dosing scoop are provided in the FDA-approved patient labeling (Patient Information). Table 2 Dosing for Patients 2 Years and Older Weighing at least 10 kg Using VIREAD Oral Powder Body Weight (kg) Dosing of VIREAD Oral Powder Total Daily Dosage (40 mg per scoop) 10 to less than 12 2 scoops once daily 80 mg 12 to less than 14 2.5 scoops once daily 100 mg 14 to less than 17 3 scoops once daily 120 mg 17 to less than 19 3.5 scoops once daily 140 mg 19 to less than 22 4 scoops once daily 160 mg 22 to less than 24 4.5 scoops once daily 180 mg 24 to less than 27 5 scoops once daily 200 mg 27 to less than 29 5.5 scoops once daily 220 mg 29 to less than 32 6 scoops once daily 240 mg 32 to less than 34 6.5 scoops once daily 260 mg 34 to less than 35 7 scoops once daily 280 mg at least 35 7.5 scoops once daily 300 mg 2.4 Dosage Adjustment in Patients with Renal Impairment Significant increase in drug exposures occurred when VIREAD was administered to subjects with moderate to severe renal impairment (creatinine clearance below 50 mL/min). Table 3 provides dosage interval adjustment for patients with renal impairment. No dosage adjustment of VIREAD tablets 300 mg is necessary for patients with mild renal impairment (creatinine clearance 50–80 mL/min) . Table 3 Dosage Interval Adjustment for Adult Patients with Altered Creatinine Clearance Creatinine Clearance (mL/min) Calculated using ideal (lean) body weight. Hemodialysis Patients 50 or greater 30–49 10–29 Recommended 300 mg Dosing Interval Every 24 hours Every 48 hours Every 72 to 96 hours Every 7 days or after a total of approximately 12 hours of dialysis Generally once weekly assuming 3 hemodialysis sessions a week of approximately 4 hours' duration. VIREAD should be administered following completion of dialysis. No data are available to make dosage recommendations in patients with creatinine clearance below 10 mL/min who are not on hemodialysis. No data are available to make dosage recommendations in pediatric patients with renal impairment.

New onset or worsening renal impairment: Can include acute renal failure and Fanconi syndrome. Avoid administering VIREAD with concurrent or recent use of nephrotoxic drugs. HIV testing: HIV antibody testing should be offered to all HBV-infected patients before initiating therapy with VIREAD. VIREAD should only be used as part of an appropriate antiretroviral combination regimen in HIV-infected patients with or without HBV coinfection. Immune reconstitution syndrome: May necessitate further evaluation and treatment. Decreases in bone mineral density (BMD): Consider assessment of BMD in patients with a history of pathologic fracture or other risk factors for osteoporosis or bone loss. Lactic acidosis/severe hepatomegaly with steatosis: Discontinue treatment in patients who develop symptoms or laboratory findings suggestive of lactic acidosis or pronounced hepatotoxicity. 5.1 Severe Acute Exacerbation of Hepatitis B in Patients with HBV Infection All patients should be tested for the presence of chronic hepatitis B virus (HBV) before or when initiating VIREAD . Discontinuation of anti-HBV therapy, including VIREAD, may be associated with severe acute exacerbations of hepatitis B. Patients infected with HBV who discontinue VIREAD should be closely monitored with both clinical and laboratory follow-up for at least several months after stopping treatment. If appropriate, resumption of anti-hepatitis B therapy may be warranted, especially in patients with advanced liver disease or cirrhosis, since posttreatment exacerbation of hepatitis may lead to hepatic decompensation and liver failure

New Onset or Worsening Renal Impairment Tenofovir is principally eliminated by the kidney. Renal impairment, including cases of acute renal failure and Fanconi syndrome (renal tubular injury with severe hypophosphatemia), has been reported with the use of VIREAD . Prior to initiation and during use of VIREAD, on a clinically appropriate schedule, assess serum creatinine, estimated creatinine clearance, urine glucose, and urine protein in all patients. In patients with chronic kidney disease, also assess serum phosphorus. Dosing interval adjustment of VIREAD and close monitoring of renal function are recommended in all patients with creatinine clearance below 50 mL/min . No safety or efficacy data are available in patients with renal impairment who received VIREAD using these dosing guidelines, so the potential benefit of VIREAD therapy should be assessed against the potential risk of renal toxicity. VIREAD should be avoided with concurrent or recent use of a nephrotoxic agent (e.g., high-dose or multiple non-steroidal anti-inflammatory drugs [NSAIDs]) . Cases of acute renal failure after initiation of high-dose or multiple NSAIDs have been reported in HIV-infected patients with risk factors for renal dysfunction who appeared stable on TDF. Some patients required hospitalization and renal replacement therapy. Alternatives to NSAIDs should be considered, if needed, in patients at risk for renal dysfunction. Persistent or worsening bone pain, pain in extremities, fractures and/or muscular pain or weakness may be manifestations of proximal renal tubulopathy and should prompt an evaluation of renal function in patients at risk of renal dysfunction

Patients Coinfected with HIV-1 and HBV Due to the risk of development of HIV-1 resistance, VIREAD should only be used in HIV-1 and HBV coinfected patients as part of an appropriate antiretroviral combination regimen. HIV-1 antibody testing should be offered to all HBV-infected patients before initiating therapy with VIREAD. It is also recommended that all patients with HIV-1 be tested for the presence of chronic hepatitis B before initiating treatment with VIREAD

Immune Reconstitution Syndrome Immune reconstitution syndrome has been reported in HIV-1 infected patients treated with combination antiretroviral therapy, including VIREAD. During the initial phase of combination antiretroviral treatment, HIV-1 infected patients whose immune system responds may develop an inflammatory response to indolent or residual opportunistic infections (such as Mycobacterium avium infection, cytomegalovirus, Pneumocystis jirovecii pneumonia [PCP], or tuberculosis), which may necessitate further evaluation and treatment. Autoimmune disorders (such as Graves' disease, polymyositis, and Guillain-Barré syndrome) have also been reported to occur in the setting of immune reconstitution; however, the time to onset is more variable, and can occur many months after initiation of treatment

Bone Loss and Mineralization Defects Bone Mineral Density In clinical trials in HIV-1 infected adults, VIREAD was associated with slightly greater decreases in bone mineral density (BMD) and increases in biochemical markers of bone metabolism, suggesting increased bone turnover relative to comparators . Serum parathyroid hormone levels and 1,25 Vitamin D levels were also higher in subjects receiving VIREAD. Clinical trials evaluating VIREAD in pediatric subjects were conducted. Under normal circumstances, BMD increases rapidly in pediatric patients. In HIV-1 infected subjects 2 years to less than 18 years of age, bone effects were similar to those observed in adult subjects and suggest increased bone turnover. Total body BMD gain was less in the VIREAD-treated HIV-1 infected pediatric subjects as compared to the control groups. Similar trends were observed in chronic HBV-infected pediatric subjects 2 years to less than 18 years of age. In all pediatric trials, normal skeletal growth (height) was not affected for the duration of the clinical trials . The effects of VIREAD-associated changes in BMD and biochemical markers on long-term bone health and future fracture risk in adults and pediatric subjects 2 years and older are unknown. The long-term effect of lower spine and total body BMD on skeletal growth in pediatric patients, and in particular, the effects of long-duration exposure in younger children is unknown. Although the effect of supplementation with calcium and vitamin D was not studied, such supplementation may be beneficial. Assessment of BMD should be considered for adult and pediatric patients who have a history of pathologic bone fracture or other risk factors for osteoporosis or bone loss. If bone abnormalities are suspected, appropriate consultation should be obtained. Mineralization Defects Cases of osteomalacia associated with proximal renal tubulopathy, manifested as bone pain or pain in extremities and which may contribute to fractures, have been reported in association with VIREAD use . Arthralgia and muscle pain or weakness have also been reported in cases of proximal renal tubulopathy. Hypophosphatemia and osteomalacia secondary to proximal renal tubulopathy should be considered in patients at risk of renal dysfunction who present with persistent or worsening bone or muscle symptoms while receiving TDF-containing products

Lactic Acidosis/Severe Hepatomegaly with Steatosis Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogs, including TDF, alone or in combination with other antiretrovirals. Treatment with VIREAD 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)

Risk of Adverse Reactions Due to Drug Interactions The concomitant use of VIREAD and other drugs may result in known or potentially significant drug interactions, some of which may lead to possible clinically significant adverse reactions from greater exposures of concomitant drugs . See Table 12 for steps to prevent or manage these possible and known significant drug interactions, including dosing recommendations. Consider the potential for drug interactions prior to and during therapy with VIREAD; review concomitant medications during therapy with VIREAD; and monitor for adverse reactions associated with the concomitant drugs.

Tenofovir disoproxil fumarate increases didanosine concentrations. Dose reduction and close monitoring for didanosine toxicity are warranted. Coadministration decreases atazanavir concentrations. When coadministered with VIREAD, use atazanavir given with ritonavir. Coadministration of VIREAD with certain HIV-1 protease inhibitors or certain drugs to treat HCV increases tenofovir concentrations. Monitor for evidence of tenofovir toxicity. Consult Full Prescribing Information prior to and during treatment for important drug interactions

Drugs Affecting Renal Function Tenofovir is primarily eliminated by the kidneys . Coadministration of VIREAD with drugs that are eliminated by active tubular secretion may increase concentrations of tenofovir and/or the coadministered drug. Some examples include, but are not limited to, acyclovir, cidofovir, ganciclovir, valacyclovir, valganciclovir, aminoglycosides (e.g., gentamicin), and high-dose or multiple NSAIDs . Drugs that decrease renal function may increase concentrations of tenofovir. In the treatment of chronic hepatitis B, VIREAD should not be administered in combination with HEPSERA (adefovir dipivoxil)

Established and Significant Interactions Table 12 provides a listing of established or clinically significant drug interactions. The drug interactions described are based on studies conducted with TDF . Table 12 Established and Significant This table is not all inclusive. Drug Interactions: Alteration in Dose or Regimen May Be Recommended Based on Drug Interaction Trials Concomitant Drug Class: Drug Name Effect on Concentration ↑=Increase, ↓=Decrease Clinical Comment NRTI: didanosine ↑ didanosine Patients receiving VIREAD and didanosine should be monitored closely for didanosine-associated adverse reactions. Discontinue didanosine in patients who develop didanosine-associated adverse reactions. Higher didanosine concentrations could potentiate didanosine-associated adverse reactions, including pancreatitis, and neuropathy. Suppression of CD4+ cell counts has been observed in patients receiving VIREAD with didanosine 400 mg daily. In patients weighing greater than 60 kg, reduce the didanosine dose to 250 mg when it is coadministered with VIREAD. In patients weighing less than 60 kg, reduce the didanosine dose to 200 mg when it is coadministered with VIREAD. When coadministered, VIREAD and Videx EC may be taken under fasted conditions or with a light meal (less than 400 kcal, 20% fat). HIV-1 Protease Inhibitor s: atazanavir ↓ atazanavir When coadministered with VIREAD, atazanavir 300 mg should be given with ritonavir 100 mg. lopinavir/ritonavir atazanavir/ritonavir darunavir/ritonavir ↑ tenofovir Monitor patients receiving VIREAD concomitantly with lopinavir/ritonavir, ritonavir-boosted atazanavir, or ritonavir-boosted darunavir for TDF-associated adverse reactions. Discontinue VIREAD in patients who develop TDF-associated adverse reactions. Hepatitis C Antiviral Agents: sofosbuvir/velpatasvir sofosbuvir/velpatasvir/voxilaprevir ↑ tenofovir Monitor patients receiving VIREAD concomitantly with EPCLUSA ® (sofosbuvir/velpatasvir) for adverse reactions associated with TDF. ledipasvir/sofosbuvir Monitor patients receiving VIREAD concomitantly with HARVONI ® (ledipasvir/sofosbuvir) without an HIV-1 protease inhibitor/ritonavir or an HIV-1 protease inhibitor/cobicistat combination, for adverse reactions associated with TDF. In patients receiving VIREAD concomitantly with HARVONI and an HIV-1 protease inhibitor/ritonavir or an HIV-1 protease inhibitor/cobicistat combination, consider an alternative HCV or antiretroviral therapy, as the safety of increased tenofovir concentrations in this setting has not been established. If coadministration is necessary, monitor for adverse reactions associated with TDF.