These Highlights Do Not Include All The Information Needed To Use Vemlidy Safely And Effectively. See Full Prescribing Information For Vemlidy.

Adverse Reactions in Adult Subjects with Chronic Hepatitis B and Compensated Liver Disease

The safety assessment of VEMLIDY was based on pooled data through the Week 96 data analysis from 1298 subjects in two randomized, double-blind, active-controlled trials, Trial 108 and Trial 110, in adult subjects with chronic hepatitis B and compensated liver disease. A total of 866 subjects received VEMLIDY 25 mg once daily [see Clinical Studies (14.2)]. Further safety assessment was based on pooled data from Trials 108 and 110 from subjects who continued to receive their original blinded treatment through Week 120 and additionally from subjects who received open-label VEMLIDY from Week 96 through Week 120 (n = 361 remained on VEMLIDY; n = 180 switched from TDF to VEMLIDY at Week 96).

Based on the Week 96 analysis, the most common adverse reaction (all Grades) reported in at least 10% of subjects in the VEMLIDY group was headache. The proportion of subjects who discontinued treatment with VEMLIDY or TDF due to adverse reactions of any severity was 1.5% and 0.9%, respectively. Table 1 displays the frequency of the adverse reactions (all Grades) greater than or equal to 5% in the VEMLIDY group.

Additional adverse reactions occurring in less than 5% of subjects in Trials 108 and 110 included vomiting, rash, and flatulence.

The safety profile of VEMLIDY in subjects who continued to receive blinded treatment through Week 120 was similar to that at Week 96. The safety profile of VEMLIDY in subjects who remained on VEMLIDY in the open-label phase through Week 120 was similar to that in subjects who switched from TDF to VEMLIDY at Week 96.

Store below 30 °C (86 °F).

• Keep container tightly closed.
• Dispense only in original container.

PRINCIPAL DISPLAY PANEL - 25 mg Tablet Bottle Label

NDC 61958- 2301-1



30 tablets

Vemlidy ^®



(tenofovir alafenamide)



tablets, 25 mg

Note to pharmacist:



Do not cover ALERT box with pharmacy label.

ALERT: Find out about medicines that



should NOT be taken with Vemlidy

If overdose occurs, monitor patient for evidence of toxicity. Treatment of overdosage with VEMLIDY consists of general supportive measures including monitoring of vital signs as well as observation of the clinical status of the patient. Tenofovir is efficiently removed by hemodialysis with an extraction coefficient of approximately 54%.

VEMLIDY is a tablet containing tenofovir alafenamide for oral administration. Tenofovir alafenamide, a hepatitis B virus (HBV) nucleoside analog reverse transcriptase inhibitor, is converted in vivo to tenofovir, an acyclic nucleoside phosphonate (nucleotide) analog of adenosine 5′-monophosphate.

Each tablet contains 25 mg of tenofovir alafenamide (equivalent to 28 mg of tenofovir alafenamide fumarate). The tablets include the following inactive ingredients: croscarmellose sodium, lactose monohydrate, magnesium stearate, and microcrystalline cellulose. The tablets are film coated with a coating material containing: iron oxide yellow, polyethylene glycol, polyvinyl alcohol, talc, and titanium dioxide.

The chemical name of tenofovir alafenamide fumarate drug substance is L-alanine, N-[(S)-[[(1R)-2-(6-amino-9H-purin-9-yl)-1-methylethoxy]methyl]phenoxyphosphinyl]-, 1-methylethyl ester, (2E)-2-butenedioate (2:1).

It has an empirical formula of C₂₁H₂₉O₅N₆P∙½(C₄H₄O₄) and a formula weight of 534.50. It has the following structural formula:

Tenofovir alafenamide fumarate is a white to off-white or tan powder with a solubility of 4.7 mg per mL in water at 20 °C.

The pharmacokinetics, safety, and effectiveness of VEMLIDY for the treatment of chronic HBV infection have been established in pediatric patients between the ages of 6 to less than 18 years and weighing at least 25 kg (N=59) in Trial 1092 up to 96 weeks. No clinically meaningful differences in pharmacokinetics or safety were observed in comparison to those observed in adults [see Adverse Reactions (6.1), Clinical Pharmacology (12.3), and Clinical Studies (14.5)].

Safety and effectiveness of VEMLIDY has not been established in pediatric patients with chronic HBV infection who are less than 6 years of age or weigh less than 25 kg.

In clinical trials, VEMLIDY was administered to 89 subjects aged 65 and over. No clinically significant differences in safety or efficacy have been observed between elderly subjects and subjects between 18 and less than 65 years of age.

None.

The following adverse reactions are discussed in other sections of the labeling:

• Severe Acute Exacerbation of Hepatitis B [see Warnings and Precautions (5.1)]
• New Onset or Worsening of Renal Impairment [see Warnings and Precautions (5.3)]
• Lactic Acidosis/Severe Hepatomegaly with Steatosis [see Warnings and Precautions (5.4)]

VEMLIDY is a substrate of P-glycoprotein (P-gp) and BCRP. Drugs that strongly affect P-gp and BCRP activity may lead to changes in VEMLIDY absorption. Consult the full prescribing information prior to and during treatment for potential drug-drug interactions. (7)

No dosage adjustment of VEMLIDY is required in patients with mild, moderate, or severe renal impairment, or in patients with ESRD (estimated creatinine clearance below 15 mL per minute) who are receiving chronic hemodialysis. On days of hemodialysis, administer VEMLIDY after completion of hemodialysis treatment [see Dosage and Administration (2.3)].

The safety and efficacy of VEMLIDY in HBV-infected adult subjects with moderate to severe renal impairment (estimated creatinine clearance between 15 and 59 mL per minute by Cockcroft-Gault method) and ESRD (estimated creatinine clearance of less than 15 mL per minute by Cockcroft-Gault method) receiving chronic hemodialysis were evaluated in 78 and 15 subjects, respectively, in an open-label trial (Trial 4035, Part A). Overall, 98% of subjects achieved HBV DNA <20 IU/mL at Week 24 (Cohort 1, 97%; Cohort 2, 100%) and the safety of VEMLIDY was similar to that observed in clinical trials of VEMLIDY in subjects with compensated liver disease but without renal impairment [see Adverse Reactions (6.1) and Clinical Studies (14.4)].

The safety and efficacy of elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide 150/150/200/10 mg was previously evaluated in 55 virologically suppressed HIV-1 infected subjects with ESRD receiving chronic hemodialysis in an open-label trial (Trial 1825). Tenofovir alafenamide exposures are similar when comparing tenofovir alafenamide 25 mg and tenofovir alafenamide 10 mg as part of elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide.

Among subjects with ESRD receiving chronic hemodialysis and administered tenofovir alafenamide, higher exposures of tenofovir were observed in HBV-infected subjects (Trial 4035 Part A) compared to HIV-infected subjects (Trial 1825). The clinical significance of these higher exposures is not established [see Clinical Pharmacology (12.3)].

VEMLIDY is not recommended in patients with ESRD (estimated creatinine clearance below 15 mL per minute by Cockcroft-Gault method) who are not receiving chronic hemodialysis as the safety of VEMLIDY has not been established in this population [see Dosage and Administration (2.3) and Clinical Pharmacology (12.3)].

The pharmacokinetic properties of VEMLIDY are provided in Table 5. The multiple dose PK parameters of tenofovir alafenamide and its metabolite tenofovir are provided in Table 6.

No dosage adjustment of VEMLIDY is required in patients with mild hepatic impairment (Child-Pugh A). The safety and efficacy of VEMLIDY in patients with decompensated cirrhosis (Child-Pugh B or C) have not been established; therefore, VEMLIDY is not recommended in patients with decompensated (Child-Pugh B or C) hepatic impairment [see Dosage and Administration (2.4) and Clinical Pharmacology (12.3)].

VEMLIDY is indicated for the treatment of chronic hepatitis B virus (HBV) infection in adults and pediatric patients 6 years of age and older and weighing at least 25 kg with compensated liver disease [see Clinical Studies (14)].

Tenofovir alafenamide is an antiviral drug against the hepatitis B virus [see Microbiology (12.4)].

• HBV and HIV-1 coinfection: VEMLIDY alone is not recommended for the treatment of HIV-1 infection. HIV-1 resistance may develop in these patients. (5.2)
• New onset or worsening renal impairment: Prior to or when initiating VEMLIDY, and during treatment on a clinically appropriate schedule, assess serum creatinine, estimated creatinine clearance, urine glucose, and urine protein in all patients. Also assess serum phosphorus in patients with chronic kidney disease. (5.3)
• Lactic acidosis/severe hepatomegaly with steatosis: Discontinue treatment in patients who develop symptoms or laboratory findings suggestive of lactic acidosis or pronounced hepatotoxicity. (5.4)

• Testing: Prior to initiation of VEMLIDY, test patients for HIV infection. VEMLIDY alone should not be used in patients with HIV infection. Prior to or when initiating VEMLIDY, and during treatment on a clinically appropriate schedule, assess serum creatinine, estimated creatinine clearance, urine glucose, and urine protein in all patients. Also assess serum phosphorus in patients with chronic kidney disease. (2.1)
• Recommended dosage: 25 mg (one tablet) taken orally once daily with food. (2.2)
• Renal Impairment: VEMLIDY is not recommended in patients with estimated creatinine clearance below 15 mL per minute who are not receiving chronic hemodialysis. In patients on chronic hemodialysis, on hemodialysis days, administer VEMLIDY after hemodialysis. (2.3)
• Hepatic Impairment: VEMLIDY is not recommended in patients with decompensated (Child-Pugh B or C) hepatic impairment. (2.4)

Tablets: 25 mg of tenofovir alafenamide (equivalent to 28 mg of tenofovir alafenamide fumarate) — yellow, round, film-coated tablets, debossed with "GSI" on one side of the tablet and "25" on the other side.

The following adverse reactions have been identified during post approval use of VEMLIDY or other products containing tenofovir alafenamide. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

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

Advise the patient to read the FDA-approved patient labeling (Patient Information).

Because tenofovir is primarily excreted by the kidneys by a combination of glomerular filtration and active tubular secretion, coadministration of VEMLIDY with drugs that reduce renal function or compete for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs and this may increase the risk of adverse reactions. Some examples of drugs that are eliminated by active tubular secretion include, but are not limited to, acyclovir, cidofovir, ganciclovir, valacyclovir, valganciclovir, aminoglycosides (e.g., gentamicin), and high-dose or multiple NSAIDs [see Warnings and Precautions (5.3)].

The efficacy and safety of VEMLIDY were evaluated in the trials summarized in Table 11.

VEMLIDY tablets containing 25 mg of tenofovir alafenamide are yellow, round, film-coated, debossed with "GSI" on one side and "25" on the other side. Each bottle contains 30 tablets (NDC 61958-2301-1), a silica gel desiccant, polyester coil, and is closed with a child-resistant closure.

Minimal to slight infiltration of mononuclear cells in the posterior uvea was observed in dogs with similar severity after three- and nine-month administration of tenofovir alafenamide; reversibility was seen after a three-month recovery period. At the NOAEL for eye toxicity, the systemic exposure in dogs was 5 (tenofovir alafenamide) and 14 (tenofovir) times the exposure seen in humans at the recommended daily VEMLIDY dosage.

Prior to initiation of VEMLIDY, patients should be tested for HIV-1 infection. VEMLIDY alone should not be used in patients with HIV-1 infection [see Warnings and Precautions (5.2)].

Prior to or when initiating VEMLIDY, and during treatment with VEMLIDY 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 [see Warnings and Precautions (5.3)].

Postmarketing cases of renal impairment, including acute renal failure, proximal renal tubulopathy (PRT), and Fanconi syndrome have been reported with TAF-containing products; while most of these cases were characterized by potential confounders that may have contributed to the reported renal events, it is also possible these factors may have predisposed patients to tenofovir-related adverse events [see Adverse Reactions (6.2)].

Patients taking tenofovir prodrugs who have impaired renal function and those taking nephrotoxic agents, including non-steroidal anti-inflammatory drugs, are at increased risk of developing renal-related adverse reactions [see Drug Interactions (7.2)].

Prior to or when initiating VEMLIDY, and during treatment with VEMLIDY 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. Discontinue VEMLIDY in patients who develop clinically significant decreases in renal function or evidence of Fanconi syndrome [see Adverse Reactions (6.1) and Use in Specific Populations (8.6)].

No dosage adjustment of VEMLIDY is required in patients with estimated creatinine clearance greater than or equal to 15 mL per minute, or in patients with end stage renal disease (ESRD; estimated creatinine clearance below 15 mL per minute) who are receiving chronic hemodialysis. On days of hemodialysis, administer VEMLIDY after completion of hemodialysis treatment.

VEMLIDY is not recommended in patients with ESRD who are not receiving chronic hemodialysis [see Use in Specific Populations (8.6) and Clinical Pharmacology (12.3)].

No data are available to make dose recommendations in pediatric patients with renal impairment.

No dosage adjustment of VEMLIDY is required in patients with mild hepatic impairment (Child-Pugh A). VEMLIDY is not recommended in patients with decompensated (Child-Pugh B or C) hepatic impairment [see Use in Specific Populations (8.7) and Clinical Pharmacology (12.3)].

VEMLIDY is a substrate of P-glycoprotein (P-gp) and BCRP. Drugs that strongly affect P-gp and BCRP activity may lead to changes in tenofovir alafenamide absorption (see Table 4). Drugs that induce P-gp activity are expected to decrease the absorption of tenofovir alafenamide, resulting in decreased plasma concentrations of tenofovir alafenamide, which may lead to loss of therapeutic effect of VEMLIDY. Coadministration of VEMLIDY with other drugs that inhibit P-gp and BCRP may increase the absorption and plasma concentration of tenofovir alafenamide.

Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogs, including tenofovir disoproxil fumarate (TDF), another prodrug of tenofovir, alone or in combination with other antiretrovirals. Treatment with VEMLIDY 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).

Since tenofovir alafenamide is rapidly converted to tenofovir and a lower tenofovir exposure in rats and mice was observed after tenofovir alafenamide administration compared to TDF administration, carcinogenicity studies were conducted only with TDF. Long-term oral carcinogenicity studies of TDF in mice and rats were carried out at exposures up to approximately 10 times (mice) and 4 times (rats) those observed in humans at the 300 mg therapeutic dose of TDF for chronic hepatitis B. The tenofovir exposure in these studies was approximately 151 times (mice) and 50 times (rat) those observed in humans after administration of VEMLIDY treatment. At the high dose in female mice, liver adenomas were increased at tenofovir exposures approximately 151 times those observed after VEMLIDY administration in humans. In rats, the study was negative for carcinogenic findings.

Tenofovir alafenamide was not genotoxic in the reverse mutation bacterial test (Ames test), mouse lymphoma or rat micronucleus assays.

There were no effects on fertility, mating performance or early embryonic development when tenofovir alafenamide was administered to male rats at a dose equivalent to 155 times the human dose based on body surface area comparisons for 28 days prior to mating and to female rats for 14 days prior to mating through Day 7 of gestation.

Table 4 provides a listing of established or potentially clinically significant drug interactions. The drug interactions described are based on studies conducted with tenofovir alafenamide or are predicted drug interactions that may occur with VEMLIDY [For magnitude of interaction, see Clinical Pharmacology (12.3)]. Information regarding potential drug-drug interactions with HIV antiretrovirals is not provided (see the prescribing information for emtricitabine/tenofovir alafenamide for interactions with HIV antiretrovirals). The table includes potentially significant interactions but is not all inclusive.

Discontinuation of anti-hepatitis B therapy, including VEMLIDY, may result in severe acute exacerbations of hepatitis B. Hepatic function should be monitored closely with both clinical and laboratory follow-up for at least several months in patients who discontinue anti-hepatitis B therapy, including VEMLIDY. If appropriate, resumption of anti-hepatitis B therapy may be warranted [see Warnings and Precautions (5.1)].

Based on drug interaction studies conducted with VEMLIDY, no clinically significant drug interactions have been observed with: ethinyl estradiol, ledipasvir/sofosbuvir, midazolam, norgestimate, sertraline, sofosbuvir, sofosbuvir/velpatasvir, and sofosbuvir/velpatasvir/voxilaprevir.

Discontinuation of anti-hepatitis B therapy, including VEMLIDY, may result in severe acute exacerbations of hepatitis B. Patients who discontinue VEMLIDY 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.

Due to the risk of development of HIV-1 resistance, VEMLIDY alone is not recommended for the treatment of HIV-1 infection. The safety and efficacy of VEMLIDY have not been established in patients coinfected with HBV and HIV-1. HIV antibody testing should be offered to all HBV-infected patients before initiating therapy with VEMLIDY, and, if positive, an appropriate antiretroviral combination regimen that is recommended for patients coinfected with HIV-1 should be used.

In Trial 4035, Part A, the efficacy and safety of switching from TDF and/or other antivirals to VEMLIDY were evaluated in an open-label clinical trial of virologically suppressed chronic hepatitis B infected adults with moderate to severe renal impairment (estimated creatinine clearance between 15 and 59 mL per minute by Cockcroft-Gault method) (Cohort 1, N=78) or ESRD (estimated creatinine clearance below 15 mL per minute by Cockcroft-Gault method) on hemodialysis (Cohort 2, N=15). At baseline, 98% of subjects in Part A had baseline HBV DNA <20 IU/mL. Median age was 65 years, 74% were male, 77% were Asian, 16% were White, and 83% were HBeAg-negative. Previous treatment with oral antivirals included TDF (Cohort 1, N=57; Cohort 2, N=1), lamivudine (N=46), adefovir dipivoxil (N=46), and entecavir (N=43). At baseline, 97% and 95% of subjects had ALT ≤ULN based on central laboratory criteria and 2018 AASLD criteria, respectively; median estimated creatinine clearance by Cockcroft-Gault was 43 mL per minute (45 mL per minute in Cohort 1 and 7 mL per minute in Cohort 2); and 34% of subjects had a history of cirrhosis.

Overall, 98% of subjects achieved HBV DNA <20 IU/mL at Week 24 (Cohort 1, 97%; Cohort 2, 100%). Two subjects in Cohort 1 discontinued treatment early (due to subject decision); last available HBV DNA for both of these subjects was <20 IU/mL. The overall mean (SD) change from baseline in ALT values was +1 (11.3) U/L (Cohort 1, +1 [11.9] U/L; Cohort 2, +3 [7.9] U/L) at Week 24. No subject had HBeAg or HBsAg loss at Week 24. The mean (SD) changes in HBsAg level from baseline were -0.05 (0.122) log₁₀ IU/mL (-0.05 [0.124] log₁₀ IU/mL for Cohort 1 and -0.07 [0.115] log₁₀ IU/mL for Cohort 2) at Week 24.

The efficacy and safety of VEMLIDY in the treatment of adults with chronic hepatitis B virus infection with compensated liver disease are based on 48-week data from two randomized, double-blind, active-controlled trials, Trial 108 (N=425) and Trial 110 (N=873). In both trials, besides trial treatment, subjects were not allowed to receive other nucleosides, nucleotides, or interferon.

In Trial 108, HBeAg-negative treatment-naïve and treatment-experienced subjects with compensated liver disease (no evidence of ascites, hepatic encephalopathy, variceal bleeding, INR <1.5× ULN, total bilirubin <2.5× ULN, and albumin >3.0 mg/dL) were randomized in a 2:1 ratio to receive VEMLIDY 25 mg (N=285) once daily or TDF 300 mg (N=140) once daily for 48 weeks. The mean age was 46 years, 61% were male, 72% were Asian, 25% were White, 2% were Black, and 1% were other races. 24%, 38%, and 31% had HBV genotype B, C, and D, respectively. 21% were treatment experienced [previous treatment with oral antivirals, including entecavir (N=41), lamivudine (N=42), TDF (N=21), or other (N=18)]. At baseline, mean plasma HBV DNA was 5.8 log₁₀ IU/mL, mean serum ALT was 94 U/L, and 9% of subjects had a history of cirrhosis.

In Trial 110, HBeAg-positive treatment-naïve and treatment-experienced subjects with compensated liver disease were randomized in a 2:1 ratio to receive VEMLIDY 25 mg (N=581) once daily or TDF 300 mg (N=292) once daily for 48 weeks. The mean age was 38 years, 64% were male, 82% were Asian, 17% were White, and 1% were Black or other races. 17%, 52%, and 23% had HBV genotype B, C, and D, respectively. 26% were treatment experienced [previous treatment with oral antivirals, including adefovir (N=42), entecavir (N=117), lamivudine (N=84), telbivudine (N=25), TDF (N=70), or other (n=17)]. At baseline, mean plasma HBV DNA was 7.6 log₁₀ IU/mL, mean serum ALT was 120 U/L, and 7% of subjects had a history of cirrhosis.

In both trials, randomization was stratified on prior treatment history (nucleoside naïve or experienced) and baseline HBV DNA (<7, ≥7 to <8, and ≥8 log₁₀ IU/mL in Trial 108; and <8 and ≥8 log₁₀ IU/mL in Trial 110). The efficacy endpoint in both trials was the proportion of subjects with plasma HBV DNA levels below 29 IU/mL at Week 48. Additional efficacy endpoints include the proportion of subjects with ALT normalization, HBsAg loss and seroconversion, and HBeAg loss and seroconversion in Trial 110.

Treatment outcomes of Trials 108 and 110 at Week 48 are presented in Table 12 and Table 13.

In Trial 108, the proportion of subjects with cirrhosis who achieved HBV DNA <29 IU/mL at Week 48 was 92% (22/24) in the VEMLIDY group and 93% (13/14) in the TDF group. The corresponding proportions in Trial 110 were 63% (26/41) and 67% (16/24) in the VEMLIDY and TDF groups, respectively.

In Trial 1092, the efficacy and safety of VEMLIDY in chronic HBV-infected subjects were evaluated in a randomized, double-blind, placebo-controlled clinical trial of treatment-naïve and treatment-experienced subjects between the ages of 12 to less than 18 years weighing at least 35 kg (Cohort 1; N=70) and 6 to less than 12 years weighing at least 25 kg (Cohort 2, Group 1; N=18). Subjects were randomized to receive VEMLIDY (N=59) or placebo (N=29) once daily. Baseline demographics and HBV disease characteristics were comparable between the VEMLIDY treatment arm and the placebo arm: in the VEMLIDY group, 58% were male, 63% were Asian, and 27% were White; 9%, 24%, 22%, and 44% had HBV genotype A, B, C, and D, respectively; 98% percent were HBeAg positive. At baseline, overall median HBV DNA was 8.1 log₁₀ IU/mL, mean ALT was 107 U/L, median HBsAg was 4.5 log₁₀ IU/mL. Previous treatment included oral antivirals (N=20 [23%]), including entecavir (N=10 [11%]), lamivudine (N=10 [11%]), and TDF (N=2 [2%]), and/or interferons (N=13 [15%]).

The results for each treatment group and cohort for HBV DNA < 20 IU/mL at Weeks 24, 48 and 96 are presented in Table 16 below.

At Week 96, the overall mean (SD) change from baseline in HBV DNA for VEMLIDY-treated subjects and subjects who switched from placebo to VEMLIDY, respectively, was -6.18 (1.495) log₁₀ IU/mL and -5.92 (1.775) log₁₀ IU/mL. The overall median change from baseline in ALT values for the VEMLIDY and placebo-VEMLIDY treatment groups, respectively, was -39.5 U/L and -46.5 U/L at Week 96. ALT normalization (AASLD criteria) was achieved for 54% of VEMLIDY-treated subjects and 57% of subjects who switched from placebo to VEMLIDY.

At Week 96, 14/58 (24%) VEMLIDY-treated subjects and 5/29 (17%) subjects who switched from placebo to VEMLIDY experienced HBeAg loss with anti-HBe seroconversion. One of 47 (2%) subjects in the Cohort 1 VEMLIDY group achieved HBsAg loss at Week 96.

The recommended dosage of VEMLIDY in adults and pediatric patients 6 years of age and older and weighing at least 25 kg is one 25 mg tablet taken orally once daily with food [see Clinical Pharmacology (12.3)].

The efficacy and safety of switching from TDF to VEMLIDY in virologically suppressed adults with chronic hepatitis B virus infection is based on 48-week data from a randomized, double-blind, active-controlled trial, Trial 4018 (N=488). Subjects must have been taking TDF 300 mg once daily for at least 12 months, with HBV DNA less than the Lower Limit of Quantitation by local laboratory assessment for at least 12 weeks prior to screening and HBV DNA <20 IU/mL at screening. Subjects were stratified by HBeAg status (HBeAg-positive or HBeAg-negative) and age (≥50 or <50 years) and randomized in a 1:1 ratio to either switch to VEMLIDY 25 mg once daily (N=243) or stay on TDF 300 mg once daily (N=245). The mean age was 51 years (22% were ≥60 years), 71% were male, 82% were Asian, 14% were White, and 68% were HBeAg-negative. At baseline, median duration of prior TDF treatment was 220 and 224 weeks in the VEMLIDY and TDF groups, respectively. At baseline, mean serum ALT was 27 U/L, and 16% of subjects had a history of cirrhosis.

The primary efficacy endpoint was the proportion of subjects with plasma HBV DNA levels ≥20 IU/mL at Week 48. Additional efficacy endpoints in Trial 4018 included the proportion of subjects with HBV DNA <20 IU/mL, ALT normal and normalization, HBsAg loss and seroconversion, and HBeAg loss and seroconversion.

Treatment outcomes of Trial 4018 at Week 48 are presented in Table 14 and Table 15.

Adverse Reactions in Adult Subjects with Chronic Hepatitis B and Compensated Liver Disease

The safety assessment of VEMLIDY was based on pooled data through the Week 96 data analysis from 1298 subjects in two randomized, double-blind, active-controlled trials, Trial 108 and Trial 110, in adult subjects with chronic hepatitis B and compensated liver disease. A total of 866 subjects received VEMLIDY 25 mg once daily [see Clinical Studies (14.2)]. Further safety assessment was based on pooled data from Trials 108 and 110 from subjects who continued to receive their original blinded treatment through Week 120 and additionally from subjects who received open-label VEMLIDY from Week 96 through Week 120 (n = 361 remained on VEMLIDY; n = 180 switched from TDF to VEMLIDY at Week 96).

Based on the Week 96 analysis, the most common adverse reaction (all Grades) reported in at least 10% of subjects in the VEMLIDY group was headache. The proportion of subjects who discontinued treatment with VEMLIDY or TDF due to adverse reactions of any severity was 1.5% and 0.9%, respectively. Table 1 displays the frequency of the adverse reactions (all Grades) greater than or equal to 5% in the VEMLIDY group.

Additional adverse reactions occurring in less than 5% of subjects in Trials 108 and 110 included vomiting, rash, and flatulence.

The safety profile of VEMLIDY in subjects who continued to receive blinded treatment through Week 120 was similar to that at Week 96. The safety profile of VEMLIDY in subjects who remained on VEMLIDY in the open-label phase through Week 120 was similar to that in subjects who switched from TDF to VEMLIDY at Week 96.

Store below 30 °C (86 °F).

• Keep container tightly closed.
• Dispense only in original container.

PRINCIPAL DISPLAY PANEL - 25 mg Tablet Bottle Label

NDC 61958- 2301-1



30 tablets

Vemlidy ^®



(tenofovir alafenamide)



tablets, 25 mg

Note to pharmacist:



Do not cover ALERT box with pharmacy label.

ALERT: Find out about medicines that



should NOT be taken with Vemlidy

If overdose occurs, monitor patient for evidence of toxicity. Treatment of overdosage with VEMLIDY consists of general supportive measures including monitoring of vital signs as well as observation of the clinical status of the patient. Tenofovir is efficiently removed by hemodialysis with an extraction coefficient of approximately 54%.

VEMLIDY is a tablet containing tenofovir alafenamide for oral administration. Tenofovir alafenamide, a hepatitis B virus (HBV) nucleoside analog reverse transcriptase inhibitor, is converted in vivo to tenofovir, an acyclic nucleoside phosphonate (nucleotide) analog of adenosine 5′-monophosphate.

Each tablet contains 25 mg of tenofovir alafenamide (equivalent to 28 mg of tenofovir alafenamide fumarate). The tablets include the following inactive ingredients: croscarmellose sodium, lactose monohydrate, magnesium stearate, and microcrystalline cellulose. The tablets are film coated with a coating material containing: iron oxide yellow, polyethylene glycol, polyvinyl alcohol, talc, and titanium dioxide.

The chemical name of tenofovir alafenamide fumarate drug substance is L-alanine, N-[(S)-[[(1R)-2-(6-amino-9H-purin-9-yl)-1-methylethoxy]methyl]phenoxyphosphinyl]-, 1-methylethyl ester, (2E)-2-butenedioate (2:1).

It has an empirical formula of C₂₁H₂₉O₅N₆P∙½(C₄H₄O₄) and a formula weight of 534.50. It has the following structural formula:

Tenofovir alafenamide fumarate is a white to off-white or tan powder with a solubility of 4.7 mg per mL in water at 20 °C.

The pharmacokinetics, safety, and effectiveness of VEMLIDY for the treatment of chronic HBV infection have been established in pediatric patients between the ages of 6 to less than 18 years and weighing at least 25 kg (N=59) in Trial 1092 up to 96 weeks. No clinically meaningful differences in pharmacokinetics or safety were observed in comparison to those observed in adults [see Adverse Reactions (6.1), Clinical Pharmacology (12.3), and Clinical Studies (14.5)].

Safety and effectiveness of VEMLIDY has not been established in pediatric patients with chronic HBV infection who are less than 6 years of age or weigh less than 25 kg.

In clinical trials, VEMLIDY was administered to 89 subjects aged 65 and over. No clinically significant differences in safety or efficacy have been observed between elderly subjects and subjects between 18 and less than 65 years of age.

None.

The following adverse reactions are discussed in other sections of the labeling:

• Severe Acute Exacerbation of Hepatitis B [see Warnings and Precautions (5.1)]
• New Onset or Worsening of Renal Impairment [see Warnings and Precautions (5.3)]
• Lactic Acidosis/Severe Hepatomegaly with Steatosis [see Warnings and Precautions (5.4)]

VEMLIDY is a substrate of P-glycoprotein (P-gp) and BCRP. Drugs that strongly affect P-gp and BCRP activity may lead to changes in VEMLIDY absorption. Consult the full prescribing information prior to and during treatment for potential drug-drug interactions. (7)

No dosage adjustment of VEMLIDY is required in patients with mild, moderate, or severe renal impairment, or in patients with ESRD (estimated creatinine clearance below 15 mL per minute) who are receiving chronic hemodialysis. On days of hemodialysis, administer VEMLIDY after completion of hemodialysis treatment [see Dosage and Administration (2.3)].

The safety and efficacy of VEMLIDY in HBV-infected adult subjects with moderate to severe renal impairment (estimated creatinine clearance between 15 and 59 mL per minute by Cockcroft-Gault method) and ESRD (estimated creatinine clearance of less than 15 mL per minute by Cockcroft-Gault method) receiving chronic hemodialysis were evaluated in 78 and 15 subjects, respectively, in an open-label trial (Trial 4035, Part A). Overall, 98% of subjects achieved HBV DNA <20 IU/mL at Week 24 (Cohort 1, 97%; Cohort 2, 100%) and the safety of VEMLIDY was similar to that observed in clinical trials of VEMLIDY in subjects with compensated liver disease but without renal impairment [see Adverse Reactions (6.1) and Clinical Studies (14.4)].

The safety and efficacy of elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide 150/150/200/10 mg was previously evaluated in 55 virologically suppressed HIV-1 infected subjects with ESRD receiving chronic hemodialysis in an open-label trial (Trial 1825). Tenofovir alafenamide exposures are similar when comparing tenofovir alafenamide 25 mg and tenofovir alafenamide 10 mg as part of elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide.

Among subjects with ESRD receiving chronic hemodialysis and administered tenofovir alafenamide, higher exposures of tenofovir were observed in HBV-infected subjects (Trial 4035 Part A) compared to HIV-infected subjects (Trial 1825). The clinical significance of these higher exposures is not established [see Clinical Pharmacology (12.3)].

VEMLIDY is not recommended in patients with ESRD (estimated creatinine clearance below 15 mL per minute by Cockcroft-Gault method) who are not receiving chronic hemodialysis as the safety of VEMLIDY has not been established in this population [see Dosage and Administration (2.3) and Clinical Pharmacology (12.3)].

The pharmacokinetic properties of VEMLIDY are provided in Table 5. The multiple dose PK parameters of tenofovir alafenamide and its metabolite tenofovir are provided in Table 6.

No dosage adjustment of VEMLIDY is required in patients with mild hepatic impairment (Child-Pugh A). The safety and efficacy of VEMLIDY in patients with decompensated cirrhosis (Child-Pugh B or C) have not been established; therefore, VEMLIDY is not recommended in patients with decompensated (Child-Pugh B or C) hepatic impairment [see Dosage and Administration (2.4) and Clinical Pharmacology (12.3)].

VEMLIDY is indicated for the treatment of chronic hepatitis B virus (HBV) infection in adults and pediatric patients 6 years of age and older and weighing at least 25 kg with compensated liver disease [see Clinical Studies (14)].

Tenofovir alafenamide is an antiviral drug against the hepatitis B virus [see Microbiology (12.4)].

• HBV and HIV-1 coinfection: VEMLIDY alone is not recommended for the treatment of HIV-1 infection. HIV-1 resistance may develop in these patients. (5.2)
• New onset or worsening renal impairment: Prior to or when initiating VEMLIDY, and during treatment on a clinically appropriate schedule, assess serum creatinine, estimated creatinine clearance, urine glucose, and urine protein in all patients. Also assess serum phosphorus in patients with chronic kidney disease. (5.3)
• Lactic acidosis/severe hepatomegaly with steatosis: Discontinue treatment in patients who develop symptoms or laboratory findings suggestive of lactic acidosis or pronounced hepatotoxicity. (5.4)

• Testing: Prior to initiation of VEMLIDY, test patients for HIV infection. VEMLIDY alone should not be used in patients with HIV infection. Prior to or when initiating VEMLIDY, and during treatment on a clinically appropriate schedule, assess serum creatinine, estimated creatinine clearance, urine glucose, and urine protein in all patients. Also assess serum phosphorus in patients with chronic kidney disease. (2.1)
• Recommended dosage: 25 mg (one tablet) taken orally once daily with food. (2.2)
• Renal Impairment: VEMLIDY is not recommended in patients with estimated creatinine clearance below 15 mL per minute who are not receiving chronic hemodialysis. In patients on chronic hemodialysis, on hemodialysis days, administer VEMLIDY after hemodialysis. (2.3)
• Hepatic Impairment: VEMLIDY is not recommended in patients with decompensated (Child-Pugh B or C) hepatic impairment. (2.4)

Tablets: 25 mg of tenofovir alafenamide (equivalent to 28 mg of tenofovir alafenamide fumarate) — yellow, round, film-coated tablets, debossed with "GSI" on one side of the tablet and "25" on the other side.

The following adverse reactions have been identified during post approval use of VEMLIDY or other products containing tenofovir alafenamide. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

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

Advise the patient to read the FDA-approved patient labeling (Patient Information).

Because tenofovir is primarily excreted by the kidneys by a combination of glomerular filtration and active tubular secretion, coadministration of VEMLIDY with drugs that reduce renal function or compete for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs and this may increase the risk of adverse reactions. Some examples of drugs that are eliminated by active tubular secretion include, but are not limited to, acyclovir, cidofovir, ganciclovir, valacyclovir, valganciclovir, aminoglycosides (e.g., gentamicin), and high-dose or multiple NSAIDs [see Warnings and Precautions (5.3)].

The efficacy and safety of VEMLIDY were evaluated in the trials summarized in Table 11.

VEMLIDY tablets containing 25 mg of tenofovir alafenamide are yellow, round, film-coated, debossed with "GSI" on one side and "25" on the other side. Each bottle contains 30 tablets (NDC 61958-2301-1), a silica gel desiccant, polyester coil, and is closed with a child-resistant closure.

Minimal to slight infiltration of mononuclear cells in the posterior uvea was observed in dogs with similar severity after three- and nine-month administration of tenofovir alafenamide; reversibility was seen after a three-month recovery period. At the NOAEL for eye toxicity, the systemic exposure in dogs was 5 (tenofovir alafenamide) and 14 (tenofovir) times the exposure seen in humans at the recommended daily VEMLIDY dosage.

Prior to initiation of VEMLIDY, patients should be tested for HIV-1 infection. VEMLIDY alone should not be used in patients with HIV-1 infection [see Warnings and Precautions (5.2)].

Prior to or when initiating VEMLIDY, and during treatment with VEMLIDY 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 [see Warnings and Precautions (5.3)].

Postmarketing cases of renal impairment, including acute renal failure, proximal renal tubulopathy (PRT), and Fanconi syndrome have been reported with TAF-containing products; while most of these cases were characterized by potential confounders that may have contributed to the reported renal events, it is also possible these factors may have predisposed patients to tenofovir-related adverse events [see Adverse Reactions (6.2)].

Patients taking tenofovir prodrugs who have impaired renal function and those taking nephrotoxic agents, including non-steroidal anti-inflammatory drugs, are at increased risk of developing renal-related adverse reactions [see Drug Interactions (7.2)].

Prior to or when initiating VEMLIDY, and during treatment with VEMLIDY 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. Discontinue VEMLIDY in patients who develop clinically significant decreases in renal function or evidence of Fanconi syndrome [see Adverse Reactions (6.1) and Use in Specific Populations (8.6)].

No dosage adjustment of VEMLIDY is required in patients with estimated creatinine clearance greater than or equal to 15 mL per minute, or in patients with end stage renal disease (ESRD; estimated creatinine clearance below 15 mL per minute) who are receiving chronic hemodialysis. On days of hemodialysis, administer VEMLIDY after completion of hemodialysis treatment.

VEMLIDY is not recommended in patients with ESRD who are not receiving chronic hemodialysis [see Use in Specific Populations (8.6) and Clinical Pharmacology (12.3)].

No data are available to make dose recommendations in pediatric patients with renal impairment.

No dosage adjustment of VEMLIDY is required in patients with mild hepatic impairment (Child-Pugh A). VEMLIDY is not recommended in patients with decompensated (Child-Pugh B or C) hepatic impairment [see Use in Specific Populations (8.7) and Clinical Pharmacology (12.3)].

VEMLIDY is a substrate of P-glycoprotein (P-gp) and BCRP. Drugs that strongly affect P-gp and BCRP activity may lead to changes in tenofovir alafenamide absorption (see Table 4). Drugs that induce P-gp activity are expected to decrease the absorption of tenofovir alafenamide, resulting in decreased plasma concentrations of tenofovir alafenamide, which may lead to loss of therapeutic effect of VEMLIDY. Coadministration of VEMLIDY with other drugs that inhibit P-gp and BCRP may increase the absorption and plasma concentration of tenofovir alafenamide.

Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogs, including tenofovir disoproxil fumarate (TDF), another prodrug of tenofovir, alone or in combination with other antiretrovirals. Treatment with VEMLIDY 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).

Since tenofovir alafenamide is rapidly converted to tenofovir and a lower tenofovir exposure in rats and mice was observed after tenofovir alafenamide administration compared to TDF administration, carcinogenicity studies were conducted only with TDF. Long-term oral carcinogenicity studies of TDF in mice and rats were carried out at exposures up to approximately 10 times (mice) and 4 times (rats) those observed in humans at the 300 mg therapeutic dose of TDF for chronic hepatitis B. The tenofovir exposure in these studies was approximately 151 times (mice) and 50 times (rat) those observed in humans after administration of VEMLIDY treatment. At the high dose in female mice, liver adenomas were increased at tenofovir exposures approximately 151 times those observed after VEMLIDY administration in humans. In rats, the study was negative for carcinogenic findings.

Tenofovir alafenamide was not genotoxic in the reverse mutation bacterial test (Ames test), mouse lymphoma or rat micronucleus assays.

There were no effects on fertility, mating performance or early embryonic development when tenofovir alafenamide was administered to male rats at a dose equivalent to 155 times the human dose based on body surface area comparisons for 28 days prior to mating and to female rats for 14 days prior to mating through Day 7 of gestation.

Table 4 provides a listing of established or potentially clinically significant drug interactions. The drug interactions described are based on studies conducted with tenofovir alafenamide or are predicted drug interactions that may occur with VEMLIDY [For magnitude of interaction, see Clinical Pharmacology (12.3)]. Information regarding potential drug-drug interactions with HIV antiretrovirals is not provided (see the prescribing information for emtricitabine/tenofovir alafenamide for interactions with HIV antiretrovirals). The table includes potentially significant interactions but is not all inclusive.

Discontinuation of anti-hepatitis B therapy, including VEMLIDY, may result in severe acute exacerbations of hepatitis B. Hepatic function should be monitored closely with both clinical and laboratory follow-up for at least several months in patients who discontinue anti-hepatitis B therapy, including VEMLIDY. If appropriate, resumption of anti-hepatitis B therapy may be warranted [see Warnings and Precautions (5.1)].

Based on drug interaction studies conducted with VEMLIDY, no clinically significant drug interactions have been observed with: ethinyl estradiol, ledipasvir/sofosbuvir, midazolam, norgestimate, sertraline, sofosbuvir, sofosbuvir/velpatasvir, and sofosbuvir/velpatasvir/voxilaprevir.

Discontinuation of anti-hepatitis B therapy, including VEMLIDY, may result in severe acute exacerbations of hepatitis B. Patients who discontinue VEMLIDY 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.

Due to the risk of development of HIV-1 resistance, VEMLIDY alone is not recommended for the treatment of HIV-1 infection. The safety and efficacy of VEMLIDY have not been established in patients coinfected with HBV and HIV-1. HIV antibody testing should be offered to all HBV-infected patients before initiating therapy with VEMLIDY, and, if positive, an appropriate antiretroviral combination regimen that is recommended for patients coinfected with HIV-1 should be used.

In Trial 4035, Part A, the efficacy and safety of switching from TDF and/or other antivirals to VEMLIDY were evaluated in an open-label clinical trial of virologically suppressed chronic hepatitis B infected adults with moderate to severe renal impairment (estimated creatinine clearance between 15 and 59 mL per minute by Cockcroft-Gault method) (Cohort 1, N=78) or ESRD (estimated creatinine clearance below 15 mL per minute by Cockcroft-Gault method) on hemodialysis (Cohort 2, N=15). At baseline, 98% of subjects in Part A had baseline HBV DNA <20 IU/mL. Median age was 65 years, 74% were male, 77% were Asian, 16% were White, and 83% were HBeAg-negative. Previous treatment with oral antivirals included TDF (Cohort 1, N=57; Cohort 2, N=1), lamivudine (N=46), adefovir dipivoxil (N=46), and entecavir (N=43). At baseline, 97% and 95% of subjects had ALT ≤ULN based on central laboratory criteria and 2018 AASLD criteria, respectively; median estimated creatinine clearance by Cockcroft-Gault was 43 mL per minute (45 mL per minute in Cohort 1 and 7 mL per minute in Cohort 2); and 34% of subjects had a history of cirrhosis.

Overall, 98% of subjects achieved HBV DNA <20 IU/mL at Week 24 (Cohort 1, 97%; Cohort 2, 100%). Two subjects in Cohort 1 discontinued treatment early (due to subject decision); last available HBV DNA for both of these subjects was <20 IU/mL. The overall mean (SD) change from baseline in ALT values was +1 (11.3) U/L (Cohort 1, +1 [11.9] U/L; Cohort 2, +3 [7.9] U/L) at Week 24. No subject had HBeAg or HBsAg loss at Week 24. The mean (SD) changes in HBsAg level from baseline were -0.05 (0.122) log₁₀ IU/mL (-0.05 [0.124] log₁₀ IU/mL for Cohort 1 and -0.07 [0.115] log₁₀ IU/mL for Cohort 2) at Week 24.

The efficacy and safety of VEMLIDY in the treatment of adults with chronic hepatitis B virus infection with compensated liver disease are based on 48-week data from two randomized, double-blind, active-controlled trials, Trial 108 (N=425) and Trial 110 (N=873). In both trials, besides trial treatment, subjects were not allowed to receive other nucleosides, nucleotides, or interferon.

In Trial 108, HBeAg-negative treatment-naïve and treatment-experienced subjects with compensated liver disease (no evidence of ascites, hepatic encephalopathy, variceal bleeding, INR <1.5× ULN, total bilirubin <2.5× ULN, and albumin >3.0 mg/dL) were randomized in a 2:1 ratio to receive VEMLIDY 25 mg (N=285) once daily or TDF 300 mg (N=140) once daily for 48 weeks. The mean age was 46 years, 61% were male, 72% were Asian, 25% were White, 2% were Black, and 1% were other races. 24%, 38%, and 31% had HBV genotype B, C, and D, respectively. 21% were treatment experienced [previous treatment with oral antivirals, including entecavir (N=41), lamivudine (N=42), TDF (N=21), or other (N=18)]. At baseline, mean plasma HBV DNA was 5.8 log₁₀ IU/mL, mean serum ALT was 94 U/L, and 9% of subjects had a history of cirrhosis.

In Trial 110, HBeAg-positive treatment-naïve and treatment-experienced subjects with compensated liver disease were randomized in a 2:1 ratio to receive VEMLIDY 25 mg (N=581) once daily or TDF 300 mg (N=292) once daily for 48 weeks. The mean age was 38 years, 64% were male, 82% were Asian, 17% were White, and 1% were Black or other races. 17%, 52%, and 23% had HBV genotype B, C, and D, respectively. 26% were treatment experienced [previous treatment with oral antivirals, including adefovir (N=42), entecavir (N=117), lamivudine (N=84), telbivudine (N=25), TDF (N=70), or other (n=17)]. At baseline, mean plasma HBV DNA was 7.6 log₁₀ IU/mL, mean serum ALT was 120 U/L, and 7% of subjects had a history of cirrhosis.

In both trials, randomization was stratified on prior treatment history (nucleoside naïve or experienced) and baseline HBV DNA (<7, ≥7 to <8, and ≥8 log₁₀ IU/mL in Trial 108; and <8 and ≥8 log₁₀ IU/mL in Trial 110). The efficacy endpoint in both trials was the proportion of subjects with plasma HBV DNA levels below 29 IU/mL at Week 48. Additional efficacy endpoints include the proportion of subjects with ALT normalization, HBsAg loss and seroconversion, and HBeAg loss and seroconversion in Trial 110.

Treatment outcomes of Trials 108 and 110 at Week 48 are presented in Table 12 and Table 13.

In Trial 108, the proportion of subjects with cirrhosis who achieved HBV DNA <29 IU/mL at Week 48 was 92% (22/24) in the VEMLIDY group and 93% (13/14) in the TDF group. The corresponding proportions in Trial 110 were 63% (26/41) and 67% (16/24) in the VEMLIDY and TDF groups, respectively.

In Trial 1092, the efficacy and safety of VEMLIDY in chronic HBV-infected subjects were evaluated in a randomized, double-blind, placebo-controlled clinical trial of treatment-naïve and treatment-experienced subjects between the ages of 12 to less than 18 years weighing at least 35 kg (Cohort 1; N=70) and 6 to less than 12 years weighing at least 25 kg (Cohort 2, Group 1; N=18). Subjects were randomized to receive VEMLIDY (N=59) or placebo (N=29) once daily. Baseline demographics and HBV disease characteristics were comparable between the VEMLIDY treatment arm and the placebo arm: in the VEMLIDY group, 58% were male, 63% were Asian, and 27% were White; 9%, 24%, 22%, and 44% had HBV genotype A, B, C, and D, respectively; 98% percent were HBeAg positive. At baseline, overall median HBV DNA was 8.1 log₁₀ IU/mL, mean ALT was 107 U/L, median HBsAg was 4.5 log₁₀ IU/mL. Previous treatment included oral antivirals (N=20 [23%]), including entecavir (N=10 [11%]), lamivudine (N=10 [11%]), and TDF (N=2 [2%]), and/or interferons (N=13 [15%]).

The results for each treatment group and cohort for HBV DNA < 20 IU/mL at Weeks 24, 48 and 96 are presented in Table 16 below.

At Week 96, the overall mean (SD) change from baseline in HBV DNA for VEMLIDY-treated subjects and subjects who switched from placebo to VEMLIDY, respectively, was -6.18 (1.495) log₁₀ IU/mL and -5.92 (1.775) log₁₀ IU/mL. The overall median change from baseline in ALT values for the VEMLIDY and placebo-VEMLIDY treatment groups, respectively, was -39.5 U/L and -46.5 U/L at Week 96. ALT normalization (AASLD criteria) was achieved for 54% of VEMLIDY-treated subjects and 57% of subjects who switched from placebo to VEMLIDY.

At Week 96, 14/58 (24%) VEMLIDY-treated subjects and 5/29 (17%) subjects who switched from placebo to VEMLIDY experienced HBeAg loss with anti-HBe seroconversion. One of 47 (2%) subjects in the Cohort 1 VEMLIDY group achieved HBsAg loss at Week 96.

The recommended dosage of VEMLIDY in adults and pediatric patients 6 years of age and older and weighing at least 25 kg is one 25 mg tablet taken orally once daily with food [see Clinical Pharmacology (12.3)].

The efficacy and safety of switching from TDF to VEMLIDY in virologically suppressed adults with chronic hepatitis B virus infection is based on 48-week data from a randomized, double-blind, active-controlled trial, Trial 4018 (N=488). Subjects must have been taking TDF 300 mg once daily for at least 12 months, with HBV DNA less than the Lower Limit of Quantitation by local laboratory assessment for at least 12 weeks prior to screening and HBV DNA <20 IU/mL at screening. Subjects were stratified by HBeAg status (HBeAg-positive or HBeAg-negative) and age (≥50 or <50 years) and randomized in a 1:1 ratio to either switch to VEMLIDY 25 mg once daily (N=243) or stay on TDF 300 mg once daily (N=245). The mean age was 51 years (22% were ≥60 years), 71% were male, 82% were Asian, 14% were White, and 68% were HBeAg-negative. At baseline, median duration of prior TDF treatment was 220 and 224 weeks in the VEMLIDY and TDF groups, respectively. At baseline, mean serum ALT was 27 U/L, and 16% of subjects had a history of cirrhosis.

The primary efficacy endpoint was the proportion of subjects with plasma HBV DNA levels ≥20 IU/mL at Week 48. Additional efficacy endpoints in Trial 4018 included the proportion of subjects with HBV DNA <20 IU/mL, ALT normal and normalization, HBsAg loss and seroconversion, and HBeAg loss and seroconversion.

Treatment outcomes of Trial 4018 at Week 48 are presented in Table 14 and Table 15.