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

HIV Genotypic Testing

HIV genotypic testing is recommended for antiretroviral treatment-experienced patients. However, when HIV genotypic testing is not feasible, PREZCOBIX can be used in protease inhibitor-naïve patients, but is not recommended in protease inhibitor-experienced patients.

Human experience of acute overdose with PREZCOBIX is limited. No specific antidote is available for overdose with PREZCOBIX. Treatment of overdose with PREZCOBIX consists of general supportive measures including monitoring of vital signs and observation of the clinical status of the patient. Since both darunavir and cobicistat are highly protein bound, dialysis is unlikely to be beneficial in significant removal of the active substance.

PREZCOBIX ^®is a fixed-dose combination tablet containing darunavir and cobicistat. Darunavir is an inhibitor of the human immunodeficiency virus (HIV-1) protease. Cobicistat is a mechanism-based inhibitor of cytochrome P450 (CYP) enzymes of the CYP3A family.

PREZCOBIX tablets are for oral administration. Each tablet contains darunavir ethanolate equivalent to 800 mg of darunavir and 150 mg of cobicistat. The tablets include the following inactive ingredients: colloidal silicon dioxide, crospovidone, hypromellose, magnesium stearate, and silicified microcrystalline cellulose. The tablets are film-coated with a coating material containing iron oxide black, iron oxide red, polyethylene glycol, polyvinyl alcohol (partially hydrolyzed), talc, and titanium dioxide.

There have been reports of increased bleeding, including spontaneous skin hematomas and hemarthrosis in patients with hemophilia type A and B treated with HIV PIs. In some patients, additional factor VIII was given. In more than half of the reported cases, treatment with HIV PIs was continued or reintroduced if treatment had been discontinued. A causal relationship between PI therapy and these episodes has not been established.

Darunavir contains a sulfonamide moiety. Monitor patients with a known sulfonamide allergy after initiating PREZCOBIX. In clinical studies with darunavir co-administered with ritonavir, the incidence and severity of rash were similar in subjects with or without a history of sulfonamide allergy.

The safety and effectiveness of PREZCOBIX for the treatment of HIV-1 infection in pediatric patients weighing at least 40 kg was established through a trial with components of PREZCOBIX. Use of PREZCOBIX in this group is supported by evidence from adequate and well-controlled studies in adults with additional pharmacokinetic, safety, and virologic data from a study of components of PREZCOBIX (Trial GS-US-216-0128) in pediatric subjects with HIV-1 infection aged 12 to less than 18 years [see Adverse Reactions (6.1), Clinical Pharmacology (12.3), and Clinical Studies (14.2)] .

The safety and effectiveness of PREZCOBIX have not been established in pediatric patients weighing less than 40 kg. Darunavir, a component of PREZCOBIX is not recommended in pediatric patients below 3 years of age because of toxicity and mortality observed in juvenile rats dosed with darunavir.

Clinical trials of PREZCOBIX did not include sufficient numbers of patients aged 65 and over to determine whether they respond differently from younger patients. In general, caution should be exercised in the administration and monitoring of PREZCOBIX in elderly patients, reflecting the greater frequency of decreased hepatic function, and of concomitant disease or other drug therapy [see Clinical Pharmacology (12.3)] .

During the darunavir clinical development program (N=3063), where darunavir was co-administered with ritonavir 100 mg once or twice daily, drug-induced hepatitis (e.g., acute hepatitis, cytolytic hepatitis) was reported in 0.5% of subjects. Patients with pre-existing liver dysfunction, including chronic active hepatitis B or C, have an increased risk for liver function abnormalities including severe hepatic adverse reactions.

Post-marketing cases of liver injury, including some fatalities, have also been reported with darunavir co-administered with ritonavir. These have generally occurred in patients with advanced HIV-1 disease taking multiple concomitant medications, having co-morbidities including hepatitis B or C co-infection, and/or developing immune reconstitution syndrome. A causal relationship with darunavir co-administered with ritonavir has not been established.

Appropriate laboratory testing should be conducted prior to initiating therapy with PREZCOBIX and patients should be monitored during treatment. Increased AST/ALT monitoring should be considered in patients with underlying chronic hepatitis, cirrhosis, or in patients who have pre-treatment elevations of transaminases, especially during the first several months of PREZCOBIX treatment.

Evidence of new or worsening liver dysfunction (including clinically significant elevation of liver enzymes and/or symptoms such as fatigue, anorexia, nausea, jaundice, dark urine, liver tenderness, hepatomegaly) in patients on PREZCOBIX should prompt consideration of interruption or discontinuation of treatment.

Darunavir and cobicistat are both inhibitors of the cytochrome P450 3A (CYP3A) isoform. PREZCOBIX should not be co-administered with medicinal products that are highly dependent on CYP3A for clearance and for which increased plasma concentrations are associated with serious and/or life threatening events (narrow therapeutic index). Darunavir and cobicistat are both substrates of the cytochrome P450 3A (CYP3A) isoform. Co-administration of PREZCOBIX with CYP3A inducers may lead to lower exposures of darunavir and cobicistat and potential loss of efficacy of darunavir and possible resistance. Examples of drugs that are contraindicated for co-administration with PREZCOBIX [see Drug Interactions (7.3)and Clinical Pharmacology (12.3)] are listed below.

• Alpha 1-adrenoreceptor antagonist: alfuzosin
• Anticonvulsants: carbamazepine, phenobarbital, phenytoin
• Anti-gout: colchicine, in patients with renal and/or hepatic impairment
• Antimycobacterial: rifampin
• Antipsychotics: lurasidone, pimozide
• Cardiac Disorders: dronedarone, ivabradine, ranolazine
• Ergot derivatives, e.g. dihydroergotamine, ergotamine, methylergonovine
• Herbal product: St. John's wort ( Hypericum perforatum)
• Hepatitis C direct acting antiviral: elbasvir/grazoprevir
• Lipid modifying agents: lomitapide, lovastatin, simvastatin
• Opioid Antagonist: naloxegol
• PDE-5 inhibitor: sildenafil when used for treatment of pulmonary arterial hypertension
• Sedatives/hypnotics: orally administered midazolam, triazolam

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

• Hepatotoxicity [see Warnings and Precautions (5.1)]
• Severe skin reactions [see Warnings and Precautions (5.2)]
• Effects on serum creatinine [see Warnings and Precautions (5.3)]
• New onset or worsening renal impairment when used with tenofovir DF [see Warnings and Precautions (5.4)]
• Immune Reconstitution Syndrome [see Warnings and Precautions (5.10)]

• Co-administration of PREZCOBIX with other drugs can alter the concentration of other drugs and other drugs may alter the concentrations of darunavir or cobicistat. Consult the full prescribing information prior to and during treatment for potential drug interactions. ( 4, 5.6, 7, 12.3)

A renal impairment trial was not conducted for darunavir co-administered with cobicistat [see Clinical Pharmacology (12.3)] . Cobicistat has been shown to decrease estimated creatinine clearance without affecting actual renal glomerular function. Dosing recommendations are not available for drugs that require dosage adjustment for renal impairment when used in combination with PREZCOBIX [see Warnings and Precautions (5.3)and Clinical Pharmacology (12.2)] .

The pharmacokinetics of darunavir co-administered with cobicistat (150 mg) have been evaluated in healthy adult subjects and in HIV-1 infected subjects.

Darunavir is primarily metabolized by CYP3A. Cobicistat inhibits CYP3A, thereby increasing the plasma concentrations of darunavir.

Under fed (535 total kcal, 171 kcal from fat, 268 kcal from carbohydrates, 96 kcal from protein) and fasted conditions in healthy subjects, the 90% confidence intervals when comparing darunavir exposure between PREZCOBIX and darunavir 800 mg co-administered with cobicistat 150 mg as single entities were within 80–125%.

Darunavir exposure when comparing darunavir co-administered with cobicistat (as single entities) to darunavir co-administered with ritonavir was evaluated in a relative bioavailability trial [see cobicistat full prescribing information].Table 2 displays the population pharmacokinetic estimates of darunavir after oral administration of darunavir 800 mg co-administered with ritonavir 100 mg once daily (based on sparse sampling in 335 subjects in Trial TMC114-C211 and 280 subjects in Trial TMC114-C229) and darunavir 800 mg co-administered with cobicistat 150 mg once daily administered as single entities (based on sparse sampling in 298 subjects in Trial GS-US-216-0130) to HIV-1 infected subjects.

PREZCOBIX is a fixed-dose combination product containing 800 mg of darunavir and 150 mg of cobicistat. In treatment-naïve and treatment-experienced adults and pediatric patients weighing at least 40 kg with no darunavir resistance-associated substitutions, the recommended dosage of PREZCOBIX is one tablet taken once daily orally with food. Administer PREZCOBIX in conjunction with other antiretroviral agents.

Redistribution/accumulation of body fat, including central obesity, dorsocervical fat enlargement (buffalo hump), peripheral wasting, facial wasting, breast enlargement, and "cushingoid appearance" have been observed in patients receiving antiretroviral therapy. The mechanism and long-term consequences of these events are currently unknown. A causal relationship has not been established.

No clinical trials were conducted with darunavir co-administered with cobicistat in hepatically impaired subjects and the effect of hepatic impairment on darunavir exposure when co-administered with cobicistat has not been evaluated. Based on the recommendations for darunavir co-administered with ritonavir, a dose adjustment for patients with mild or moderate hepatic impairment is not necessary. No pharmacokinetic or safety data are available regarding the use of darunavir in subjects with severe hepatic impairment. Therefore, PREZCOBIX is not recommended for use in patients with severe hepatic impairment [see Clinical Pharmacology (12.3)] .

PREZCOBIX is indicated in combination with other antiretroviral agents for the treatment of human immunodeficiency virus (HIV-1) infection in treatment-naïve and treatment-experienced adults and pediatric patients weighing at least 40 kg with no darunavir resistance-associated substitutions (V11I, V32I, L33F, I47V, I50V, I54L, I54M, T74P, L76V, I84V, L89V).

PREZCOBIX is a fixed-dose combination of an HIV-1 antiviral drug, darunavir and a CYP3A inhibitor, cobicistat [see Microbiology (12.4)].

During the darunavir clinical development program (n=3063), where darunavir was co-administered with ritonavir 100 mg once or twice daily, severe skin reactions, accompanied by fever and/or elevations of transaminases in some cases, was reported in 0.4% of subjects. Stevens-Johnson Syndrome was rarely (less than 0.1%) reported during the clinical development program. During post-marketing experience toxic epidermal necrolysis, drug rash with eosinophilia and systemic symptoms, and acute generalized exanthematous pustulosis have been reported. Discontinue PREZCOBIX immediately if signs or symptoms of severe skin reactions develop. These can include but are not limited to severe rash or rash accompanied with fever, general malaise, fatigue, muscle or joint aches, blisters, oral lesions, conjunctivitis, hepatitis and/or eosinophilia.

Mild-to-moderate rash was also reported and often occurred within the first four weeks of treatment and resolved with continued dosing.

• Drug-induced hepatitis (e.g., acute hepatitis, cytolytic hepatitis), liver injury, including some fatalities can occur with PREZCOBIX. Monitor liver function before and during therapy, especially in patients with underlying chronic hepatitis, cirrhosis, or in patients who have pre-treatment elevations of transaminases. ( 5.1)
• Skin reactions ranging from mild to severe, including Stevens-Johnson Syndrome, toxic epidermal necrolysis, drug rash with eosinophilia and systemic symptoms and acute generalized exanthematous pustulosis, can occur with PREZCOBIX. Discontinue treatment if severe reaction develops. ( 5.2)
• When PREZCOBIX is used in combination with a tenofovir disoproxil fumarate (tenofovir DF) containing regimen, cases of acute renal failure and Fanconi syndrome have been reported. ( 5.4)
• PREZCOBIX is not recommended in combination with other antiretroviral drugs that require pharmacokinetic boosting. ( 5.6)
• Monitor in patients with a known sulfonamide allergy. ( 5.7)
• Patients receiving PREZCOBIX may develop new onset or exacerbations of diabetes mellitus/hyperglycemia ( 5.8), redistribution/accumulation of body fat ( 5.9), and immune reconstitution syndrome. ( 5.10)
• Patients with hemophilia may develop increased bleeding events. ( 5.11)

Recommended dosage:One tablet taken once daily with food in adults and pediatric patients weighing at least 40 kg. ( 2.1)

Testing Prior to Initiation:HIV genotypic testing is recommended for antiretroviral treatment experienced patients. Assess estimated creatinine clearance in all patients prior to starting PREZCOBIX. When used with tenofovir DF: Assess urine glucose and urine protein at baseline and monitor creatinine clearance, urine glucose, and urine protein. Monitor serum phosphorus in patients with or at risk for renal impairment. ( 2.2)

PREZCOBIX is supplied as pink, oval-shaped, film-coated tablets containing darunavir ethanolate equivalent to 800 mg of darunavir and 150 mg cobicistat. Each tablet is debossed with "800" on one side and "TG" on the other side.

The following adverse reactions have been identified during post-approval use of darunavir. 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.

• Pregnancy: PREZCOBIX is not recommended during pregnancy due to substantially lower exposures of darunavir and cobicistat during pregnancy. ( 8.1, 12.3)
• Lactation: Breastfeeding is not recommended. ( 8.2)
• Pediatrics: Not recommended for pediatric patients weighing less than 40 kg. ( 8.4)

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 clinical practice.

Cobicistat decreases estimated creatinine clearance due to inhibition of tubular secretion of creatinine without affecting actual renal glomerular function. This effect should be considered when interpreting changes in estimated creatinine clearance in patients initiating PREZCOBIX, particularly in patients with medical conditions or receiving drugs needing monitoring with estimated creatinine clearance.

Prior to initiating therapy with PREZCOBIX, assess estimated creatinine clearance [see Dosage and Administration (2.2)] . Dosage recommendations are not available for drugs that require dosage adjustments in PREZCOBIX-treated patients with renal impairment [see Drug Interactions (7.3)and Clinical Pharmacology (12.2)] . Consider alternative medications that do not require dosage adjustments in patients with renal impairment.

Although cobicistat may cause modest increases in serum creatinine and modest declines in estimated creatinine clearance without affecting renal glomerular function, patients who experience a confirmed increase in serum creatinine of greater than 0.4 mg/dL from baseline should be closely monitored for renal safety.

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

Immune reconstitution syndrome has been reported in patients treated with combination antiretroviral therapy, including PREZCOBIX. During the initial phase of combination antiretroviral treatment, patients whose immune systems respond may develop an inflammatory response to indolent or residual opportunistic infections (such as Mycobacterium aviuminfection, cytomegalovirus, Pneumocystis jiroveciipneumonia [PCP], or tuberculosis), which may necessitate further evaluation and treatment.

Autoimmune disorders (such as Graves' disease, polymyositis, Guillain-Barré syndrome and autoimmune hepatitis) 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 antiretroviral treatment.

PREZCOBIX is not recommended in combination with other antiretroviral drugs that require pharmacokinetic boosting (i.e., another protease inhibitor or elvitegravir) because dosing recommendations for such combinations have not been established and co-administration may result in decreased plasma concentrations of the antiretroviral agents, leading to loss of therapeutic effect and development of resistance.

PREZCOBIX is not recommended in combination with products containing the individual components of PREZCOBIX (darunavir and cobicistat) or with ritonavir. For additional recommendations on use of PREZCOBIX with other antiretroviral agents, [see Drug Interactions (7)] .

New onset diabetes mellitus, exacerbation of pre-existing diabetes mellitus, and hyperglycemia have been reported during postmarketing surveillance in patients with HIV-1 infection receiving HIV protease inhibitor (PI) therapy. Some patients required either initiation or dose adjustments of insulin or oral hypoglycemic agents for treatment of these events. In some cases, diabetic ketoacidosis has occurred. In those patients who discontinued PI therapy, hyperglycemia persisted in some cases. Because these events have been reported voluntarily during clinical practice, estimates of frequency cannot be made and causal relationships between HIV PI therapy and these events have not been established.

Product: 50090-1723

NDC: 50090-1723-0 30 TABLET, FILM COATED in a BOTTLE

PREZCOBIX is not recommended during pregnancy because of substantially lower exposures of darunavir and cobicistat during the second and third trimesters [see Use in Specific Populations (8.1)and Clinical Pharmacology (12.3)] .

PREZCOBIX should not be initiated in pregnant individuals. An alternative regimen is recommended for those who become pregnant during therapy with PREZCOBIX.

PREZCOBIX co-administered with tenofovir DF is not recommended in patients who have an estimated creatinine clearance below 70 mL per minute [see Warnings and Precautions (5.4)and Adverse Reactions (6.1)] .

PREZCOBIX is not recommended for use in patients with severe hepatic impairment [see Use in Specific Populations (8.6)and Clinical Pharmacology (12.3)] .

Darunavir co-administered with cobicistat is an inhibitor of CYP3A and CYP2D6. Cobicistat inhibits the following transporters: P-glycoprotein (P-gp), BCRP, MATE1, OATP1B1 and OATP1B3. Therefore, co-administration of PREZCOBIX with drugs that are primarily metabolized by CYP3A and/or CYP2D6 or are substrates of P-gp, BCRP, MATE1, OATP1B1 or OATP1B3 may result in increased plasma concentrations of such drugs, which could increase or prolong their therapeutic effect and can be associated with adverse events. Co-administration of PREZCOBIX with drugs that have active metabolite(s) formed by CYP3A may result in reduced plasma concentrations of these active metabolite(s), potentially leading to loss of their therapeutic effect (see Table 1).

Darunavir is metabolized by CYP3A. Cobicistat is metabolized by CYP3A, and to a minor extent, by CYP2D6. Co-administration of PREZCOBIX and drugs that induce CYP3A activity are expected to increase the clearance of darunavir and cobicistat, resulting in lowered plasma concentrations of darunavir and cobicistat which may lead to loss of therapeutic effect and development of resistance. Co-administration of PREZCOBIX and other drugs that inhibit CYP3A may result in increased plasma concentrations of darunavir and cobicistat (see Table 1).

The efficacy of PREZCOBIX in adults with HIV-1 infection is based on efficacy demonstrated in clinical trials of darunavir co-administered with ritonavir [see darunavir full prescribing information].

Table 1 provides dosing recommendations for expected clinically relevant interactions with PREZCOBIX (this table is not all inclusive). These recommendations are based on either drug interaction trials or predicted interactions due to the expected magnitude of interaction and potential for serious adverse events or loss of therapeutic effect. The table includes examples of potentially significant interactions but is not all inclusive ,and therefore the label of each drug that is co-administered with PREZCOBIX should be consulted for information related to the route of metabolism, interaction pathways, potential risks, and specific actions to be taken with regard to co-administration. For the list of examples of contraindicated drugs, [see Contraindications (4)] .

Clinically relevant drug-drug interactions have not been observed or are not anticipated with concomitant use of darunavir and cobicistat with rilpivirine, dolutegravir, raltegravir, abacavir, emtricitabine, emtricitabine/tenofovir alafenamide, tenofovir DF, lamivudine, stavudine, zidovudine, or acid modifying medications (antacids, H ₂-receptor antagonists, proton pump inhibitors).

Trial GS-US-216-0128 was a Phase 2/3 multicenter, open-label trial to evaluate the pharmacokinetics, safety, and efficacy of darunavir co-administered with cobicistat in adolescents aged 12 years and older with HIV-1 infection who were virolgically suppressed and had a baseline estimated creatinine clearance ≥90 mL/min/1.73 m ². Subjects were on a stable antiretroviral regimen (for at least 3 months), consisting of darunavir administered with ritonavir, combined with 2 NRTIs. These subjects (N=7) were switched from ritonavir to cobicistat 150 mg once daily and continued darunavir and 2 NRTIs.

The median age of subjects was 14 years (range 12–16 years), median weight was 60 kg (range 45–78 kg), and 43% were male. At baseline, all subjects had plasma HIV-1 RNA <50 copies/mL. At Week 48, 86% (6/7) of subjects remained suppressed (HIV-1 RNA <50 copies/mL), and 1 subject had missing data. From a median baseline CD4+ cell count and CD4+% of 1,117 cells/mm ³(range 658 to 2,416 cells/mm ³) and 45% (range 28% to 56%), respectively, the median change from baseline in CD4+ cell count and CD4+% at Week 48 was -342 cells/mm ³(range -1,389 to 219 cells/mm ³) and -6% (range -12% to 5%), respectively. All 6 subjects with available data had CD4+ cell counts above 800 cells/mm ³at Week 48.

Renal impairment, including cases of acute renal failure and Fanconi syndrome, has been reported when cobicistat, a component of PREZCOBIX, was used in an antiretroviral regimen that contained tenofovir DF. Co-administration of PREZCOBIX and tenofovir DF is not recommended in patients who have an estimated creatinine clearance below 70 mL/min [see Dosage and Administration (2.3)] .

• Document urine glucose and urine protein at baseline [see Dosage and Administration (2.2)] and perform routine monitoring of estimated creatinine clearance, urine glucose, and urine protein during treatment when PREZCOBIX is used with tenofovir DF. Measure serum phosphorus in patients with or at risk for renal impairment when used with tenofovir DF.
• Co-administration of PREZCOBIX and tenofovir DF in combination with concomitant or recent use of a nephrotoxic agent is not recommended.

See cobicistat full prescribing information for additional information regarding cobicistat.

Initiation of PREZCOBIX, which inhibits CYP3A, in patients receiving medications metabolized by CYP3A, or initiation of medications metabolized by CYP3A in patients already receiving PREZCOBIX may increase plasma concentrations of medications metabolized by CYP3A and reduce plasma concentrations of active metabolite(s) formed by CYP3A. Initiation of medications that inhibit or induce CYP3A may respectively increase or decrease concentrations of PREZCOBIX.

These interactions may lead to:

• clinically significant adverse reactions, potentially leading to severe, life threatening, or fatal events from higher exposures of concomitant medications.
• clinically significant adverse reactions from higher exposures of PREZCOBIX.
• loss of therapeutic effect of the concomitant medications from lower exposures of active metabolite(s).
• loss of therapeutic effect of PREZCOBIX and possible development of resistance from lower exposures of PREZCOBIX.

See Table 1for 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 PREZCOBIX therapy; review concomitant medications during PREZCOBIX therapy; and monitor for the adverse reactions associated with concomitant medications [see Contraindications (4)and Drug Interactions (7)] .

When used with concomitant medications, PREZCOBIX may result in different drug interactions than those observed or expected with darunavir co-administered with ritonavir. Complex or unknown mechanisms of drug interactions preclude extrapolation of drug interactions with darunavir co-administered with ritonavir to certain PREZCOBIX interactions [see Drug Interactions (7)and Clinical Pharmacology (12.3)] .

HIV Genotypic Testing

HIV genotypic testing is recommended for antiretroviral treatment-experienced patients. However, when HIV genotypic testing is not feasible, PREZCOBIX can be used in protease inhibitor-naïve patients, but is not recommended in protease inhibitor-experienced patients.

Human experience of acute overdose with PREZCOBIX is limited. No specific antidote is available for overdose with PREZCOBIX. Treatment of overdose with PREZCOBIX consists of general supportive measures including monitoring of vital signs and observation of the clinical status of the patient. Since both darunavir and cobicistat are highly protein bound, dialysis is unlikely to be beneficial in significant removal of the active substance.

PREZCOBIX ^®is a fixed-dose combination tablet containing darunavir and cobicistat. Darunavir is an inhibitor of the human immunodeficiency virus (HIV-1) protease. Cobicistat is a mechanism-based inhibitor of cytochrome P450 (CYP) enzymes of the CYP3A family.

PREZCOBIX tablets are for oral administration. Each tablet contains darunavir ethanolate equivalent to 800 mg of darunavir and 150 mg of cobicistat. The tablets include the following inactive ingredients: colloidal silicon dioxide, crospovidone, hypromellose, magnesium stearate, and silicified microcrystalline cellulose. The tablets are film-coated with a coating material containing iron oxide black, iron oxide red, polyethylene glycol, polyvinyl alcohol (partially hydrolyzed), talc, and titanium dioxide.

There have been reports of increased bleeding, including spontaneous skin hematomas and hemarthrosis in patients with hemophilia type A and B treated with HIV PIs. In some patients, additional factor VIII was given. In more than half of the reported cases, treatment with HIV PIs was continued or reintroduced if treatment had been discontinued. A causal relationship between PI therapy and these episodes has not been established.

Darunavir contains a sulfonamide moiety. Monitor patients with a known sulfonamide allergy after initiating PREZCOBIX. In clinical studies with darunavir co-administered with ritonavir, the incidence and severity of rash were similar in subjects with or without a history of sulfonamide allergy.

The safety and effectiveness of PREZCOBIX for the treatment of HIV-1 infection in pediatric patients weighing at least 40 kg was established through a trial with components of PREZCOBIX. Use of PREZCOBIX in this group is supported by evidence from adequate and well-controlled studies in adults with additional pharmacokinetic, safety, and virologic data from a study of components of PREZCOBIX (Trial GS-US-216-0128) in pediatric subjects with HIV-1 infection aged 12 to less than 18 years [see Adverse Reactions (6.1), Clinical Pharmacology (12.3), and Clinical Studies (14.2)] .

The safety and effectiveness of PREZCOBIX have not been established in pediatric patients weighing less than 40 kg. Darunavir, a component of PREZCOBIX is not recommended in pediatric patients below 3 years of age because of toxicity and mortality observed in juvenile rats dosed with darunavir.

Clinical trials of PREZCOBIX did not include sufficient numbers of patients aged 65 and over to determine whether they respond differently from younger patients. In general, caution should be exercised in the administration and monitoring of PREZCOBIX in elderly patients, reflecting the greater frequency of decreased hepatic function, and of concomitant disease or other drug therapy [see Clinical Pharmacology (12.3)] .

During the darunavir clinical development program (N=3063), where darunavir was co-administered with ritonavir 100 mg once or twice daily, drug-induced hepatitis (e.g., acute hepatitis, cytolytic hepatitis) was reported in 0.5% of subjects. Patients with pre-existing liver dysfunction, including chronic active hepatitis B or C, have an increased risk for liver function abnormalities including severe hepatic adverse reactions.

Post-marketing cases of liver injury, including some fatalities, have also been reported with darunavir co-administered with ritonavir. These have generally occurred in patients with advanced HIV-1 disease taking multiple concomitant medications, having co-morbidities including hepatitis B or C co-infection, and/or developing immune reconstitution syndrome. A causal relationship with darunavir co-administered with ritonavir has not been established.

Appropriate laboratory testing should be conducted prior to initiating therapy with PREZCOBIX and patients should be monitored during treatment. Increased AST/ALT monitoring should be considered in patients with underlying chronic hepatitis, cirrhosis, or in patients who have pre-treatment elevations of transaminases, especially during the first several months of PREZCOBIX treatment.

Evidence of new or worsening liver dysfunction (including clinically significant elevation of liver enzymes and/or symptoms such as fatigue, anorexia, nausea, jaundice, dark urine, liver tenderness, hepatomegaly) in patients on PREZCOBIX should prompt consideration of interruption or discontinuation of treatment.

Darunavir and cobicistat are both inhibitors of the cytochrome P450 3A (CYP3A) isoform. PREZCOBIX should not be co-administered with medicinal products that are highly dependent on CYP3A for clearance and for which increased plasma concentrations are associated with serious and/or life threatening events (narrow therapeutic index). Darunavir and cobicistat are both substrates of the cytochrome P450 3A (CYP3A) isoform. Co-administration of PREZCOBIX with CYP3A inducers may lead to lower exposures of darunavir and cobicistat and potential loss of efficacy of darunavir and possible resistance. Examples of drugs that are contraindicated for co-administration with PREZCOBIX [see Drug Interactions (7.3)and Clinical Pharmacology (12.3)] are listed below.

• Alpha 1-adrenoreceptor antagonist: alfuzosin
• Anticonvulsants: carbamazepine, phenobarbital, phenytoin
• Anti-gout: colchicine, in patients with renal and/or hepatic impairment
• Antimycobacterial: rifampin
• Antipsychotics: lurasidone, pimozide
• Cardiac Disorders: dronedarone, ivabradine, ranolazine
• Ergot derivatives, e.g. dihydroergotamine, ergotamine, methylergonovine
• Herbal product: St. John's wort ( Hypericum perforatum)
• Hepatitis C direct acting antiviral: elbasvir/grazoprevir
• Lipid modifying agents: lomitapide, lovastatin, simvastatin
• Opioid Antagonist: naloxegol
• PDE-5 inhibitor: sildenafil when used for treatment of pulmonary arterial hypertension
• Sedatives/hypnotics: orally administered midazolam, triazolam

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

• Hepatotoxicity [see Warnings and Precautions (5.1)]
• Severe skin reactions [see Warnings and Precautions (5.2)]
• Effects on serum creatinine [see Warnings and Precautions (5.3)]
• New onset or worsening renal impairment when used with tenofovir DF [see Warnings and Precautions (5.4)]
• Immune Reconstitution Syndrome [see Warnings and Precautions (5.10)]

• Co-administration of PREZCOBIX with other drugs can alter the concentration of other drugs and other drugs may alter the concentrations of darunavir or cobicistat. Consult the full prescribing information prior to and during treatment for potential drug interactions. ( 4, 5.6, 7, 12.3)

A renal impairment trial was not conducted for darunavir co-administered with cobicistat [see Clinical Pharmacology (12.3)] . Cobicistat has been shown to decrease estimated creatinine clearance without affecting actual renal glomerular function. Dosing recommendations are not available for drugs that require dosage adjustment for renal impairment when used in combination with PREZCOBIX [see Warnings and Precautions (5.3)and Clinical Pharmacology (12.2)] .

The pharmacokinetics of darunavir co-administered with cobicistat (150 mg) have been evaluated in healthy adult subjects and in HIV-1 infected subjects.

Darunavir is primarily metabolized by CYP3A. Cobicistat inhibits CYP3A, thereby increasing the plasma concentrations of darunavir.

Under fed (535 total kcal, 171 kcal from fat, 268 kcal from carbohydrates, 96 kcal from protein) and fasted conditions in healthy subjects, the 90% confidence intervals when comparing darunavir exposure between PREZCOBIX and darunavir 800 mg co-administered with cobicistat 150 mg as single entities were within 80–125%.

Darunavir exposure when comparing darunavir co-administered with cobicistat (as single entities) to darunavir co-administered with ritonavir was evaluated in a relative bioavailability trial [see cobicistat full prescribing information].Table 2 displays the population pharmacokinetic estimates of darunavir after oral administration of darunavir 800 mg co-administered with ritonavir 100 mg once daily (based on sparse sampling in 335 subjects in Trial TMC114-C211 and 280 subjects in Trial TMC114-C229) and darunavir 800 mg co-administered with cobicistat 150 mg once daily administered as single entities (based on sparse sampling in 298 subjects in Trial GS-US-216-0130) to HIV-1 infected subjects.

PREZCOBIX is a fixed-dose combination product containing 800 mg of darunavir and 150 mg of cobicistat. In treatment-naïve and treatment-experienced adults and pediatric patients weighing at least 40 kg with no darunavir resistance-associated substitutions, the recommended dosage of PREZCOBIX is one tablet taken once daily orally with food. Administer PREZCOBIX in conjunction with other antiretroviral agents.

Redistribution/accumulation of body fat, including central obesity, dorsocervical fat enlargement (buffalo hump), peripheral wasting, facial wasting, breast enlargement, and "cushingoid appearance" have been observed in patients receiving antiretroviral therapy. The mechanism and long-term consequences of these events are currently unknown. A causal relationship has not been established.

No clinical trials were conducted with darunavir co-administered with cobicistat in hepatically impaired subjects and the effect of hepatic impairment on darunavir exposure when co-administered with cobicistat has not been evaluated. Based on the recommendations for darunavir co-administered with ritonavir, a dose adjustment for patients with mild or moderate hepatic impairment is not necessary. No pharmacokinetic or safety data are available regarding the use of darunavir in subjects with severe hepatic impairment. Therefore, PREZCOBIX is not recommended for use in patients with severe hepatic impairment [see Clinical Pharmacology (12.3)] .

PREZCOBIX is indicated in combination with other antiretroviral agents for the treatment of human immunodeficiency virus (HIV-1) infection in treatment-naïve and treatment-experienced adults and pediatric patients weighing at least 40 kg with no darunavir resistance-associated substitutions (V11I, V32I, L33F, I47V, I50V, I54L, I54M, T74P, L76V, I84V, L89V).

PREZCOBIX is a fixed-dose combination of an HIV-1 antiviral drug, darunavir and a CYP3A inhibitor, cobicistat [see Microbiology (12.4)].

During the darunavir clinical development program (n=3063), where darunavir was co-administered with ritonavir 100 mg once or twice daily, severe skin reactions, accompanied by fever and/or elevations of transaminases in some cases, was reported in 0.4% of subjects. Stevens-Johnson Syndrome was rarely (less than 0.1%) reported during the clinical development program. During post-marketing experience toxic epidermal necrolysis, drug rash with eosinophilia and systemic symptoms, and acute generalized exanthematous pustulosis have been reported. Discontinue PREZCOBIX immediately if signs or symptoms of severe skin reactions develop. These can include but are not limited to severe rash or rash accompanied with fever, general malaise, fatigue, muscle or joint aches, blisters, oral lesions, conjunctivitis, hepatitis and/or eosinophilia.

Mild-to-moderate rash was also reported and often occurred within the first four weeks of treatment and resolved with continued dosing.

• Drug-induced hepatitis (e.g., acute hepatitis, cytolytic hepatitis), liver injury, including some fatalities can occur with PREZCOBIX. Monitor liver function before and during therapy, especially in patients with underlying chronic hepatitis, cirrhosis, or in patients who have pre-treatment elevations of transaminases. ( 5.1)
• Skin reactions ranging from mild to severe, including Stevens-Johnson Syndrome, toxic epidermal necrolysis, drug rash with eosinophilia and systemic symptoms and acute generalized exanthematous pustulosis, can occur with PREZCOBIX. Discontinue treatment if severe reaction develops. ( 5.2)
• When PREZCOBIX is used in combination with a tenofovir disoproxil fumarate (tenofovir DF) containing regimen, cases of acute renal failure and Fanconi syndrome have been reported. ( 5.4)
• PREZCOBIX is not recommended in combination with other antiretroviral drugs that require pharmacokinetic boosting. ( 5.6)
• Monitor in patients with a known sulfonamide allergy. ( 5.7)
• Patients receiving PREZCOBIX may develop new onset or exacerbations of diabetes mellitus/hyperglycemia ( 5.8), redistribution/accumulation of body fat ( 5.9), and immune reconstitution syndrome. ( 5.10)
• Patients with hemophilia may develop increased bleeding events. ( 5.11)

Recommended dosage:One tablet taken once daily with food in adults and pediatric patients weighing at least 40 kg. ( 2.1)

Testing Prior to Initiation:HIV genotypic testing is recommended for antiretroviral treatment experienced patients. Assess estimated creatinine clearance in all patients prior to starting PREZCOBIX. When used with tenofovir DF: Assess urine glucose and urine protein at baseline and monitor creatinine clearance, urine glucose, and urine protein. Monitor serum phosphorus in patients with or at risk for renal impairment. ( 2.2)

PREZCOBIX is supplied as pink, oval-shaped, film-coated tablets containing darunavir ethanolate equivalent to 800 mg of darunavir and 150 mg cobicistat. Each tablet is debossed with "800" on one side and "TG" on the other side.

The following adverse reactions have been identified during post-approval use of darunavir. 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.

• Pregnancy: PREZCOBIX is not recommended during pregnancy due to substantially lower exposures of darunavir and cobicistat during pregnancy. ( 8.1, 12.3)
• Lactation: Breastfeeding is not recommended. ( 8.2)
• Pediatrics: Not recommended for pediatric patients weighing less than 40 kg. ( 8.4)

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 clinical practice.

Cobicistat decreases estimated creatinine clearance due to inhibition of tubular secretion of creatinine without affecting actual renal glomerular function. This effect should be considered when interpreting changes in estimated creatinine clearance in patients initiating PREZCOBIX, particularly in patients with medical conditions or receiving drugs needing monitoring with estimated creatinine clearance.

Prior to initiating therapy with PREZCOBIX, assess estimated creatinine clearance [see Dosage and Administration (2.2)] . Dosage recommendations are not available for drugs that require dosage adjustments in PREZCOBIX-treated patients with renal impairment [see Drug Interactions (7.3)and Clinical Pharmacology (12.2)] . Consider alternative medications that do not require dosage adjustments in patients with renal impairment.

Although cobicistat may cause modest increases in serum creatinine and modest declines in estimated creatinine clearance without affecting renal glomerular function, patients who experience a confirmed increase in serum creatinine of greater than 0.4 mg/dL from baseline should be closely monitored for renal safety.

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

Immune reconstitution syndrome has been reported in patients treated with combination antiretroviral therapy, including PREZCOBIX. During the initial phase of combination antiretroviral treatment, patients whose immune systems respond may develop an inflammatory response to indolent or residual opportunistic infections (such as Mycobacterium aviuminfection, cytomegalovirus, Pneumocystis jiroveciipneumonia [PCP], or tuberculosis), which may necessitate further evaluation and treatment.

Autoimmune disorders (such as Graves' disease, polymyositis, Guillain-Barré syndrome and autoimmune hepatitis) 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 antiretroviral treatment.

PREZCOBIX is not recommended in combination with other antiretroviral drugs that require pharmacokinetic boosting (i.e., another protease inhibitor or elvitegravir) because dosing recommendations for such combinations have not been established and co-administration may result in decreased plasma concentrations of the antiretroviral agents, leading to loss of therapeutic effect and development of resistance.

PREZCOBIX is not recommended in combination with products containing the individual components of PREZCOBIX (darunavir and cobicistat) or with ritonavir. For additional recommendations on use of PREZCOBIX with other antiretroviral agents, [see Drug Interactions (7)] .

New onset diabetes mellitus, exacerbation of pre-existing diabetes mellitus, and hyperglycemia have been reported during postmarketing surveillance in patients with HIV-1 infection receiving HIV protease inhibitor (PI) therapy. Some patients required either initiation or dose adjustments of insulin or oral hypoglycemic agents for treatment of these events. In some cases, diabetic ketoacidosis has occurred. In those patients who discontinued PI therapy, hyperglycemia persisted in some cases. Because these events have been reported voluntarily during clinical practice, estimates of frequency cannot be made and causal relationships between HIV PI therapy and these events have not been established.

Product: 50090-1723

NDC: 50090-1723-0 30 TABLET, FILM COATED in a BOTTLE

PREZCOBIX is not recommended during pregnancy because of substantially lower exposures of darunavir and cobicistat during the second and third trimesters [see Use in Specific Populations (8.1)and Clinical Pharmacology (12.3)] .

PREZCOBIX should not be initiated in pregnant individuals. An alternative regimen is recommended for those who become pregnant during therapy with PREZCOBIX.

PREZCOBIX co-administered with tenofovir DF is not recommended in patients who have an estimated creatinine clearance below 70 mL per minute [see Warnings and Precautions (5.4)and Adverse Reactions (6.1)] .

PREZCOBIX is not recommended for use in patients with severe hepatic impairment [see Use in Specific Populations (8.6)and Clinical Pharmacology (12.3)] .

Darunavir co-administered with cobicistat is an inhibitor of CYP3A and CYP2D6. Cobicistat inhibits the following transporters: P-glycoprotein (P-gp), BCRP, MATE1, OATP1B1 and OATP1B3. Therefore, co-administration of PREZCOBIX with drugs that are primarily metabolized by CYP3A and/or CYP2D6 or are substrates of P-gp, BCRP, MATE1, OATP1B1 or OATP1B3 may result in increased plasma concentrations of such drugs, which could increase or prolong their therapeutic effect and can be associated with adverse events. Co-administration of PREZCOBIX with drugs that have active metabolite(s) formed by CYP3A may result in reduced plasma concentrations of these active metabolite(s), potentially leading to loss of their therapeutic effect (see Table 1).

Darunavir is metabolized by CYP3A. Cobicistat is metabolized by CYP3A, and to a minor extent, by CYP2D6. Co-administration of PREZCOBIX and drugs that induce CYP3A activity are expected to increase the clearance of darunavir and cobicistat, resulting in lowered plasma concentrations of darunavir and cobicistat which may lead to loss of therapeutic effect and development of resistance. Co-administration of PREZCOBIX and other drugs that inhibit CYP3A may result in increased plasma concentrations of darunavir and cobicistat (see Table 1).

The efficacy of PREZCOBIX in adults with HIV-1 infection is based on efficacy demonstrated in clinical trials of darunavir co-administered with ritonavir [see darunavir full prescribing information].

Table 1 provides dosing recommendations for expected clinically relevant interactions with PREZCOBIX (this table is not all inclusive). These recommendations are based on either drug interaction trials or predicted interactions due to the expected magnitude of interaction and potential for serious adverse events or loss of therapeutic effect. The table includes examples of potentially significant interactions but is not all inclusive ,and therefore the label of each drug that is co-administered with PREZCOBIX should be consulted for information related to the route of metabolism, interaction pathways, potential risks, and specific actions to be taken with regard to co-administration. For the list of examples of contraindicated drugs, [see Contraindications (4)] .

Clinically relevant drug-drug interactions have not been observed or are not anticipated with concomitant use of darunavir and cobicistat with rilpivirine, dolutegravir, raltegravir, abacavir, emtricitabine, emtricitabine/tenofovir alafenamide, tenofovir DF, lamivudine, stavudine, zidovudine, or acid modifying medications (antacids, H ₂-receptor antagonists, proton pump inhibitors).

Trial GS-US-216-0128 was a Phase 2/3 multicenter, open-label trial to evaluate the pharmacokinetics, safety, and efficacy of darunavir co-administered with cobicistat in adolescents aged 12 years and older with HIV-1 infection who were virolgically suppressed and had a baseline estimated creatinine clearance ≥90 mL/min/1.73 m ². Subjects were on a stable antiretroviral regimen (for at least 3 months), consisting of darunavir administered with ritonavir, combined with 2 NRTIs. These subjects (N=7) were switched from ritonavir to cobicistat 150 mg once daily and continued darunavir and 2 NRTIs.

The median age of subjects was 14 years (range 12–16 years), median weight was 60 kg (range 45–78 kg), and 43% were male. At baseline, all subjects had plasma HIV-1 RNA <50 copies/mL. At Week 48, 86% (6/7) of subjects remained suppressed (HIV-1 RNA <50 copies/mL), and 1 subject had missing data. From a median baseline CD4+ cell count and CD4+% of 1,117 cells/mm ³(range 658 to 2,416 cells/mm ³) and 45% (range 28% to 56%), respectively, the median change from baseline in CD4+ cell count and CD4+% at Week 48 was -342 cells/mm ³(range -1,389 to 219 cells/mm ³) and -6% (range -12% to 5%), respectively. All 6 subjects with available data had CD4+ cell counts above 800 cells/mm ³at Week 48.

Renal impairment, including cases of acute renal failure and Fanconi syndrome, has been reported when cobicistat, a component of PREZCOBIX, was used in an antiretroviral regimen that contained tenofovir DF. Co-administration of PREZCOBIX and tenofovir DF is not recommended in patients who have an estimated creatinine clearance below 70 mL/min [see Dosage and Administration (2.3)] .

• Document urine glucose and urine protein at baseline [see Dosage and Administration (2.2)] and perform routine monitoring of estimated creatinine clearance, urine glucose, and urine protein during treatment when PREZCOBIX is used with tenofovir DF. Measure serum phosphorus in patients with or at risk for renal impairment when used with tenofovir DF.
• Co-administration of PREZCOBIX and tenofovir DF in combination with concomitant or recent use of a nephrotoxic agent is not recommended.

See cobicistat full prescribing information for additional information regarding cobicistat.

Initiation of PREZCOBIX, which inhibits CYP3A, in patients receiving medications metabolized by CYP3A, or initiation of medications metabolized by CYP3A in patients already receiving PREZCOBIX may increase plasma concentrations of medications metabolized by CYP3A and reduce plasma concentrations of active metabolite(s) formed by CYP3A. Initiation of medications that inhibit or induce CYP3A may respectively increase or decrease concentrations of PREZCOBIX.

These interactions may lead to:

• clinically significant adverse reactions, potentially leading to severe, life threatening, or fatal events from higher exposures of concomitant medications.
• clinically significant adverse reactions from higher exposures of PREZCOBIX.
• loss of therapeutic effect of the concomitant medications from lower exposures of active metabolite(s).
• loss of therapeutic effect of PREZCOBIX and possible development of resistance from lower exposures of PREZCOBIX.

See Table 1for 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 PREZCOBIX therapy; review concomitant medications during PREZCOBIX therapy; and monitor for the adverse reactions associated with concomitant medications [see Contraindications (4)and Drug Interactions (7)] .

When used with concomitant medications, PREZCOBIX may result in different drug interactions than those observed or expected with darunavir co-administered with ritonavir. Complex or unknown mechanisms of drug interactions preclude extrapolation of drug interactions with darunavir co-administered with ritonavir to certain PREZCOBIX interactions [see Drug Interactions (7)and Clinical Pharmacology (12.3)] .