Enfuvirtide (Fuzeon)

FUZEON is available in a single-dose lyophilized powder for injection containing 108 mg enfuvirtide per vial.

FUZEON is administered subcutaneously into the upper arm, anterior thigh or abdomen after reconstituting the lyophilized powder containing 108 mg enfuvirtide with 1 mL of Sterile Water for Injection [see Dosage and Administration (2.5)]. Patients should contact their healthcare provider for any questions regarding the administration of FUZEON by calling the toll-free number 1-877-4-FUZEON (1-877-438-9366) or visiting the FUZEON website, www.FUZEON.com.

The recommended dosage of FUZEON is 90 mg (1 mL) twice daily injected subcutaneously into the upper arm, anterior thigh or abdomen [see Dosage and Administration (2.5 and 2.6)].

The recommended dosage of FUZEON in pediatric patients weighing at least 11 kg is 2 mg per kg twice daily up to a maximum dose of 90 mg twice daily injected subcutaneously into the upper arm, anterior thigh or abdomen [see Dosage and Administration (2.5 and 2.6) and Use in Specific Populations (8.4)]. Table 1 contains dosing recommendations for FUZEON based on body weight. Weight should be monitored periodically and the FUZEON dose adjusted accordingly.

FUZEON for injection can be administered by patients after training by medical professional using aseptic technique. Refer patients to FUZEON Injection Instructions for step by step instructions during self-administration.

A vial is suitable for single-dose only; unused portions must be discarded.

Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration. Patients should return product to pharmacy if there is evidence of particulate matter after mixing FUZEON with sterile water as described below.

• Remove the flip-off cap from the single-dose Sterile Water for Injection vile and from the FUZEON vial.
• Wipe each vial with a new sterile alcohol swab and let the tops air-dry.
• Using the 3 mL (large) syringe with the plunger pulled back to the 1 mL mark, slowly inject the air into the sterile water vial.
• Insert sterile syringe needle into the vial through the center of the stopper.
• Turn the vial upside down and draw 1 mL of the sterile water into the syringe then remove the needle and syringe from the vial.
• Insert the syringe with sterile water into the FUZEON vial at an angle.
• Inject the sterile water slowly, so that it drips down the side of the vial into the FUZEON powder.
• Never shake the vial but gently tap the FUZEON vial with fingertip for 10 seconds to start dissolving the powder.
• Then gently roll the FUZEON vial between hands to reduce the mixing time, making sure no FUZEON is stuck to the vial wall.
• Once the powder starts to dissolve, just set it aside and it will completely dissolve; it could take up to 45 minutes for the powder to completely dissolve and become a solution.
• When completely mixed, the FUZEON solution should be clear, colorless and without bubbles or particulate matter. If the FUZEON is foamy or jelled, allow more time for it to dissolve.

FUZEON contains no preservatives. Once reconstituted, FUZEON should be injected immediately or kept refrigerated in the original vial until use. Reconstituted FUZEON must be used within 24 hours. Refrigerated reconstituted solution should be brought to room temperature before injection and the vial should be inspected visually again to ensure that the contents are fully dissolved in solution and that the solution is clear, colorless, and without bubbles or particulate matter.

The subsequent dose of FUZEON can be reconstituted in advance but must be stored in the refrigerator in the original vial and used within 24 hours.

Each injection should be given at a site different from the preceding injection site, and only where there is no current injection site reaction from an earlier dose.

Do not inject FUZEON:

• Near anatomical areas where large nerves course close to the skin, such as near the elbow, knee, groin or the inferior or medial section of the buttocks.
• Directly over or near skin abnormalities such as moles, scar tissue, bruises, surgical scars, tattoos or burn sites.
• Directly over a blood vessel.
• Near the naval.

• Clean the injection site with a new sterile alcohol pad.
• Clean the FUZEON vial top again, using a new sterile alcohol pad.
• Using the 1 mL (small) syringe with plunger pulled back to 1 mL, insert the syringe with needle into the vial FUZEON solution.
• Before turning the vial upside down, slowly inject the air into the FUZEON.
• Gently turn the vial upside down and slowly pull the plunger to get 1 mL of FUZEON solution and remove the needle and syringe from the vial.
• Pinch and hold a fold of skin around the injection site and pierce the skin. The needle should be inserted most of the way in. Slowly push the plunger all the way to inject FUZEON.
• Remove the needle from the injection site.
• Instruct patients how to safely discard the syringe and needle.
• Cover the injection site with a small bandage if needed.

The majority of subjects (98%) receiving FUZEON in randomized, controlled, open-label, multicenter clinical trials had at least one local injection site reaction; ISRs occurred throughout treatment with FUZEON. Manifestations may include pain and discomfort, induration, erythema, nodules and cysts, pruritus, and ecchymosis [see Adverse Reactions (6)]. Reactions are often present at more than one injection site. Patients must be familiar with the FUZEON Injection Instructions in order to know how to inject FUZEON appropriately and how to monitor carefully for signs or symptoms of cellulitis or local infection.

Nerve pain (neuralgia and/or paresthesia) lasting up to 6 months associated with administration at anatomical sites where large nerves course close to the skin, bruising and hematomas have occurred with use of the Biojector 2000 needle-free device for administration of FUZEON.

Patients receiving anticoagulants or persons with hemophilia, or other coagulation disorders, may have a higher risk of post-injection bleeding.

Systemic hypersensitivity reactions have been associated with FUZEON therapy and may recur on re-challenge. Hypersensitivity reactions have occurred in <1% of subjects studied and have included combinations of: rash, fever, nausea and vomiting, chills, rigors, hypotension, and/or elevated serum liver transaminases. Other adverse events that may be immune mediated and have been reported in subjects receiving FUZEON include primary immune complex reaction, respiratory distress, glomerulonephritis, and Guillain-Barre syndrome. Patients developing signs and symptoms suggestive of a systemic hypersensitivity reaction should discontinue FUZEON and should seek medical evaluation immediately. Therapy with FUZEON should not be restarted following systemic signs and symptoms consistent with a hypersensitivity reaction. Risk factors that may predict the occurrence or severity of hypersensitivity to FUZEON have not been identified.

An increased rate of bacterial pneumonia was observed in subjects treated with FUZEON in the Phase 3 clinical trials compared to the control arm. The incidence of pneumonia was 2.7% or 3.2 events/100 patient-years in subjects receiving FUZEON+background regimen. On analysis of all diagnoses of pneumonia (pneumonia, bacterial pneumonia, bronchopneumonia, and related terms) in T20-301 and T20-302, an increased rate of bacterial pneumonia was observed in subjects treated with FUZEON compared to the control arm (6.9%, 6.7 pneumonia events per 100 patient-years versus 0.6 events per 100 patient-years, respectively). Approximately half of the study subjects with pneumonia required hospitalization. Three subject deaths in the FUZEON arm were attributed to pneumonia; all three had serious concomitant AIDS-related illnesses that contributed to their deaths. Risk factors for pneumonia included low initial CD4 lymphocyte count, high initial viral load, intravenous drug use, smoking, and a prior history of lung disease.

Because it was unclear whether the higher incidence rate of pneumonia was related to FUZEON use, an observational study in 1850 HIV-infected patients (740 FUZEON treated patients and 1110 non-FUZEON treated patients) was conducted to evaluate the risk of pneumonia in patients treated with FUZEON. A total of 123 patients had a confirmed or probable pneumonia event in this study (62 in the FUZEON treatment arm with 1962 patient-years of observation and 61 in the non-FUZEON treatment arm with 3378 patient-years of observation). The incidence of pneumonia was 3.2 events/100 patient-years in the FUZEON treatment arm and 1.8 events/100 patient-years in the non-FUZEON treatment arm. The hazard ratio, adjusting for other baseline risk factors, was 1.34 (95% C.I. = 0.90 – 2.00). Based on this observational study, it is not possible to exclude an increased risk of pneumonia in patients treated with FUZEON compared to non-FUZEON treated patients.

It is unclear if the increased incidence of pneumonia is related to FUZEON use. However, because of these findings, patients with HIV-1 infection should be carefully monitored for signs and symptoms of pneumonia, especially if they have underlying conditions which may predispose them to pneumonia. Risk factors for pneumonia included low initial CD4 cell count, high initial viral load, intravenous drug use, smoking, and a prior history of lung disease.

There is a theoretical risk that FUZEON use may lead to the production of anti-enfuvirtide antibodies which cross react with HIV gp41. This could result in a false positive HIV test with an ELISA assay; a confirmatory western blot test would be expected to be negative. FUZEON has not been studied in non-HIV infected individuals.

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

Autoimmune disorders (such as Graves' disease, polymyositis, and Guillain-Barré syndrome) have also been reported to occur in the setting of immune reconstitution, however, the time to onset is more variable, and can occur many months after initiation of treatment.

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.

The overall safety profile of FUZEON is based on 2131 subjects who received at least 1 dose of FUZEON during various clinical trials. This includes 2051 adults, 658 of whom received the recommended dose for greater than 48 weeks, and 63 pediatric subjects.

Assessment of treatment-emergent adverse events is based on the pooled data from the two randomized, controlled, open-label, multicenter trials in treatment-experienced subjects, T20-301 (TORO 1) and T20-302 (TORO 2).

The following adverse reaction has been identified during post approval use of FUZEON. 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.

Use of FUZEON in pediatric patients weighing at least 11kg is supported by evidence from adequate and well-controlled studies of FUZEON in adult and by two pediatric studies evaluating the safety, pharmacokinetics and efficacy of FUZEON in subjects 6 years of age and older:

• T20-204 was an open-label, multicenter trial that evaluated the safety and antiviral activity of FUZEON in 11, treatment-experienced pediatric subjects 6 to 12 years (median age of 9 years) [see Clinical Pharmacology (12.3) and Clinical Studies (14.2)].
• T20-310 was an open-label, multicenter trial that evaluated the pharmacokinetics, safety, and antiviral activity of FUZEON in 52, treatment-experienced pediatric subjects 5 years and older (median age of 12 years) [see Clinical Pharmacology (12.3) and Clinical Studies (14.2)].

Overall, the adverse experiences, including ISRs in the 63 pediatric subjects were similar to those observed in adult subjects, although infections at site of injection (cellulitis or abscess) were more frequent in adolescents than in adults, with 4 events occurring in 3 of 28 (11%) subjects [see Adverse Reactions (6.1)].

Clinical studies of FUZEON did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. In general, appropriate caution should be exercised in the administration and monitoring of FUZEON in elderly patients reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.

No dosage adjustments of FUZEON are needed in patients with hepatic impairment [see Clinical Pharmacology (12.3)].

No dosage adjustments of FUZEON are needed in patients with renal impairment [see Clinical Pharmacology (12.3)].

Enfuvirtide is an antiretroviral drug [see Microbiology (12.4)].

The pharmacokinetic properties of enfuvirtide were evaluated in HIV-1 infected adult and pediatric subjects.

T20-301 and T20-302 were randomized, controlled, open-label, multicenter trials in HIV-1 infected subjects. Subjects were required to have either (1) viremia despite 3 to 6 months prior therapy with a nucleoside reverse transcriptase inhibitor (NRTI), non-nucleoside reverse transcriptase inhibitor (NNRTI), and protease inhibitor (PI) or (2) viremia and documented resistance or intolerance to at least one member in each of the NRTI, NNRTI, and PI classes.

All subjects received an individualized background regimen consisting of 3 to 5 antiretroviral agents selected on the basis of the subject's prior treatment history and baseline genotypic and phenotypic viral resistance measurements. Subjects were then randomized at a 2:1 ratio to FUZEON 90 mg twice daily with background regimen or background regimen alone.

After week 8, subjects on either treatment arm who met protocol defined criteria for virological failure were permitted to revise their background regimens; those on background regimen alone were also permitted to add FUZEON.

Demographic characteristics for studies T20-301 and T20-302 are shown in Table 6. Subjects had prior exposure to a median of 12 antiretrovirals for a median of 7 years.

The disposition and efficacy outcomes of T20-301 and T20-302 are shown in Table 7.

At 48 weeks, 154 (23%) of subjects in the FUZEON+background regimen and 27 (8%) in the background regimen alone had HIV-1 RNA levels <50 copies/mL, and 225 (34%) of subjects receiving FUZEON+background regimen had HIV-1 RNA levels <400 copies/mL compared to 44 (13%) in the background regimen alone. Subjects achieving HIV-1 RNA levels <50 copies/mL were included in the <400 copies/mL category and both categories were incorporated in the overall virologic responder category of achieving HIV-1 RNA at least 1 log₁₀ below baseline.

The mean log change in HIV-1 RNA from baseline was -1.4 log₁₀ copies/mL in subjects receiving FUZEON+background and -0.5 in those receiving background alone. The mean change in CD4 cell count from baseline to week 48 was +91 cells/mm³ in the FUZEON+background arm and +45 cells/mm³ in the background alone arm.

Subjects in the FUZEON+background arm achieved a better virologic and immunologic outcome than subjects in the background alone arm across all subgroups based on baseline CD4 cell count, baseline HIV-1 RNA, number of prior ARVs or number of active ARVs in the background regimen.

Sixty-three HIV-1 infected pediatric subjects ages 5 through 16 years have received FUZEON in two open-label, single-arm clinical trials.

T20-204 was an open-label, multicenter trial that evaluated the safety and antiviral activity of FUZEON in treatment-experienced pediatric subjects. Eleven subjects from 6 to 12 years were enrolled (median age of 9 years). Median baseline CD4 cell count was 495 cells/µL and the median baseline HIV-1 RNA was 4.6 log₁₀ copies/mL.

Ten of the 11 study subjects completed 48 weeks of chronic therapy. At week 48, 6/11 (55%) subjects had ≥1 log₁₀ decline in HIV-1 RNA and 4/11 (36%) subjects were below 400 copies/mL of HIV-1 RNA. The median changes from baseline (for the As Treated population) in HIV-1 RNA and CD4 cell count were -1.48 log₁₀ copies/mL and +122 cells/µL, respectively.

T20-310 was an open-label, multicenter trial that evaluated the pharmacokinetics, safety, and antiviral activity of FUZEON in treatment-experienced pediatric subjects. Fifty-two subjects from 5 through 16 years were enrolled (median age of 12 years). Median baseline CD4 cell count was 117 cells/µL and the median baseline HIV-1 RNA was 5.0 log₁₀ copies/mL.

Thirty-two of the 52 study subjects completed 48 weeks of chronic therapy. At week 48, 17/52 (33%) of subjects had ≥1 log₁₀ decline in HIV-1 RNA, 11/52 (21%) of subjects were below 400 copies/mL of HIV-1 RNA and 5/52 (10%) were below 50 copies/mL. The median changes from baseline (for the As Treated population) in HIV-1 RNA and CD4 cell count were -1.17 log₁₀ copies/mL and +106 cells/µL, respectively.

How Supplied

FUZEON (enfuvirtide) for Injection is a white to off-white, sterile, lyophilized powder and it is packaged in a single-dose clear glass vial containing 108 mg of enfuvirtide for the delivery of approximately 90 mg/1 mL when reconstituted with 1 mL of Sterile Water for Injection.

FUZEON is available in a Convenience Kit containing 60 single-dose vials of FUZEON (90 mg strength), 60 vials (2 cartons of 30 each) of Sterile Water for Injection (1 mL per vial), 60 reconstitution syringes (3 cc), 60 administration syringes (1 cc), Package Insert, Patient Package Insert, and Injection Instructions (NDC 0004-0381-40).

Storage Conditions

Store at 25ºC (77ºF); excursions permitted to 15º to 30ºC (59º to 86ºF) [see USP Controlled Room Temperature].

Reconstituted solution should be stored in the original vial under refrigeration at 2º to 8ºC (36º to 46ºF) and used within 24 hours.

Injection Site Reactions

Inform patients that injection site reactions occur in almost all patients taking FUZEON. Patients must be familiar with the FUZEON Injection Instructions for instructions on how to appropriately inject FUZEON and how to carefully monitor for signs or symptoms of cellulitis or local infection. Instruct patients when to contact their healthcare provider about these reactions [see Warnings and Precautions (5.1)].

Administration with Biojector^® 2000

Inform patients that nerve pain (neuralgia and/or paresthesia) associated with administration at anatomical sites where large nerves course close to the skin, bruising and hematomas have occurred with use of the Biojector 2000 needle-free device for administration of FUZEON [see Warnings and Precautions (5.2)].

Post-injection Bleeding

Advise patients about the risk of post-injection bleeding if they are receiving anticoagulants or have coagulation disorders such as hemophilia [see Warnings and Precautions (5.3)].

Systemic Hypersensitivity

Advise patients of the possibility of a systemic hypersensitivity reaction to FUZEON. Advise patients to discontinue therapy and immediately seek medical evaluation if they develop signs/symptoms of systemic hypersensitivity such as combinations of rash, fever, nausea and vomiting, chills, rigors, and/or hypotension [see Warnings and Precautions (5.4)].

Pneumonia

Advise patients that an increased rate of bacterial pneumonia was observed in subjects treated with FUZEON in clinical trials. Advise patients to seek medical evaluation immediately if they develop signs or symptoms suggestive of pneumonia (cough with fever, rapid breathing, shortness of breath) [see Warnings and Precautions (5.5)].

Pregnancy Exposure Registry

Advise patients that there is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to antiretroviral medicines during pregnancy [see Use in Specific Populations (8.1)].

Lactation

Instruct mothers with HIV-1 infection not to breastfeed because HIV-1 can be passed to the baby in breast milk [see Use in Specific Populations (8.2)].

Important Dosing and Administration Instructions

• Inform patients that FUZEON must be taken as part of a combination antiretroviral regimen and that use of FUZEON alone may lead to rapid development of virus resistant to FUZEON and possibly other agents of the same class.
• Instruct patients and caregivers in the use of aseptic technique when administering FUZEON in order to avoid injection site infections. Appropriate training for FUZEON reconstitution and self-injection must be given by a healthcare provider, including a careful review of the FUZEON Patient Package Insert and FUZEON Injection Instructions. The first injection should be performed under the supervision of an appropriately qualified healthcare provider. It is recommended that the patient and/or caregiver's understanding and use of aseptic injection techniques and procedures be periodically re-evaluated.
• Instruct patients and caregivers on the preferred anatomical sites for administration (upper arm, abdomen, anterior thigh). FUZEON should not be injected near any anatomical areas where large nerves course close to the skin, such as near the elbow, knee, groin or the inferior or medial sections of the buttocks, skin abnormalities, including directly over a blood vessel, into moles, scar tissue, bruises, or near the navel, surgical scars, tattoos or burn sites.
• Instruct patients and caregivers in the proper techniques for preparation, injection and disposal of needles and syringes (including not recapping needles) in order to avoid needle stick injuries. Advise patients not to reuse needles or syringes, and of safe disposal procedures, including the use of a puncture-resistant container, for disposal of used needles and syringes. Instruct patients on the safe disposal of full containers as per local requirements. Caregivers who experience an accidental needle stick after patient injection should contact a healthcare provider immediately.
• Inform patients to contact their healthcare provider for any questions regarding the administration of FUZEON.
• Inform patients not to change the dose or dosing schedule of FUZEON or any antiretroviral medication without consulting their healthcare provider.
• Inform patients to contact their healthcare provider immediately if they stop taking FUZEON or any other drug in their antiretroviral regimen.
• Inform patients that they can obtain more information on the self-administration of FUZEON at www.FUZEON.com or by calling 1-877-4-FUZEON (1-877-438-9366).