Avonex Drug Information

Generic name: INTERFERON BETA-1A

Interferon beta [EPC]

Save on Avonex at your pharmacy Compare prices near you and start saving today—no enrollment required.
See Prices

Uses of Avonex

AVONEX is indicated for the treatment of relapsing forms of multiple sclerosis (MS), to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, in adults.

Dosage & Administration of Avonex

Dosing Information AVONEX is administered intramuscularly

The recommended dose is 30 micrograms once a week. To reduce the incidence and severity of flu-like symptoms that may occur when initiating AVONEX therapy at a dose of 30 micrograms, AVONEX may be started at a dose of 7.5 micrograms and the dose may be increased by 7.5 micrograms each week for the next three weeks until the recommended dose of 30 micrograms is achieved (see Table 1 ). An AVOSTARTGRIP™ kit containing 3 titration devices can be used for titration and is to be used only with AVONEX Prefilled Syringes.

Table 1: Schedule for Dose Titration

Important Administration Instructions (All Dosage Forms)

AVONEX dosage forms (prefilled syringe and prefilled autoinjector) are single-dose. See Patient's Instructions for Use for complete administration instructions. The first AVONEX injection should be performed under the supervision of an appropriately qualified healthcare professional.

If patients or caregivers are to administer AVONEX, train them in the proper intramuscular injection technique and assess their ability to inject intramuscularly to ensure the proper administration of AVONEX. Advise patients and caregivers to: Rotate injection sites with each administration to minimize the likelihood of injection site reactions, including necrosis or localized infection NOT inject into an area of the body where the skin is irritated, reddened, bruised, infected or scarred in any way Check the injection site after 2 hours for redness, swelling, or tenderness Contact their healthcare provider if they have a skin reaction and it does not clear up in a few days Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. A 25 gauge, 5/8” needle specific to the prefilled autoinjector is supplied with the AVONEX PEN ® Administration Dose Pack.

DO NOT use any other needle with the autoinjector. Use safe disposal procedures for needles and syringes. DO NOT re-use needles, prefilled syringes, or autoinjectors.

Following the administration of each titrated dose, discard any remaining product.

Premedication for Flu-like Symptoms

Concurrent use of analgesics and/or antipyretics on treatment days may help ameliorate flu-like symptoms associated with AVONEX use.

Table 1: Schedule for Dose Titration
1 Dosed once a week, intramuscularly
AVONEX Dose 1Recommended Dose
Week 17.5 micrograms1/4 dose
Week 215 micrograms1/2 dose
Week 322.5 micrograms3/4 dose
Week 4+30 microgramsfull dose

Side Effects of Avonex

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of AVONEX cannot be directly compared to rates in clinical trials of other drugs and may not reflect the rates observed in practice. Symptoms can include chills, fever, myalgia and asthenia occurring within hours to days following an injection. Most people who take AVONEX have flu-like symptoms early during the course of therapy.

Usually, these symptoms last for a day after the injection. For many people, these symptoms lessen or go away over time. The most frequently reported adverse reactions resulting in clinical intervention (for example, discontinuation of AVONEX or the need for concomitant medication to treat an adverse reaction symptom) were flu-like symptoms and depression.

Table 2 enumerates adverse reactions that occurred with AVONEX-treated patients at an incidence of at least 2% more than that observed in the placebo-treated patients in the pooled placebo-controlled studies in patients with relapsing forms of MS. Table 2: Immunogenicity Anaphylaxis and other allergic reactions have occurred in AVONEX-treated patients. As with all therapeutic proteins, there is a potential for immunogenicity.

These data reflect the percentage of patients whose test results were considered positive for antibodies to AVONEX using a two-tiered assay (ELISA binding assay followed by an antiviral cytopathic effect assay), and are highly dependent on the sensitivity and specificity of the assay. Additionally, the observed incidence of neutralizing activity in an assay may be influenced by several factors including sample handling, timing of sample collection, concomitant medications, and underlying disease. For these reasons, comparison of the incidence of antibodies to AVONEX with the incidence of antibodies to other products may be misleading.

Postmarketing Experience

The following additional adverse reactions have been identified during post-approval use of AVONEX. 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. Hemolytic anemia Menorrhagia and metrorrhagia Pulmonary Arterial Hypertension Rash (including vesicular rash) Rare cases of injection site abscess or cellulitis requiring surgical intervention

Table 2: Adverse Reactions in the Placebo-Controlled Studies
PlaceboAVONEX
Adverse Reaction(N = 333)(N = 351)
Body as a Whole
Headache55%58%
Flu-like symptoms (otherwise unspecified)29%49%
Pain21%23%
Asthenia18%24%
Fever9%20%
Chills5%19%
Abdominal pain6%8%
Injection site pain6%8%
Infection4%7%
Injection site inflammation2%6%
Chest pain2%5%
Injection site reaction1%3%
Toothache1%3%
Nervous System
Depression14%18%
Dizziness12%14%
Respiratory System
Upper respiratory tract infection12%14%
Sinusitis12%14%
Bronchitis5%8%
Digestive System
Nausea19%23%
Musculoskeletal System
Myalgia22%29%
Arthralgia6%9%
Urogenital
Urinary tract infection15%17%
Urine constituents abnormal0%3%
Skin and Appendages
Alopecia2%4%
Special Senses
Eye disorder2%4%
Hemic and Lymphatic System
Injection site ecchymosis4%6%
Anemia1%4%
Cardiovascular System
Migraine3%5%
Vasodilation0%2%

Warnings & Cautions for Avonex

Depression, Suicide, and Psychotic Disorders

Patients treated with AVONEX and their caregivers should be advised to report immediately any symptoms of depression, suicidal ideation, and/or psychosis to their prescribing physicians. If a patient develops depression or other severe psychiatric symptoms, cessation of AVONEX therapy should be considered. Depression and suicide have been reported to occur with increased frequency in patients receiving AVONEX.

In Study 1, the incidence of depression was similar in placebo-treated and in AVONEX-treated patients, but suicidal tendency was seen more frequently in AVONEX-treated patients (4% in AVONEX group vs. 1% in placebo group). In Study 2, there was a greater incidence of depression in AVONEX-treated patients than in placebo-treated patients (20% in AVONEX group vs. 13% in placebo group). Additionally, there have been postmarketing reports of depression, suicidal ideation, and/or development of new or worsening of other pre-existing psychiatric disorders, including psychosis.

For some of these patients, symptoms of depression improved upon cessation of AVONEX.

Hepatic Injury

Severe hepatic injury, including cases of hepatic failure, has been reported rarely in patients taking AVONEX. Asymptomatic elevation of hepatic transaminases has also been reported, and in some patients has recurred upon rechallenge with AVONEX. In some cases, these events have occurred in the presence of other drugs that have been associated with hepatic injury.

The potential risk of AVONEX used in combination with known hepatotoxic drugs or other products (e.g., alcohol) should be considered prior to starting AVONEX, or before starting hepatotoxic drugs. Patients should be monitored for signs of hepatic injury.

Anaphylaxis and Other Allergic-Reactions Anaphylaxis has been reported as a rare complication of AVONEX use. Other allergic reactions have included dyspnea, orolingual edema, skin rash and urticaria. Discontinue AVONEX if anaphylaxis or other allergic reactions occur.

Injection Site Reactions Including Necrosis

Injection site reactions, including injection site necrosis, can occur with the use of interferon beta products, including AVONEX. In controlled clinical trials, injection site reactions (e.g., injection site pain, bruising or erythema) occurred in 18% of patients receiving AVONEX and 13% in the placebo group. These reactions included injection site inflammation (6%), injection site pain (8%), injection site mass (<1%), nonspecific reactions.

Injection site abscesses and cellulitis and injection site necrosis have been reported in the postmarketing setting with interferon beta products, including AVONEX. Some cases required treatment with hospitalization for surgical drainage and intravenous antibiotics. Periodically evaluate patient understanding and use of aseptic self-injection techniques and procedures, particularly if injection site necrosis has occurred.

Whether to discontinue therapy following a single site of necrosis is dependent on the extent of necrosis. For patients who continue therapy with AVONEX after injection site necrosis has occurred, avoid administration of AVONEX into the affected area until it is fully healed. If multiple lesions occur, change injection site or discontinue therapy until healing occurs.

Congestive Heart Failure Patients with pre-existing congestive heart failure should be monitored for worsening of their cardiac condition during initiation of and continued treatment with AVONEX. While beta interferons do not have any known direct cardiac toxicity, during the postmarketing period cases of congestive heart failure, cardiomyopathy, and cardiomyopathy with congestive heart failure have been reported in patients without known predisposition to these events, and without other etiologies being established. In some cases, these events have been temporally related to the administration of AVONEX.

In some of these instances recurrence upon rechallenge was observed.

Decreased Peripheral Blood Counts

Decreased peripheral blood counts in all cell lines, including rare pancytopenia and thrombocytopenia, have been reported from postmarketing experience in AVONEX-treated patients. In some cases, platelet counts were below 10,000/microliter. Some cases recurred with rechallenge.

Patients should be monitored for symptoms or signs of decreased blood counts.

Thrombotic Microangiopathy Cases of thrombotic microangiopathy (TMA), including thrombotic thrombocytopenic purpura and hemolytic uremic syndrome, some fatal, have been reported with interferon beta products, including AVONEX. Cases have been reported several weeks to years after starting interferon beta products. Discontinue AVONEX if clinical symptoms and laboratory findings consistent with TMA occur, and manage as clinically indicated.

Pulmonary Arterial Hypertension Cases of pulmonary arterial hypertension (PAH) have been reported in patients treated with interferon beta products, including AVONEX. PAH has occurred in patients treated with interferon beta products in the absence of other contributory factors. Many of the reported cases required hospitalization, including one case with interferon beta in which the patient underwent a lung transplant.

PAH has developed at various time points after initiating therapy with interferon beta products and may occur several years after starting treatment. Patients who develop unexplained symptoms (e.g., dyspnea, new or increasing fatigue) should be assessed for PAH. If alternative etiologies have been ruled out and a diagnosis of PAH is confirmed, discontinue treatment and manage as clinically indicated.

Seizures Seizures have been temporally associated with the use of beta interferons in clinical trials and postmarketing safety surveillance. In the two placebo-controlled studies in multiple sclerosis (Studies 1 and 2), 4 patients receiving AVONEX experienced seizures, while no seizures occurred in the placebo group. Three of these 4 patients had no prior history of seizure.

It is not known whether these events were related to the effects of multiple sclerosis alone, to AVONEX, or to a combination of both.

Autoimmune Disorders

Postmarketing reports of autoimmune disorders of multiple target organs in AVONEX-treated patients included idiopathic thrombocytopenia, hyper- and hypothyroidism, and rare cases of autoimmune hepatitis. If AVONEX-treated patients develop a new autoimmune disorder, consider stopping the therapy.

Laboratory Tests

In addition to those laboratory tests normally required for monitoring patients with multiple sclerosis, complete blood and differential white blood cell counts, platelet counts, and blood chemistries, including liver function tests, are recommended during AVONEX therapy. Patients with myelosuppression may require more intensive monitoring of complete blood cell counts, with differential and platelet counts. Thyroid function should be monitored periodically.

If patients have or develop symptoms of thyroid dysfunction (hypo- or hyperthyroidism), thyroid function tests should be performed according to standard medical practice.

Pregnancy Safety for Avonex

Pregnancy Risk Summary Data from a large population-based cohort study, as well as other published studies over several decades, have not identified a drug-associated risk of major birth defects with the use of interferon beta products during early pregnancy. Findings regarding a potential risk for low birth weight or miscarriage with the use of interferon beta products in pregnancy have been inconsistent (see Data ). In a study in pregnant monkeys, administration of interferon beta during pregnancy resulted in an increased rate of abortion at doses greater than those used clinically ( see Data ).

In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is respectively. The background risk of major birth defects and miscarriage for the indicated population is unknown. Data Human Data The majority of observational studies reporting on pregnancies exposed to interferon beta products did not identify an association between the use of interferon beta products during early pregnancy and an increased risk of major birth defects.

In a population-based cohort study conducted in Finland and Sweden, data were collected from 1996--2014 in Finland and 2005--2014 in Sweden on 2,831 pregnancy outcomes from women with MS. 797 pregnancies were in women exposed to interferon beta only. No evidence was found of an increased risk of major birth defects among women with MS exposed to interferon beta products compared to women with MS that were unexposed to any non-steroid therapy for MS (n=1,647) within the study. No increased risks were observed for miscarriages and ectopic pregnancies, though there were limitations in obtaining complete data capture for these outcomes, making the interpretation of the findings more difficult.

Two small cohort studies that examined pregnancies exposed to interferon beta products (without differentiating between subtypes of interferon beta products) suggested that a decrease in mean birth weight may be associated with interferon beta exposure during pregnancy, but this finding was not confirmed in larger observational studies. Two small studies observed an increased prevalence of miscarriage, although the finding was only statistically significant in one study. Most studies enrolled patients later in pregnancy which made it difficult to ascertain the true percentage of miscarriages.

In one small cohort study, a significantly increased risk of preterm birth following interferon beta exposure during pregnancy was observed. Animal Data In pregnant monkeys given interferon beta at 100 times the recommended weekly human dose (based upon a body surface area comparison), no adverse effects on embryofetal development were observed. Abortifacient activity was evident following 3 to 5 doses at this level.

No abortifacient effects were observed in monkeys treated at 2 times the recommended weekly human dose (based upon mg/m 2 ).

Pediatric Use of Avonex

Pediatric Use Safety and effectiveness in pediatric patients have not been established.

Contraindications for Avonex

AVONEX is contraindicated in patients with a history of hypersensitivity to natural or recombinant interferon beta, or any other component of the formulation. The formerly available lyophilized vial formulation of AVONEX is contraindicated in patients with a history of hypersensitivity to albumin (human).

Clinical Studies of Avonex

The clinical effects of AVONEX in patients with relapsing forms of multiple sclerosis (MS) were studied in two randomized, multicenter, double-blind, placebo-controlled studies in patients with MS (Studies 1 and 2). Safety and efficacy of treatment with AVONEX beyond 3 years is not known. In Study 1, 301 patients received either 30 micrograms of AVONEX (n=158) or placebo (n=143) by intramuscular injection once weekly.

Patients received injections for up to 2 years, and continued to be followed until study completion. Two hundred eighty-two patients completed 1 year on study, and 172 patients completed 2 years on study. All patients had a definite diagnosis of multiple sclerosis of at least 1 year duration and had at least 2 exacerbations in the 3 years prior to study entry (or 1 per year if the duration of disease was less than 3 years).

The EDSS is a scale that quantifies disability in patients with MS and ranges from 0 (normal neurologic exam) to 10 (death due to MS). Patients with chronic progressive multiple sclerosis were excluded from this study. Disability The primary outcome assessment was time to progression in disability, measured as an increase in the EDSS score of at least 1 point that was sustained for at least 6 months.

An increase in EDSS score reflects accumulation of disability. This endpoint was used to help distinguish permanent increase in disability from a transient increase due to an exacerbation. As shown in Figure 1, the time to onset of sustained progression in disability was significantly longer in AVONEX-treated patients than in placebo-treated patients in Study 1 (p = 0.02).

The percentage of patients progressing by the end of 2 years was 35% for placebo-treated patients and 22% for AVONEX-treated patients. This represents a 37% relative reduction in the risk of accumulating disability in the AVONEX-treated group compared to the placebo-treated group. 1 Kaplan-Meier Methodology; Disability progression was defined as at least a 1 point increase in EDSS score sustained for at least 6 months. The distribution of confirmed EDSS change from study entry (baseline) to the end of the study is shown in Figure 2.

There was a statistically significant difference between the AVONEX and placebo groups in confirmed change for patients with at least 2 scheduled visits (p = 0.006). Figure 1 Figure 2 Exacerbations The rate and frequency of MS exacerbations were secondary outcomes. For all patients included in the study, irrespective of time on study, the annual exacerbation rate was 0.67 per year in the AVONEX-treated group and 0.82 per year in the placebo-treated group (p = 0.04).

MRI Results Gadolinium (Gd)-enhanced and T2-weighted magnetic resonance imaging (MRI) scans of the brain were obtained in most patients at baseline and at the end of 1 and 2 years of treatment. Secondary outcomes included Gd-enhanced lesion number and volume, and T2-weighted lesion volume. Gd-enhancing lesions seen on brain MRI scans represent areas of breakdown of the blood brain barrier thought to be secondary to inflammation.

The volume of Gd-enhanced lesions showed similar treatment effects in the AVONEX and placebo groups (p ≤ 0.03). Percentage change in T2-weighted lesion volume from study entry to Year 1 was significantly lower in AVONEX-treated than placebo-treated patients (p = 0.02). A significant difference in T2-weighted lesion volume change was not seen between study entry and Year 2 in the AVONEX and placebo groups.

Summary of Effects of Clinical and MRI Endpoints in Study 1 A summary of the effects of AVONEX on the clinical and MRI endpoints of this study is presented in Table 3. Table 3: Clinical and In Study 2, 383 patients who had recently experienced an isolated demyelinating event involving the optic nerve, spinal cord, or brainstem/cerebellum, and who had lesions typical of multiple sclerosis on brain MRI, received either 30 micrograms of AVONEX (n = 193) or placebo (n = 190) by intramuscular injection once weekly. Patients were enrolled into the study over a two-year period and followed for up to three years or until they developed a second clinical exacerbation in an anatomically distinct region of the central nervous system.

Exacerbations In Study 2, the primary outcome measure was time to development of a second exacerbation in an anatomically distinct region of the central nervous system. Time to development of a second exacerbation was significantly delayed in AVONEX-treated compared to placebo-treated patients (p = 0.002). The relative rate of developing a second exacerbation in the AVONEX group was 0.56 of the rate in the placebo group (95% confidence interval 0.38 to 0.81). 1 Kaplan-Meier Methodology Figure 3 MRI Findings Secondary outcomes were brain MRI measures, including the cumulative increase in the number of new or enlarging T2 lesions, T2 lesion volume at baseline compared to results at 18 months, and the number of Gd-enhancing lesions at 6 months.

See Table 4 for the 0.87 1.49

Table 3: Clinical and MRI Endpoints in Patients with MS in Study 1
EndpointPlaceboAVONEXP-Value
PRIMARY ENDPOINT:
Time to sustained progression in disability (N: 143, 158) 1--- See Figure 1 ---0.02 2
Percentage of patients progressing in disability at 2 years (Kaplan-Meier estimate) 135%22%
SECONDARY ENDPOINTS: DISABILITY
Mean confirmed change in EDSS from study entry to end of study (N: 136, 150) 10.500.200.006 3
EXACERBATIONS
Number of exacerbations in subset completing 2 years (N: 87, 85)
026%38%0.03 3
130%31%
211%18%
314%7%
≥ 418%7%
Percentage of patients exacerbation-free in subset completing 2 years (N: 87, 85)26%38%0.10 4
Annual exacerbation rate (N: 143, 158)10.820.670.04 5
Table 3 (continued): Clinical and MRI Endpoints in Study 1
Note: (N:, ) denotes the number of evaluable placebo and AVONEX patients, respectively.
1 Patient data included in this analysis represent variable periods of time on study.
2 Analyzed by Mantel-Cox (logrank) test.
3 Analyzed by Mann-Whitney rank-sum test.
4 Analyzed by Cochran-Mantel-Haenszel test.
5 Analyzed by likelihood ratio test.
EndpointPlaceboAVONEXP-Value
MRI
Number of Gd-enhanced lesions:
At study entry (N: 132, 141)
Mean (Median)2.3 (1.0)3.2 (1.0)
Range0-230-56
Year 1 (N: 123, 134)
Mean (Median)1.6 (0)1.0 (0)0.02 3
Range0-220-28
Year 2 (N: 82, 83)
Mean (Median)1.6 (0)0.8 (0)0.05 3
Range0-340-13
T2 lesion volume:
Percentage change from study entry to Year 1 (N: 116, 123)
Median-3.3%-13.1%0.02 3
Percentage change from study entry to Year 2 (N: 83, 81)
Median-6.5%-13.2%0.36 3
Table 4: Brain MRI Results in Study 2
1 P value <0.001
2 P value <0.03
P value from a Mann-Whitney rank-sum test
AVONEXPlacebo
CHANGE FROM BASELINE IN T2 VOLUME OF LESIONS AT 18 MONTHS:N = 119N = 109
Actual Change (mm 3 ) 1* Median (25 th %, 75 th %)28 (-576, 397)313 (5, 1140)
Percentage Change 1* Median (25 th %, 75 th %)1 (-24, 29)16 (0, 53)
NUMBER OF NEW OR ENLARGING T2 LESIONS AT 18 MONTHS 1*:N = 132 N (%)N = 119 N (%)
062 (47)22 (18)
1-341 (31)47 (40)
≥429 (22)50 (42)
Mean (SD)2.13 (3.2)4.97 (7.7)
NUMBER OF GD-ENHANCING LESIONS AT 6 MONTHS 2*:N = 165 N (%)N = 152 N (%)
0115 (70)93 (61)
127 (16)16 (11)
>123 (14)43 (28)
Mean (SD)0.87 (2.3)1.49 (3.1)

Drug information sourced from the FDA. This content is for informational purposes only and does not constitute medical advice. Consult a healthcare professional before making any medication decisions.

Ready to save on Avonex?

Compare prescription prices at over 70,000 pharmacies and start saving today—no enrollment required.

Compare Avonex Prices