Other
AVONEX® (interferon beta-1a) Intramuscular Injection
Immunogenicity
Anaphylaxis and other allergic reactions have occurred in AVONEX-treated patients [see Warnings and Precautions (5.3)]. As with all therapeutic proteins, there is a potential for immunogenicity. In studies assessing immunogenicity in multiple sclerosis patients administered AVONEX for at least 1 year, 5% (21 of 390 patients) showed the presence of neutralizing antibodies at one or more times.
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.
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).
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).
AVONEX treatment significantly decreased the frequency of exacerbations in the subset of patients who were enrolled in the study for at least 2 years (87 placebo-treated patients and 85 AVONEX-treated patients; p = 0.03; see Table 3).
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. AVONEX-treated patients demonstrated significantly lower Gd-enhanced lesion number after 1 and 2 years of treatment than placebo-treated patients (p ≤ 0.05; see Table 3). 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.
The exact relationship between MRI findings and the clinical status of MS patients is unknown. The prognostic significance of MRI findings in these studies has not been evaluated.
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.
Note: (N: , ) denotes the number of evaluable placebo and AVONEX patients, respectively. | |||
1Patient data included in this analysis represent variable periods of time on study. | |||
2Analyzed by Mantel-Cox (logrank) test. | |||
3Analyzed by Mann-Whitney rank-sum test. | |||
4Analyzed by Cochran-Mantel-Haenszel test. | |||
5Analyzed by likelihood ratio test. | |||
| Endpoint | Placebo | AVONEX | P-Value |
| PRIMARY ENDPOINT: | |||
| Time to sustained progression | |||
| in disability (N: 143, 158)1 | --- See Figure 1 --- | 0.022 | |
| Percentage of patients progressing | |||
| in disability at 2 years | |||
| (Kaplan-Meier estimate)1 | 35% | 22% | |
| SECONDARY ENDPOINTS: | |||
| DISABILITY | |||
| Mean confirmed change in EDSS | |||
| from study entry to end of study | |||
| (N: 136, 150)1 | 0.50 | 0.20 | 0.0063 |
| EXACERBATIONS | |||
| Number of exacerbations in subset | |||
| completing 2 years (N: 87, 85) | |||
| 0 | 26% | 38% | 0.033 |
| 1 | 30% | 31% | |
| 2 | 11% | 18% | |
| 3 | 14% | 7% | |
| ≥ 4 | 18% | 7% | |
| Percentage of patients exacerbation- | |||
| free in subset completing 2 years | |||
| (N: 87, 85) | 26% | 38% | 0.104 |
| Annual exacerbation rate | |||
| (N: 143, 158)1 | 0.82 | 0.67 | 0.045 |
| Table 3 (continued): Clinical and MRI Endpoints in Study 1 | |||
| Endpoint | Placebo | AVONEX | P-Value |
| MRI | |||
| Number of Gd-enhanced lesions: | |||
| At study entry (N: 132, 141) | |||
| Mean (Median) | 2.3 (1.0) | 3.2 (1.0) | |
| Range | 0-23 | 0-56 | |
| Year 1 (N: 123, 134) | |||
| Mean (Median) | 1.6 (0) | 1.0 (0) | 0.023 |
| Range | 0-22 | 0-28 | |
| Year 2 (N: 82, 83) | |||
| Mean (Median) | 1.6 (0) | 0.8 (0) | 0.053 |
| Range | 0-34 | 0-13 | |
| T2 lesion volume: | |||
| Percentage change from study | |||
| entry to Year 1 (N: 116, 123) | |||
| Median | -3.3% | -13.1% | 0.023 |
| Percentage change from study | |||
| entry to Year 2 (N: 83, 81) | |||
| Median | -6.5% | -13.2% | 0.363 |
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 Kaplan-Meier estimates of the percentage of patients developing an exacerbation within 24 months were 39% in the placebo group and 21% in the AVONEX group (see Figure 3). 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
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 MRI results.
1 P value <0.001 | |||
2 P value <0.03 | |||
* P value from a Mann-Whitney rank-sum test | |||
| AVONEX | Placebo | ||
| CHANGE FROM BASELINE IN T2 VOLUME OF LESIONS AT 18 MONTHS: | N = 119 | N = 109 | |
| Actual Change (mm3)1* Median (25th%, 75th%) | 28 (-576, 397) | 313 (5, 1140) | |
| Percentage Change1* Median (25th%, 75th%) | 1 (-24, 29) | 16 (0, 53) | |
| NUMBER OF NEW OR ENLARGING T2 LESIONS AT 18 MONTHS1*: | N = 132 N (%) | N = 119 N (%) | |
| 0 | 62 (47) | 22 (18) | |
| 1-3 | 41 (31) | 47 (40) | |
| ≥4 | 29 (22) | 50 (42) | |
| Mean (SD) | 2.13 (3.2) | 4.97 (7.7) | |
| NUMBER OF GD-ENHANCING LESIONS AT 6 MONTHS2*: | N = 165 N (%) | N = 152 N (%) | |
| 0 | 115 (70) | 93 (61) | |
| 1 | 27 (16) | 16 (11) | |
| >1 | 23 (14) | 43 (28) | |
| Mean (SD) | 0.87 (2.3) | 1.49 (3.1) | |
Instruction on Self-injection Technique and Procedures
Provide appropriate instruction for reconstitution of AVONEX and methods of self-injection, including careful review of the AVONEX Medication Guide. Instruct patients in the use of aseptic technique when administering AVONEX.
Inform patients that their healthcare provider should show them or their caregiver how to prepare and inject AVONEX before administering the first dose. Their healthcare provider should watch the first AVONEX injection given. Tell patients not to re-use needles or syringes and instruct patients on safe disposal procedures. Inform patients to dispose of used needles and syringes in a puncture-resistant container and instruct the patient regarding safe disposal of full containers.
Advise patients:
- of the importance of rotating areas of injection with each dose to minimize the likelihood of injection site reactions. [see Choose an Injection Site section of the Medication Guide].
- NOT to inject area of the body where the skin is irritated, reddened, bruised, infected or scarred in any way
- to 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
Pregnancy
Advise patients that AVONEX should not be used during pregnancy unless the potential benefit justifies the potential risk to the fetus [see Use in Special Population (8.1)].
Depression
Advise patients of the symptoms of depression, suicidal ideation, or psychotic disorders as they have been reported with the use of AVONEX and instruct patients to report them immediately to their physician [see Warnings and Precautions (5.1)].
Liver Disease
Advise patients that severe hepatic injury, including hepatic failure, has been reported during the use of AVONEX. Advise patients of symptoms of hepatic dysfunction, and instruct patients to report them immediately to their physician [see Warnings and Precautions (5.2)].
Allergic Reactions and Anaphylaxis
Advise patients of the symptoms of allergic reactions and anaphylaxis, and instruct patients to seek immediate medical attention if these symptoms occur [see Warnings and Precautions (5.3)].
Congestive Heart Failure
Advise patients that worsening of pre-existing congestive heart failure has been reported in patients using AVONEX. Advise patients of symptoms of worsening cardiac condition, and instruct patients to report them immediately to their physician [see Warnings and Precautions (5.4)].
Seizures
Advise patients that seizures have been reported in patients using AVONEX. Instruct patients to report seizures immediately to their physician [see Warnings and Precautions (5.7)].
Flu-like Symptoms
Inform patients that flu-like symptoms are common following initiation of therapy with AVONEX [see Dosage and Administration (2.3) and Adverse Reactions (6)]. Advise patients that starting with a lower dose than 30 micrograms and increasing the dose over 3 weeks reduces the incidence and severity of flu-like symptoms.
Manufactured by:
Biogen Inc.
Cambridge, MA 02142 USA
U.S. License #1697
© Biogen [1996-2016]. All rights reserved.
1-800-456-2255
*MICRO PIN® is the trademark of B. Braun Medical Inc.