REBIF SIDE EFFECTS
- Generic Name: interferon beta-1a
- Brand Name: Rebif
- Drug Class: Immunomodulators
SIDE EFFECTS
The following adverse reactions are discussed in more detail in the Warnings and Precautions section of the label:
- Depression and Suicide
- Hepatic Injury
- Anaphylaxis and Other Allergic Reactions
- Injection Site Reactions including Necrosis
- Decreased Peripheral Blood Counts
- Thrombotic Microangiopathy
- Seizures
- Laboratory Tests
Clinical Trial Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of REBIF cannot be directly compared to rates in the clinical trials of other drugs and may not reflect the rates observed in practice.
A total of 712 patients with relapsing-remitting multiple sclerosis (RRMS) in two controlled clinical trials took REBIF (22 mcg or 44 mcg given three times per week). Ages ranged from 18 to 55 years. Nearly three-fourths of the patients were female, and more than 90% were Caucasian, largely reflecting the general demographics of the population of patients with multiple sclerosis.
The most commonly reported adverse reactions were injection site disorders, influenza-like symptoms (headache, fatigue, fever, rigors, chest pain, back pain, myalgia), abdominal pain, depression, elevation of liver enzymes and hematologic abnormalities. The most frequently reported adverse reactions resulting in clinical intervention (e.g., discontinuation of REBIF, adjustment in dosage, or the need for concomitant medication to treat an adverse reaction were injection site disorders, influenza-like symptoms, depression, and elevation of liver enzymes.
Study 1 was a 2-year placebo-controlled study in RRMS patients treated with REBIF 22 mcg (n=189), 44 mcg (n=184), or placebo (n=187). Table 1 enumerates adverse reactions and laboratory abnormalities that occurred at an incidence that was at least 2% more in either REBIF-treated group than was observed in the placebo group.
Table 1: Adverse Reactions and Laboratory Abnormalities in Study 1
| Body System Preferred Term | Placebo tiw (n=187) % |
REBIF 22 mcg tiw (n=189) % |
REBIF 44 mcg tiw (n=184) % |
| BODY AS A WHOLE | |||
| Influenza-like symptoms | 51 | 56 | 59 |
| Headache | 63 | 65 | 70 |
| Fatigue | 36 | 33 | 41 |
| Fever | 16 | 25 | 28 |
| Rigors | 5 | 6 | 13 |
| Chest pain | 5 | 6 | 8 |
| Malaise | 1 | 4 | 5 |
| INJECTION SITE DISORDERS | |||
| Injection Site Reaction | 39 | 89 | 92 |
| Injection Site Necrosis | 0 | 1 | 3 |
| NERVOUS SYSTEM DISORDERS | |||
| Hypertonia | 5 | 7 | 6 |
| Coordination Abnormal | 2 | 5 | 4 |
| Convulsions | 2 | 5 | 4 |
| Somnolence | 1 | 4 | 5 |
| ENDOCRINE DISORDERS | |||
| Thyroid Disorder | 3 | 4 | 6 |
| GASTROINTESTINAL SYSTEM DISORDERS | |||
| Abdominal Pain | 17 | 22 | 20 |
| Dry Mouth | 1 | 1 | 5 |
| LIVER AND BILIARY SYSTEM DISORDERS | |||
| SGPT Increased | 4 | 20 | 27 |
| SGOT Increased | 4 | 10 | 17 |
| Bilirubinemia | 1 | 3 | 2 |
| MUSCULO-SKELETAL SYSTEM DISORDERS | |||
| Myalgia | 20 | 25 | 25 |
| Back Pain | 20 | 23 | 25 |
| Skeletal Pain | 10 | 15 | 10 |
| HEMATOLOGIC DISORDERS | |||
| Leukopenia | 14 | 28 | 36 |
| Lymphadenopathy | 8 | 11 | 12 |
| Thrombocytopenia | 2 | 2 | 8 |
| Anemia | 3 | 3 | 5 |
| SKIN DISORDERS | |||
| Rash Erythematous | 3 | 7 | 5 |
| Rash Maculo-Papular | 2 | 5 | 4 |
| Hyperhidrosis | 2 | 4 | 4 |
| URINARY SYSTEM DISORDERS | |||
| Micturition Frequency | 4 | 2 | 7 |
| Urinary Incontinence | 2 | 4 | 2 |
| VISION DISORDERS | |||
| Vision Abnormal | 7 | 7 | 13 |
| Xerophthalmia | 0 | 3 | 1 |
Adverse reactions in Study 2, a 1-year active-controlled (vs. interferon beta-1a, 30 mcg once weekly intramuscular injection, n=338) study including 339 patients with MS treated with REBIF were generally similar to those in Study 1, taking into account the disparity in study durations.
Immunogenicity
Anaphylaxis and other allergic reactions have been observed with the use of REBIF. As with all therapeutic proteins, there is a potential for immunogenicity. In Study 1, the presence of neutralizing antibodies (NAb) to REBIF was determined by collecting and analyzing serum pre-study and at 6 month time intervals during the 2 years of the clinical trial. Serum NAb were detected in 59/189 (31%) and 45/184 (24%) of REBIF-treated patients at the 22 mcg and 44 mcg three times per week doses, respectively, at one or more times during the study. The data reflect the percentage of patients whose test results were considered positive for antibodies to REBIF using an antiviral cytopathic effect assay, and are highly dependent on the sensitivity and specificity of the assay. Additionally, the observed incidence of NAb positivity 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 REBIF with the incidence of antibodies to other products may be misleading.
Postmarketing Experience
The following adverse reactions have been identified during post-approval use of REBIF. 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.
Autoimmune Disorders: Drug-induced lupus erythematosus, autoimmune hepatitis
Eye Disorders: Retinal vascular disorders (i.e. retinopathy, cotton wool spots or obstruction of retinal artery or vein) Skin and
Subcutaneous Tissue Disorders: Erythema multiforme, Stevens-Johnson syndrome
Blood and Lymphatic System Disorders: Hemolytic anemia.
SRC: NLM .