PRISMS
Subcutaneous interferon beta-1a
PRISMS demonstrated dose-related clinical and MRI efficacy of subcutaneous interferon beta-1a given three times weekly.
- Phase
- Phase III
- Population
- Relapsing-remitting multiple sclerosis (RRMS)
- Controlled period
- May 1994 — Feb 1997
What was compared
Intervention
Interferon beta-1a 44 μg
Subcutaneously three times weekly
n=184Comparator
Placebo
Matching subcutaneous injection three times weekly
n=187Additional randomized arm
Interferon beta-1a 22 μg
Subcutaneously three times weeklyn=189560 randomized2 years controlled phase
Primary endpoint
Prespecified outcome
Mean relapses per patient
2 years
Outcome figure
Primary endpoint results
Intervention Comparator or reference
Mean relapses per participant
Mean relapses
33% and 27% relative reductions for the 44 μg and 22 μg doses.
Selected secondary outcomes
Disability
Both doses delayed defined disability progression versus placebo.
MRI
Active lesions and accumulated burden of disease were lower with both doses.
Study population
- Randomized
- 560 randomized
- Age
- 18–50 years eligible
- Disability
- EDSS 0–5.0
- Disease definition
- Relapsing-remitting multiple sclerosis
Who entered the trial
Key inclusion criteria
- Relapsing-remitting multiple sclerosis
- At least two relapses during the previous 2 years
- Baseline EDSS 0–5.0
Key exclusion criteria
- Progressive MS without qualifying relapses
- Recent corticosteroid or immunosuppressive treatment
- Major systemic illness or pregnancy
Safety signal
- The primary report described both regimens as generally well tolerated.
- Influenza-like symptoms, injection-site reactions, and laboratory abnormalities are central interferon-associated tolerability considerations.
Why it mattered
PRISMS established the clinical and radiologic evidence base for a higher-frequency subcutaneous interferon regimen.
Important limitation
The principal efficacy comparison involved two active doses and placebo; the study did not directly compare this regimen with other interferon products.