Plegridy 5 Year follow-up at AAN

ADVANCE Phase 3 Extension Study (ATTAIN): Peginterferon Beta-1a 125 mcg Every 2 Weeks Demonstrated Sustained Efficacy in RMS Patients Treated up to 5 Years 

Authors: Damian Fiore; Serena Hung, MD; Weihua Tang; Yue Cui; Xiaojun You, PhD; Shulian Shang; Thomas Scott, MD Objective: To investigate the long-term clinical efficacy of peginterferon beta-1a in patients with relapsing multiple sclerosis (RMS). 

Background: Peginterferon beta-1a every 2 weeks has been approved in the US for the treatment of RMS (and is approved in >20 countries), based on Year 1 results from the pivotal Phase 3 2-year ADVANCE study. The secondary outcomes for the 2-year ATTAIN study, the extension of ADVANCE, evaluate long-term efficacy of peginterferon beta-1a. 
Design/Methods: RMS patients who had completed ADVANCE were eligible for enrollment in ATTAIN. Patients were maintained on the peginterferon beta-1a dosing regimen they were assigned in ADVANCE Year 2. The study was considered complete when the last patient completed Week 96 of ATTAIN. Annualized relapse rates (ARRs) were evaluated in all patients who had received peginterferon beta-1a beginning in Year 1 of ADVANCE, for all years that they had received therapy (up to 6 years). In the absence of a long-term placebo comparator, peginterferon beta-1a every 4 weeks was used as a control for the approved peginterferon beta-1a every 2 weeks dosing regimen. 
Results: The ITT population for Years 0 to 6 was n=376 for patients receiving peginterferon beta-1a every 2 weeks, and n=354 every 4 weeks (ATTAIN ITT population). Over 6 years, adjusted ARR was significantly improved in the peginterferon beta-1a every 2 weeks group (0.188) compared with the every 4 weeks group (0.263; rate ratio 0.714; 95% CI 0.563-0.904; P=0.0052). Year-over-year adjusted ARRs were generally reduced in the every 2 weeks group (Years 0-1: 0.241, n=376; Years 1-2: 0.179, n=376; Years 2-3: 0.203, n=376; Years 3-4: 0.129, n=338). 
Conclusions: At the approved every 2 weeks dosing schedule, peginterferon beta-1a displays significantly improved ARR over 6 years compared with every 4 weeks dosing. Additionally, year-over-year results for peginterferon beta-1a every 2 weeks demonstrate sustained efficacy with long-term treatment. 

If the answer is CRAB! What's the question?

But as beta interferons come out of patent, phamra have repurposed beta interferon by adding anti-freeze (Polyethylen glycol = PEG). This gives it a longer time in circulation. So this study shows it works over 5years of use but the results are about twice as bad as generic cladribine,