Clinical data from the Avonex^® and Betaseron^® trials showed:

• 5% of patients who were on Avonex for up to 18 months were NAb+
• 26% of patients who were on Betaseron for up to 18 months were NAb+

Treatment with Avonex*			Treatment with Betaseron**
Months treatment	% NAb+*	# NAb+/ # tested	Months treatment	% NAb+*	# NAb+/ # tested
3	0%	0/75	>0-6	0%	0/23
6	0%	0/74
9	1%	1/69	7-11	10%	3/29
12	3%	2/63
15	2%	1/50	12-18	21%	9/42
18	5%	2/40	>18	26%	6/23

*From Safety extension study: IFN-bnaïve (not previously treated with interferon products), NAb+, titer>20
**From Safety extension study: Patients naïve to Avonex before study entry, previously treated with Betaseron, and discontinued Betaseron treatment within 2 weeks of entering safety extension study, NAb+, titer>20
Reprinted with permission from a slideshow by Dr. Timothy Vartanian.¹

In his talk, Vartanian emphasized, "nearly five times as many patients on Betaseron developed NAbs, compared to patients on Avonex."¹

Avonex is a registered trademark of Biogen, Inc.
Betaseron is a registered trademark of Berlex Laboratories, Inc.