Zweimal 25 vs. einmal 50 mg

Braun J, McHugh N, Singh A, Wajdula JS, Sato R. 
Improvement in patient-reported outcomes for patients with ankylosing spondylitis treated with etanercept 50 mg once-weekly and 25 mg twice-weekly.
Rheumatology (Oxford). 2007 Jun;46(6):999-1004

van der Heijde D, Da Silva JC, Dougados M, Geher P, van der Horst-Bruinsma I, Juanola X, Olivieri I, Raeman F, Settas L, Sieper J, Szechinski J, Walker D, Boussuge MP, Wajdula JS, Paolozzi L, Fatenejad S;
Etanercept Study 314 Investigators. Etanercept 50 mg once weekly is as effective as 25 mg twice weekly in patients with ankylosing spondylitis.
Ann Rheum Dis. 2006 Dec;65(12):1572-7.