Firategrast for relapsing remitting multiple sclerosis: a phase 2, randomised, double-blind, placebo-controlled trial.
BACKGROUND
Monoclonal antibody therapy against α4β-integrin is efficacious in patients with multiple sclerosis (MS) with some safety concerns. We assessed the safety and efficacy of firategrast, a small oral anti-α4β-integrin molecule, in patients with relapsing remitting MS.


METHODS
We did a multicentre, phase 2, randomised, double-blind, placebo-controlled, dose-ranging study in participants with clinically definite relapsing-remitting MS. A 24-week treatment period was followed by 12 weeks of core follow-up and 40 weeks of extended follow-up. Participants were randomly assigned, via computer-generated block randomisation in a 1:2:2:2 ratio, to receive one of four treatments twice a day: firategrast 150 mg, firategrast 600 mg, or firategrast 900 mg (women) or 1200 mg (men), or placebo. Brain scans were obtained at 4-week intervals to the end of core follow-up. The primary outcome was cumulative number of new gadolinium-enhancing brain lesions during the treatment phase and was analysed using a generalised linear model with an underlying negative binomial distribution, adjusted for sex, baseline number of new gadolinium-enhancing lesions, and country. This study is registered with ClinicalTrials.gov, NCT00395317.


RESULTS
Of 343 individuals enrolled, 49 received firategrast 150 mg, 95 received firategrast 600 mg, 100 received firategrast 900 mg or 1200 mg, and 99 received placebo. A 49% reduction (95% CI 21·2-67·6; p=0·0026) in the cumulative number of new gadolinium-enhancing lesions was seen for the 900 mg or 1200 mg firategrast group (n=92, mean number of lesions 2·69 [SE 1·18]) versus the placebo group (90, 5·31 [1·18]). In the 600 mg group (86, 4·12 [SE 1·19]), a non-significant 22% reduction (95% CI -21·3 to 49·7; p=0·2657) occurred in mean number of new gadolinium-enhanced lesions relative to placebo; for the 150 mg group (47, 9·51 [SE 1·24]), a 79% increase (95% CI 4·1-308·1; p=0·0353) occurred relative to placebo. Firategrast was generally well tolerated at all doses. The frequency of all adverse events was similar across all treatment groups except for an increased rate of urinary tract infections in the high-dose firategrast group. No cases of progressive multifocal leukoencephalopathy or evidence of reactivation of JC virus were identified.


CONCLUSIONS
This study showed efficacy on imaging endpoints for firategrast at the highest dose tested, and suggests that further investigation of oral short-acting α4β integrin blockade therapies is warranted.


BACKGROUND
GlaxoSmithKline.
Department of Neuroinflammation, London, UK. david.h.miller@ucl.ac.uk
David H
DH
Miller
Thomas
T
Weber
Richard
R
Grove
Claire
C
Wardell
Joseph
J
Horrigan
Ole
O
Graff
Gillian
G
Atkinson
Pinky
P
Dua
Tarek
T
Yousry
David
D
Macmanus
Xavier
X
Montalban
D000328:Adult; D000911:Antibodies, Monoclonal / Q000008:administration & dosage* / Q000009:adverse effects; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D005682:Gadolinium; D006801:Humans; D039041:Integrin alpha4beta1 / Q000037:antagonists & inhibitors*; D008297:Male; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000188:drug therapy* / Q000473:pathology; D010919:Placebos; D016896:Treatment Outcome
D000911:Antibodies, Monoclonal; D039041:Integrin alpha4beta1; D010919:Placebos; D005682:Gadolinium