Ozanimod (RPC1063) is a high orallybioavailable agonist of the sphingosine-1-phosphate receptor subtypes 1 (S1P1) and 5 (S1P5). S1P receptors belong to the family of G-protein-coupled receptor which contains five subtypes, denoting S1P1-5. S1P receptors are involved in coronary artery caliber,endothelial integrity, cardiac function, and lymphocyte recirculation [1].

In vitro: Ozanimod(RPC1063) was a specific agonist for S1P1 and S1P5 receptors. The EC50values were 160 ± 60 pM and 410 ± 160 pM for S1P1 receptors in the inhibition of cAMP generation and[35S]-GTPγS binding. The 83% Emax value of ozanimod against S1P5 receptor was 11 ± 4.3 nM. RPC1063 dose-dependently decreased S1P1 receptor re-expression on the cell surface and resulted in near complete and sustained loss of cell surface receptor expression at concentrations above 10 nM in S1P1 receptor-HEK293T cells after 1 h incubation [1].

In vivo: The t1/2 of ozanimod was 4.7 h and 5.1 h in mice and rats after p.o. administration, respectively. About 81–82% decrease in circulating T lymphocyte was observed after dosing administration for 6 h, with a maximal blood concentration of 45 nM and 159 nM in rats and mice respectively. Oral gavage of ozanimod dose-dependently reduced the disease score of mice in both doses (0.2 or 0.6 mg/kg/day) [1].

Clinical trial: In the double-blind, placebo-controlled phase 2 trial in adult patients with moderate-to-severe ulcerative colitis, when treated with 1 mg ozanimod for 8 weeks, clinical response occurred in 57% of the patients while 0.5 mg ozanimod caused a 54% response. At week 32, the rate of clinical remission was 21% and 26% at the dose of 1 mg and 0.5 mg. The side effects were mainly anemia and headache [2].

References:
Scott F L, Clemons B, Brooks J, et al.  Ozanimod (RPC1063) is a potent sphingosine‐1‐phosphate receptor‐1 (S1P1) and receptor‐5 (S1P5) agonist with autoimmune disease‐modifying activity[J]. British Journal of Pharmacology, 2016.
Sandborn WJ, Feagan BG1, et al.  Ozanimod Induction and Maintenance Treatment for Ulcerative Colitis. N Engl J Med. 2016, 374(18):1754-1762.