US-based Arena Pharmaceuticals has started dosing patients in an investigational Phase Ib clinical trial of APD334, an oral drug candidate that targets the sphingosine 1-phosphate subtype 1 (S1P1) receptor, to treat a number of autoimmune diseases.
The randomised, double-blind and placebo-controlled trial is designed to evaluate the safety, tolerability and pharmacokinetics of multiple-ascending doses of APD334 in about 96 healthy adult volunteers.
Discovered by Arena, APD334 targets the S1P1 receptor, with therapeutic potential in a spectrum of autoimmune diseases, such as multiple sclerosis, psoriasis and rheumatoid arthritis.
S1P1 receptors have been shown to be involved in the modulation of several biological responses, including lymphocyte trafficking from lymph nodes to the peripheral blood.
"The company has optimised APD334 as a potent and selective small molecule S1P1 receptor agonist that reduces the severity of disease in preclinical autoimmune disease models."
By isolating lymphocytes in lymph nodes, fewer immune cells are available in the circulating blood to effect tissue damage, the company said.
Arena senior vice-president and chief medical officer William Shanahan said: "We continue to make progress in advancing our novel pipeline of internally discovered drug candidates, and remain committed to our vision of leading the industry in the discovery, development and commercialisation of GPCR-directed medicines."
Autoimmune diseases are characterised by an inappropriate immune response against substances and tissues that are normally present in the body.
A person's antibodies and immune cells target healthy tissues, triggering an inflammatory response in an autoimmune reaction.
Reducing the immune or inflammatory response is a major goal in the treatment of autoimmune diseases.
The company is focused on improving health by seeking to bring new medicines targeting G protein-coupled receptors to patients.
Arena's internally discovered drug, BELVIQ (lorcaserin HCl), is approved in the US, and the company is focused on discovering, developing and commercialising additional drugs to address unmet medical needs.