Etrasimod (APD334), a Potential MS Treatment Candidate

EtrasimodĀ (formerly known as APD334) is Arena Pharmaceuticalsā€™ therapeutic candidate to treat autoimmune diseases like multiple sclerosis (MS) andĀ ulcerative colitis. The drug is an oral formulation agonist (a substance which exerts its effect after binding to a particular receptor) that targets the S1PĀ receptor. This receptor is involved in the regulation of the body’s immune response and is anĀ important target ofĀ treatments for autoimmune disorders.

How etrasimod works

S1P receptors are heavily involved in immune modulation, immune cell (lymphocyte) regulation and development, and in suppressing the innate immune response of T-cells (a type of lymphocyte).

S1P receptors are found on the outside of lymphocytes. The activation of these receptors triggers the lymphocytes to leave lymph nodes and enter the bloodstream, ultimately making their way into target tissue. In MS patients, lymphocytes enter and accumulate in the brain and spinal cord, causing damage to nerve cells through inflammation.

S1PĀ receptor modulators are immunosuppressive and anti-inflammatory in nature as they block S1P signaling and prevent the lymphocytes from entering tissues. This is how etrasimod works.

Research has shown that the drug successfully reduced the rate ofĀ inflammation in preclinical mouse models of MS.

Etrasimod in clinicalĀ trials

WithĀ positive results from preclinical studies, a Phase 1b randomized, double-blind and placebo-controlled trial was undertakenĀ to evaluate the safety, tolerability, pharmacodynamics, and pharmacokinetics of multiple-ascending doses of etrasimod. Results from this study, inĀ 50 healthy volunteers given etrasimod and 10 others given a placebo, demonstratedĀ that the treatmentĀ can reduceĀ the lymphocyte count in the blood, with mean decreases of up to 69% over a 21-day period from baseline. No serious adverse effects were recorded, and those reported were mild to moderate cases of dizziness, headache, constipation, or diarrhea.

Arena is currently running Phase 2 clinical trials, assessing the safety and efficacy of estrasimod in patients with a number of autoimmune diseases, including inflammatory bowel disease (NCT03139032), ulcerative colitis (NCT02447302 and NCT02536404), primaryĀ biliary cholangitis (NCT03155932), and pyodermaĀ gangrenosum (NCT03072953). Currently, no clinical studies are being prepared to assess estrasimod as an MS treatment.

Note: Multiple Sclerosis News TodayĀ is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.