Ulcerative colitis is a chronic inflammatory bowel disease characterized by inflammation in the colon and rectum, often leading to symptoms such as rectal bleeding, diarrhea, and weight loss. Ozanimod, marketed as Zeposia, represents an oral medication approved for the treatment of this condition. It offers a targeted approach to managing the immune response implicated in ulcerative colitis.
Understanding Ulcerative Colitis and Ozanimod
Ulcerative colitis is a long-term inflammatory condition that primarily affects the large intestine, including the colon and rectum. This inflammation can cause ulcers and bleeding along the lining of these organs. Managing ulcerative colitis often involves achieving and maintaining remission, which means reducing symptoms and inflammation over time.
Ozanimod is an oral medication classified as a sphingosine 1-phosphate (S1P) receptor modulator. It is the first S1P receptor modulator approved for adults with moderately to severely active ulcerative colitis. This medication aims to reduce the inflammation associated with ulcerative colitis.
How Ozanimod Works
Ozanimod works by modulating the activity of sphingosine 1-phosphate receptors, specifically binding with high affinity to the S1P1 and S1P5 receptor subtypes. This binding leads to the internalization of the S1P1 receptors. By doing so, ozanimod effectively reduces the capacity of certain immune cells, known as lymphocytes, to exit from lymph nodes and enter the bloodstream.
The reduction in lymphocyte migration into the intestine is a primary way ozanimod helps to lessen inflammation in the gut. In patients with ulcerative colitis, there is often an increased migration of these immune cells to the inflamed areas of the colon, contributing to the disease activity.
Clinical Effectiveness in Ulcerative Colitis
Clinical trials have demonstrated ozanimod’s effectiveness in inducing and maintaining remission in adults with moderately to severely active ulcerative colitis. The Phase 3 True North trial evaluated ozanimod in patients who had not responded adequately to or were intolerant of other therapies. In this trial, 18% of patients treated with ozanimod achieved clinical remission at 10 weeks, compared to 6% in the placebo group.
For maintenance therapy, 37% of ozanimod-treated patients achieved clinical remission at 52 weeks, versus 19% of those on placebo. The trial also showed improvements in clinical response, with 60% of ozanimod patients achieving this outcome compared to 41% with placebo. Endoscopic improvement, indicating reduced inflammation visible during a colonoscopy, was achieved by 46% of ozanimod recipients compared to 26% of placebo recipients.
Additionally, 30% of patients on ozanimod achieved endoscopic-histologic mucosal improvement, a more comprehensive measure of healing, versus 14% on placebo. Patients also experienced reductions in rectal bleeding and stool frequency as early as two weeks after starting treatment. These findings suggest that ozanimod can provide durable and sustained benefits for patients with ulcerative colitis.
Administering and Safety Considerations
Ozanimod is an oral medication taken once daily, with or without food. It is often started with a gradual dose increase over the first week to help the body adjust and mitigate initial side effects.
Ozanimod can cause a temporary slowing of the heart rate, particularly during the initial eight days of treatment. Patients should report symptoms like dizziness, lightheadedness, or a sensation of a slow heart rate to their healthcare provider. Blood pressure may also increase, so regular monitoring is recommended. Other potential side effects include infections due to a reduction in lymphocyte counts. Liver problems and a vision issue called macular edema are also possible, requiring monitoring. Patients should discuss their full medical history, including any heart conditions, liver disease, or previous infections, with their doctor before starting ozanimod.