Over the last few days, the American Society of Retina Specialists (ASRS) held their Annual Virtual Meeting; coined “2020 Virtual Sessions,” professionals converged online to share insights into ophthalmological topics, ranging from treatment and patient care to burgeoning research. In one such presentation, Dr. Michael N. Cohen, MD, and his team shared that a Phase 2 clinical trial testing X-82 was stopped. X-82, a VEGF/PDGF inhibitor, is designed to treat patients with wet macular degeneration (wet AMD). However, the trial was since halted due to concerns over toxicity. Find the full study, including information on design, here.
Macular Degeneration
Currently, there are no cures for macular degeneration, an eye disease which causes vision loss. Many doctors believe macular degeneration is caused by a mix of genetic and environmental elements. The condition can either be dry, which accounts for up to 90% of diagnoses, or wet, a severe form making up only 10-15% of cases. Macular degeneration impacts the macula, a part of the retina, and is the leading cause of vision loss in America.
Symptoms include:
- Difficulty recognizing faces or distinguishing between colors
- Blurred vision
- A need for brighter light
- Difficulty adjusting to glares
- “Floaters” in the range of vision
Find out more about macular degeneration here.
Phase 2 X-82 Trial
For patients with wet macular degeneration, vascular endothelial growth factor (VEGF) can play a part in ocular damage. Wet AMD usually occurs when blood vessels grow and burst, leaking blood or other fluid. VEGF can promote blood vessel growth. As a result, VEGF-inhibitors such as X-82 block kinase (enzyme) activity to prevent or slow this growth.
In the Phase 1 trial, researchers analyzed 35 patients. Of these, 7 never received treatment for their AMD. After a 6-month period using X-82, 60% (21 patients) no longer required anti-VEGF injections. Moving into the Phase 2 trial, researchers hoped for similarly promising results.
The randomized and double-blind Phase 2 trial included 157 participants, all of whom were diagnosed with AMD. Additionally, all participants previously received at least 2 anti-VEGF injections. During the trial, patients received either 50mg X-82, 100mg X-82, 200mg X-82, or a placebo each day. Overall, researchers wanted to determine how X-82 impacted vision loss and retinal thickness.
Although 103 patients participated for all 56 weeks, researchers ultimately stopped the trial. Though most participants experienced slowed vision loss, and required less additional anti-VEGF injections, researchers noted a concern for hepatobiliary toxicity. Hepatobiliary refers to the liver, bile ducts, and gallbladder. So, according to the researchers, X-82 does not present enough benefit for patients when compared to potential risks.
Read the source article here.
Find the original study here.
