Moxidectin Receives FDA Approval for Treatment of River Blindness

This is the first new treatment for river blindness approved by the US FDA in 20 years.

Medicines Development for Global Health (MDGH) and the World Health Organization Special Programme for Research and Training in Tropical Diseases (TDR) have announced the approval by US Food and Drug Administration (FDA) of moxidectin 8mg oral for the treatment of river blindness in patients aged 12 and older.

Moxidectin, a macrocyclic lactone anthelmintic medicine, operates by selectively binding to the parasite's glutamate-gated chloride ion channels. These channels are critical to the function of muscle cells and invertebrate nerves.

The approval of moxidectin was based on the results from 2 randomized, double-blind, active-controlled clinical studies in Ghana, Liberia, and the Democratic Republic of the Congo. Each study achieved its respective objectives and demonstrated a “statistically significant superiority” of moxidectin in suppressing the presence of microfilariae in the skin in comparison with ivermectin. Results from the phase 3 study were published in the Lancet in January.

"FDA approval is a momentous achievement for any biopharmaceutical company, but it is a particularly rare and exciting event in the neglected diseases setting. It takes a broad community to develop a new medicine. FDA approval represents decades of work by thousands of scientists, disease control specialists, expert advisors, community health workers, funders and study participants,” Mark Sullivan, founder and managing director of MDGH, said in the announcement statement.

The medicine was developed by MDGH and TDR with a $13 million investment from the Global Health Investment Fund.

Additionally, the FDA awarded MDGH with a priority review voucher (PRV). The FDA’s neglected diseases PRV program was designed to promote the development of new drug and treatment options for neglected diseases.

"This is exactly what we had in mind when we proposed the PRV program. The voucher incentive helped Medicines Development for Global Health attract funding to complete testing and registration for a drug that had been on the shelf,” David Ridley, PhD, a professor at Duke University and an author of the 2006 paper on which the voucher program is based said. “I'm delighted that the voucher program is playing a role in treating patients with river blindness, and one day eliminating the disease."

According to Sullivan, MDGH will continue to explore treatment options for river blindness, particularly in children.

River blindness, or onchocerciasis, is caused by a parasitic worm called Onchocerca volvulus, which is transmitted to humans through exposure with infected black flies. The disease can cause severe itching, disfiguring skin conditions, visual impairment, and in extreme cases, permanent blindness. Currently, nearly 200 million individuals are at risk for the disease and 99% of those infected with the disease live in Sub-Saharan Africa. The only drug currently approved by the FDA for treatment of river blindness, ivermectin, has had success in reducing the burden of the disease, but there is still a need to work towards eliminating the transmission of the parasite.