Much of our news in 2020 was filled with headlines around COVID-19, the viral pandemic which now has over 96.2 million global diagnoses. As we enter into 2021, the numbers are sobering: 2.06 million global deaths, with 24.5 million cases and 406,000 fatalities in the United States alone. Drug developers are quickly working not only on developing a vaccine, but on learning what drugs might be used as treatment options for patients with severe cases. However, for pharmaceutical company Alexion Pharmaceuticals (“Alexion”), their goals might soon be cut short. The company recently stopped enrollment on a Phase 3 clinical trial evaluating Ultomiris for patients with severe COVID-19 after the drug failed to meet efficacy endpoints.

Ultomiris

Currently, Ultomiris is indicated for the treatment of atypical hemolytic uremic syndrome (aHUS) and paroxysmal nocturnal hemoglobinuria (PNH). The drug is a C5 inhibitor, meaning it inhibits or restrains the C5 protein which plays a role in the complement system. According to Britannica, the complement system is:

a complex system of more than 30 proteins that act in concert to help eliminate infectious microorganisms. Specifically, the complement system causes the lysis (bursting) of foreign and infected cells, the phagocytosis (ingestion) of foreign particles and cell debris, and the inflammation of surrounding tissue.

Basically, your complement system is part of your immune system and plays a role in immune health. Some doctors have shared that patients with COVID-19 experience such severe symptoms because of a cytokine storm and the over activation of the immune system. Thus, by inhibiting part of the complement system, Alexion researchers wondered if the virus’ severity could be lessened.

Alexion paused enrollment following a recommendation from the clinical trial’s monitoring committee. Altogether, researchers found Ultomiris to be similarly effective to supportive care, with no additional benefits. While patients who are still enrolled will continue receiving treatment, Alexion now must figure out how to proceed. Although the trials in the United States are paused, one study in the United Kingdom is still evaluating Ultomiris in hospitalized patients who do not need additional ventilation.