Shares in a Seattle biotech firm shot up 80% Monday after a preliminary trial suggested a new drug could boost survival rates for patients with severe COVID-19 symptoms.

Omeros, a biopharmaceutical firm focused on immune-related diseases and other disorders, said the trials showed its drug narsoplimab improved recovery and survival for patients with acute respiratory distress syndrome associated with COVID-19.

Those results, coupled with news that Omeros was in talks to receive federal funding to scale up production of narsoplimab, pushed the company’s share price to a high of $25.46, or 80% above Friday’s closing price, before it fell back below $20 in after-hours trading.

“We look forward to being able to make narsoplimab broadly available to hospitalized COVID-19 patients,” Omeros’s CEO, Greg Demopulos, said in a statement. Because the company is currently seeking additional investment, Demopulos declined to comment about results in order to adhere to U.S. securities rules.

Omeros initially developed narsoplimab for other applications, including treating complications of hematopoietic stem cell transplant therapy, and the drug has already undergone trials for safety. But researchers realized that one side effect of hematopoietic stem cell transplant therapy — damage to the linings of blood vessels — is similar to a key effect of COVID-19, which also damages blood vessels. 

According to a statement from Omeros, the COVID-19 study was undertaken at the behest of Dr. Alessandro Rambaldi, who works at Papa Giovanni XXIII hospital in Bergamo, Italy, an early center of the pandemic. Rambaldi, who was also involved in a stem-cell trial for narsoplimab, asked Omeros to offer the drug to patients who had severe COVID-19 symptoms and had been put on mechanical ventilators. 


All six patients in the study recovered and were discharged from the hospital. Patients in a separate study who had similar symptoms, demographics, and underlying conditions but who did not receive any treatment had a mortality rate of 53%, according to the study, which has been published by Immunobiology, a peer-reviewed journal.

“The patients that we treated with narsoplimab were critically ill, and the uniformly successful outcomes were truly impressive,” Dr. Rambaldi said in a statement. 

Although narsoplimab is still under review for federal approval, it is being considered for federal support under the “Operation Warp Speed” initiative, which is trying to accelerate development of COVID-19 treatments.

Omeros is just one Seattle-based biotech company doing research related to the illness.

Adaptive Biotechnologies recently announced what it described as a first-of-its-kind tool to help researchers more accurately measure the T-cell immune response to COVID-19 infection during vaccine trials.

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