Gilead Sciences' promising antiviral drug, remdesivir, is entering the second phase of a clinical trial sponsored by the National Institute of Allergy and Infectious Diseases.

After successfully demonstrating it can reduce the time COVID-19 patients spend in hospitals in the first phase, the drug will now be paired with an anti-inflammatory pill called baricitinib. Baricitinib was approved in 2018 to treat rheumatoid arthritis and researchers are hoping combining the two drugs will address COVID-19's extreme inflammatory response, which many experts believe is more damaging than the virus itself.

According to NBC News, baricitinib, manufactured by Eli Lilly, blocks an enzyme that helps produces chemicals that can cause inflammation.

"If we can minimize the inflammation, and minimize the viral replication at the same time, we could further increase the clinical benefits of the patient," Dr. Andre Kalil, a principle investigator for the trial at the University of Nebraska Medical Center in Omaha, told NBC News.

Baricitinib, like any drug, has side effects that could be worrisome. It lowers the immune system and might also increase platelet count which could cause blood clots. Since an increase in blood clots has already been reported in COVID-19 patients, researchers will carefully monitor the 600-700 patients who will be recruited for the second phase.

The drug, marketed as Olumiant, comes with a boxed warning it can cause serious infections such as pneumonia, herpes zoster, and urinary tract infection, according to DocWire News. Researchers said preliminary results from the trial should be available in the summer and hope to have a variety of treatments to be effective against the coronavirus.

"We will just not stop," Kalil told NBC News. "We'll keep trying different treatments that are going to have the potential to improve patients."