Daewoong Pharmaceutical said that it has failed to reach the primary endpoint in the topline result of its phase 2b clinical trial for Coviblock (ingredient: camostat mesylate), an oral Covid-19 treatment candidate.
The company conducted a clinical trial at 24 institutions in Korea from February to July with 342 mild Covid-19 patients. The company either gave Covidblock or a placebo to 327 patients in a placebo-controlled, randomized, double-blind test.
The primary endpoint was the time it took for clinical symptoms to improve, and other major endpoints were safety and the share of worsening patients. The clinical symptoms included fever, cough, shortness of breath, chills, muscle pain, headache, and sore throat, and the company determined that the improvement in the severity of symptoms for 24 hours.
The company confirmed the drug's safety in all patients, but there was no statistical difference in its time for clinical symptoms to improve. Patients administered with Covidblock took seven days compared to eight days in the placebo group.
"It is true the company failed to achieve the primary endpoint due to the phase 2b result of Covidblock," a company official told Korea Biomedical Review on Tuesday.
The official explained that it was difficult to ascertain the difference in the time it takes to improve symptoms, as the subjects were patients with mild symptoms who show a high rate of natural healing and low adherence to medication due to the characteristics of mild patients.
"In fact, in this clinical trial, neither the Coviblock group nor the placebo group had a single serious patient whose symptoms deteriorated enough to undergo high flow oxygenation therapy," the company said. "This is consistent with the result that the fatality rate continues to decrease despite the recent spread of Covid-19."
However, the researchers found statistically significant results in patients who took more than 70 percent of the dose of Coviblock or placebo during the trial period.
The symptom improvement time of 175 patients (86 patients in the Coviblock group and 89 patients in the placebo group) who had at least one respiratory symptom of cough or shortness of breath, which is the most representative symptom of Covid-19 and the main indicator of worsening symptoms, showed a difference in symptom improvement time.
The Covidblock group improved symptoms within five days compared to the eight days in the placebo group, showing that the improvement was about 40 percent faster and confirmed statistically significant results.
"Notably, in patients over 50 with a high probability of the Covid-19 symptoms advancing into a severe disease, Covidblock reduced the time to improve respiratory symptoms by less than half," the company said.
Despite such positive results, the company spokesperson stressed that they are unsure if they will conduct phase 3 clinical trials for the drug.
"Whether to give up the phase 3 clinical trial has not been decided yet," the official said. "We plan to draw up the overall results and decide on the phase 3 study through discussion with government officials."
Daewoong CEO Jeon Seng-ho also said, "We will fulfill our social responsibility as a pharmaceutical company to overcome Covid-19 by considering all possible options, such as the development of a nasal spray formulation that can block the infection route itself and research on combination with other treatments."