Pharming Group N.V. announced the topline results from two randomized, open label, controlled, pilot clinical trials of patients hospitalized with COVID-19 treated with RUCONEST® (recombinant human C1 inhibitor) for the prevention of severe SARS-CoV-2 infection. The primary endpoint in both studies was disease severity on the 7-point WHO ordinal scale on Day 7. In the US study, conducted under a Pharming IND, which had included 32 patients at the time of the interim analysis, patients treated with RUCONEST® plus standard of care had statistically significant lower WHO disease severity scores at Day 7 (mean 1.83, SD 0.65) as compared with those patients who received standard of care alone (mean 3.22, SD 1.86; p=0.0056). Data on secondary endpoints and biomarker evaluations were concordant with the primary endpoint findings. In the investigator-led study, conducted in Switzerland, Brazil and Mexico and part of the National Research Program "COVID-19" (NRP 78) of the Swiss National Science Foundation (SNSF), which included 83 patients by the time of the interim analysis, no difference in the primary variable was observed between the treatment groups. However, there was a significant difference in disease severity at baseline, i.e., prior to treatment, between the groups. Specifically, patients in the RUCONEST® arm had statistically significant more severe disease than those patients in the standard of care arm (p=0.0324). Although the two studies used a similar design and both enrolled patients who were being admitted to the hospital with severe pneumonia due to COVID-19 infection, different dosing regimens of RUCONEST® were used. In the Investigator-led study RUCONEST® was dosed in addition to the standard of care for three days, whereas in the US study it was four days. Also, there were differences in the patient populations enrolled and in the standard of care regimens administered.