Pharming Group N.V. announced encouraging results from five patients with confirmed COVID-19 (SARS-CoV-2) infections hospitalised with related severe pneumonia that were treated with RUCONEST® (recombinant human C1 inhibitor) under a compassionate use program at the University Hospital Basel, Switzerland. Four male patients and one female patient (between 53-85 years of age) with COVID-19 and suffering from related severe pneumonia, who did not improve despite standard treatment, including hydroxychloroquine and lopinavir/ritonavir, were administered RUCONEST® at an initial dose of 8400 U, followed by 4200 U every 12 hours for three additional doses. No allergic reactions or drug related adverse events were reported. Following treatment with RUCONEST®, fever resolved in four of the five patients within 48 hours, and laboratory markers of inflammation decreased significantly (CRP, IL-6). Soon thereafter, the patients were discharged from the hospital as fully recovered. One patient had increased oxygen requirement and was temporarily transferred to the ICU for intubation, but over the subsequent days recovered and was released from the ICU. Following these initial results, a multinational, randomized, controlled, investigator-initiated clinical trial with up to 150 patients with confirmed COVID-19 infections, requiring hospitalisation due to significant COVID-19 related symptoms is planned. The study will be led by Dr. Michael Osthoff, University Hospital Basel, Switzerland.