Efficacy and safety of Huashi Baidu granule plus Nirmatrelvir-Ritonavir combination therapy in patients with high-risk factors infected with Omicron (B.1.1.529): A multi-arm single-center, open-label, randomized controlled trial

Huashi Baidu granule (HSBD) and Paxlovid (Nirmatrelvir-Ritonavir) are antiviral Chinese patent medicine and western medicine specially developed for treating coronavirus disease 2019 (COVID-19). Their efficacy and safety in treating COVID-19 are still under investigated. To assess and compare the efficacy and safety of HSBD, Paxlovid, and the combination in treating high-risk patients infected with SARS-CoV-2 Omicron. The study was a prospective single-center, open-label, randomized, controlled clinical trial conducted from April 18 to June 5, 2022. (ClinicalTrial.gov registration number: ChiCTR2200059390) 312 severe patients aged 18 years and older infected with SARS-CoV-2 Omicron from Shuguang Hospital in Shanghai were randomly allocated to HSBD monotherapy (orally 137 g twice daily for 7 days, n = 105), Paxlovid monotherapy (orally 300 mg of Nirmatrelvir plus 100 mg of Ritonavir every 12 h for 5 days, n = 103), or combination therapy (n = 104). The primary outcome was SARS-CoV-2 nucleic acid negative conversion within 7-day treatment. The secondary outcome included hospital discharging conditions, severe conversion of symptom, and adverse events. Of 312 participants, 85 (82%) of 104 in combination therapy, 71 (68%) of 105 in HSBD monotherapy, and 73 (71%) of 103 in Paxlovid monotherapy had a primary outcome event. The hazard ratios of primary outcome were 1.37 (95% CI 1.03 – 1.84, p = 0.012) for combination versus HSBD, 1.28 (0.98–1.69, p = 0.043) for combination versus Paxlovid, and 0.88 (0.66–1.18, p = 0.33) for HSBD versus Paxlovid. There was no statistical difference of efficacy between HSBD and Paxlovid, while combination therapy exhibited more effective than either alone. For secondary outcomes, the hospital discharging rates within 7 days exhibited the significant increase in combination therapy than in HSBD or Paxlovid monotherapy (71% (74/104) vs 55% (58/105) vs 52% (54/103), p < 0.05). The risk of severe conversion of symptom showed no statistical significance among three interventions (1% (1/104) vs 3% (3/105) vs 3% (3/103), p > 0.05). No severe adverse events occurred among combination therapy and monotherapies in the trial. For patients with severe COVID-19, HSBD exhibits similar efficacy to Paxlovid, while combination therapy is more likely to increase the curative efficacy of Omicron variant than monotherapies, with few serious adverse events.