Safety and efficacy of lentinan nasal drops in patients infected with the variant of COVID-19: a randomized, placebo-controlled trial

Authors: Wenhan Fan, Benming You, Xinyu Wang, Xu Zheng, Aijing Xu, Yangang Liu, Haoran Peng, Wei Yin, Mingxiao Xu, Xu Dong, Yayun Liu, Ping Zhao, and Xuesong Liang

Journal: Frontiers in Pharmacology

Study Design: The study was conducted in two phases:

• Phase I: Dose-escalation trial to evaluate the safety and tolerability of lentinan nasal drops in 24 COVID-19 patients.
• Phase II: Randomized, placebo-controlled trial to assess the efficacy of lentinan nasal drops in 70 COVID-19 patients. The optimal dose from Phase I (100 μg/day) was used.

Participants:

• Phase I: 24 COVID-19 patients
• Phase II: 70 COVID-19 patients

Intervention:

• Phase I: Lentinan nasal drops at escalating doses (50, 75, and 100 μg/day) for 5 days
• Phase II:
  • Lentinan group: 100 μg/day lentinan nasal drops for 5 days
  • Placebo group: Saline nasal drops for 5 days

Outcome Measures:

• Phase I:
  • Primary endpoint: Safety and tolerability
  • Secondary endpoint: Time to virus clearance (negative RT-PCR results)
• Phase II:
  • Primary endpoint: Antigen negative conversion rate on day 5
  • Secondary endpoint: Remission of clinical symptoms

Summary: The study evaluated the safety and efficacy of lentinan nasal drops in treating COVID-19 patients infected with the Omicron variant. The dose-escalation trial (Phase I) demonstrated that lentinan nasal drops were well-tolerated, with no serious adverse events reported. Additionally, the 100 μg/day dose showed a significant reduction in virus shedding time compared to the control group. In the randomized, placebo-controlled trial (Phase II), the 100 μg/day lentinan group exhibited a significantly shorter time for COVID-19 antigen to turn negative compared to the placebo group. However, no significant difference in symptom improvement was observed between the two groups. The study concluded that lentinan nasal drops are safe and can accelerate virus clearance in COVID-19 patients.