A recently published patent of Union Therapeutics, Denmark (US11045434) (granted extremely rapidly by USPTO within 8 months from filing date) claims an inhalable cyclodextrin-based formulation of a repurposed drug niclosamide for the treatment of a viral infection. Niclosamide has bronchodilating effects and may inhibit excessive mucus production. Due to its effects on intracellular Ca2+ levels, the drug also inhibits the release of proinflammatory cytokines such as IL-8 and possibly also other cytokines, which could be of utmost importance to curb the cytokine storm frequently observed in hospitalized Covid-19 patients. Another fortunate aspect is the antibacterial activity of niclosamide that could be useful in fighting potential pulmonary superinfections.
The main claim of US11045434 is as follows:
A method of treating COVID-19 caused by SARS-CoV-2 in a subject in need thereof, the method comprising administering to the subject by inhalation intraorally and/or intranasally, a therapeutically effective amount of a formulation, wherein said formulation is a liquid formulation comprising:
0.5-1.5% niclosamide or a pharmaceutically acceptable salt thereof;
5-20% hydroxypropyl β-cyclodextrin;
the balance being water,
wherein the percentages are by weight based on the weight of the liquid formulation.
Many promising repurposed drugs failed in human tests to treat COVID-19, yet a positive commentary was published on this research in a high profile newspaper (The Lancet Regional Health – Europe Volume 4, May 2021, 100094). Clinical phases II-III are still ahead, but the above features of the drug may theoretically indeed predestine success in the treatment of respiratory failure.