Yearly influenza epidemics strike millions of people, resulting in up to 500,000 deaths. Fatalities caused by most seasonal influenza viruses is <0.03%, with significant mortality in the young and elderly populations. Presently, influenza treatments are only partially effective, and some influenza strains are resistant to the currently marketed therapeutics. Zanamivir (ZAN, Relenza®), remains highly active against resistant influenza strains, however, its therapeutic impact is severely limited by its route of administration, oral inhalation, which renders it unsuitable for patients with compromised respiratory systems.

Therefore, the development of a novel delivery alternative for ZAN will address a significant unmet medical need. Transdermal drug delivery offers several improvements over other delivery systems. The drug directly enters the systemic circulation, avoiding syringe needles, and could allow large numbers of patients to be reached during an influenza pandemic outbreak. ZAN itself cannot cross the human skin barrier at therapeutic rates, however, microarray-enabled transdermal delivery is an elegant, efficient, and painless method for increasing the skin permeation of many drugs, including ZAN. Our novel drug-device combination product, TSR-066, consists of a swellable microarray patch (MAP), which continuously delivers ZAN over 5 days. This delivery approach for ZAN will expand its reach into patient groups for which Relenza® is contraindicated.

Based on the well-established preclinical and clinical safety of ZAN, TSRL has achieved an agreement with the FDA that TSR-066 can be developed using a 505(b)2 regulatory strategy. Upon collection of sufficient data to support the change in the route of administration, TSRL plans to submit an investigational new application (IND) in 2025.

The project has been supported by $12M in non-dilutive funding to date, which covers expenses through the Phase 1 clinical trial scheduled for 1Q26.