On Jun. 21, 2021, Tonix Pharmaceuticals announced that it planned to develop TNX-102 SL (cyclobenzaprine HCl sublingual tablets) as a potential treatment for Long COVID Syndrome (Long COVID) known officially as Post-Acute Sequelae of COVID-19 (PASC1).

Tonix planned to meet with the U.S. Food and Drug Administration in the third quarter of 2021 to seek agreement on the design of a potential Phase 2 pivotal study and the overall clinical development plan to qualify TNX-102 SL as an indicated treatment for Long COVID.