On Mar. 31, 2022, Sorrento Therapeutics announced that the FDA had given clearance to commence the Phase 3 clinical trial of Abivertinib in severe COVID-19 patients (hospitalized patients with respiratory compromise requiring oxygen supplementation).

The clinical trial was conducted in 2 phases, and the initial run-in defined the RP3D. In October 2021, Sorrento released preliminary results of two phase 2 studies that seemed to show that patients hospitalized with severe pneumonia due to COVID-19, especially those requiring non-invasive ventilation or high flow oxygen supplementation, were up to 5-fold more likely to benefit from Abivertinib therapy than those patients who required low flow supplementation. Such patients represent a high-risk population with few treatment options.