In San Francisco on December 18, 2025, Rezolute, Inc. (NASDAQ: RZLT) experienced a significant drop in share price, plummeting by up to 90% on December 11, 2025. This decline followed the announcement of the failure of the Phase 3 sunRIZE trial for ersodetug ("erso"). The specific trial focused on erso, and the company faced challenges with its Phase 3 trial results.