Core Insights - Several clinical-stage biotech companies experienced significant after-hours trading momentum due to anticipated trial data releases and pipeline updates [1] Company Summaries - **MBX Biosciences Inc. (MBX)**: Shares surged 33% in after-hours trading, rising from $10.00 to $13.77, following the announcement of topline results from its Phase 2 trial of Canvuparatide, expected on September 22 [2][3] - **Structure Therapeutics Inc. (GPCR)**: Stock increased 11.37% to $26.26 after closing at $23.58, driven by interest in its lead candidate aleniglipron, with topline results from two Phase 2b trials expected by the end of 2025 [4] - **Cartesian Therapeutics Inc. (RNAC)**: Shares rose 5.51% to $9.96 after a decline during the day, with preliminary data from the Phase 2 trial of Descartes-08 expected in the second half of 2025 [5][6] - **Rapport Therapeutics Inc. (RAPP)**: Stock increased 3.60% to $27.31, following positive topline results from its Phase 2a trial for RAP-219, with Phase 3 trials expected to start in 2026 [9][10] - **Rezolute Inc. (RZLT)**: Shares rose 3.77% to $7.99 after a decline during the day, with topline data from the Phase 3 sunRIZE trial for congenital hyperinsulinism expected in December 2025 [11][12]