Biotech stocks lit up the after-hours session on September 9, 2025, with several small- and mid-cap names posting sharp gains following fresh clinical updates, insider buying, and investor conference appearances. Companies like Immutep, Nautilus Biotechnology, Pliant Therapeutics, Phio Pharmaceuticals, and Kura Oncology all saw renewed momentum, driven by near-term catalysts that are drawing attention across the healthcare sector. Here's a quick look at the biggest movers and what's fueling their post-mark ...