Mustang Bio shares surge 30.97% premarket after FDA grants orphan drug designation for MB-101 brain cancer therapy.

Mustang Bio (NASDAQ:MBIO) surged 30.97% in premarket trading following the U.S. FDA’s granting of Orphan Drug Designation to its investigational therapy MB-101 (IL13Ra2-targeted CAR T-cells) for treating astrocytomas and glioblastoma. This regulatory milestone, first reported on July 7, 2025, and reiterated in subsequent news, provides the company with tax incentives, market exclusivity, and expedited review pathways, bolstering investor confidence in its pipeline. The designation aligns with recent positive coverage, including a July 10 report noting an 180% intraday jump in the stock, underscoring the therapy’s strategic value. While earlier events like facility exits and compliance measures impacted the stock negatively in early 2025, the July development directly drove the premarket rally.