In a mid-stage trial, Arrowhead’s investigational RNAi therapy targeting ALK7 nearly doubled four-month weight loss when added to an established obesity drug, increasing average patient weight loss from 12.3% to 22.1%. The combination also delivered a 3.4-fold reduction in visceral fat volume versus the monotherapy group (–28% vs. –8.2%), based on MRI assessments of abdominal adiposity. Enrolled patients exhibited an average baseline body mass index of 38.7 kg/m² and had a history of metabolic comorbidities, including type 2 diabetes in 42% of participants. The therapy’s safety profile remained favorable, with transient injection-site reactions in 15% of subjects and no serious adverse events attributed to the RNAi agent. These results underscore Arrowhead’s ability to enhance existing treatment regimens and could reshape market expectations for next-generation obesity drugs.

On January 5, the company’s Chief Medical Officer sold 4,625 shares, reducing his holding to 207,497 shares following a transaction reported on Form 4. Concurrently, a board director disposed of 7,530 shares in a block trade valued at approximately $527,100, trimming his ownership by 9.8% to 69,053 shares valued at roughly $4.8 million. These insider transactions were executed at average prices of $61.24 and $70.00 per share, respectively. Despite these sales, the company’s 50-day moving average trend remains upward—currently at $53.54—reflecting sustained institutional investor support. Trading volume for the day reached 2.7 million shares, while the stock traded between daily intraday highs and lows of $60.62 and $68.00, underscoring heightened market activity around the company’s R&D milestones.