Sling Therapeutics closed a $123 million Series C financing to support its Phase 3 confirmatory trial for oral thyroid eye disease (TED) candidate linsitinib (Orbit). The randomized study compares linsitinib 150 mg twice daily versus placebo over 24 weeks in about 130 patients with moderate to severe active TED. The company is positioning the oral pill as a potential alternative to approved injectables, including Amgen’s Tepezza and Viridian Therapeutics’ Lumvoa. While initial signals have raised questions about efficacy relative to injectables, Sling is betting on safety and convenience to win patient and clinician adoption if Phase 3 confirms differentiated outcomes. The financing extends the TED competition, adding another late-stage mechanism-and-route strategy as investors continue to fund oral convenience plays in specialty autoimmune eye disease.