Sling raises $123M to advance repurposed cancer drug for thyroid eye disease
Sling Therapeutics, a small Michigan biotech, has secured $123 million in funding to run a Phase 3 trial of a drug originally developed by Astellas for cancer, now being tested for thyroid eye disease. The investment reflects growing interest in treatments for this condition, which has drawn significant venture capital and pharmaceutical attention. The company aims to resurrect the asset in a new therapeutic area.
This funding round highlights a growing trend in drug development: repurposing existing compounds for new indications. Sling’s candidate, originally explored as an oncology therapy by Astellas, is now being redirected toward thyroid eye disease, a condition with limited treatment options. The $123 million raise will support a late-stage trial, signaling investor confidence in this strategy. By leveraging prior safety data, repurposed drugs can potentially shorten development timelines and reduce early-stage risk, making them attractive to biotech firms seeking faster paths to market.
If successful, this approach could expand treatment choices for thyroid eye disease patients, who currently face few approved therapies. It may also encourage other small biotechs to revisit shelved oncology assets for non-cancer conditions, potentially lowering costs and accelerating access. However, Phase 3 trials carry uncertainty, and outcomes will determine whether patients benefit. The funding itself reflects broader investor appetite for niche, high-need diseases, which could shape future research priorities.