Sling Therapeutics has begun its global phase 3 ORBIT trial, treating moderate to severe active thyroid eye disease (TED) with linsitinib.
Linistinib is an oral inhibitor of insulin-like growth factor-1 receptor (IGF-1R) and of insulin receptor. By blocking downstream signaling, it prevents fibroblast activation, inflammation, and proptosis. It is the only small molecule in late-stage development for TED.
In the current clinical trial, participants will receive either 150 mg of the drug or a placebo twice daily for 24 weeks. The primary endpoint is a reduction in proptosis of at least 2 mm in the study eye with no worsening in the fellow eye. The ORBIT trial is the second pivotal study, the first being the phase 2b/3 LIDS trial, which achieved positive topline results, including a 52% proptosis responder rate at week 24.