Sling Therapeutics Raises $123 Million for Thyroid Eye Disease Drug

Sling Therapeutics has raised $123 million in a Series C financing to advance linsitinib, an oral drug being developed for thyroid eye disease (TED).

The financing was led by Forbion, with participation from existing investor TPG Life Sciences Innovations and new investor Sectoral Asset Management. Sling plans to use the funds to support the clinical development of linsitinib as it moves through a global Phase 3 study.

Linsitinib is an oral small-molecule inhibitor of insulin-like growth factor 1 receptor (IGF-1R), a target that has been studied in thyroid eye disease. Sling has started the Phase 3 ORBIT pivotal trial in adults with moderate to severe active TED.

The company reached agreement with the US Food and Drug Administration (FDA) on the design of the Phase 3 study following an End-of-Phase 2 meeting earlier this year.

The ORBIT trial follows Sling’s Phase 2b/3 LIDS study, which met its primary goal of reducing proptosis, or eye bulging, in patients with moderate to severe TED. Sling also reported a safety profile that it said was differentiated in areas of interest for IGF-1R therapies, including hearing impairment, changes in blood sugar levels and menstrual cycle changes.

Based on the clinical data, linsitinib received Fast Track designation from the FDA. The designation can provide companies with more frequent communication with the agency during drug development and may allow eligible medicines to access programs such as Rolling Review, Accelerated Approval and Priority Review.

Ryan Zeidan, president and CEO of Sling Therapeutics, said the new funding will support the company as it advances linsitinib toward potential commercialization. He said the company believes an oral treatment could offer patients another option that may be easier to use than some existing approaches.

Thyroid eye disease is an autoimmune condition that can cause swelling around the eyes, eye bulging and other changes that can affect vision and daily life. Current treatment approaches can include medicines, infusions and surgery, depending on the patient’s condition.

Alongside the financing, Regina Salvat of Forbion and François Beaubien of Sectoral Asset Management have joined Sling’s board of directors.

The company will now focus on advancing the Phase 3 ORBIT trial and generating further clinical data on linsitinib for patients with active thyroid eye disease.