Sling Therapeutics Presents Data from Phase 2b/3 LIDS Clinical Trial Demonstrating Durability of Linsitinib in Thyroid Eye Disease at ASOPRS 57th Annual Fall Scientific Symposium

Linsitinib achieved a statistically significant proptosis responder rate of 52% vs. 19% for placebo at Week 24 (p=0.010)

82% of Week 24 proptosis responders maintained their response through Week 72 (48 weeks after treatment completion), representing a highly favorable durability profile

Low incidence of IGF-1R–associated adverse events of special interest; no treatment-related hearing impairment reported

Confirmatory Phase 3 ORBIT pivotal trial currently enrolling moderate to severe active TED patients

ANN ARBOR, Mich.--(BUSINESS WIRE)--Sling Therapeutics, Inc., a clinical-stage biopharmaceutical company developing the first and only late-stage oral small-molecule therapy for thyroid eye disease (TED), today announced the presentation of efficacy, safety and new durability results from its Phase 2b/3 LIDS trial of linsitinib in adults with moderate to severe active TED. The data were highlighted in an oral presentation and in a poster session at the American Society of Ophthalmic Plastic and Reconstructive Surgery (ASOPRS) 57th Annual Fall Scientific Symposium.

Linsitinib is the first and only oral IGF-1R inhibitor in Phase 3 development and only small molecule therapy to significantly reduce proptosis in TED, with more convenient oral dosing compared to currently available IV and injectable IGF-1R inhibitors.

“Full LIDS results reinforce that linsitinib can deliver clinically meaningful proptosis reductions with a differentiated safety, delivery and durability profile,” said Ryan Zeidan, Ph.D., President and Chief Executive Officer of Sling Therapeutics. “Importantly, the data demonstrate that for the majority of proptosis responders in the trial, those improvements held for nearly a year after their last dose. This durability is particularly encouraging for patients, who are facing a disease that can remain active for years and often returns after treatment. With our confirmatory pivotal Phase 3 ORBIT trial now enrolling, we are focused on building the evidence to establish linsitinib as a convenient oral treatment that can deliver meaningful and durable benefit for people living with TED.”

“For physicians, Clinical Activity Scores are an important measure in determining whether TED is active and at risk of flaring. Data from LIDS indicates treatment with linsitinib resulted in sustained suppression of disease activity after treatment ended, with further improvement over the follow-up period,” said Raymond Douglas, M.D., Ph.D., board-certified aesthetic and reconstructive oculoplastic surgeon. “Furthermore, quality of life scores among linsitinib responders continued to rise after treatment ended, alongside sustained proptosis improvement and low disease activity. For patients living with a visible, often distressing disease, that continued improvement off therapy is an important benefit."

Presentation Highlights

Week 24 Efficacy & Safety

LIDS enrolled 90 adults with moderate to severe active TED, defined as onset within 12 months, proptosis ≥3 mm and Clinical Activity Scores (CAS) ≥4. Participants were randomized 1:1:1 to linsitinib 75 mg twice daily (BID), linsitinib 150 mg BID or placebo for 24 weeks. The primary endpoint was the proportion of proptosis responders at Week 24, defined as a reduction in proptosis of at least 2 mm from baseline.

• Linsitinib 150 mg BID achieved a statistically significant proptosis responder rate of 51.7%, compared with 18.8% for placebo (p=0.010).
• Linsitinib 75 mg BID achieved a proptosis responder rate of 38.9% (p=0.09 vs. placebo). The prespecified significance threshold for each dose was p<0.0125.
• Most AEs were mild to moderate and reversible.
• The most common treatment-emergent AEs in the 150 mg BID arm (>10% in any arm) were: diarrhea, headache and nausea (each 20.7%), fatigue (17.2%), ALT increase and hyperhidrosis (each 13.8%), muscle spasms and AST increase (each 10.3%).
• Serious AEs occurred in 3.2% of placebo patients, 0% of 75 mg patients and 6.9% of 150 mg patients.
• Among IGF-1R–associated adverse events of special interest:
  • No menstrual changes in any arm
  • No encephalopathy
  • Hyperglycemia occurred in one patient in each linsitinib arm
  • One report of hypoacusis and one report of tinnitus in the 150 mg arm were assessed as unrelated to treatment
• Treatment discontinuations occurred in 16.7%, 20.0% and 33.3% of the placebo, 75 mg and 150 mg arms, respectively.

Long-term Follow Up & Durability

Twenty pooled linsitinib-treated patients who were proptosis responders at Week 24 entered a 48-week off-drug follow-up period. A post-hoc analysis of the durability of clinical response to linsitinib through Week 72 was assessed.

• Response was maintained in:
  • 95% at Week 36, 48, and 60
  • 82% at Week 72
• Mean CAS remained low throughout follow-up, improving from 1.2 at Week 24 to 0.8 at Week 72.
• Mean overall Graves' Ophthalmopathy Quality of Life (GO-QoL) scores increased from 74.0 to 95.2 over the same period.
• During follow-up, no treatment-related AEs, serious AEs or AEs leading to discontinuation were reported.

In September 2026, Sling announced a successful End-of-Phase 2 meeting with the U.S. Food and Drug Administration (FDA) and the initiation and active enrollment of its confirmatory Phase 3 ORBIT pivotal trial in patients with moderate to severe active TED.

About the Phase 2b/3 LIDS Trial

The LIDS Trial (NCT05276063) was a Phase 2b/3, randomized, double-masked, placebo-controlled trial evaluating the efficacy, safety and pharmacokinetics of oral linsitinib in adults with moderate to severe active TED. A total of 90 patients were randomized 1:1:1 to linsitinib 75 mg BID, linsitinib 150 mg BID or placebo for 24 weeks. Week 24 responders then entered a 48-week off-drug extension period to assess durability.

About Thyroid Eye Disease (TED)

Thyroid Eye Disease (TED) is a serious, progressive, and vision-threatening rare autoimmune disease that is estimated to affect more than 200,000 people in the U.S. TED often occurs in people living with Graves’ disease and hyperthyroidism and is caused by dysfunction in the IGF-1R (insulin-like growth factor 1 receptor) signaling pathway, which results in fibrous tissue growth behind the eyes. This leads to several negative symptoms that may have long-term, irreversible damage as the tissue growth pushes the eyes forward or causes the eyes and eyelids to become red and swollen. As the disease progresses, it can lead to pain, eye bulging (proptosis), and vision loss in severe cases, thus dramatically impacting a patient’s quality of life. TED predominantly affects women, and most frequently affects people with hyperthyroidism due to Graves’ disease. The current standard of care typically involves either invasive orbital surgery or a lengthy series of infusions with potential adverse events like loss of hearing, hyperglycemia, or menstrual cycle changes.

About Linsitinib

Linsitinib is a convenient oral small molecule in clinical development for thyroid eye disease (TED). Linsitinib inhibits IGF-1R (insulin-like growth factor 1 receptor) intracellularly. IGF-1R is a validated target in TED and the only target for currently approved therapies. Activation of the IGF-1R drives the inflammation, tissue expansion, and proptosis seen in TED. By blocking this signaling, linsitinib is designed to reduce these effects. Linsitinib has an established safety profile through treatment of more than 900 patients in 15 clinical trials in multiple diseases and has received Fast Track Designation from the U.S. FDA.

About Sling Therapeutics

Sling Therapeutics is a clinical-stage biopharmaceutical company focused on the late-stage advancement of an oral small molecule therapy for the treatment of thyroid eye disease (TED). Linsitinib, the first and only oral small-molecule intracellular IGF-1R (insulin-like growth factor 1 receptor) inhibitor in Phase 3 clinical development, is designed to provide TED patients with an effective, convenient oral treatment option while reducing the treatment burden on patients, physicians and healthcare systems. For more information, visit www.slingtx.com.