Insilico Medicine Nominates ISM1354 GIPR Antagonist

Cambridge, MA – Insilico Medicine has nominated ISM1354, a next-generation small-molecule GIPR antagonist, as a clinical candidate for obesity treatment. The compound was created with the company’s Chemistry42 platform and is intended for use alongside existing GLP-1 receptor agonist therapies. Early modeling suggests the combination could achieve up to 31.3% body-weight loss, a result that would rank it among the most effective obesity drugs in development.

Why Add a GIPR Antagonist?

The GLP-1 market has expanded rapidly. Tirzepatide alone generated $36.5 billion in sales in 2025, reflecting strong demand for weight-management solutions. However, GLP-1 drugs have known limitations. Patients often experience dose-related side effects, and some see reduced efficacy over time. Adding a GIPR antagonist may address these issues. The GIPR pathway works with GLP-1 signaling to control appetite and glucose metabolism. Blocking GIPR while activating GLP-1 could produce a stronger, longer-lasting weight-loss effect than either mechanism alone. The 31.3% figure from preclinical modeling supports this dual-target approach. Insilico previously nominated ISM0676, an oral GIPR antagonist, as a clinical candidate. The addition of ISM1354 gives the company two GIPR molecules to explore. Multiple candidates reduce the risk that a single failure would halt the entire program.

Chemistry42 Platform and Drug Design

ISM1354 was generated through Chemistry42, which combines generative AI models with predictive pharmacology tools. The platform manages the workflow from target identification to lead optimization. For GIPR antagonists, the key challenge is achieving selectivity over related receptors while keeping oral bioavailability and metabolic stability. AI-driven design can screen millions of virtual compounds before any synthesis occurs. This reduces the time and cost needed to reach a clinically nominated candidate. Insilico has applied this method across several therapeutic areas, and the GIPR program is one of its most commercially significant efforts given the size of the obesity market.

Competitive Landscape and Outlook

The obesity drug space is crowded. Companies such as Eli Lilly and Novo Nordisk are advancing dual- and triple-mechanism candidates that target GLP-1, GIPR, and glucagon receptors. Insilico’s entry with a GIPR antagonist positions it for combination-therapy partnerships rather than as a standalone product. The next steps for ISM1354 include preclinical validation and IND-enabling studies. If the compound moves into clinical trials, head-to-head comparisons with existing GLP-1 therapies will be critical. The 31.3% weight-loss projection must be confirmed in humans to differentiate ISM1354 from other candidates. Having both ISM1354 and ISM0676 gives Insilico multiple paths to generate the needed clinical data.

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