Summary                      

￭ IPG7236 is a first-in-class, orally administered, small-molecule antagonist of the chemokine receptor CCR8, positioning it as the global leader in this novel class of cancer immunotherapies. 

￭  IPG7236 features a unique dual-indication development strategy, targeting immunosuppressive regulatory T cells (Tregs) in oncology and pathogenic plasmacytoid dendritic cells (pDCs) in the rare autoimmune condition IgG4-Related Disease (IgG4-RD). 

￭  Developed with a novel chemical structure that delivers superior druggability and exceptional selectivity, IPG7236 has demonstrated a significant safety advantage over competing antibody-based approaches in clinical trials. 

￭  As the most advanced oral CCR8 antagonist in global development, IPG7236 is poised to unlock the immune system's full potential against solid tumors and provide a transformative first-in-class therapy for a rare disease with no approved targeted treatments.

IPG7236 in IgG4-RD

Mechanism of Action

￭  In IgG4-RD, CCR8 is selectively overexpressed on pathogenic plasmacytoid dendritic cells (pDCs). These activated pDCs migrate to affected organs and produce pro-inflammatory and pro-fibrotic cytokines (including IFN-I and IL-33) that drive the Th2 immune response, progressive tissue fibrosis, and production of pathogenic IgG4 antibodies.

￭  IPG7236 is designed to specifically block CCR8-mediated pDC migration, thereby reducing their accumulation at disease lesion sites. This action interrupts the chronic inflammatory cycle, alleviates tissue inflammation and fibrosis, and helps restore normal immune tolerance.

Key Differentiation

￭   Addressing a Critical Unmet Medical Need: Current first-line therapy for IgG4-RD is high-dose glucocorticoids, which are associated with severe long-term side effects including osteoporosis, diabetes, and immunosuppression. There are currently no approved small molecule therapies for IgG4-RD.

￭   Precision Targeted Oral Therapy: As a selective, oral small molecule, IPG7236 offers a more precise and convenient treatment option compared to the broad immunosuppression of steroids or the intravenous administration of B-cell depleting biologics like rituximab.

￭   Significant Orphan Drug Market Potential: IgG4-RD is an orphan disease with a growing global patient population and a clear need for safer, more effective treatments.

Current Development & Status

￭   Phase 1 (Healthy Subjects) (Completed): An initial Phase 1 trial in healthy volunteers in Australia demonstrated that IPG7236 is well-tolerated across all dose levels and exhibits linear pharmacokinetics supporting once-daily dosing.

￭   Well-tolerated Safety Prodile: The favorable safety and tolerability profile demonstrated in ongoing oncology trials provides a robust foundation for accelerated development in the IgG4-RD patient population.

￭   Next Steps: A global Phase 2 clinical trial for IgG4-RD is planned to commence in 2027.

Preclinical In vivo Efficacy

Using a surrogate anti-CCR8 antibody (IPG0521) in a validated mouse model of IgG4-RD, treatment resulted in significant, dose-dependent therapeutic effects:

• Reduced Organ Damage: Markedly decreased immune cell infiltration, parenchymal destruction, and fibrosis in the pancreas and salivary glands.

• Downregulated Pathogenic Cytokines: Significantly reduced the expression of key pro-inflammatory and pro-fibrotic cytokines, including IL-6, IL-1β, IFN-γ, and TGF-β, in affected tissues.

IPG7236 in Oncology

Mechanism of Action

￭ CCR8 is predominantly and selectively expressed on tumor-infiltrating regulatory T cells (Tregs), which are the primary drivers of immunosuppression within the tumor microenvironment (TME). These Tregs actively suppress the body’s natural antitumor immune response by inhibiting effector T cell function.

￭  IPG7236 works by potently and selectively blocking the CCL1-CCR8 signaling axis, which disrupts the recruitment and retention of these immunosuppressive Tregs at the tumor site. This action breaks down the immunosuppressive shield, enhances the infiltration and cytotoxic activity of tumor-killing CD8⁺ T cells, and enables the immune system to effectively recognize and eliminate cancer cells.

Key Differentiation

￭ Oral Small-Molecule Advantage: IPG7236's oral administration provides transformative benefits over large-molecule antibody competitors, including lower manufacturing costs, easier global distribution, and superior patient compliance and convenience.

￭  Novel Mechanism of Action (Signaling Blockade vs. Cell Depletion): Unlike competing ADCC-enhanced antibodies that non-specifically deplete all CCR8-expressing cells (including healthy peripheral Tregs), IPG7236 selectively blocks Treg function without inducing systemic cell death. This targeted mechanism is expected to deliver a markedly superior safety profile by eliminating on-target, off-tumor toxicity.

￭  Exceptional Safety Profile: In the Completed Phase 1 clinical trial, IPG7236 has been dose-escalated up to 1000 mg twice daily (BID) without Dose-limited Toxicity (DLT) observed, highlighting its excellent systemic tolerability.

￭  Proven Synergy with PD-1 Inhibitors: Preclinical data demonstrates a strong, statistically significant synergistic effect with anti-PD-1 antibodies, positioning IPG7236 as a prominent combination partner to overcome resistance to current checkpoint inhibitor therapies.

Current Development & Status

￭ Phase 1 MRCT (Monotherapy): A multi-center clinical trial for advanced solid tumors has completed in both the U.S. and China.

￭ Phase 1/2 (PD-1 Combination): A Phase 1/2 cinical trial is onging to commerce to evaluate IPG7236 in combination with an anti-PD-1 therapy for patients with advanced solid tumor.

Preclinical In vivo Efficacy

In comprehensive preclinical studies, IPG7236 has demonstrated robust, dose-dependent antitumor efficacy across multiple humanized solid tumor models:

￭ Tumor Microenvironment Modulation: In a humanized MDA-MB-231 triple-negative breast cancer model, IPG7236 treatment caused a significant, dose-dependent reduction in tumor-infiltrating Tregs and a corresponding dose-dependent increase in tumor-killing CD8⁺ T cells.

￭  Single-Agent Activity: IPG7236 monotherapy (10 mg/kg BID) demonstrated significant tumor growth inhibition (TGI = 47.2%, P < 0.05), while anti-PD-1 antibody (JS001) monotherapy showed only modest activity (TGI = 31.6%) that did not reach statistical significance in this model.

￭  Synergistic Combination Efficacy: The combination of IPG7236 and JS001 achieved superior antitumor efficacy (TGI = 73.8%, P < 0.01) that exceeded the sum of individual monotherapy effects, confirming true biological synergy between CCR8 blockade and PD-1 inhibition.

￭  Mechanistic Conclusion: This synergistic effect arises from complementary mechanisms of action: IPG7236 reduces CCR8⁺ Treg-mediated immunosuppression and enhances CD8⁺ T cell infiltration, while JS001 prevents T cell exhaustion via PD-1/PD-L1 blockade. These data strongly support the clinical development of IPG7236 in combination with PD-1/PD-L1 inhibitors for solid tumors.

Publications

•Wu Y, Xi J, Li Y, Li Z, Zhang Y, Wang J, Fan GH. Discovery of a Potent and Selective CCR8 Small Molecular Antagonist IPG7236 for the Treatment of Cancer. J Med Chem. 2023 Apr 13;66(7):4548-4564. doi: 10.1021/acs.jmedchem.3c00030. Epub 2023 Mar 29. PMID: 36988587.