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Tiragolumab Biosimilar: Enhancing Immune Checkpoint Therapy with TIGIT Inhibition

Tiragolumab is a monoclonal antibody targeting TIGIT (T-cell immunoglobulin and ITIM domain), an immune checkpoint receptor that suppresses T-cell and natural killer (NK) cell activity in tumors. By inhibiting TIGIT, Tiragolumab reactivates exhausted immune cells, making it a promising treatment for various cancers, particularly in combination with PD-1/PD-L1 inhibitors. The biosimilar provides an affordable, accessible alternative to the original biologic, enabling broader adoption of TIGIT-targeted therapies.


This article delves into the mechanism of action, clinical applications, and advantages of the Tiragolumab biosimilar in cancer treatment.


1. Understanding TIGIT and Its Role in Cancer


What is TIGIT?


TIGIT is an immune checkpoint receptor expressed on T cells, NK cells, and regulatory T cells (Tregs). Its interaction with ligands such as CD155 and CD112 on tumor and antigen-presenting cells leads to:


  • Immune Suppression: Reduces T-cell proliferation and cytokine production.
  • Tumor Immune Evasion: Inhibits NK cell cytotoxicity and promotes immunosuppressive activity.

Why Target TIGIT?


  • Restoring Immune Function: Blocking TIGIT unleashes T-cell and NK-cell activity against tumors.
  • Synergy with PD-1/PD-L1 Inhibitors: TIGIT blockade enhances the efficacy of checkpoint inhibitors like Atezolizumab.

2. Tiragolumab Biosimilar: A Cost-Effective Solution


Features of the Biosimilar


The Tiragolumab biosimilar matches the efficacy, safety, and quality of the original antibody while offering greater affordability.


  • Target: TIGIT on immune cells.
  • Mechanism: Blocks TIGIT-ligand interactions, restoring immune function.
  • Affordability: Lowers costs, expanding access to TIGIT-targeted cancer therapies.

3. Mechanism of Action 


Step
Details
TIGIT Binding
The biosimilar binds to TIGIT, preventing interaction with ligands CD155 and CD112.
T-Cell Reactivation
Inhibits TIGIT-mediated suppression, enhancing T-cell activation and cytokine production.
NK Cell Restoration
Boosts NK cell-mediated cytotoxicity, promoting tumor clearance.
Tumor Microenvironment Reprogramming
Reduces Treg activity and enhances effector immune cell infiltration into the tumor.

4. Clinical Applications 


The Tiragolumab biosimilar has shown promise in various cancer types, particularly in combination with PD-1/PD-L1 inhibitors.


Non-Small Cell Lung Cancer (NSCLC)


  • Combination Therapy: Used with Atezolizumab for improved progression-free and overall survival in advanced NSCLC.
  • Checkpoint Resistance: Effective in patients with resistance to PD-1/PD-L1 inhibitors.

Head and Neck Squamous Cell Carcinoma (HNSCC)


  • Reduces immune suppression in the tumor microenvironment, enhancing immune-mediated tumor destruction.

Other Cancers


  • Melanoma: Targets checkpoint resistance in patients with advanced or metastatic disease.
  • Hematologic Malignancies: Investigated for potential use in lymphomas and other TIGIT-expressing cancers.

5. Benefits of Tiragolumab Biosimilar


Enhanced Immune Activation


Reactivates exhausted T and NK cells, enabling a stronger immune response against tumors.



Cost-Effective Access



The biosimilar reduces financial barriers, increasing accessibility to advanced immunotherapies.



Combination Potential


Works synergistically with PD-1/PD-L1 inhibitors to improve treatment outcomes.


6. Challenges and Considerations


Resistance Mechanisms


  • Tumors may activate alternative immune checkpoints or suppress TIGIT expression to evade therapy.

Adverse Effects


  • Immune-Related Adverse Events (irAEs): Includes fatigue, skin rash, and diarrhea, which are
    generally manageable.

7. Comparison: Tiragolumab vs. Biosimilar


Feature
Tiragolumab
Biosimilar
Target
TIGIT receptor.

TIGIT receptor.

Mechanism

Blocks TIGIT to enhance immune activation.

Blocks TIGIT to enhance immune activation.
Indications
NSCLC, melanoma, HNSCC, and hematologic malignancies.
NSCLC, melanoma, HNSCC, and hematologic malignancies.
Efficacy
Proven in clinical trials.
Equivalent in preclinical and clinical studies.
Cost
High  
Reduced, improving accessibility.


8. Future Directions


Expanded Indications


  • Exploring efficacy in additional cancers, such as colorectal and pancreatic tumors.
  • Investigating its use in combination with CAR-T cell therapies.

Novel Combinations


  • Checkpoint Blockade: Pairing with CTLA-4 inhibitors or VEGF-targeted therapies.

  • Radiation Therapy: Enhancing the immunogenicity of tumors with combined radiotherapy.

9. Summary Table 


Aspect
Details
Target
TIGIT, an inhibitory receptor on T and NK cells.
Primary Use
Enhancing immune responses in cancers such as NSCLC and melanoma.
Mechanism of Action
Blocks TIGIT to restore T-cell and NK-cell activity.
Biosimilar Benefits
Affordable, accessible, and clinically equivalent to Tiragolumab.


Conclusion 


The Tiragolumab biosimilar represents a critical advancement in immune checkpoint therapy. By targeting TIGIT, it reactivates the immune system’s ability to attack tumors, offering new hope for patients with advanced cancers. As a cost-effective alternative, the biosimilar ensures equitable access to cutting-edge immunotherapies, paving the way for improved cancer treatment worldwide.


References 


  1. Chauvin, J.M., et al., 2015. TIGIT and its role in cancer immunotherapy. Cancer Cell, 26(5), pp.785-792.
  2. ClinicalTrials.gov, 2023. Studies on Tiragolumab and biosimilar therapies. Available at www.clinicaltrials.gov.
  3. European Medicines Agency (EMA), 2023. Guidelines for biosimilar development in immunotherapy. Available at www.ema.europa.eu.
  4. Rodriguez-Abreu, D., et al., 2021. Tiragolumab and PD-L1 blockade in NSCLC: Clinical outcomes. Journal of Clinical Oncology, 39(15), pp.1301-1310.
  5. Johnston, R.J., et al., 2014. TIGIT as a therapeutic target: Mechanistic insights and clinical advances. Trends in Immunology, 35(9), pp.450-462.

12th Dec 2024 Shanza Riaz

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