Introduction to Immunotherapy

Introduction to Immunotherapy

• Immunotherapy is a cancer treatment leveraging the immune system to combat cancer cells.
• It boosts or modifies immune responses to target and destroy cancer cells.
• It differs from traditional treatments (surgery, chemotherapy, radiation) which directly target and kill cancer cells.

Types of Immunotherapy

• Immune checkpoint inhibitors: Drugs blocking proteins (checkpoints) that prevent immune attack on healthy cells, unleashing the immune system against cancer. Examples: ipilimumab, nivolumab.
• Cancer vaccines: Stimulate the immune system to recognize and attack cancer cells. Personalized to patient's cancer type, offering preventative or therapeutic benefit.
• Adoptive cell therapy: Involves extracting immune cells (T-cells), modifying them to better target cancer, and returning them to the patient. Chimeric antigen receptor (CAR) T-cell therapy is a significant example.
• Cytokines: Immune system proteins boosting immune response to attack cancer. Examples: interferon, interleukin-2.
• Oncolytic viruses: Genetically modified viruses selectively infecting and killing cancer cells without harming healthy cells, and triggering an immune response against the tumor.

Mechanisms of Action

• Targeting immune checkpoints: Preventing immune response inhibition against cancer cells, enabling sustained immune attack.
• Stimulating immune cells: Activating the immune system by directly stimulating immune cells or inducing cytokine production.
• Modifying immune cells: Involves isolating immune cells (usually T-cells), genetically modifying them to target tumors, and reintroducing them to the patient.
• Delivering cargo to target tumors: Introducing immune components or molecules to target cancers, triggering an immune response.

Applications

• Specific cancer types: Immunotherapy shows success in treating various cancers including melanoma, lung cancer, kidney cancer, and leukemia.
• Combination therapies: Frequently used alongside other cancer treatments (chemotherapy) to enhance effectiveness and reduce side effects.
• Personalized medicine: Research into personalized cancer vaccines targeting unique tumor antigens is advancing toward tailored treatments.

Side Effects

• Immune-related adverse events (irAEs): Side effects from immune system overactivation, ranging from mild to severe, encompassing colitis, skin rash, and fatigue.
• Inflammation: Immune response causing inflammation as it attacks cancer cells or affected tissues.
• Autoimmune disorders: In some cases, triggering an autoimmune response, targeting healthy cells.

Advantages

• Targeted approach: Targeting immune response pathways rather than the cancer directly may decrease side effects and target specific tumors.
• Potential for long-term remission: Immunotherapy can sometimes induce lasting remission.
• Reduced reliance on chemotherapy: This can minimize the harsh side effects typically associated with chemotherapy.

Limitations

• Response variability: Not all patients respond to immunotherapy, and the response varies in extent.
• Toxicity: Some side effects (irAEs) can be serious, requiring close monitoring and management.
• Cost: Treatment costs can be substantial.
• Complexity: Development and implementation are complex procedures.

Current Research

• Combination therapies: Research continues to study improving immunotherapy effectiveness through combining it with other treatments.
• Personalized strategies: Development of tailored vaccines and other methods continues to enhance outcomes.
• Biomarker identification: Ongoing research into biomarkers predicting immunotherapy response across diverse cancers.
• Targeting mechanisms: Research into more targeted and effective immunotherapy strategies.