by Cancer remains one of the leading causes of death around the world. Conventional treatments like chemotherapy, radiation therapy, and surgery have helped patients fight cancer for decades. However, these treatments also have severe side effects and limitations. Immunotherapy presents a new and promising approach that aims to harness the body’s own immune system to fight cancer in a targeted way with fewer side effects.
What is Immunotherapy?
Immunotherapy Drugs, also called biologic therapy, works by boosting the body’s natural defenses to target and destroy cancer cells. The immune system protects the body from infection and disease through a complex network of cells, tissues, and organs that work together. However, cancer cells can evade detection by the immune system. Immunotherapy drugs try to recognize cancer cells as foreign and stimulate the immune system to attack them. This approach is less toxic than chemotherapy because it utilizes the body’s in-built defense mechanism rather than introducing foreign chemicals. Several types of immunotherapy drugs are currently being studied and used to treat different cancer types.
Checkpoint Inhibitors
One of the most promising classes of immunotherapy drugs are checkpoint inhibitors. These drugs work by blocking certain checkpoint proteins like PD-1 and CTLA-4 that cancer cells use to avoid detection by T-cells – a type of white blood cell critical to the immune response. By blocking these checkpoints, checkpoint inhibitors help T-cells recognize and attack cancerous tumors. Checkpoint inhibitors have shown durable responses in various cancers including melanoma, lung cancer, kidney cancer, bladder cancer, and Hodgkin’s lymphoma. Drugs approved for use include pembrolizumab (Keytruda), nivolumab (Opdivo), and ipilimumab (Yervoy). Research is ongoing to expand the use of checkpoint inhibitors to additional cancer types.
CAR T-cell Therapy
Chimeric Antigen Receptor (CAR) T-cell therapy is a type of immunotherapy that utilizes gene therapy techniques. In this approach, T-cells are collected from a patient’s blood and genetically modified in the lab to produce chimeric antigen receptors (CARs) targeting specific proteins on cancer cells. The engineered CAR T-cells are then infused back into the patient where they recognize and destroy cancer cells expressing the targeted antigen. Remarkably, CAR T-cell therapy has achieved remission rates over 90% in some blood cancers like acute lymphoblastic leukemia and lymphoma. Drugs approved for use are tisagenlecleucel (Kymriah) and axicabtagene ciloleucel (Yescarta). Wider applications in solid tumors are being evaluated.
Adoptive Cell Transfer Therapy
Adoptive cell transfer (ACT) therapy involves cultivating and growing specific types of immune cells outside the body and infusing them back into cancer patients in large numbers to induce an anti-tumor response. This includes techniques like autologous tumor-infiltrating lymphocyte (TIL) therapy and natural killer (NK) cell therapy. In autologous TIL therapy, T-cells are harvested directly from the patient’s own tumor, selectively grown in the lab, and infused back to recognize and eradicate residual cancer cells. Early studies show promise in melanoma and other cancers. NK cell therapy utilizes NK cells, a type of white blood cell that can identify and attack tumor cells, to target cancers like leukemia, lymphoma, and multiple myeloma. More research is ongoing to expand the role of ACT therapy.
Vaccine-Based Immunotherapy
Cancer vaccines aim to trigger protective immune responses against tumor-specific antigens – substances that immune cells recognize as foreign. The goal is to train the immune system to selectively eliminate cancer cells expressing those antigens. Some cancer vaccines contain whole tumor cells or parts of cancer cells modified to be more immunogenic. Others contain only the antigen alone or antigen attached to an adjuvant to further stimulate the immune system. While no cancer vaccine has yet proven successful against advanced cancers, some prophylactic and therapeutic vaccines have shown encouraging results in preventing recurrence in bladder cancer and cervical cancer. Research combining vaccines with other immunotherapy approaches holds promise.
Adverse Effects and Safety Considerations
While immunotherapy offers novel mechanisms to fight cancer, these powerful drugs can also cause inflammatory side effects as the immune system responds robustly throughout the body. Common adverse effects of immunotherapy include fatigue, rash, diarrhea, nausea, loss of appetite, and fever. More severe effects like pneumonitis (lung inflammation) and colitis (bowel inflammation) can also rarely occur and require prompt management. Close monitoring by healthcare providers is essential during immunotherapy treatment. Certain patients with pre-existing conditions like autoimmune diseases may not be suitable candidates. With appropriate patient selection and management of side effects, the benefits of immunotherapy can far outweigh the risks for many cancer patients.
The Future of Cancer Care
Immunotherapy is revolutionizing cancer treatment by tapping into the immune system’s disease-fighting potential. Combining different immunotherapy drugs or pairing them with conventional treatments often yields even better responses than single agents alone. With more clinical trials underway, the arsenal of immunotherapy options is rapidly expanding. As research unravels more intimate details about cancer immunology, newer targeted agents and combination regimens will likely achieve higher rates and longer durations of remission across broader patient populations and cancer stages. In the future, immunotherapy may be deployed in earlier disease settings, as an adjuvant or neoadjuvant therapy, replace chemotherapy in some cases, or prevent cancer recurrence after primary treatment. Immunotherapy holds immense promise to fundamentally change the landscape of cancer care, leading to better patient outcomes and quality of life.
Immunotherapy harnesses the incredible powers of the immune system to fight cancer with a gentler approach than standard treatments. Significant progress has already been made, especially with checkpoint inhibitors and CAR T-cell therapies. While challenges remain in expanding benefits across all cancer types, ongoing research efforts are relentless in developing new immunotherapy strategies and combinations. The future of cancer care is increasingly becoming immunotherapy-based, with the goal of long-term remission and possible cures. By improving our understanding of cancer immunology, new immunotherapy advances will continue transforming cancer from a fatal disease to a manageable condition.
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1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
