What is immunotherapy & how does it work? immunotherapy types & Cost in India.

What is Immunotherapy?

Introduction of immunotherapy

Immunotherapy is a form of treatment that harnesses the power of the body’s immune system to combat infections and other illnesses. The immune system is made up of various components such as white blood cells, antibodies, cytokines, lymph nodes, and organs. Immunotherapy is also called biological therapy/biological response modifier therapy since it involves the use of the body’s antibodies or immune cells to target diseases.

Immunotherapy is now widely used as a standard treatment option for different types of cancer such as lung, kidney, skin, and liver cancer. As of March 2022, the U.S. Food and Drug Administration has approved more than 60 immunotherapies that can be used to treat almost every major type of cancer.

How does Immunotherapy work?

Immunotherapy helps in the treatment by altering the body’s immune reactions to the disease. Immunotherapy boosts the body’s immune response and helps in identifying and destroying the cancer cells thereby reducing the tumor cells from further spreading.

Immunomodulators are the drugs that can either enhance or suppress the immune functions. If a drug activates the immune system it is called immunostimulant. Immunostimulants are used in treating cancer, immunodeficiency, and infections. If a drug suppresses the immune they are called immunosuppressants. These are used in treating autoimmune disorders and in cases of organ transplantation to inhibit the immune response leading to organ rejection by the body.

Immunosuppressants are not generally considered as immunotherapy because even though immunosuppressants and immunostimulants act by tampering with the immune system they have different functions and mechanisms of action.

Different types of immunotherapies

Studies reveal that as of March 2022, there are over 60 immunotherapy treatments approved by the USFDA, used in treating various types of cancer. Different types of immunotherapy function in different ways, it can either slow the growth of the cancer cells or help the immune cells to destroy the abnormal cells. The therapy selection depends upon various factors like type, size, place of cancer occurrence, age, body weight, and other health issues.

Some of the types of immunotherapy are as follows:

Monoclonal antibodies: These are lab-made immune proteins also called mAbs or MoAbs. They will imitate the body’s immune response to foreign substances or antigens. They are target-specific, aiming at the proteins present on the surface of the cancer cells, designed to block the growth or destroy the cancer cells by attacking them.
Immune checkpoint inhibitors: These immunotherapy agents act on the proteins present in the cancer or immune cells, the checkpoints control the immunological reactions. Checkpoint inhibitors work by causing breakdowns in the immune system, which allows the immune cells to effectively show their immune responses to the cancer cells. Some of the common checkpoints are CTLA-4 and PD-L1 pathways.
T Cell transfer therapy: It is a process in which the immune cells are genetically engineered to present certain types of antigens. later these immune cells will be inserted back into the body. Now these genetically engineered cells can recognise the target proteins leading to their destruction. The 2 main types of Tcell transfer therapy are CAR T-cell therapy and tumor-infiltrating lymphocyte therapy
Cancer vaccines: The main aim is to identify and combat the cancer cells. These vaccines cannot prevent the occurrence of cancer but they train the body to fight against it.
Nonspecific immunotherapy: Also referred to as nonspecific immunomodulators aid the immune system in identifying and destroying the tumor cells.
Cytokines: These are the signaling proteins of the immune system that help to control immune reactions. Interferon and interleukin-2 are the cytokines utilized in the therapy of cancer.
Bacillus Calmette Guerin(BCG): This is used in the treatment of bladder cancer. Here BCG is attached directly to the inner lining of the bladder using a catheter helping in the destruction of the cancer cells.

Key Immunotherapy drugs

Currently, many potential immunotherapy drugs are in use and under development. They have been divided into various classes depending on their mechanism of action. Some of the classes are mentioned below

Monoclonal antibodies/ mAbs: Rituximab
Checkpoint inhibitors: Atezolizumab, Ipilimumab
Cytokines: Interferon , Interleukin 2
Oncolytic viruses: Talimogene laherparepvec
Bispecific antibodies: Blinatumomab/ Blincyto

Side affects associated with Immunotherapy

Immunotherapy is a treatment that typically lasts for an extended period. However, one of its drawbacks is that the active immune system may attack not only cancerous cells but also healthy cells, leading to several side effects. The appearance of side effects can vary depending on several factors, such as the type and stage of cancer, the duration of the therapy, and your health condition before starting the treatment.

The side effects experienced by the patient can range from mild to moderate depending on the treatment employed. These are commonly listed side effects complained by the patients. Skin inflammation like redness, soreness, pain, itching, fever, dizziness, vomiting, fatigue, headache, infection, organ infection and others.

Who could be helped by immunotherapy?

Immunotherapy treatment is usually employed when cancer doesn’t respond to other treatments for example in skin cancer, this type of cancer doesn’t respond well to chemotherapy, or radiation therapy but works if immunotherapy is given.
In cases where there is a reoccurrence of cancer in the patients. as immunotherapy involves targeting the immune system, immune cells are likely to remember (immunomemory) the foreign cells and attack upon their return.
It can benefit in the case of combination therapy, where immunotherapy along with other treatments has a more effective response

What is cost of Immunotherapy in India?

The cost of immunotherapy treatment in India varies depending on the type of treatment and the stage or severity of the cancer. Unfortunately, cancer treatment can be quite expensive and may not be affordable for those with low or middle income. The estimated cost of immunotherapy can range from ₹1 lakh to ₹4 lakh. In addition to the treatment cost, there are other expenses like consultation fees, imaging tests, biopsy, blood tests, pretreatment costs and extra medication costs to be considered.

Current research on immunotherapy

A recent Indian study on immunotherapy found that an immunotherapy drug named nivolumab treated patients with head and neck cancer with a lower dose. The dose of 6% is generally used in the US and Europe making it comparatively cost effective.

Exploring newer checkpoint inhibitors: ongoing research focuses on PD-1 and PDL-1. The discovery of novel inhibitors and an understanding of the mechanisms behind resistance can be groundbreaking therapies.

Development of cancer vaccines: helps the immune system to attack the cancer cells making them an emerging treatment that is getting more attention over the years.

Drug delivery system: prodrug delivery system, biomimetic and nanoparticle associated cell membrane delivery means to have a promising synergistic effect when given along with primary chemotherapy or radiation therapy. These are believed to have lesser off-target effects.

Conclusion:

Immunotherapy is a field that is rapidly advancing, however, the search for more patient-friendly therapies is ongoing. While immunotherapy has its advantages and disadvantages, it is a targeted alternative to traditional chemotherapy treatments. Each class of immunotherapy drugs offers a unique mechanism of action, with distinct treatment plans for different diseases and patient populations. Immunotherapy has made remarkable progress, but there are still challenges that need to be addressed. These challenges include managing the side effects of treatment, optimizing treatment combinations, and ensuring that all patients have access to affordable treatments. Researchers are continuing their efforts to improve our understanding of immunotherapy and to enhance treatment outcomes.