Biosimilar drugs are used as cost-effective alternatives to their reference biologic medicines. They are highly similar to the original biologic products in terms of safety and efficacy. Biosimilars help increase patient access to essential treatments while offering potential cost savings in healthcare systems.

Biosimilar drugs, or biosimilar, is a medicine that is very close in structure and function to a biologic drug.

Biologic drugs are proteins made by living organisms such as yeast, bacteria, or animal cells, whereas traditional drugs are chemicals, referred to as small molecules. Biologic drugs are much larger than "small-molecule drugs" like aspirin. Familiar biologic drugs include widely prescribed therapies like etanercept (Enbrel), infliximab (Remicade), adalimumab (Humira), and others.

Biologic drugs act in a variety of ways. Depending on the drug, it may:-

• Stimulate the body's immune system to detect and destroy cancer cells more effectively.
• Work against specific proteins in or on cancer cells to limit their growth.
• Strengthen the immune system by stimulating it.

Biologic medicines used in cancer treatment include immunotherapy and targeted therapy therapies.

One or more biosimilars are available for some brand-name biologic drugs. A biosimilar medicine has a structure that is similar to, but not identical to, that of a brand-name biologic drug. A biosimilar reacts similarly to its brand-name biologic in such a way that there are "no significant differences." This indicates the biosimilar medicine is just as safe and effective as the biologic drug. Both are derived from biological systems.

All biosimilars are prescription drugs. You cannot get them without your health care professional's prescription.

SO ARE BIOSIMILARS GENERIC DRUGS?

You've probably heard about generic medicines. A generic drug is a copy of a brand-name drug. These function in the same way and can be used in the same ways as their brand-name drugs. In other words, a generic drug is an equal substitute for its brand-name drug and can be used to treat the same condition.

You can think of biosimilars as sort of like generic drugs. But this is technically not true, since biosimilars are not completely identical copies of their reference drugs.

Here are some similarities between the biosimilar and generic drugs:-

(a) In clinical studies, both are evaluated and compared to a brand-name drug.

(b) The brand-name drugs against which they are being tested have previously been approved by the Food and Drug Administration (FDA).

(c) When compared to brand-name drugs, both go through a thorough but shortened FDA review process.

(d) They are both safe and effective as their brand-name drugs.

(e) Both may be less expensive treatment options than their brand-name drugs.

Here are some differences between the biosimilar and generic drugs:-

(a) A biosimilar is produced from a biologic (natural) source, whereas a generic is made using chemicals.

(b) A biosimilar is derived from the same natural source as its brand name biologic drug and is comparable in certain aspects, whereas a generic is an identical chemical copy of its brand name drug.

(c) The FDA usually requires more information from studies comparing a biosimilar to its original biologic than from studies on generic drugs. This is because a biosimilar is derived from a natural source and cannot be manufactured as an identical copy of the brand-name drug.

(d) Biosimilars and generic drugs are approved by the FDA in different ways.

All of these significant differences are due to the way by which biologic (and biosimilar) drugs are manufactured in the laboratory utilizing a natural source (a living system such as yeast, bacteria, or animal cells).

ARE BIOSIMILARS SAFE?

Like other drugs, a biosimilar requires to be tested in clinical trials and approved by the FDA before it can be utilized to treat a disease. In clinical trials, the biosimilar is compared to its original biologic drug, which was developed first. The original biologic is a brand-name drug that has already passed through clinical trials, has been approved, and is being utilized to treat a disease. Clinical trials are needed to test if the biosimilar is safe and effective to treat the same disease as the brand-name biologic drug.

The clinical trials that test all drugs are thorough and strict. But the clinical trials that test a biosimilar can move along faster than the clinical trials that were required of the brand-name biologic drug when it was being tested. During the studies on the biosimilar, testing is done to be sure it is the same as the brand name drug in certain ways. Testing needs to show that both drugs:-

(a) Are derived from the same source

(b) Have the same dose and strength

(c) Are administered to patients in the same manner (for example, via mouth)

(d) Have the same benefits in the treatment of a disease

(e) Possess the same possible side effects

The FDA carefully reviews the study data to ensure that the biosimilar is equally as safe and effective as the brand-name drug.

A biosimilar medicine is tested in clinical trials to ensure that it is safe for human usage. If the FDA approves a biosimilar drug, it implies it has met the FDA's strict safety standards.

WHAT IS THE REASON FOR THE DEVELOPMENT OF BIOSIMILAR DRUGS?

Because biologic drugs are expensive to study and manufacture, they are usually very expensive. Their high cost often makes it difficult for people to utilize them, even if they are the best therapy for a condition. The Biologics Price Competition and Innovation Act were approved by Congress to make biologic drugs more affordable and accessible to more people. This act allows the FDA to shorten the approval process of biosimilar drugs.

Researchers and Congress think one benefit to biosimilar drugs is that they might lead to lower drug costs by allowing patients more options for treatment. Some experts have estimated that biosimilar drugs could decrease the cost of biologics over time by many billions of dollars. But this depends on how many biosimilar drugs are tested, certified, and become available. It also depends on what types of diseases can be treated with biosimilar drugs and how much the approved drugs are used.

HOW ARE BIOSIMILARS BEING UTILIZED FOR CANCER TREATMENT?

Many biologic drugs, such as targeted or immunotherapy drugs, are currently utilized to treat cancer, and biosimilar versions of some of these are accessible. Some biosimilar medicines have been approved to treat certain forms of cancer, and others to minimize adverse effects.

The number of biosimilar medicines approved to treat cancer is expected to rise in the coming years. Many experts feel that increasing the availability of biosimilar medicines would reduce the cost of treating some malignancies.

Some insurance companies will pay the cost of a biosimilar medication or a part of the cost. Others may not. If a biosimilar medication is a treatment choice for you, you must consult with your insurance company.

WHAT KINDS OF BIOSIMILAR ARE USED TO TREAT CANCER?

In the United States, FDA-approved biosimilars can be used to treat breast cancer, colorectal cancer, stomach cancer, and other cancers. They can also be used to treat side effects of cancer treatments, such as low white blood cell counts that increase the risk of infections.

Below are some of the cancer-related biosimilars currently approved in the United States.

• In March 2015, the FDA approved the first biosimilar, called filgrastim-sndz (Zarxio). It is a biosimilar that assists your body fight infection. Filgrastim-sndz stimulates the body to make white blood cells. People with cancer who receive chemotherapy, bone marrow transplants, and other treatments can usually have low levels of white blood cells. Filgrastim-sndz's reference drug is named as filgrastim (Neupogen). Filgrastim-aafi (Nivestym) is another FDA-approved biosimilar to filgrastim.
• In September 2017, the FDA approved bevacizumab-awwb (Mvasi) as the first biosimilar to treat cancer. Bevacizumab-awwb treats certain colorectal, lung, brain, kidney, and cervical cancers. Its reference drug is called bevacizumab (Avastin). Bevacizumab-bvzr (Zirabev) is another FDA-approved biosimilar to bevacizumab.
• From 2017 to 2019, the FDA approved trastuzumab-dkst (Ogivri), trastuzumab-anns (Kanjinti), trastuzumab-pkrb (Herzuma), trastuzumab-dttb (Ontruzant), and trastuzumab-qyyp (Trazimera), which are biosimilars that treat certain breast and stomach cancers. Their reference drug is trastuzumab (Herceptin).
• From 2018 to 2019, the FDA approved pegfilgrastim-jmdb (Fulphila), pegfilgrastim-cbqv (Udenyca), and pegfilgrastim-bmez (Ziextenzo), which are biosimilars that assist fight infection, specifically in people with non-myeloid cancer treated with chemotherapy. Their reference drug is pegfilgrastim (Neulasta).
• In November 2018, the FDA approved rituximab-abbs (Truxima) as the first biosimilar to treat people with non-Hodgkin lymphoma. Its reference drug is rituximab (Rituxan). Rituximab-pvvr (Ruxience) is another FDA-approved biosimilar to rituximab.