Like Life?

A word I hear every few weeks at chemotherapy is Neulasta. I looked it up since I was being given an injection each time I heard the word. I went directly to the manufacturer’s website at https://www.neulasta.com/learn-about-neulasta/ to find out just what it was:

“Neulasta^® is a prescription medicine used to help reduce the chance of infection due to a low white blood cell count, in people with certain types of cancer (non-myeloid), who receive anti-cancer medicines (chemotherapy) that can cause fever and low blood cell count.”

But then I needed to define ‘non-myeloid’ for myself. No problem. I called up my old standby The Merriam-Webster Dictionary at https://www.merriam-webster.com/medical/nonmyeloid:

“not being, involving, or affecting bone marrow”

Okay, got it. Neulasta reduces low white blood cell count infection in cancer that doesn’t affect the bone marrow. By the way, this is accomplished by forcing white blood cells – the infection fighting blood cells – to mature quickly.

No sooner did I get that straight in my mind than I started hearing a different word: Udenyca. It turned out that Udenya is a biosimilar for Neulasta. Now we get to the meat of the matter.

Just what is a biosimilar? I took a former English teacher’s stab at the definition and decided it meant ‘like life.’ But does it? The Free Medical Dictionary at https://medical-dictionary.thefreedictionary.com/biosimilarity helped us out here:

“biosimilar

(bī′ō-sĭm′ə-lər)

adj.

Highly similar in function and effect to an existing biological product,

especially to a biologic that has al-ready been clinically tested and approved for use.

n.

A biological product that is biosimilar to an existing product,

especially to a biologic”

Keep in mind that an adjective (adj.) describes a noun, while a noun (n.) is a person, place, thing, or idea.

Frankly, I didn’t find this very helpful. So I did what I considered the logical thing and looked to the Food and Drug Administration (FDA) website at https://www.fda.gov/media/108905/download for more explanation:

“A biosimilar is a biological product

FDA-approved biosimilars have been compared to an FDA-approved biologic, known as the reference product. Reference and biosimilar products are:

Large and generally complex molecules

Produced from living organisms

Carefully monitored to ensure consistent quality

Meet FDA’s rigorous standards for approval

Are manufactured in FDA-licensed facilities

Are tracked as part of post-market surveillance to ensure continued safety

A biosimilar is highly similar to a reference product

For approval, the structure and function of an approved biosimilar were compared to a reference product, looking at key characteristics such as:

Purity

Molecular structure

Bioactivity

The data from these comparisons must show that the biosimilar is highly similar to the reference product.

A biosimilar has no clinically meaningful differences from a reference product

Studies were performed to show that biosimilars have no clinically meaningful differences in safety, purity or potency (safety and effectiveness) compared to the reference product:

Pharmacokinetic and, if needed, armacodynamic studies

Immunogenicity assessment

Additional clinical studies as needed

Studies may be done independently or combined.

A biosimilar is approved by FDA after rigorous evaluation and testing by the applicant

Prescribers and patients should have no concerns about using these medications instead of reference products because biosimilars:

Meet FDA’s rigorous standards for approval

Are manufactured in FDA-licensed facilities

Are tracked as part of post-market surveillance to ensure continued safety”

Okay! Now we’re talking. Pretty simple to understand, isn’t it? Well, maybe there’s a word or three we might need defined. Let’s take another look. These two definitions are from Dictionary.com.

“Pharmacokinetic – the branch of pharmacology that studies the fate of pharmacological substances in thebody, as their absorption, distribution, metabolism, and elimination.

Immunogenicity – causing or capable of producing an immune response.”

Wikipedia offered this interesting difference between Pharmacokinetic and Pharmacodynamics.

“Pharmacodynamics is the study of how a drug affects an organism, whereas pharmacokinetics is the study of how the organism affects the drug. Both together influence dosing, benefit, and adverse effects.”

The point here is that the synthetic drug and biosimilars are not the same. Maybe my guess at their definition is far off the mark.  And lest you’re beginning to think this is a cancer blog rather than a Chronic Kidney Disease blog, biosimilars are used in CKD, too.

This snippet from the Clinical Journal of the American Society of Nephrology (CJASN) at https://cjasn.asnjournals.org/content/early/2018/08/03/CJN.01980218 will give you the idea:

“Most recognizable to nephrologists is the biologic recombinant human erythropoietin (rHuEPO). Considerably more expensive to develop and produce, biologics are more structurally complex than small-molecule drugs. By 2020, biologics will constitute an estimated 27% of spending on worldwide pharmacologics.”

Remember erythropoietin, more commonly known among CKD patients as epo? Not to worry; MedicineNet at https://www.medicinenet.com/erythropoietin/article.htm will remind us:

“Erythropoietin (EPO) is a hormone produced by the kidney that promotes the formation of red blood cells by the bone marrow. The kidney cells that make erythropoietin are sensitive to low oxygen levels in the blood that travels through the kidney.”

Un-oh, I almost forgot to explain the difference between biosimilars and biologics. According to the Congressional Research Service at https://fas.org/sgp/crs/misc/R44620.pdf:

“A biological product, or biologic, is a preparation, such as a drug or a vaccine, that is made from living organisms. Compared with conventional chemical drugs, biologics are relatively large and complex molecules. They may be composed of proteins (and/or their constituent amino acids), carbohydrates (such as sugars), nucleic acids (such as DNA), or combinations of these substances.

Biologics may also be cells or tissues used in transplantation. A biosimilar, sometimes referred to as a follow-on biologic, is a therapeutic drug that is highly similar but not structurally identical, to a brand-name biologic (i.e., the reference product). This is in contrast to a generic chemical drug, which is an exact copy of a brand-name chemical drug (i.e., the reference listed drug). Because biologics are more complex than chemical drugs, both in composition and method of manufacture, biosimilars will not be exact replicas of the brand-name product, but may instead be shown to be highly similar. However, for many years, the drug industry and the Food and Drug Administration (FDA) have coped with the inherent variability in biological products from natural sources. FDA maintains that the batch-to-batch and lot-to-lot variability that occurs for both brand-name biologics and biosimilars can be assessed and managed effectively.”

Hmmm, looks like I’ve made a fairly simple concept terribly complex.

Until next week,

Keep living your life!