Biological drugs, often known as biologics, are a sophisticated class of medicines derived from living organisms like microorganisms, plant, or animal cells. They are composed of intricate molecules such as proteins, sugars, DNA, or even living tissues. Their origin from natural biological processes makes them advanced therapeutic options.
Manufacturing and Composition of Biological Drugs
Biological drugs are large, complex molecules, often proteins. They are much larger and more complex than traditional small-molecule drugs, which are simple chemical compounds. For instance, a small-molecule drug like aspirin might consist of around 21 atoms, whereas a biologic can be comprised of over 25,000 atoms, akin to comparing a bicycle to a sophisticated airplane in terms of complexity and scale.
The creation of biologics involves biomanufacturing processes, utilizing living organisms such as bacteria, yeast, or mammalian cells. Scientists engineer specific cells, like E. coli or Chinese hamster ovary (CHO) cells, by inserting a gene that instructs them to produce a desired protein. These engineered cells are then cultivated in highly controlled environments within large bioreactors, some capable of holding up to 20,000 liters.
Maintaining precise conditions, including temperature, pH, nutrient levels, and oxygen concentration, is important during this growth phase to ensure the cells thrive and produce the intended protein. Once produced, the protein is extracted and purified. Various filtering technologies are employed to isolate the desired molecules based on their size, molecular weight, and electrical charge, removing any remaining cellular material or contaminants.
Because biologics are derived from living systems, their manufacturing processes result in slight batch variations, making exact replication impossible. This contrasts with small-molecule drugs, which are chemically synthesized to be precisely replicated. The demanding nature of these biological processes contributes to the higher complexity and cost associated with producing biologic medications compared to conventional pharmaceuticals.
Therapeutic Applications
Biological drugs offer targeted approaches for numerous diseases, particularly those challenging to treat with conventional medications. These therapies often function by interacting with specific components of the immune system or cellular pathways involved in disease progression. This targeted action helps modulate the body’s natural responses, leading to improved outcomes for many patients.
One primary area where biologics demonstrate impact is in the management of autoimmune disorders. Conditions such as rheumatoid arthritis, psoriasis, Crohn’s disease, ulcerative colitis, and multiple sclerosis benefit from these treatments. For instance, certain biologics, known as monoclonal antibodies, bind to specific proteins or cells within the immune system, reducing inflammation or preventing immune responses that damage healthy tissues. Tumor necrosis factor (TNF) inhibitors, a type of biologic, block an inflammatory protein called TNF to alleviate symptoms.
Biologics also play an important role in cancer treatment. They are employed to combat various types of cancers, including solid tumors and blood cancers. Some biologics work as immunotherapies, empowering the body’s own immune system to recognize and destroy cancer cells. Additionally, growth factor biologics, such as G-CSF, can stimulate the production of white blood cells, assisting patients in recovering from chemotherapy or radiation side effects.
Beyond autoimmune conditions and cancer, biologics treat metabolic diseases, with insulin being a long-standing example for managing diabetes. Insulin, a recombinant protein, helps regulate blood sugar levels. Other applications extend to conditions like anemia, growth hormone deficiency, and the prevention of infectious diseases through vaccines, which are also classified as biologics.
Administration of Biologics
Unlike many conventional medications, most biological drugs cannot be taken orally. This is because biologics are large, complex protein structures that would be broken down by the digestive system if ingested. Their delicate nature also makes them sensitive to heat and susceptible to microbial contamination.
To ensure the medication remains intact and effective, biologics are primarily administered through injections or intravenous (IV) infusions. Subcutaneous injections, given just under the skin, are a common method some patients can learn to perform at home using prefilled syringes or autoinjectors. This allows for convenience and flexibility in their treatment regimen.
Alternatively, some biologics are delivered via intravenous infusion, where the medication is slowly dripped directly into a vein. This method requires administration in a healthcare setting, such as a doctor’s office or clinic, under medical supervision. Both injection and infusion methods ensure the biologic reaches the bloodstream directly, allowing it to exert its intended therapeutic action without degradation.
Understanding Biosimilars
A biosimilar is a biological product highly comparable to an approved original biologic (reference product). Regulatory agencies ensure there are no clinically meaningful differences between a biosimilar and its reference product concerning safety, purity, and potency. This means patients can expect the same treatment benefits and risks from a biosimilar as from the original medication.
Unlike generic drugs, which are exact chemical duplicates of small-molecule medications, biosimilars are not identical copies. This distinction arises because biologics are manufactured using complex living systems, making exact replication impossible. Even different batches of the original biologic can have minor variations due to their biological origin.
To gain approval, biosimilars undergo a stringent regulatory review process by bodies such as the U.S. Food and Drug Administration (FDA). This process includes extensive analytical studies and clinical trials comparing the biosimilar directly to the reference product. The goal is to demonstrate that the biosimilar is just as safe and effective, providing equivalent therapeutic outcomes. The availability of biosimilars can also offer more affordable treatment options, potentially broadening patient access to these advanced therapies.