What are generic drugs and biosimilars?
My patient has been on a pill to treat her Breast Cancer for 2 years. She goes to the pharmacy to fill her next month’s supply, and is given a bottle with a different name on the label. My office gets a frantic phone call that they gave her the wrong drug. Several phone calls later, we are able to assure her that the new refill contains a generic compound that is identical to the brand name drug she has been taking. Switching to the generic will not affect the efficacy, and will save her money.
Drug development companies develop new drugs to treat diseases. Sometimes they produce a drug by designing the structure of the chemical for a specific purpose. Sometimes they test a vast array of products in test tube cells and laboratory animals to see if there is any benefit, then isolate the active principle, manufacture it for safety and efficacy in humans. It then goes through serial clinical trials, and the Food and Drug Administration approval process. Sometimes the drug is approved; other times the company is asked to do more testing. Once approved, the company is given the right to market the drug under its brand name. The company patents the drug, and patent protection lasts for 20 years. They own exclusive rights to that drug. After 20 years, other companies can manufacture and market the drugs, which are not “branded”, but “generic”. Brand name drugs are given a 20-year head start to recover their investment in the drug’s development. Generic drugs are less expensive, because they have not invested the time and money to develop the drug. There is no difference in the active compound. Some people do say that they do not tolerate the generic drug as they do the brand name drug. A possible reason could be the binding agent or the capsule cover, but not the active drug.
I have had patients who had to switch back to brand name drugs, but that has been rare. Now, when we write prescriptions, we have to specifically sign for a brand name drug, when a generic is available, and justify the reason.
Other newer categories of drugs are different from the previously manufactured chemical drugs. These are biologic agents, e.g. antibodies, which act by modifying the body’s immune system. Others act through a cell’s receptors (or gateways to the cell’s internal signals) to modify a cell’s behavior. They can be used to modify the body’s immune system, or target stem cells, which manufacture blood cells. Generic equivalents are called bio-similars. They do have to undergo FDA approval for safety, efficacy, and show they are equal to the brand name agent. Again, they are less expensive than the brand name agent.
My patient is now completing her course of treatment with a generic agent, and has not suffered any ill effects.