Imagine having a disease in which you constantly feel like you are struggling to breathe. Imagine feeling like you’ve just run a marathon and your only source of air is through a tiny cocktail straw while an NFL linebacker is giving you a bearhug. What if the only medications that your doctor can come up with don’t seem to work anymore, and you dread going to bed because you know it’s going to be another sleepless night? How would you feel not knowing whether or not you would be able to go to work in the morning or if you would be stuck in an emergency department for the sixth time this year? For patients with severe asthma, this nightmare is their reality. Fortunately for them, there are some new treatment options that may offer them a new hope.
Most people with asthma can’t relate to this scenario because they are on appropriate medications to control their symptoms. It’s those who are on the end of the spectrum for asthma severity where nothing seems to work who are all too familiar with this description. If they have tried and failed treatment with typical therapies such as inhaled steroids, long-acting bronchodilators, etc and still find themselves gasping for air and wheezing, they may benefit from newer medications that offer a more precise target to their asthma.
There are currently 3 drugs that have been approved to treat this type of asthma, and they all have difficult-to-pronounce, generic names and only slightly more user-friendly brand names. All 3 belong to a class of medications referred to as “biologics” because they are found naturally in biology. In other words, they aren’t the typical chemical compound cooked up in a traditional lab, but they use a part of the immune system (antibodies) that specifically target one aspect of cell signaling.
All 3 medications can reduce asthma exacerbations, but all 3 have to be given in a doctor’s office. Xolair (omalizumab is the generic name), pronounced “zole-air”, specifically targets IgE antibodies which are found in allergic asthma, and has been shown to improve the quality of life for patients with severe asthma. The other 2 biologics approved for severe asthma, Nucala (mepolizumab) and Cinqair (reslizumab) bind to a molecule known as IL-5. This molecule is known as a cytokine and is involved in increasing allergic inflammation. This particular cytokine is needed for cells in the immune system to talk other cells into making life difficult for patients with severe asthma. These new drugs act as the immune system’s parental controls to block those messages. When patients are placed on either of these medications, their lung function typically improves.
Think of a steroid injection as a shotgun blast (not very specific), and these biologic medications as a blow gun shot by a ninja. Sure, the shotgun may hit it’s target, but it also hits some other stuff around the target that’s not so good for the patient. This is why steroid injections and steroid pills (like prednisone) are associated with unintended side effects like brittle bones, stomach ulcers, cataracts, etc. This is the reason why so many doctors are cautious about prescribing steroids that easily enter the bloodstream such as injectable steroids or steroid pills (i.e. systematic steroids). Inhaled steroids, on the other hand, are considerably less problematic than the systemic steroids because most of the anti-inflammatory action stays in the target area (the lungs). When those inhaled steroids are not enough, it may be time to start calling in the ninjas and their blow guns.
Xolair and Nucala are given subcutaneously (i.e. the ninja just darts you in the back of the arm) either once or twice a month depending on the situation, whereas Cinqair requires the ninja to dart you in a blood vessel (i.e. it is given intravenously) once a month. Other ninja weapons that are still not yet approved to be used in US will target other cytokines involved in allergic inflammation or transcription factors in the cells that provide the mRNA “recipe” for making some of the cytokines.
Biologic medications are not the answer to all of our problems in asthma. They are expensive, and they require several hoops to jump through (i.e. paperwork) in order for them to be approved by insurance. Even though none of these medications are likely to cure allergy or asthma anytime soon, at least there is hope for patients who have been hopeless for so long.
Biologic Therapy and Novel Molecular Targets of Severe Asthma
Pepper, Amber N. et al.
The Journal of Allergy and Clinical Immunology: In Practice , Volume 5 , Issue 4 , 909 – 916