An Update on New Treatments for Asthma
Asthma is a common health condition affecting 1 in 12 adults and 1 in 10 children. The incidence of asthma is in fact increasing. While many patients can be managed with traditional treatments, 5-10% of patients do not respond to such therapy. Fortunately, research has led to the development of other treatments that have proven to be life-changing. Below is a short summary regarding some of the newer treatments for uncontrolled asthma. Of course, these treatments are not indicated for everyone and we would recommend consulting your Allergy Partners physician for more information to see if one of these medications is right for you. Ultimately, the right treatment should be able to control your asthma so that it does not interfere with your life. Many Olympians in fact have asthma which goes to show that when asthma is controlled with the right medications, it should never limit one’s activities.
IgE is a type of antibody that causes allergic reactions including asthma. A medication called Xolair binds to IgE and inhibits the activation of allergy-type cells. Xolair is indicated for patients 6 years and older with allergies and uncontrolled asthma. It is also approved for the treatment of another condition with chronic, daily hives. In regards to asthma, Xolair has been shown to decrease the risk of asthma attacks and improve quality of life. It is administered as an injection every 2-4 weeks, and the most serious adverse effect (though very rare) is a life-threatening allergic reaction. Hence, Xolair must be administered in a healthcare setting for close observation.
Anti-IL5: Nucala, Cinqair and Benralizumab
Eosinophils (a specific type of allergy-related cell) are not normally present in healthy lungs, but they can be present in a small group of asthma patients that sometimes do not respond to typical treatments. Upon activation, these cells release signals that promote inflammation and asthma attacks. Nucala and Cinqair are the newest approved medications and inactivate IL5 which is critical for the survival of eosinophils.
Nucala was approved in 11/2015 for patients aged 12 years and older with uncontrolled asthma and elevated eosinophil counts. Nucala causes a decrease in eosinophils and subsequently a decrease in airway inflammation leading to less asthma attacks and improved quality of life. Like Xolair, Nucala is administered as an injection every 4 weeks.
Cinqair was approved in 03/2016 for patients 18 years and older with uncontrolled asthma and elevated eosinophil counts. While Cinqair has similar effects compared to Nucala, Cinqair is an IV infusion. There is a small risk of developing an allergic reaction to both Nucala and Cinqair, and thus both need to be administered in a healthcare setting for proper observation.
While Nucala and Cinqair bind to IL5 and block its effects, Benralizumab binds to the IL5 signal receptor on eosinophils subsequently inducing death in these cells. Initial Benralizumab trials have been promising, and it could be approved for asthma as soon as this fall.
Anti-IL4 and Anti-IL13: Dupixent
Dupixent blocks the receptor of two cell signals (IL4 and IL13) that promote inflammation and allergic responses similar to IL5 as above. Early studies with Dupixent for the treatment of asthma were very promising. While not officially approved for asthma quite yet, Dupixent was approved in 03/2017 for the treatment of adult patients with allergic eczema. It is a self-administered injection given every other week. The results of additional asthma studies are said to be forthcoming.
A mast cell is a type of white blood cell that is part of the immune system, and it contains many granules that are rich in histamine and several other chemicals. Mast cells are best known for their role in allergic reactions which are initiated by allergens cross-linking high-affinity IgE receptors on their surface. This leads to the release of histamine which typically leads to hives, swelling, hypotension (low blood pressure), bronchospasm with symptom of cough, wheeze and chest tightness, and digestive problems such as diarrhea and vomiting. However, mast cells can cause problems outside of classic allergic reactions as well.
One of the mast cell diseases is mastocytosis, which is characterized by the overproduction of mast cells and CD34+ mast cell precursors. People affected by mastocytosis are susceptible to itching, hives, and anaphylactic shock, caused by the release of histamine from the abundant mast cells. Most cases of mastocytosis are localized to skin, or cutaneous. The most common form of this cutaneous mastocytosis is called urticaria pigmentosa. Urticaria pigmentosa can be diagnosed by identifying dark brown and fixed lesions that forms a hive (or urticates) when scratched. However, urticaria pigmentosa can evolve into systemic mastocytosis which involves the bone marrow and other rare mast cell diseases, such as mast cell leukemia and mast cell sarcoma.
A blood test called a serum tryptase level is the initial screening test for suspected systemic mastocytosis. To confirm the diagnosis a biopsy of the bone marrow or the affected organ to identify an increased numbers of mast cells is needed. There is currently no cure for mastocytosis, but the symptoms are alleviated by a number of medications, such as antihistamines, leukotriene blockers, mast cell stablilizers, corticosteroids, and epinephrine. Other medications that have been used in mastocytosis include proton pump inhibitors to reduce the increased gastric acid production, bronchodilators like Albuterol to reverse bronchoconstriction, calcium channel blockers to reduce mast cell degranulation, and chemotherapy or Gleevec in severe systemic disease.
Another mast cell disorder is mast cell activation syndrome (MCAS) which is characterized by the same symptoms as mastocytosis. In MCAS, however, there is a normal number of mast cells which are defined as “hyperresponsive.” Named as a new diagnosis as recently as 2007, MCAS is often found in patients with Ehlers-Danlos syndrome, postural orthostatic tachycardia syndrome, and idiopathic anaphylaxis. Symptoms can be caused or worsened by triggers such as specific foods and drinks (especially alcohol), temperature extremes, exercise, and emotional stress. Diagnosis of MCAS is often difficult, but laboratory evidence of elevated mast cell mediators such as N-methyl histamine and prostaglandin D2 is helpful, as is a good response to the same drugs used in mastocytosis.
Although rare, mast cell disorders mimic the symptoms of severe allergic reactions and anaphylaxis. Allergy Partners’ board certified Allergist-Immunologists are specialty trained in the diagnosis and treatment of both anaphylaxis and mast cell disorders. To learn more, visits www.allergypartners.com or contact your trusted Allergy Partners physician.
Dr. Sol Drapkin,
Allergy Partners of Chicago