New Delhi: The US Food and Drug Administration (FDA) has approved Omalizumab, which is sold under the brand name Xolair, to treat severe food allergies — making it the first drug to get regulatory approval for the indication.
In a statement released last week, the US FDA said that the approval for Xolair injection was for food allergy in certain adults and children one year or older. It can reduce allergic reactions, including the risk of anaphylaxis — a life-threatening condition that may occur with accidental exposure to one or more foods.
The drug is not intended for use during an allergic reaction, but is designed to be taken repeatedly every few weeks to help reduce the risk of reactions over time, it said.
The FDA, however, clarified that people taking the medication should continue to avoid foods they are allergic to.
Currently, there is no cure for food allergy, said the FDA, adding that the existing treatment requires strict avoidance of the food the patient is allergic to, and prompt administration of epinephrine — a hormone and a neurotransmitter — to treat anaphylaxis in case of accidental exposures.
However, in certain cases, like peanut allergy, an allergen powder, palforzia — an oral immunotherapy product — has been approved in patients aged 4-17 years for the mitigation of allergic reactions, including anaphylaxis, that may occur with accidental exposure to peanuts, but its benefits are restricted only to peanut allergy.
Xolair, on the other hand, is the first FDA-approved medication to reduce allergic reactions to more than one type of food after accidental exposure.
It was originally approved in 2003 for the treatment of moderate to severe persistent allergic asthma in certain patients. It was also approved to treat chronic spontaneous urticaria (hives) and chronic rhinosinusitis with nasal polyps in certain patients.
It belongs to a class of medicines called monoclonal antibodies, which are laboratory-produced molecules designed to serve as substitute antibodies that can restore, enhance, modify, or mimic the immune system’s attack on unwanted cells in the body.
According to the Centers for Disease Control and Prevention (CDC) in the US, almost 6 percent of people in the country (US) in 2021 had a food allergy. This also included those exposed to a particular food, which can lead to anaphylaxis.
Speaking to ThePrint, gastroenterologist and medical researcher Dr Rajeev Jayadevan said, “The medication (Xolair) was already being used for certain cases of allergic asthma. By expanding its use to prevent food allergy, it provides one more weapon that protects people from the potentially devastating effects of food allergy.”
Jayadevan also highlighted a drawback of the drug stating that “it is expensive and requires monthly injections for a long time.” In the US, the cost of the drug is about $2,900 (Rs 2,40,263) per month for children and $5,000 (Rs 4,14,248) for adults, though it can be covered under insurance.
How the medicine works
Xolair works by binding to a type of antibody called immunoglobulin E or IgE, which triggers allergic reactions. By blocking IgE from attaching to its receptors, Xolair prevents the release of chemicals that cause allergic reactions.
Jayadevan explained that IgE-type of antibodies are released from memory B cells stored inside the body for the long term.
Xolair, the doctor said, works by binding to IgE antibodies in the bloodstream — preventing it from attaching to cells and triggering the allergic response.
According to him, a higher number of people having food allergies in countries like the US compared to India is due to less antigen exposure. An antigen is a substance that prompts the immune system to produce antibodies.
A 2020 study by the Lancet Global Health had estimated that only 0.14 percent of the children aged 6-11 years in India had food allergies. There was no reliable estimate of adults with food allergies in India.
“The hygiene hypothesis says that in countries which are too clean and where young children are given more processed food, kids are not exposed to the large variety of antigens our children in India are exposed to,” Jayadevan explained. “Thus when select allergens like peanuts are first encountered, the body decides it is something dangerous, mainly due to the high amount of protein it has and responds aggressively.”
Pros and cons of Xolair
The FDA has maintained that Xolair should only be started in a healthcare setting equipped to manage anaphylaxis, with a boxed warning for the condition, which can be life-threatening based on pre-marketing and post-marketing reports of anaphylaxis that occurred after Xolair administration.
The symptoms of anaphylaxis include a skin rash, itching, nausea, vomiting, difficulty breathing, wheezing, and shock — and it needs immediate medical care.
For selected patients who can tolerate initial Xolair treatments in a healthcare setting without anaphylaxis, self-administration or administration by a caregiver may be appropriate and should be discussed with a healthcare provider, the FDA said.
A study in 2022-23 showed that Xolair was safe and effective in lowering allergic reactions in people with food allergies. The study involved 168 children and adults who were at least one year old and had peanut allergy and two or more other food allergies, such as milk, egg, wheat, cashew, hazelnut or walnut. The study was multi-center, double-blind and placebo-controlled.
Researchers randomly gave subjects either Xolair or placebo treatment for 16 to 20 weeks.
The primary measure of Xolair’s efficacy was the percentage of subjects who were able to eat a single dose of peanut protein without moderate to severe allergic symptoms, such as moderate to severe skin, respiratory, or gastrointestinal symptoms, at the end of the 16-to-20-week treatment course.
Of those who received Xolair, 68 percent were able to eat the single dose of peanut protein without moderate to severe allergic symptoms, compared to 6 percent who received a placebo.
“These results are statistically significant and clinically meaningful for subjects with food allergy,” the FDA noted. Similar results were seen for those with allergies against cashew, milk, egg, wheat, cashew, hazelnut, or walnut, it added.
As a result, Xolair treatment is approved for certain patients with one or more IgE-mediated food allergies, the FDA said.
It added that the most common side effects of Xolair observed included injection site reactions and fever, but the drug comes with certain warnings and precautions, such as anaphylaxis, malignancy, fever, joint pain, rash, parasitic infection and abnormal laboratory tests.
Dr Sudarshan Reddy, senior consultant physician with Yashoda Hospitals in Hyderabad, said that in many patients on the drug, it can cause joint pains, itching, rashes, dizziness, lethargy and headaches apart from fever.
“Apart from these side effects, it can be used safely in people aged above 6 years,” he told ThePrint.
(Edited by Richa Mishra)
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