Xolair, the first medication shown to help protect from allergic reactions to multiple food allergens, is about to have company.
A wave of Xolair biosimilars is headed for the U.S. market. The increased competition is expected to lower costs and expand access for families managing food allergies, asthma and other allergic conditions.
The Food and Drug Administration approved Omlyclo, the first Xolair biosimilar, in March 2025. Its manufacturer, Celltrion, expects to launch the drug in the United States in September 2026.
More competitors are already lining up. Amneal Pharmaceuticals submitted a Biologics License Application for its Xolair biosimilar in September 2025. Amneal is hopeful for a 2027 launch, according to their website.
Meanwhile, Teva Pharmaceuticals’ announced in March 2026 that the FDA is reviewing its biologics license application for another Xolair biosimilar.
Together, the arrivals signal a more competitive market for omalizumab, the biologic drug that Genentech and Novartis market under the Xolair name.
“As a biosimilar, we will have all the indications that the originator has, and we will be used in the same way,” says Thomas Nusbickel, Celltrion’s chief commercial officer. “The hope is by having a biosimilar, there will be the opportunity for good value care and perhaps expanded access for patients.”
The FDA approved omalizumab anti-IgE therapy over 20 years ago in asthma, then for other allergy-related conditions. In early 2024, the regulator expanded its approval of Xolair to food allergies. Allergists prescribe it to help reduce the chances of severe reactions to allergen exposures in patients ages one through adulthood.
Adoption of the injectable medicine as a food allergy treatment sparked big interest in an older drug. U.S. annual sales of Xolair climbed to a reported $4 billion at the end of July 2025.
What is a Xolair Biosimilar?
Like Xolair, Omlyclo and the other biosimilar hopefuls are biologic medications. These are made from living cells, rather than through traditional chemical manufacturing.
Xolair, for example, is a lab-made antibody that targets IgE antibodies, which drive allergic reactions. By binding to circulating IgE, Xolair prevents IgE from attaching to mast cells and triggering symptoms such as hives, itch, wheezing, swelling, and potentially anaphylaxis.
Like generic drugs, biosimilars must demonstrate the same effectiveness, potency and safety as the original.
But unlike generics, biosimilars aren’t exact copies. Rather, the FDA refers to them as “highly similar.” Whereas a generic drug like aspirin or ibuprofen can follow an exact chemical recipe of the original, biologics are derived from living cells. Small variations naturally occur.
“A biosimilar should be identical in terms of what the antibody does inside the body, but it’s being produced slightly differently,” says Dr. Brian Schroer, an allergist-immunologist at Ohio’s Cleveland Clinic.
Although Omlyclo is the first biosimilar approved for allergic conditions, biosimilars are already common in specialties such as in rheumatology, oncology and gastroenterology, says Dr. Kristin Sokol. She’s an allergist-immunologist with Schreiber Allergy in Rockville, Maryland.
According to the FDA, 76 biosimilars are currently approved in the United States. Celltrion, a South Korea-based company, has 11 FDA-approved biosimilars.
“Other specialties are very familiar with them,” Sokol says. “In allergy, we aren’t yet, but hopefully we will be. There is no clinically meaningful difference in the safety, the efficacy or the purity of the drug. But, they can’t be copied exactly.”
Interchangeable With Xolair
The FDA’s approval of omalizumab-igec, Omlyclo’s drug name, was based on a Phase 3 trial involving 619 adults with chronic spontaneous urticaria, or chronic hives. The study found comparable improvements in symptoms and safety between Omlyclo and Xolair.
Although the biosimilar wasn’t directly studied in food allergy or asthma, the FDA approved it for all Xolair indications through “extrapolation.” The approach allows a biosimilar to gain approval across multiple conditions when there is strong scientific evidence it will function the same way as the original.
Many biosimilars, including Omlyclo, are designated “interchangeable.” This means the pharmacist can substitute it for Xolair without a doctor’s approval.
Dr. Corinne Keet, an allergist-immunologist at University of North Carolina at Chapel Hill, said she’d be comfortable prescribing a biosimilar.
“They have been shown to not be different in a meaningful way from the approved medication,” says Keet. She was one of the researchers on the OUtMATCH trial that led to Xolair’s approval for food allergy.
Omlyclo, which is given by injection, will be available in a prefilled syringe at strengths of 75 and 150 milligrams (mg). The timing for a 300 mg prefilled syringe hasn’t been determined.
Biosimilar’s Rollout Begins
September 2026 is the earliest date Celltrion can launch Omlyclo in the United States under a legal settlement with Xolair manufacturers Genentech and Novartis.
Nusbickel says Celltrion representatives have been attending medical conferences and speaking with allergists and pulmonologists to familiarize them with the medication. “As the first biosimilar, we are anxious to make sure we take full advantage of that timing when we have access to the market,” he says.
Stacey Sturner, founder of the Food Allergy Treatment Talk Facebook group, said patient education will be critical. Families may worry about switching.
“My hunch is patients will want to stay on Xolair,” Sturner says. “Having a conversation with the patient about the biosimilar and why it’s essentially the same, so there isn’t that fear, is going to be really important.”
Other biosimilars may also face legal challenges in coming to market. Based on the results of the OUtMATCH trial, Genentech and Novartis were granted a new patent for using Xolair to treat food allergy that goes through 2043.
On May 26, 2026, Amneal and Kashiv BioSciences petitioned the U.S. Patent and Trademark Office to invalidate the food allergy use patent. (The previous settlement with Celltrion only includes the parties in that lawsuit).
Amneal and Kashiv argue that the new patent should never have been granted. They say clinical studies had established well before OUtMATCH that Xolair raises reaction thresholds and improves food allergen tolerance.
Will Costs Go Down?
Likely, yes, and almost definitely for insurers. Biosimilars are typically introduced at lower prices than the original, and competition tends to push down prices over time.
How much patients benefit, however, is complicated. Insurers negotiate prices with manufacturers and determine coverage. Pharmacy benefit managers and employers also influence what patients ultimately pay.
“The cost isn’t going to change overnight, but as biosimilars become more widespread and there are more options, that is going to improve affordability,” says Sokol. “We may also see broader insurance coverage and few restrictive policies.”
Biologics are among the most expensive drugs on the market. According to the FDA, biologics account for only about 5 percent of U.S. prescriptions but roughly 51 percent of total drug spending.
Xolair’s list price ranges from $30,000 to $60,000 per year. Many insured families pay far less. Some patients with commercial insurance pay nothing through a manufacturer co-pay assistance program.
Celltrion declined to disclose Omlyclo’s U.S. list price.
If biosimilars bring a drop in price, they could also help to expand access, Nusbickel says. As costs fall, insurers may be more willing to cover the drugs, with fewer restrictions, he says.
“With the cost going down due to the increased competition of biosimilars, the cost to the healthcare system and to patients should go down,” he says. “And potentially this may lead insurers to allow broader access to a therapy that they are restricting in some way.”
How is Xolair Access Now?
Physicians and patients say access to Xolair for food allergies remains inconsistent, with coverage rules varying among insurers.
Sokol has encountered insurance plans that required step therapy before approval. That isn’t really possible with food allergies, where food avoidance remains the main “treatment” strategy.
She’s also had insurers deny patients Xolair coverage because they were already undergoing oral immunotherapy (OIT). “For the majority of our patients, we can get [omalizumab] approved,” Sokol says. “Sometimes we have to stop OIT prior. If they want to start both at the same time, we have to tell them, ‘you may have to pay out of pocket for one of these.’”
Heidi Einsweiler’s Blue Cross Blue Shield plan for federal employees repeatedly denied coverage Xolair for her son Lukas Skerjan, 8, who has a peanut allergy.
Lukas had participated in OIT. But he continued to have symptoms after his peanut dose, and his tolerance threshold remained stubbornly low. Their allergist felt Xolair could ease symptoms and help him to continue OIT updosing.
But the insurer required criteria beyond the FDA approval – specifically, a peanut allergy plus two additional allergies. Those were the allergens tested in the Phase 3 OUtMATCH trial. Yet, the label states that Xolair is approved for protection from accidental exposure “to one or more foods.”
“I feel like they were trying to gatekeep this drug because it’s expensive,” says the Iowa mother and attorney.
Their allergist’s multiple appeals were denied. After the family switched insurance providers, Xolair was approved under the pharmacy benefit. But the first three shots are supposed to be administered in a doctor’s office in case of anaphylaxis. Approval for that under the medical benefit took several more frustrating months. Meanwhile, her son continued to have stomach pain and other symptoms after his peanut dose.
“It takes time, money and effort to navigate through this system and get your kid this drug they need,” Einsweiler says.
Efforts with Insurers
Schroer too has had success with appealing denials. He has seen insurers deny coverage until patients get blood tests showing certain IgE levels before approving treatment. By “making it harder to get, some patients and some clinicians just don’t put in the effort,” he says. “And therefore the company [insurer] doesn’t pay that money for that medication.”
Some allergists offices have hired biologics coordinators to deal with insurers.
Even with manufacturer co-pay programs, costs can remain a barrier, Schroer says. Xolair’s copay assistance caps at $15,000 annually. For many patients, this reduces costs to zero. But some families still face high deductibles or other out-of-pocket expenses.
Kylie McCardle struggled to get Xolair coverage for her son, Graham, a fourth grader with peanut, tree nut and sesame allergies. After multiple appeals through her Premera Blue Cross plan for Amazon employees, the injections were finally covered under the medical benefit. This requires monthly visits to an infusion clinic rather than home injections.
McCardle says it’s worth it. Her son was leaving for an overnight class trip. “I’m not worried if the chocolate in the s’mores is cross-contaminated anymore,” McCardle says. “It is such a better quality of life.”
Europe Offers Early Glimpse
The FDA has stepped up actions to simplify biosimilar studies with the intent of expediting approvals and bringing down health costs. Whether Xolair’s new and upcoming rivals will be among the biosimilars to have that effect will be seen in the year ahead.
The European Union and the United Kingdom, where Omlyclo has already launched, offer an early sense. Xolair still dominates. But since Omlyclo’s country-by-country rollout began in late 2025, the biosimilar accounted for nearly half of IgE-blocker prescriptions in Spain and 10 percent in Germany.
European approvals for Omlyclo cover allergic asthma, chronic spontaneous urticaria (hives) and chronic rhinosinusitis with nasal polyps. Neither Xolair nor Omlyclo is approved in Europe for food allergy.
Omlyclo was also approved in Canada in 2025 for the same indications as Europe. While it still represents only a small share of the Canadian market, Nusbickel expects it to grow.
Related Reading:
Xolair and OIT Comparable for Bringing Multiple Allergens into Diet
Microneedle Stamp for Peanut Allergy Launches Clinical Trial
