The Excellergy acquisition will complement Novartis’ existing allergy profile, anchored by the IgE blocker Xolair that in February 2024 was approved to treat food allergies in children and adults.
After buffing up its cancer pipeline last week, Novartis is now investing into its immunology portfolio by absorbing California-based Excellergy and its anti-IgE antibody for allergic conditions.
The acquisition agreement is valued at up to $2 billion, according to a news release on Friday, encompassing both upfront and milestone payments. Novartis did not provide a more detailed breakdown of its financial commitments. The companies expect to close the transaction in the second half of 2026.
The star of the takeover is Excellergy’s anti-IgE therapy Exl-111, a next-generation antibody therapy that, unlike medicines currently on the market, targets and removes IgE molecules that are already bound to receptors on immune cells. This mechanism, according to Excellergy’s website, prevents the activation of those receptors and thus the molecular cascade that would have otherwise resulted in an allergic response.
Additionally, by taking away bound IgE, Exl-111 also downregulates the expression of the corresponding receptors, which according to the biotech “reduces the re-sensitization potential.”
“Exl-111 is designed to go beyond conventional anti-IgE therapy, with the potential to deliver faster and deeper suppression of IgE signaling as well as improved symptom control,” Fiona Marshall, president of biomedical research at Novartis, said in a prepared statement.
Exl-111 is in an ongoing Phase 1, early pharmacokinetic data from which show signs of sustained drug exposure and “support a differentiated profile,” Novartis said on Friday. The pharma is looking to leverage Exl-111’s therapeutic potential for food allergy, chronic spontaneous urticaria, allergic asthma and other IgE-driven diseases.
Once in the Novartis fold, Exl-111 will run alongside Novartis’ other allergy assets, including the Roche-partnered Xolair, which was originally approved in 2003 for asthma but expanded in February 2024 to include use for allergic reactions, including anaphylaxis, in children and adults with IgE-mediated food allergies.
In March last year, head-to-head data from a Phase 3 trial showed that Xolair was better than oral immunotherapy at preventing allergic reactions in people with food allergies. Xolair made $1.72 billion in 2025.
Novartis is on a mission to build out its pipeline, with CEO Vas Narasimhan telling investors during the pharma’s 2025 earnings call that “there’s really no change in our M&A strategy.” That is, he continued, the company will continue to look for early-stage deals in the “sub-$2-billion range” while also seeking out “medicines that could launch in the next five years.”
In October 2025, the pharma scooped up Avidity Biosciences for roughly $12 billion—one of that year’s largest acquisition agreements. The purchase gave the pharma a host of late-stage RNA programs for a variety of neuromuscular indications, including Duchenne muscular dystrophy and myotonic dystrophy type 1.
Novartis has since followed that up with a series of smaller deals. These include a $1.5 billion bet in January with China’s SciNeuro for an anti-amyloid antibody for Alzheimer’s disease and a $1.7 billion cardio contract with Unnatural Products in February. Last week, the pharma snapped up a breast cancer drug from Synnovation Therapeutics for $2 billion upfront and up to $1 billion in milestones.
