Novartis has entered into an agreement to acquire Excellergy, Inc., a private US-based biotech developing next-generation anti-IgE therapies, for up to USD 2 billion in upfront and milestone payments. The Novartis Excellergy acquisition reinforces the company's immunology strategy by adding a differentiated Phase I asset, Exl-111, designed to address limitations of existing anti-IgE approaches across multiple IgE-driven diseases.
Deal terms
The total consideration of up to USD 2 billion encompasses both upfront cash and contingent milestone payments, though the split between guaranteed and performance-linked components was not disclosed. The transaction is expected to close in H2 2026, subject to customary closing conditions including regulatory approvals. As a full company acquisition, the deal confers worldwide rights to Exl-111 and Excellergy's broader platform, with no geographic carve-outs disclosed.
Exl-111 and the trifunctional ECRI platform
The deal is driven by Exl-111, a half-life extended, high-affinity anti-IgE monoclonal antibody classified as a trifunctional allergic Effector Cell Response Inhibitor (ECRI). Conventional anti-IgE therapy, exemplified by omalizumab (Xolair), primarily neutralizes free circulating IgE. Exl-111 operates through a distinct trifunctional mechanism: it dissociates IgE already bound to the high-affinity receptor FcεRIα on mast cells and basophils, drives downregulation of FcεRIα itself, and sustains suppression of IgE re-binding — all without triggering effector-cell degranulation.
Preclinical data presented at the 2026 AAAAI Annual Meeting demonstrated that Exl-111 dissociated receptor-bound IgE from human-donor whole-blood basophils in under 24 hours at tested concentrations. In primate studies, the antibody achieved rapid and near-complete removal of receptor-bound IgE from basophils, exceeding 99% clearance, while driving substantial FcεRIα downregulation. Early human pharmacokinetic data from the ongoing Phase I DISARM trial, in which first subjects were dosed in February 2026, showed sustained exposure consistent with the molecule's half-life extended design.