Yuhan says allergy drug candidate tops Novartis' Xolair, eyes blockbuster licensing deal

Yuhan Corp.’s experimental allergy drug, YH35324, has outperformed Novartis’ Xolair (omalizumab) in a phase 1b trial, demonstrating superior suppression of immunoglobulin E (IgE) and longer-lasting symptom control.

The findings, published in the February issue of the Journal of Allergy and Clinical Immunology, position YH35324 as a potential blockbuster—what one Yuhan official described as a “next Leclaza”—and a prime candidate for a major global licensing deal within the year.

“Now that phase 1b is complete, an announcement could come soon,” the Yuhan official said Thursday.  While he declined to name potential partners or disclose the status of discussions, he said Yuhan is seeking a deal that “not only generates revenue but also ensures the drug reaches patients worldwide.”

The company's 2024 revenue surpassed 2 trillion won ($1.4 billion), propelled by the success of its lung cancer drug Leclaza (lazertinib). The company is now positioning YH35324 as its next major asset.

YH35324, based on IgE Trap-Fc fusion protein technology, was originally developed by GI Innovation under the code name GI-301. Yuhan acquired its rights in 2020 through a 1.4 trillion won licensing deal, securing exclusive global rights except in Japan. 

Unlike Xolair, which is approved for allergic asthma, chronic idiopathic urticaria, and nasal polyps but not moderate-to-severe atopic dermatitis, YH35324’s mechanism suggests a broader treatment potential while minimizing the risk of anaphylaxis.

The phase 1b study focused on patients with chronic spontaneous urticaria (CSU) who had not responded to H1 antihistamines. It directly compared YH35324 to Xolair, the only approved IgE-targeting therapy for CSU. Results showed that patients receiving YH35324 at 6 mg/kg achieved the strongest IgE suppression and the longest duration of effect. 

Half of the patients in the 6 mg/kg YH35324 group reached complete symptom control (UAS7 = 0), compared to 16.7 percent in both the 3 mg/kg YH35324 group and the Xolair group. Additionally, 66.7 percent of the 6 mg/kg group achieved a well-controlled state (UAS7 ≤ 6), far exceeding Xolair’s performance.

The trial also confirmed a dose-dependent response: higher doses correlated with increased drug concentration in the blood and a more pronounced reduction in free IgE levels. Safety results were favorable—only five patients (27.8 percent) reported mild adverse events, with no serious or drug-related reactions recorded.

“One blockbuster isn’t enough,” the Yuhan official said. “To keep expanding, we need more than just Leclaza. That’s why we’re investing heavily in allergy treatments.”

Under its deal with GI Innovation, Yuhan will share revenue equally if a licensing agreement is secured.

The company is scheduled to present the Phase 1b trial results at the American Academy of Allergy, Asthma & Immunology (AAAAI) conference, which will be held from Feb. 25 to March 4 in Pennsylvania.