lesigercept (GI-301) / GI Innovation, Yuhan Corp, Maruho - LARVOL DELTA

A multiple ascending dose, phase1b study to evaluate safety, tolerability, pharmacokinetics, and pharmacodynamics of lesigercept, a long-acting IgETrap-Fc fusion protein, in participants with atopy or allergic diseases. (PubMed, Int Immunopharmacol) - "Lesigercept exhibited favorable safety, predictable PK, and durable serum free IgE suppression after repeated dosing, supporting further clinical development."

Journal • P1 data • PK/PD data • Allergy • Atopic Dermatitis • Dermatitis • Dermatology • Immunology

Yuhan marks centennial, drives second Leclaza with heavy R&D and AI push (Chosun Biz) - "Lesigercept, a candidate allergy treatment, is in a multinational phase 2 trial. Lesigercept inhibits immunoglobulin E (IgE), which triggers allergic reactions. Allergies have at times not been controlled even with conventional antihistamines. The company expects Lesigercept could replace them. Yuhan's Gaucher disease treatment candidate YH35995 was designated an orphan drug in the United States and Europe in the first half of this year. The candidate is an oral therapy designed to cross the blood–brain barrier. It is expected to help Gaucher patients with accompanying neurological symptoms."

Clinical • Allergy • Gaucher Disease

Yuhan Corporation announced on the 16th that it presented the results of a Phase 1b clinical trial for its allergy treatment ’Lesigercept’ (development code YH35324) at the annual scientific meeting of the European Academy of Allergy and Clinical Immunology (EAACI) 2026 (The Asia Business Daily) - "This Phase 1b clinical trial enrolled a total of 46 participants to evaluate the safety, tolerability, pharmacokinetic, and pharmacodynamic characteristics of repeated administration of Lesigercept....The trial results showed that Lesigercept maintained a favorable safety profile even with repeated dosing, and there were no cases of premature discontinuation or serious adverse events related to the drug....Notably, in Cohort 3, which included subjects with high baseline total IgE levels, the median duration for which blood free IgE remained below 25 ng/mL was 15 days in the Lesigercept group, compared to 0 days in both the placebo and omalizumab groups."

P1 data • Allergy

A Phase 1b Study of Lesigercept, a Long-acting High-affinity IgETrap-Fc Fusion Protein: Safety, Tolerability, PK, and PD in Atopic Healthy and Allergic Subjects (EAACI 2026) - "In Cohort 3, the median duration during which serum free IgE levels remained below 25 ng/mL was 15 days with lesigercept, compared to none (0 days) with placebo and omalizumab (both p < 0.05). Conclusion Lesigercept demonstrated a favorable safety profile as well as therapeutic potential with greater and longer-lasting suppression of serum-free IgE levels than omalizumab after multiple doses, consistent with prior clinical trials."

Clinical • P1 data • Atopic Dermatitis • Dermatitis • Immunology • Inflammation

YH35324-201: A Phase 2 Study of Lesigercept (YH35324) in Adult Patients with Chronic Spontaneous Urticaria (CLEAR) (clinicaltrialsregister.eu) - P1/2 | N=46 | Recruiting | Sponsor: Yuhan Corp.

New P1/2 trial • Chronic Spontaneous Urticaria • Dermatology • Immunology • Urticaria

YH35324-201: A Phase 2 Study of Lesigercept (YH35324) in Adult Patients with Chronic Spontaneous Urticaria (CLEAR) (clinicaltrialsregister.eu) - P1/2 | N=46 | Recruiting | Sponsor: Yuhan Corp. | Not yet recruiting ➔ Recruiting

Enrollment open • Chronic Spontaneous Urticaria • Dermatology • Immunology • Urticaria

CLEAR: Phase 2 Study of Lesigercept in Adult Patients With Chronic Spontaneous Urticaria Who Are Inadequately Controlled by H1-Antihistamines (clinicaltrials.gov) - P2 | N=150 | Recruiting | Sponsor: Yuhan Corporation | Not yet recruiting ➔ Recruiting

Enrollment open • Allergy • Chronic Spontaneous Urticaria • Dermatology • Immunology • Urticaria

Immunological Basis of Chronic Spontaneous Urticaria: Immunoglobulin E and Beyond. (PubMed, Yonsei Med J) - "Recently, dupilumab, an anti-interleukin (IL)-4/IL-13 receptor antibody that inhibits type 2 inflammation, was approved by the US Food and Drug Administration. Additionally, emerging biological agents, such as anti-KIT antibodies targeting mast cell activation and survival, and novel anti-IgE therapies (e.g., YH35324), are currently under investigation and are anticipated to become potential therapeutic options. This review provides an update on the pathogenic mechanisms of CSU, including IgE- and non-IgE-mediated mechanisms, and suggests potential therapeutic targets for improving clinical remission rates."

Journal • Review • Chronic Spontaneous Urticaria • Dermatology • Immunology • Inflammation • Urticaria • IL13

YH35324-201: A Phase 2 Study of Lesigercept (YH35324) in Adult Patients with Chronic Spontaneous Urticaria (CLEAR) (clinicaltrialsregister.eu) - P1/2 | N=30 | Not yet recruiting | Sponsor: Yuhan Corp.

New P1/2 trial • Chronic Spontaneous Urticaria • Dermatology • Immunology • Urticaria

Long-Acting IgETrap-Fc Fusion Protein YH35324 Mitigates Gliadin-Induced Anaphylaxis in a Murine Model (AAAAI 2026) - "One week later, a single subcutaneous injection of YH35324 (2.5, 10, or 40 mg/kg) or omalizumab was given. Conclusions A single administration of YH35324 provides robust protection against gliadin-induced anaphylaxis, restores Th1/Th2/Th17/Treg balance, and preserves intestinal integrity. These preclinical findings support YH35324 as a promising biologic candidate for WDEIA and other IgE-mediated food anaphylaxis."

Preclinical • Cholera • CCR4 • CCR6 • CXCR3 • FOXP3 • IFNG • IL10 • IL13 • IL17A • IL4 • IL5

The workshop also featured a presentation on 'GI-301 (development code YH35324),' GI Innovation's investigational candidate for allergic diseases. (BioNews) - "'GI-301 exhibits a binding affinity 70 times greater than that of the existing blockbuster drug Xolair, and has demonstrated robust efficacy even in patients with elevated immunoglobulin E (IgE) levels who are refractory to Xolair treatment.'"

Clinical data • Allergy

Yuhan Corporation Launches Full-Scale Global Phase 2 Trial of Allergy Drug Candidate Lesigercept (The Asia Business Daily) - "Yuhan Corporation announced on February 19 that it is moving into full-scale multinational Phase 2 clinical trials of lesigercept (development code YH35324), a novel anti-immunoglobulin E (anti-IgE) Fc fusion protein candidate, in patients with chronic spontaneous urticaria (CSU)...The Phase 2 trial is designed to evaluate the safety and efficacy of lesigercept versus placebo over 12 weeks in 150 patients with CSU. The primary endpoint is the change from baseline in UAS7 (Urticaria Activity Score over 7 days) at Week 12. The trial will be conducted in Asia and Europe, including the Republic of Korea, Japan, China, Bulgaria, and Poland....The company aims to obtain the main topline results in the fourth quarter of next year."

P2 data • Trial status • Chronic Spontaneous Urticaria

CLEAR: A Multi Dose, Phase 2 Study of YH35324 in Adult Patients With Chronic Spontaneous Urticaria Who Are Inadequately Controlled by H1-Antihistamines (clinicaltrials.gov) - P2 | N=150 | Not yet recruiting | Sponsor: Yuhan Corporation

New P2 trial • Allergy • Chronic Spontaneous Urticaria • Dermatology • Immunology • Urticaria

GI Innovation receives technology fees for GI-301 contract [Google translation] (HIT News) - "Receives 5.5 billion won in technology fees upon achieving milestones in the GI-301 license agreement with Yuhan Corporation."

Financing • Immunology

Clinical Immunology Society Reveals Phase 1b Part 2 Results of Clinical Immunology (Maeil) - P1b | N=30 | NCT05960708 | Sponsor: Yuhan Corporation | "Yuhan Corporation announced on the 15th that it announced the results of phase 1b clinical trial part 2 of its allergy treatment regurgitation therapy (YH35324) in the form of a poster at the European Allergy Clinical Immunology Society (EAACI) 2025....Clinical results showed that regsighercept strongly inhibited allergenic substances (IgE) in the blood for a long time, and also showed a clear improvement in the UAS7 (7-day urticaria activity score), an indicator of urticaria symptoms evaluation. Among the treated patients, the percentage of urticaria symptoms completely disappeared (score 0) or maintained a well-controlled state (score 6 or less) was higher than that of the control group."

P1 data • Chronic Spontaneous Urticaria

Exploratory Efficacy, Pharmacokinetics, Pharmacodynamics and Safety of YH35324, a Long-Acting high-affinity IgETrap-Fc protein, in Patients with Chronic Spontaneous Urticaria Refractory to Omalizumab (EAACI 2025) - P1 | "One or more TEAEs were reported in 3 of the subjects (50.0%) in the YH35324 group and 2 (66.7%) of those in the placebo group; no serious or drug-related TEAEs were noted in the YH35324 group. Conclusion YH35324 demonstrated clinically meaningful symptom control in CSU patients refractory to Omalizumab, highlighting its therapeutic potential for this population."

Clinical • PK/PD data • Immunology

Therapeutic Efficacy of YH35324 on FcεRIα-Mediated Mast Cell/Basophil Activation. (PubMed, Allergy Asthma Immunol Res) - "YH represents a new therapeutic agent for IgE-mediated allergic disease. Further studies are needed to evaluate its additional effects on the FcεRIα-mediated autoimmune mechanism."

Journal • Allergy • Dermatology • Immunology • Urticaria • FCER2

"Lesigercept, blood free IgE suppression activity compared to omalizumab" [Google translation] (HIT News) - P1b | N=46 | NCT05564221 | Sponsor: Yuhan Corporation | "Yuhan Corporation...announced that it presented the results of the Phase 1b Part 1 clinical trial of lesigercept (development code name YH35324) as a poster at the 2025 annual meeting of the American Academy of Allergy, Asthma, and Immunology (AAAAI) on the 2nd...The purpose of Part 1 was to evaluate the characteristics of the test drugs compared to the control drugs when a single subcutaneous injection of lesigercept 3 mg/kg, 6 mg/kg or omalizumab 300 mg was administered as add-on therapy to H1 antihistamines in patients with chronic spontaneous urticaria not adequately controlled with H1 antihistamines for 8 weeks....The company said that clinical trial results showed that lesigercept showed safety in patients with chronic spontaneous urticaria and showed more potent and sustained blood free IgE suppression activity than omalizumab."

P1 data • Chronic Spontaneous Urticaria

Yuhan’s IgE inhibitor gets green light in phase 1 trial for chronic urticaria (Korea Biomedical Review) - P1 | N=30 | NCT05960708 | Sponsor: Yuhan Corporation | "According to the study’s abstract, which was released by the American Academy of Allergy, Asthma, and Immunology (AAAAI) on Monday (local time), YH35324...showed positive results in a phase 1 clinical trial in patients with chronic spontaneous urticaria (CSU)...The clinical results showed no significant differences in clinical characteristics among the three treatment groups, but YH35324 exhibited a dose-dependent pattern of increased drug exposure as the dose increased. Specifically, free IgE levels within serum in the YH35324 group decreased more significantly than those of omalizumab, with a longer duration of effect....Furthermore, when comparing the proportion of patients achieving complete control (UAS7=0) and partial control (UAS7≤6) during the eight weeks of treatment, the proportions were 16.7 percent and 50.0 percent in the YH35324 3 mg/kg group and 66.7% in the YH35324 6 mg/kg group, respectively."

P1 data • Chronic Spontaneous Urticaria

Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of YH35324, a Novel Long-Acting High-affinity IgETrap-Fc Fusion Protein, in patients with chronic spontaneous urticaria refractory to H1 antihistamines (AAAAI-WAO 2025) - P1 | "Five subjects (27.8%) experienced at least 1 TEAE (grade 1/2), while any serious or drug-related TEAEs were not observed. Conclusions These findings demonstrate the safety and superior therapeutic potential of YH35324 (in aspects of greater suppression of serum-free IgE and better symptom controls) in CSU patients compared to omalizumab."

Clinical • PK/PD data • Chronic Spontaneous Urticaria • Dermatology • Immunology • Urticaria

GI Innovation Registers European Material Patent for Next-Generation Allergy Treatment 'GI-301' [Google translation] (BioTimes) - "GI Innovation announced on the 3rd that the material patent for its allergy treatment drug GI-301 (YH35324) has been registered in Europe. With this registration, the material patent for GI-301 (YH35324) has been secured until 2039, and the period of validity can be extended up to 2044 after drug approval."

Patent • Allergy

A Multiple Ascending Dose, Phase 1b Study of YH35324 in Atopic Healthy Subjects or Subjects with Allergic Diseases (clinicaltrials.gov) - P1 | N=46 | Completed | Sponsor: Yuhan Corporation | Active, not recruiting ➔ Completed

Trial completion • Allergy • Asthma • Atopic Dermatitis • CCL2 • CCL22 • IFNG • IL10 • IL13 • IL18 • IL22 • IL33 • IL4 • IL5

A Single Dose, Phase 1 Study of YH35324 in Patients with Various Allergic Diseases (clinicaltrials.gov) - P1 | N=30 | Completed | Sponsor: Yuhan Corporation | Active, not recruiting ➔ Completed

Trial completion • Allergy • Chronic Spontaneous Urticaria • Dermatology • Immunology • Urticaria

A Single Dose, Phase 1 Study of YH35324 in Patients with Various Allergic Diseases (clinicaltrials.gov) - P1 | N=30 | Active, not recruiting | Sponsor: Yuhan Corporation | Recruiting ➔ Active, not recruiting

Enrollment closed • Allergy • Chronic Spontaneous Urticaria • Dermatology • Immunology • Urticaria

A Multiple Ascending Dose, Phase 1b Study of YH35324 in Atopic Healthy Subjects or Subjects With Allergic Diseases (clinicaltrials.gov) - P1 | N=46 | Active, not recruiting | Sponsor: Yuhan Corporation | Recruiting ➔ Active, not recruiting

Enrollment closed • Allergy • Asthma • Atopic Dermatitis • CCL2 • CCL22 • IFNG • IL10 • IL13 • IL18 • IL22 • IL33 • IL4 • IL5