– Exl-111 is an investigational allergic Effector Cell Response Inhibitor (ECRI) targeting the IgE axis and is designed to disarm allergic effector cells at the source of activation
– In primates, Exl-111 achieved rapid and near-complete (>99%) removal of receptor-bound IgE on basophils and induced a ~95% reduction in surface receptor (FcεRI) expression
– Exl-111 was well-tolerated in cynomolgus monkeys, did not induce allergic effector-cell activation and showed no adverse effects or local injection site reactions at doses up to 100 mg/kg
– In human-donor whole-blood basophils, Exl-111 potently dissociated receptor-bound IgE in less than 24 hours at therapeutically relevant concentrations without inducing activation
– First subjects dosed in Phase 1 DISARM trial as Exl-111 becomes first ECRI candidate to enter clinic
PALO ALTO, Calif., Feb. 27, 2026 (GLOBE NEWSWIRE) — Excellergy, a biotechnology company developing a novel class of allergy therapeutics, today announced new pre-clinical data further demonstrating the differentiated profile of its trifunctional allergic Effector Cell Response Inhibitor (ECRI) platform, reinforcing its potential to set a new standard in the control of allergic diseases. The data, which were presented at the 2026 American Academy of Allergy, Asthma & Immunology (AAAAI) Annual Meeting, support the speed and efficacy of Exl-111, which is currently being evaluated in the Phase 1 DISARM trial.
The preclinical pharmacokinetic (PK) and pharmacodynamic (PD) studies, conducted in cynomolgus monkeys following subcutaneous and intravenous administration, demonstrated rapid downregulation of the IgE signaling axis. Key results support the impact of the trifunctional mechanism of Exl-111:
- >99% removal of receptor-bound IgE from basophils, demonstrating active dissociation of cell-bound IgE
- ~95% reduction in basophil FcεRI surface expression, substantially reducing effector-cell sensitivity to IgE-driven signaling
- Potent and sustained neutralization of free-IgE despite high average baseline IgE levels (>4500 ng/mL)
- Well-tolerated and induced no activation of allergic effector cells
- No adverse drug-related observations or local injection site reactions were noted at doses up to 100 mg/kg
In vitro human-donor whole-blood basophil assays further showed rapid dissociation of receptor-bound IgE in less than 24 hours at therapeutically relevant concentrations, without inducing activation.
“Effector-cell sensitization is the final common pathway that converts IgE biology into real disease,” said Luke Pennington, Ph.D., Vice President of Discovery and Co-Founder of Excellergy. “These data show that Exl-111 can quickly dissociate receptor-bound IgE, drive near-complete FcεRI downregulation and sustain suppression of IgE binding, all without triggering effector-cell activation. Together, these findings support the potential for rapid and complete control of allergic activation and inflammation beyond what is achievable today. If translated clinically, this would move patients from months of ‘wait and see’ to earlier, more reliable control, with fewer allergic breakthrough episodes and less day-to-day uncertainty.”
“The data presented by Excellergy at AAAAI represent a compelling mechanistic advance in allergy therapeutics,” said Leonard B. Bacharier, M.D., Janie Robinson and John Moore Lee Chair in Pediatrics and Professor of Pediatrics, Allergy/Immunology/Pulmonary Medicine at Monroe Carell Jr. Children’s Hospital at Vanderbilt University Medical Center. “By dissociating receptor bound IgE and substantially reducing surface FcεRI expression without triggering effector cell activation, Excellergy is addressing the biology that contributes to slower onset, variable efficacy, and persistent nonresponder rates with current therapies. I am encouraged to see this program has now advanced into the clinic, and the preclinical evidence provides confidence in translation to meaningful outcomes for patients.”
“Dosing the first subjects in our Phase 1 DISARM trial marks a major milestone as we advance the first candidate from this new ECRI class of medicines into the clinic,” said Dr. Phil Brown, M.D., J.D., Chief Medical Officer. “This step brings us closer to a new era in allergy care, where patients can achieve earlier and more effective control, reclaiming their lives from debilitating allergic conditions.”
The PK/PD data from the study were used for dose selection and trial design for Excellergy’s recently initiated Phase 1 DISARM trial for Exl-111 (NCT07356713). The first cohort of subjects in the trial was dosed in early February. This randomized, double-blind, placebo-controlled, single and multiple ascending dose trial of Exl-111 will enroll approximately 70 healthy participants who have not received prior anti-IgE therapy.
Excellergy is a biotechnology company developing a first-in-class portfolio of Effector Cell Response Inhibitors (ECRIs) for the treatment of severe IgE-mediated allergic diseases. By building on clinically validated IgE biology while introducing a new level of allergic disease control, Excellergy is advancing beyond traditional anti-IgE approaches to directly target the source of allergic signaling—IgE bound to the effector cell. The Company is headquartered in Palo Alto, California, and is backed by Red Tree Venture Capital, Samsara BioCapital and Decheng Capital. To learn more, please visit www.excellergy.com.
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