This Phase 2 clinical trial (double-blind, placebo-controlled) aims to evaluate the efficacy of UB-221 as a long-acting add-on therapy for treatment of chronic spontaneous urticaria (CSU) and provide evidence of the therapeutic potential of two high-dose UB-221 treatments over a 6-month period.

Spontaneous Urticaria is categorized into acute (< six weeks) and chronic (> six weeks) variants. With an incidence rate of 0.5–1%, patients can suffer from the disease at any time. 

Nonsedating H1‐antihistamines are the mainstay of symptomatic therapy. Treatment with licensed doses relieves symptoms effectively in <50% of patients. As patients benefit little from H1‐antihistamines, new therapeutic strategies are needed. 

UB-221 is an IgG1 that targets the Cε3 domain of IgE antibody. UB-221 neutralizes soluble IgE and inhibits the IgE synthesis by binding to FcεRII (CD23) receptor on B-cells surface. Pre-clinical studies demonstrate UB-221's superiority to current therapeutic antibody targeting IgE (Xolair^{® ;} Omalizumab) by 8-folds for pharmacologic effects. UB-221 shows 2 to 5-folds inhibition of IgE synthesis in the in-vitro data, requiring 1/10 dose to achieve the same effect in huIGHE-knock-in mice model. 

The Phase 1 clinical trial revealed that CSU patients responded to UB-221 rapidly after a single dose and suppressed their serum free IgE for weeks to months^®, indicating that UB-221 could relieve symptoms of CSU more effectively than Xolair. UB-221 can also inhibit the production of new IgE by binding to the already bound- IgE on the low-affinity receptor CD23. As such, the speed of IgE rebound will be slower after treatment is discontinued.

"We are excited to begin the trial of UB-221 as a long-acting add-on therapy for patients suffering from CSU," said Dr. Shugene Lynn, CEO of United BioPharma. "The potential benefits will bring more comfort and symptom control and will be an important step in the fight against the condition and its effects."