Polyrizon Ltd. (Nasdaq: PLRZ) has completed contracting with all five U.S. clinical sites selected to participate in its planned study of NASARIX™ Allergy Blocker (PL-14), according to a press release from the Israel-based development-stage biotech company.

The planned first-in-human study is a prospective, multicenter, randomized, single-blind, two-arm clinical trial designed to evaluate the efficacy, safety, and tolerability of NASARIX™ in patients with seasonal allergic rhinitis. The study aims to enroll up to 120 randomized patients, assigned in a 1:1 ratio to receive either NASARIX™ or an isotonic saline nasal spray as a control.

The study's primary efficacy endpoint will measure the difference between treatment groups in mean daily reflective Total Nasal Symptom Score over the first 14 treatment days. Secondary measures are expected to include instantaneous Total Nasal Symptom Score, rhinoconjunctivitis-related quality of life, symptom-free days, and use of relief medication.

Polyrizon said it is advancing the study into patient pre-screening and enrollment preparation. Because the trial evaluates responses under real-world allergen exposure, enrollment timing is planned to coincide with relevant allergy seasons, with local pollen counts and weather conditions to be monitored.

"With the full clinical site network now in place, our focus shifts to patient pre-screening and readiness for enrollment as seasonal allergen exposure increases," said Tomer Izraeli, Chief Executive Officer of Polyrizon.

NASARIX™ is a nasal spray being developed as a non-drug approach intended to create a protective barrier within the nasal cavity to limit contact between inhaled allergens and the nasal mucosa.