Polyrizon Ltd. (Nasdaq: PLRZ) has completed contracts with all five U.S. clinical sites selected for its first-in-human study of NASARIX™ Allergy Blocker (PL-14), according to a company statement.

The planned 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 trial aims to enroll up to 120 randomized patients, assigned in a 1:1 ratio to receive either NASARIX™ or an isotonic saline nasal spray control.

The 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 permitted relief medication.

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

NASARIX™ is described as a nasal spray designed to create a protective barrier within the nasal cavity to help prevent contact between inhaled allergens and the nasal mucosa. It is being developed as a non-drug approach for managing seasonal allergic rhinitis.

Polyrizon is an Israel-based, development-stage biotech company focused on intranasal hydrogel medical devices.