Study of BLU-808 in Allergic Rhinoconjunctivitis

A Phase 2a Randomized Double-blinded Placebo Controlled Study to Evaluate the Safety, Tolerability, PK, PD, and Preliminary Clinical Activity of BLU-808, a Wild-type KIT Inhibitor, in Participants With Ragweed (Ambrosia Artemisiifolia)-Induced Allergic Rhinoconjunctivitis

This study will evaluate the safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD), and preliminary clinical activity of BLU-808 in participants with ragweed (Ambrosia artemisiifolia)-induced allergic rhinoconjunctivitis (ARC). Participants will undergo eligibility assessments that include exposure to ragweed pollen in an allergen exposure chamber (AEC).

Study Overview

• Status: Completed
• Conditions: Allergic Rhinoconjunctivitis
• Intervention / Treatment: Drug: Placebo; Drug: BLU-808

• Study Type: Interventional
• Enrollment (Actual): 21
• Phase: Phase 2

Contacts and Locations

Study Locations

• Canada
  • Ottawa, Canada, ON K1H E4
    • Red Maple Trials

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Key Inclusion Criteria

1. Adults, 18 years of age or older, willing to provide written informed consent, and willing to comply with all study requirements.
2. History (>2 years) of ragweed-induced ARC.
3. A positive ragweed skin prick test (mean diameter of ≥ 5 mm) in the last 6 months.
4. Must meet clinically relevant nasal and ocular symptoms as defined by the protocol.

Key Exclusion Criteria

Participants are excluded from the study if any of the following criteria are met:

1. Receiving medications (oral, nasal, topical, ocular, or injectable) to treat their ragweed or other allergy symptoms and/or receiving any medications that impact participants' safety or interfere with study assessments or interpretation of study results.
2. Have active rhinitis, sinusitis, and/or other severe allergies not associated with the ragweed pollen that may interfere with study symptom assessments.
3. Any prior or ongoing clinically significant illness, medical or psychiatric condition, surgical history, or physical finding that may interfere with the assessment or interpretation of study results.
4. Clinically significant moderate to severe, uncontrolled cardiovascular, renal or hepatic disease.
5. Significant bleeding risk or coagulation disorders.
6. Any form of smoking, vaping or history of alcohol and drug abuse.
7. Any malignancy within the past 5 years prior to Screening/AEC 1, except for basal cell or squamous cell carcinomas of the skin or carcinoma in situ.
8. Inadequately controlled asthma that could affect the safety of the participant or interfere with the assessment or interpretation of study results.
9. Known active/latent infection (viral, bacterial, fungal, helminth, or mycobacterial) such as tuberculosis, hepatitis B, hepatitis C, AIDS-related illness, or COVID-19 infection.
10. History of sinonasal conditions that may confound the assessment or interpretation of study results.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: BLU-808 Dose 1; BLU-808 will be administered orally for 28 days.	Drug: BLU-808; BLU-808 tablets
Experimental: BLU-808 Dose 2; BLU-808 will be administered orally for 28 days.	Drug: BLU-808; BLU-808 tablets
Placebo Comparator: Placebo; Placebo will be administered orally for 28 days.	Drug: Placebo; Placebo tablets

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Number of Participants with Treatment-emergent Adverse Events (TEAEs)	Day 1 through Day 56

Secondary Outcome Measures

Outcome Measure	Time Frame
Area Under the Curve (AUC) of BLU-808	Day 1 to Day 28
Maximum Plasma Concentration (Cmax) of BLU-808	Day 1 to Day 28
Minimum Plasma Concentration (Cmin) of BLU-808	Day 1 to Day 28
Apparent Clearance (CL/F) of BLU-808	Day 1 to Day 28
Apparent Volume of Distribution for the Central Compartment (Vc/F) of BLU-808	Day 1 to Day 28
Terminal Half-life (t½) of BLU-808	Day 1 to Day 28
Change in Baseline-adjusted Mean Total Nasal Symptom Score (TNSS)	Baseline, Day 14, Day 28
Change in Baseline-adjusted AUC of the TNSS	Baseline, Day 14, Day 28

Collaborators and Investigators

• Sponsor: Blueprint Medicines Corporation

Study record dates

Study Major Dates

• Study Start (Actual): April 14, 2025
• Primary Completion (Actual): September 8, 2025
• Study Completion (Actual): September 8, 2025

Study Registration Dates

• First Submitted: April 3, 2025
• First Submitted That Met QC Criteria: April 3, 2025
• First Posted (Actual): April 10, 2025

Study Record Updates

• Last Update Posted (Actual): February 10, 2026
• Last Update Submitted That Met QC Criteria: February 7, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: Ragweed; Allergic Rhinoconjunctivitis; Ambrosia Artemisiifolia; BLU-808
• Additional Relevant MeSH Terms: Immune System Diseases; Eye Diseases; Hypersensitivity, Immediate; Hypersensitivity; Conjunctival Diseases; Conjunctivitis; Conjunctivitis, Allergic
• Other Study ID Numbers: BLU-808-2201

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No