A Phase 2 interventional study of BLU-808 and Placebo in Allergic Rhinoconjunctivitis, sponsored by Blueprint Medicines Corporation. Completed at 1 site in Canada. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-03.
Sponsored by Blueprint Medicines Corporation (part of Sanofi) · Phase 2, Interventional, and Treatment
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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).
Blueprint Medicines Corporation is the lead sponsor of 32 studies on the registry; 6 are open to participants now.
Of its 14 completed or terminated interventional studies of FDA-regulated products, 3 (21%) have results posted.
First submitted before Blueprint Medicines Corporation became part of Sanofi.
Counted across the registry records on this site, refreshed daily.
Key Inclusion Criteria
Key Exclusion Criteria
Participants are excluded from the study if any of the following criteria are met:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BLU-808 will be administered orally for 28 days.
Drug: BLU-808
BLU-808 will be administered orally for 28 days.
Drug: BLU-808
Placebo will be administered orally for 28 days.
Drug: Placebo
BLU-808 tablets
Placebo tablets
Number of Participants with Treatment-emergent Adverse Events (TEAEs)
Time frame: Day 1 through Day 56
Area Under the Curve (AUC) of BLU-808
Time frame: Day 1 to Day 28
Maximum Plasma Concentration (Cmax) of BLU-808
Time frame: Day 1 to Day 28
Minimum Plasma Concentration (Cmin) of BLU-808
Time frame: Day 1 to Day 28
Apparent Clearance (CL/F) of BLU-808
Time frame: Day 1 to Day 28
Apparent Volume of Distribution for the Central Compartment (Vc/F) of BLU-808
Time frame: Day 1 to Day 28
Terminal Half-life (t½) of BLU-808
Time frame: Day 1 to Day 28
Change in Baseline-adjusted Mean Total Nasal Symptom Score (TNSS)
Time frame: Baseline, Day 14, Day 28
Change in Baseline-adjusted AUC of the TNSS
Time frame: Baseline, Day 14, Day 28
Ran from Apr 2025 to primary completion in Sep 2025, 4 months.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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