Development
Clinical development status and regulatory pathway for KP001 (REZQPUFF)
Product
KP001 (REZQPUFF)
Product rendering for illustrative purposes
KP001 (REZQPUFF) is an inhaled epinephrine metered dose inhaler (MDI) in clinical development for the emergency treatment of anaphylaxis.
The product is designed to target both the upper airway and deep lung, with the goal of local delivery to airway tissue while facilitating systemic absorption and mast cell stabilization.
Product Characteristics
Inhaled Delivery
Designed for both upper airway and deep lung deposition, targeting the dual mechanism relevant to anaphylaxis treatment.
Needle-Free
Metered dose inhaler format. A non-injection approach to epinephrine delivery in emergency situations.
Preservative-Free
Being developed without sulfite preservatives, which may be relevant for patients with sensitivity to sulfite preservatives found in existing epinephrine products.1
Regulatory Pathway
505(b)(2) Development Path
KP001 is being developed under the 505(b)(2) regulatory pathway, which allows sponsors to reference FDA's existing safety and efficacy findings for approved drugs. This pathway can reduce the scope and cost of the clinical program relative to a traditional NDA, while maintaining rigorous safety and efficacy standards.
The specific studies required between Phase 1 and NDA filing will be determined in consultation with FDA (feedback pending).
Studies Completed
Phase 1 Pharmacokinetic Study
A first-in-human, randomized, double-blind, placebo-controlled Phase 1 study evaluated systemic epinephrine absorption following administration of KP001 via the pulmonary route in healthy volunteers. The study assessed two dose levels (0.25 mg and 1.0 mg) across two dosing sequences with a crossover design.
Results showed rapid absorption with a median Tmax of approximately 2 minutes at the low dose (0.25 mg). The safety profile was consistent with the known pharmacologic effects of epinephrine, with no serious adverse events reported.2
Proof-of-Concept Study
In an investigator-initiated proof-of-concept study, 21 patients experiencing moderate-to-severe allergic reactions (WAO Grade 2-5) were treated with inhaled epinephrine via metered dose inhaler. All 21 patients achieved symptom resolution. Median time to resolution was 3.6 minutes. 48% of patients resolved after a single dose. No patients required rescue IM epinephrine.3
KP001 (REZQPUFF) is investigational and not yet FDA-approved. Preliminary findings from early-stage studies. Results may not be predictive of outcomes in larger controlled trials.
References
- Vally H, Misso NL. Adverse reactions to the sulphite additives. Gastroenterol Hepatol Bed Bench. 2012;5(1):16-23.
- Luciuk GH, Discepola L, Pimstone S, Stapleton KW. The Pharmacokinetics of a Novel Inhaled Epinephrine. J Allergy Clin Immunol. 2026;157(2 Suppl):Abstract L80. AAAAI 2026.
- Luciuk GH, Discepola L, Pimstone S, Stapleton KW. Time to Symptom Resolution: An Efficacy Endpoint for the Effectiveness of Anaphylaxis Treatments. J Allergy Clin Immunol. 2026;157(2 Suppl):Abstract 597. AAAAI 2026.
Business Development