First-in-class intranasal epinephrine spray for anaphylaxis: Dose finding clinical study

Background: Anaphylaxis is a life-threatening clinical presentation of acute systemic allergic reactions. Timely administration of epinephrine, usually by intramuscular autoinjector, is a robust life-saving treatment. Despite the critical necessity, there are multiple deterrents to patients’ proper use of epinephrine autoinjectors. FMXIN002 is a novel nasal dry powder formulation of epinephrine in a single-use device, offering first-in-class alternative treatment. Objectives: We sought to measure epinephrine pharmacokinetics, pharmacodynamics, and safety following a single administration of FMXIN002 at doses of 3.6 and 4.0 mg epinephrine versus intramuscular (IM) autoinjector 0.3 mg, in healthy adults. Methods: This was an open-label, single-dose, 3-treatment, crossover, randomized, comparative bioavailability study with 12 healthy adults, female and male. FMXIN002 stability was also tested. Results: FMXIN002 4.0 mg was absorbed faster and in higher amounts by most of the subjects, compared to IM autoinjector: 91% of subjects achieved the clinical threshold of 100 pg/mL plasma epinephrine at 6 minutes after administration of FMXIN002 4.0 mg compared to 55% of subjects treated with IM autoinjector. The area under the curve for 0 to 4 minutes’ period was significantly higher for FMXIN002 4.0 mg (geometric mean: 7.49 h ∙ pg/mL vs 2.06 h ∙ pg/mL, respectively; P = .0377). The pharmacodynamic response and safety were comparable among all treatments. No serious adverse events occurred, all events were mild and self-resolved. FMXIN002 was highly stable at all tested conditions including 5 years at 20 ± 5ºC. Conclusions: FMXIN002 4.0 mg nasal spray enables faster and higher epinephrine plasma absorbance at the short therapeutic window required for the treatment of anaphylaxis, using a patient-friendly, needle-free, stable and safe device.