AQST-109 Film Shows Strong BP Response Despite Low Exposure

“How high does it have to go to work, though? It doesn’t have to go to the Cmax,” said Golden.

Low systemic exposure of the investigational sublingual epinephrine film AQST-109 still produces fast and significant blood pressure responses, HCPLive reported on November 12, 2026, from the American College of Allergy, Asthma & Immunology annual scientific meeting in Phoenix, Arizona.

The Tech TL;DR:

• AQST-109 delivers a median Tmax of 20 minutes, matching autoinjectors and outpacing manual intramuscular injections.
• Patients in the lowest Cmax tertile showed a geometric mean peak concentration of 117.51 pg/mL, which sits below traditional reference products.
• Despite lower absorption levels, median maximum responses for systolic, diastolic, and mean arterial pressure exceeded those of EpiPen, Auvi-Q, and manual intramuscular injections.

Low Exposure Pharmacodynamics

Researchers evaluated the lowest tertile of healthy adults against standard reference products across three separate studies, utilizing Kruskal-Wallis and Mann-Whitney U tests, HCPLive reported. The analysis compared the investigational sublingual film against EpiPen, Auvi-Q, and manual intramuscular epinephrine.

Median time to maximum concentration for AQST-109 hit 20 minutes with a range spanning from 5 to 120 minutes. This absorption speed beats manual intramuscular administration while keeping pace with current autoinjector technology.

Median maximum response values for systolic blood pressure, diastolic blood pressure, and mean arterial pressure proved significantly greater with AQST-109 than with all three traditional reference comparators. The time to maximum effect for all three blood pressure measurements arrived faster than each comparator.

Cardiovascular Response Patterns

Peak heart rate values among patients in the lowest exposure tertile ran significantly higher with AQST-109 than with manual intramuscular epinephrine, overlapping with both autoinjectors. Heart rate time to maximum effect proved faster than manual intramuscular delivery, matched the EpiPen, and tracked close to the Auvi-Q.

“We’re treating people who need to have cardiovascular support in their anaphylactic reaction,” Golden told HCPLive. “Athletes, for example, get high levels of epinephrine and high levels of heart rate and blood pressure during normal exercise for them. So these are all within physiologic range. They’re not dangerous.”

Golden noted that epinephrine only requires reaching an effective therapeutic threshold, meaning a higher maximum concentration does not automatically translate to a better clinical response. The analysis challenges long-held assumptions regarding weaker clinical efficacy in patients with reduced systemic absorption when using sublingual film delivery.

Delivery Mechanism Differences

The exact physiological mechanism driving stronger cardiovascular responses under low systemic exposure remains partially unmapped. Sublingual and intranasal administration routes yield distinct pharmacokinetic and pharmacodynamic profiles compared to intramuscular delivery, where localized muscle tissue responses dictate both drug absorption and systemic impact.

Golden cautioned that these specific sublingual findings cannot be extrapolated directly to intramuscular injections. Regulatory review for the product, also known as dibutepinephrine or Anaphylm, continues under a Prescription Drug User Fee Act goal date of March 16, 2027, following an NDA resubmission acceptance announced by Aquestive Therapeutics on October 15, 2026.

What AQST-109 Is and How It Affects Blood Pressure

What is AQST-109?

AQST-109, known chemically as dibutepinephrine or by the brand name Anaphylm, is an investigational sublingual epinephrine prodrug film developed for type I allergic reactions including anaphylaxis. The Food and Drug Administration set a target action date of March 16, 2027, for the new drug application.

How does low systemic exposure affect blood pressure?

Among healthy adults in the lowest Cmax tertile, the sublingual film generated significantly greater and faster systolic, diastolic, and mean arterial pressure responses than EpiPen, Auvi-Q, and manual intramuscular epinephrine.

What were the peak concentration metrics?

In the lowest exposure group, the geometric mean Cmax reached 117.51 pg/mL with a 95% confidence interval spanning from 107.2 to 128.1 pg/mL, falling below the reference products evaluated across the clinical trials.