San Diego-based pharmaceutical giant ARS Pharmaceuticals, Inc. announced that the US Food and Drug Administration (USFDA) disapproved their New Drug Application (NDA) for an epinephrine nasal spray known as Neffy, the first alternative to Epipen (epinephrine injection) and used to treat severe allergic reactions in adults and children (over 30 kg).

According to a company statement in the Complete Response Letter (CRL), the FDA has requested a pharmacokinetic and pharmacodynamic study to compare the repeated neffy dose with an epinephrine injection.

In May 2023, the FDA Pulmonary Allergy Drug Advisory Committee (PADAC) recommended approval for neffy without additional safety and efficacy studies, the statement added.

 ASR Pharma plans to conduct a repeat-dose study under allergen-induced allergic rhinitis conditions as a post-marketing obligation. The company expects to resubmit the application during the first six months of 2024, and the expected FDA action date is in the second half of 2024.

The company states that the FDA has asked for the data from nitrosamine impurity testing and does not think the additional testing is a rate-limiting step.

Additionally, the Marketing Authorisation Application (MAA) of Neffy is under review by the European Medical Agency, and an opinion is expected by the end of 2023.

Commenting on the FDA’s decision, Richard Lowenthal, co-founder, president, and CEO of ARS Pharma, said, “We are very surprised by this action and the late requirement at this time to change the repeat-dose study from a post-marketing requirement, which we had previously aligned on with the FDA, to a pre-approval requirement, particularly given the positive Advisory Committee vote.”

“In fact, multiple Committee members highlighted the favourable profile of Neffy in our completed single-dose nasal allergy challenge study and that any decline in exposure 20 minutes after dosing, after the expected response period, is of no concern,” he added.

He said, “We are deeply disappointed that this action further delays the availability of neffy for the millions of people who are at risk of a potentially life-threatening severe allergic reaction. Patients and caregivers are waiting for Neffy, and we aim to complete the newly requested trial as quickly as possible to meet the needs of patients.”