The FDA has decided to not approve Defender Pharmaceuticals’ intranasal scopolamine candidate for motion sickness, issuing a complete response letter (CRL) to the US-based company.
Defender’s drug, known as DPI-386, is indicated for the prevention of nausea and vomiting induced by motion in adults.
Defender’s CEO Barry I Feinberg said the company plans on scheduling a formal meeting with the FDA to discuss the issues raised and to create a plan going forward, in a 30 January press release.
DPI-386 is a nasal gel version of the antimuscarinic drug scopolamine, first approved by the FDA as a transdermal patch in 1979, according to the drug’s label. Currently, patches are placed behind the ear and work with high efficacy by depressing the parasympathetic nervous system.
The gel could be particularly useful for astronauts and military personnel who are frequently exposed to motion. Nasa joined forces with Epiomed Therapeutics to develop a fast-acting nasal spray version of scopolamine in 2012. According to the St Louis Post-Dispatch, Defender purchased Epiomed in 2014 and was founded the same year. Headquartered in St Louis, Missouri, the company has also worked with the United States Naval Medical Research Unit.
Defender’s formulation aims for rapid absorption to induce quicker onset. In a Phase III trial more than 500 participants, who usually get motion sick, had improved symptoms after being exposed to open sea conditions while using DPI-386. Subjects who received the nasal gel demonstrated lower incidences of vomiting and fewer requests for rescue medication compared to a placebo group. The incidence of moderate to severe nausea was also lower.
In a September 2023 statement announcing the new drug application (NDA) acceptance, Defender said results from five phase III trials were submitted as evidence. The NDA was assigned priority review status by the FDA at the request of the US Navy.
Feinberg added: “We remain confident that our intranasal scopolamine is a safe and effective therapy for the prevention of motion sickness, and we will work closely with the FDA to ensure that we can bring this innovative new product to the market.”
Defender is also exploring the use of DPI-386 in major depressive disorder (MDD) with suicide ideation, chemical exposure accidents, and virtual reality sickness.
In October 2023, Defender announced further collaborations with Nasa to study DPI-386 in Phase II trials to mitigate G-transition-induced motion sickness and enhance sensorimotor performance.
Scopolamine recently made the news beyond the healthcare sector after rising incidences of it being linked to criminal activity. In June 2023, the US Embassy in Colombia highlighted the sedative side effects of the drug are being increasingly used to target tourists in the country. In certain doses, the drug can cause unconsciousness for 24 hours or more.
Scopolamine was also the first drug to infamously garner the “truth serum” tag.
