Incannex Healthcare Ltd met with the US Food and Drug Administration (FDA) to discuss the development of IHL-42X, a fixed dose combination of dronabinol and acetazolamide that is being developed as a treatment for obstructive sleep apnea (OSA) in adults. In a release, Incannex characterized the pre-investigational new drug application (pre-IND) meeting with the FDA as “highly constructive.”
Mark Bleackley, PhD, Incannex chief scientific officer, says in a release, “The FDA’s interest in IHL-42X as a potential therapy for OSA was extremely encouraging. The feedback provided on the overall proposed development program was positive. The agency’s responses to the specific questions we posed allow us to revise our clinical trial protocols to ensure that we are running highly efficient studies that generate the type and amount of data the FDA will require in a future marketing application. The results from the pre-IND meeting will shape the IHL-42X development program over the coming months.”
Incannex submitted the pre-IND meeting package and request in February of this year. The meeting package included an overview of the development program and specific questions relating to regulatory requirements for opening an investigational new drug (IND) application, which is required to conduct clinical trials in the United States.
The written responses, and the responses provided in a teleconference with FDA representatives, were “constructive and supportive,” according to an Incannex statement, “with interest in the project underpinned by the significant cohort of people diagnosed with OSA and the absence of pharmacological treatment solutions.”
The FDA provided guidance on the company’s long-term development strategy including specific parameters to demonstrate safety and efficacy in phase 2 and 3 pivotal studies. The guidance will inform adjustments to adjust Incannex’s clinical trial protocols to generate the data required for a 505(b)(2) new drug application (NDA).
The FDA agreed that the company does not need to conduct studies in animals, a decision that will save Incannex time and cost. In particular, the agency confirmed in the pre-IND meeting that animal toxicology and animal pharmacokinetic studies are not required for opening an IND for IHL-42X. So the next step for the development of IHL-42X will be the adjustment of clinical trial designs and arrangement of operational imperatives needed to open an IND with FDA.
In 2021, Incannex completed a phase 2 proof-of-concept clinical trial to assess IHL-42X in patients with OSA. Preliminary results show that 60% of trial participants experienced a reduction of more than 55% in their apnoea-hypopnea index (AHI) during at least one treatment compared to baseline. Twenty percent of participants experienced an AHI reduction of greater than 80%. The complete clinical study report is anticipated to be released in June 2022.