Invex Therapeutics pushes on with phase three trial design to repurpose drug for brain disorder
According to Invex, there are currently no approved treatments for idiopathic intracranial hypertension.
Invex Therapeutics (ASX: IXC) is aiming to hit some significant milestones in 2021 in its bid to use a diabetic drug for a neurological condition in desperate need for treatment.
The biopharmaceutical company is focused on repurposing the drug Exenatide, currently approved for the treatment of type two diabetes, to treat neurological conditions derived from or involving raised intracranial pressure.
Its emphasis is on idiopathic intracranial hypertension (IIH), which is considered a large and growing market opportunity with no regulatory cleared treatments to date.
The company recently revealed an estimated timeline for the 2021 calendar year, scheduling human pharmacokinetic and animal tolerability studies and filing a clinical trial application with European health authorities in the first half and starting a phase three trial in Europe in the second.
This plan follows Invex’s announcement in December that it had received protocol assistance from the European Medicines Agency (EMA) on its proposed clinical development plan for the repurposed drug, which it recently trademarked as Presendin™.
Speaking with Small Caps, Invex executive director Dr Thomas Duthy said the company’s regulatory strategy “seeks to harmonise our phase three design such that it meets the requirements of both the EMA and US FDA (Food and Drug Administration) for registration of Presendin in IIH, consistent with our orphan designation and subject to meeting key efficacy and safety endpoints”.
Large and growing market
IIH is a debilitating condition where pressure inside the brain increases due to an increased accumulation of cerebral spinal fluid, leading to daily headaches and vision problems.
It has no known cause but is typically associated with obesity and particularly, females of childbearing age.
According to Invex, incidences of the condition is growing rapidly, in line with higher rates of obesity, and published data suggests a long-term annual growth rate of 3.4%.
“Invex estimates the annual incidence of IIH in the European Union and USA to be 40,000 per annum (60%/40% split). Of those, 60% receive a diagnosis and 90% receive treatment for their condition,” the company stated in a recent fact sheet.
For one daily dose of reformulated Exenatide (Presendin™), chronically administered to an estimated 21,500 treatable patients, Invex estimates the annual market is worth $1.6 billion.
According to Dr Duthy, there is no current regulatory approved treatments and beyond Presendin™, there are no drugs in clinical development.
“This makes it attractive as a completely unencumbered market opportunity when compared to other diseases such as cancer or arthritis,” he said.
Phase three trials
Last May, Invex released strong and supportive data from its double-blind, placebo-controlled phase two trial, showing an up to 21% reduction in intracranial pressure across three-time points and a 37% reduction in headache days per month.
The phase three trial design will focus on key headache and intracranial pressure endpoints.
“Invex will also integrate key aspects of the EMA response when considering the necessary pre-IND (investigational new drug)/ type B meeting request submissions with the US FDA, including the preparation of a complete study protocol and statistical analysis plan,” the company reported in January.
Dr Duthy said Invex’s strong financial position with $33.6 million in cash by the end of December 2020 enables it to carefully consider an optimised trial design. The company plans to file documentation with the FDA to request a pre-IND meeting in the current first quarter of 2021.
Favourable market dynamics
Invex has issued US patents giving protection to at least 2035 and orphan drug designation status was achieved in 2017 in the US and Europe, providing seven- and 10-years’ market exclusivity, respectively.
“In other words, irrespective of the strength of our issued patents, which we believe are strong, the government has granted Invex market exclusivity in using Exenatide for IIH for an extended period,” Dr Duthy said.
“It adds an additional layer of protection from competitors,” he added.
Dr Duthy also noted that comparable companies on the ASX which are either repurposing approved therapies, developing orphan drugs, or developing ophthalmology therapies, such as Paradigm Biopharmaceuticals (ASX: PAR), Opthea (ASX: OPT), Race Oncology (ASX: RAC) or Neuren Pharmaceuticals (ASX: NEU), are priced significantly higher despite similar stages of development.
“Our discounted enterprise value of $25 million does not reflect Invex’s stage of development or the market opportunity of IIH, particularly when you consider the EU constitutes 60% of the addressable market for IIH and the EMA has provided protocol assistance confirming a single phase three trial will be sufficient to support an application for market approval, subject to demonstrating clinical efficacy and safety. Meanwhile we continue to progress similar discussions with the FDA” he claimed.