The confirmation is as a treatment for patients with congenital adrenal hyperplasia (CAH), and means that the company is on track to submit a Marketing Authorisation Application in the fourth quarter of 2019.

The confirmation comes despite shares in the UK specialty pharma plummeting more than 50% last year on news that its late stage study of the experimental treatment failed to meet its primary objective.

The modified release preparation of hydrocortisone has been designed to mimic the circadian rhythm of cortisol when given in a twice-a-day "toothbrush" regimen, i.e once in the morning and once at night. This helps to control androgen excess and chronic fatigue in patients with diseases of cortisol deficiency.

In Europe, Chronocort has already been granted Orphan Drug Designation in the treatment of CAH, which, if confirmed at marketing authorisation, provides market exclusivity for 10 years.

The drug has been extensively studied in humans having completed four Phase I trials, a Phase II trial in 16 CAH patients in the US in 2014, and a Phase III trial in 122 CAH patients in Europe.

Martin Whitaker, chief executive officer of Diurnal, commented: “We welcome the outcome of our meeting with the EMA based on detailed analysis of data from our studies in patients with congenital adrenal hyperplasia (CAH). This condition still results in significant increased morbidity and mortality for patients worldwide, with new therapies needed to improve these outcomes.

“We therefore continue to believe that Chronocort represents a valuable treatment option for these patients, in a market estimated at $300 million in Europe, and we look forward to submitting a Marketing Authorisation Application in Q4 2019.”

CAH is caused by deficiency of adrenal enzymes, most commonly 21-hydroxylase which is the enzyme required to produce the adrenal steroid hormone, cortisol. Even if treated, patients remain at risk of death through an adrenal crisis.