Grant of European Patent for Alkindi

20 November 2020

Diurnal Group plc

("Diurnal" or the "Company")

Grant of European Patent for Alkindi®

Diurnal Group plc (AIM: DNL), the specialty pharmaceutical company targeting patient needs in chronic endocrine (hormonal) diseases, announces the grant of a patent for Alkindi® (hydrocortisone granules in capsules for opening) by the European Patent Office.

EP2780003, entitled "Treatment of Adrenal Insufficiency", is a patent disclosing and claiming the medical use of Alkindi® for the treatment of paediatric patients with adrenal insufficiency (AI). The patent provides in-market European protection until 2032 in all designated states of the European Patent Convention. The equivalent patents from the same family are already granted in the UK, Japan, Australia, Israel, South Africa, South Korea and the US (for Alkindi® Sprinkle).

EP2780003 further expands the Company's strong exclusivity position for Alkindi® in Europe where Diurnal already has 10 years of data and market exclusivity until 2028 through a paediatric use marketing authorisation granted by the European Commission. Alkindi® is approved and marketed as the first preparation of hydrocortisone (the synthetic version of cortisol) specifically designed for use in children suffering from AI and the related condition congenital adrenal hyperplasia.

Martin Whitaker, CEO of Diurnal, commented:

"With the rapid commercialisation of Alkindi® being a core focus for Diurnal, we are pleased to receive this patent grant by the European Patent Office. This patent, which builds on our strong global intellectual property position for the product, provides protection in Europe until 2032, supporting our continued commitment to provide Alkindi® to paediatric patients suffering from adrenal insufficiency."

Notes to Editors

About Alkindi® (hydrocortisone granules in capsules for opening)

Alkindi® is the first preparation of hydrocortisone specifically designed for use in children suffering from paediatric adrenal insufficiency (AI). Alkindi® is a patented, oral, immediate-release paediatric formulation of hydrocortisone granules in capsules for opening that allows for accurate age-appropriate dosing in children. This therapeutic approach has the potential to help young patients less than eighteen years of age suffering from diseases due to cortisol deficiency including paediatric AI and congenital adrenal hyperplasia (CAH). AI requires life-long treatment and Diurnal's novel approach to product development has the potential to significantly improve these young patients' lives. The European Commission has granted a paediatric use marketing authorisation (PUMA) for Alkindi® as replacement therapy of AI in infants, children and adolescents (from birth to

Alkindi® is also approved in Israel and Australia.

Alkindi® is known as Alkindi® Sprinkle in the US and was approved by the US Food and Drug Administration (FDA) on 29 September 2020.

About Paediatric Adrenal Insufficiency

Paediatric AI is a condition characterised by deficiency in cortisol, an essential hormone in regulating metabolism and the response to stress. The primary symptoms of AI are chronic fatigue and patients are at risk of adrenal crisis and death if they do not have adequate cortisol replacement. AI is either primary or secondary, with primary AI resulting from diseases intrinsic to the adrenal gland and secondary AI resulting from pituitary diseases where there is a failure of stimulation of the adrenal by the pituitary of the signalling hormone ACTH (adrenocorticotropic hormone).

About Diurnal Group plc

Founded in 2004, Diurnal is a UK-headquartered, European specialty pharma company developing high quality products for the global market for the life-long treatment of chronic endocrine conditions, including congenital adrenal hyperplasia, adrenal insufficiency and hypogonadism. Its expertise and innovative research activities focus on circadian-based endocrinology to yield novel product candidates in the rare and chronic endocrine disease arena.

For further information about Diurnal, please visit www.diurnal.co.uk

Date of Preparation: November 2020 Code: CORP-GB-0088