15 November 2021

Diurnal Group plc

("Diurnal" or the "Company")

Eton Pharmaceuticals enters into US co-promotion deal for Alkindi Sprinkle^®

Agreement with Tolmar Pharmaceuticals facilitates leverage of Tolmar's 62-person paediatric endocrinology-focused salesforce

Diurnal Group plc (AIM: DNL), the specialty pharmaceutical company targeting patient needs in chronic endocrine (hormonal) diseases, notes that its US partner for Alkindi Sprinkle^® (hydrocortisone oral granules), Eton Pharmaceuticals ("Eton"), has announced a co-promotion agreement with Tolmar Pharmaceuticals ("Tolmar"). Under terms of this agreement, Tolmar's 62-person sales force will promote Alkindi Sprinkle^® to their paediatric endocrinology targets alongside its own existing product.

Eton has indicated that it expects the co-promotion agreement to translate to significantly faster adoption of Alkindi Sprinkle^® and to accelerate the time to reach peak conversion of patients from existing therapy. The terms of Diurnal's licensing agreement with Eton are unaffected by Eton's agreement with Tolmar.

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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), including congenital adrenal hyperplasia (CAH). 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 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 <18 years old) in Europe. Alkindi^® is approved and known as Alkindi^® Sprinkle in the US where it is licensed and marketed by Eton Pharmaceuticals. Alkindi^® is also approved in Israel and Australia.

About Paediatric Adrenal Insufficiency

Paediatric AI, including the genetic condition CAH 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

Diurnal Group plc is a European, UK-headquartered, specialty pharmaceutical company dedicated to developing hormone therapeutics to aid lifelong treatment for rare and chronic endocrine conditions, including congenital adrenal hyperplasia, adrenal insufficiency, hypogonadism and hypothyroidism. 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 2021                  Code: CORP-GB-0162.