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Procysbi® (mercaptamine bitartrate gastro-resistant hard capsules) recommended for use within NHS Wales as an option for the treatment of patients with nephropathic cystinosis

Procysbi® (mercaptamine bitartrate gastro-resistant hard capsules) recommended for use within NHS Wales as an option for the treatment of patients with nephropathic cystinosis


  • The All Wales Medicines Strategy Group (AWMSG) is the first health technology assessor in the UK to recommend Procysbi®, which will now be available on the NHS in Wales.1
  • Procysbi® is a twice-daily delayed-release formulation of mercaptamine with 12-hour dosing, which reduces cystine accumulation in some cells of patients with nephropathic cystinosis and, when treatment is started early, it delays the development of kidney failure.2


Manchester, UK, 19 May 2022 - Chiesi Limited is delighted that the AWMSG has recommended Procysbi® (mercaptamine bitartrate gastro-resistant hard capsules) as an option for use within NHS Wales for the treatment of patients with proven nephropathic cystinosis. Procysbi® was considered as an ultra-orphan medicine according to the criteria in the AWMSG appraisal process for a medicine for a rare disease.1 Procysbi® is now reimbursed in Wales, but not in England, Scotland or Northern Ireland.


Nephropathic cystinosis is a rare, lysosomal storage disorder that causes progressive damage throughout the body.3 It causes multiple organ dysfunction due to the accumulation of cystine in the tissues, leading to complications including kidney failure, diabetes, hypothyroidism, myopathy, and central nervous system deterioration.4 Sustained treatment with mercaptamine (a cystine-depleting agent) is essential to delay end-stage kidney disease and increase life expectancy.Cystinosis is estimated to affect up to 1 in 100,000 births, equating to fewer than 40 people in Wales.3,6


Before Procysbi® was recommended by AWMSG, the only routinely available treatment for patients with nephropathic cystinosis in the UK was immediate-release (IR) mercaptamine (Cystagon®). Adherence to IR-mercaptamine can be challenging, especially in adolescents and adults,5 due to the 6-hourly dosing schedule that requires night-time administration and its association with halitosis (bad breath).3,5 Procysbi® is a delayed-release formulation of mercaptamine with twice-daily 12-hour dosing, which reduces the administration burden for patient and carers when compared with a 6-hourly IR-mercaptamine regimen.7


“We are extremely pleased that patients in Wales with this devastating condition have the opportunity to access Procysbi®,” said Sarah O’Connell, Head of Rare Diseases, Chiesi Limited: “Chiesi is committed to discovering, developing and commercialising innovative therapies to address unmet needs for people living with rare diseases. We look forward to working with NHS England and NHS Scotland in future HTA assessments of Procysbi.”


About Procysbi® (mercaptamine bitartrate, also known as cysteamine)

Procysbi® is a beaded, enteric-coated, delayed-release form of cysteamine, in which the microspheronized beads are further encapsulated in hard gelatin to allow oral administration every 12 hours.7 Procysbi® is available in either 25 mg or 75 mg gastro-resistant hard capsules of cysteamine.1 Therapy should be initiated as early as possible following diagnosis and continued throughout life.8

In a pivotal Phase III trial, Procysbi® showed non-inferiority to IR- mercaptamine in the per protocol analysis in patients who were well controlled on IR- mercaptamine.7 Per protocol analysis included 38 subjects, following exclusion of three patients who had a three-day average white blood cell (WBC) level > 2 nmol hemi-cystine/mg protein during one of the IR-mercaptamine treatment periods and were, therefore, considered not well controlled.7 A total of 119 adverse events (AEs) and serious AEs were reported, of which 45% were gastrointestinal (GI). Of these, 70% during the crossover period were considered to be related to study drug (Procysbi® or IR-mercaptamine).7 More GI AEs were related to Procysbi® than to IR- mercaptamine (44% vs 15% for Procysbi® and IR- mercaptamine, respectively).7 This may be associated with proton pump inhibitors (PPIs) being stopped abruptly for patients during the Procysbi® treatment (72% of the patients using PPIs during IR- mercaptamine period stopped them when starting Procysbi®) – these participants were previously taking a stable dose of IR- mercaptamine.7 No unexpected serious AEs associated with Procysbi or IR- mercaptamine were seen during the study.7

For the Summary of Product Characteristics for Procysbi®, please visit

About Chiesi Group   

Based in Parma, Italy, Chiesi is an international research-focused pharmaceuticals and healthcare group with over 85 years’ experience, operating in 30 countries with more than 6,000 employees (Chiesi Group). To achieve its mission of improving people’s quality of life by acting responsibly towards society and the environment, the Group research, develops and markets innovative therapeutic solutions in its three focus areas: AIR (products and services that promote respiration, from new-born to adult populations), RARE (treatment for patients with rare and ultra-rare diseases) and CARE (products and services that support specialty care and consumer-facing self-care). The Group’s Research and Development centre is based in Parma and works alongside 6 other important research and development hubs in France, the U.S., Canada, China, the UK, and Sweden to pursue its pre-clinical, clinical, and regulatory programmes. Chiesi, since 2019, is the world’s largest B Corp certified pharmaceutical group. The global B Corp movement promotes business as a force for good. Moreover, Chiesi Farmaceutici S.p.A. has changed in 2018 its legal status to a Benefit Corporation, by incorporating a double purpose for the creation of shared value, and to generate value for its business, for society and the environment. As a Benefit Corporation, Chiesi Farmaceutici S.p.A. is required by law to include objectives of common benefit in its bylaws and to report annually in a transparent way. The Group is committed to becoming carbon neutral by the end of 2035. For further information:   

Chiesi Limited is the UK & Republic of Ireland affiliate of Chiesi Group. For more information, please visit


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  1. All Wales Medicines Strategy Group, Final Appraisal Recommendation Advice number: 0922, April 2022.
  2. Chiesi Limited. Procysbi Summary of Product Characteristics. Available at: Accessed 25 April 2022.
  3. Ahlenstiel-Grunow T, Kanzelmeyer N, Froede K, et al. Switching from immediate- to extended-release cysteamine in nephropathic cystinosis patients: a retrospective real-life single-center study. Pediatric nephrology. 2017;32(1):91-97.
  4. Cherqui S. Cysteamine therapy: a treatment for cystinosis, not a cure. Kidney Int 2012;81:127–9.
  5. Ariceta G, Lara E, Camacho JA, et al. Cysteamine (Cystagon(R)) adherence in patients with cystinosis in Spain: successful in children and a challenge in adolescents and adults. Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association. 2015;30(3):475-480.
  6. Office for National Statistics, 2021: mid-2020 population estimates for UK, England and Wales, Scotland and Northern Ireland. Available at: Accessed 25 April 2022
  7. Langman CB, et al. A Randomized Controlled Crossover Trial with Delayed-Release Cysteamine Bitartrate in Nephropathic Cystinosis: Effectiveness on White Blood Cell Cystine Levels and Comparison of Safety. Clin J Am Soc Nephrol. 2012;7:1112–20. [Erratum in Clin J Am Soc Nephrol. 2013;8:468].
  8. Ariceta G, Giordano V, Santos F. Effects of long-term cysteamine treatment in patients with cystinosis. Pediatr Nephrol. 2019 Apr;34(4):571-578.


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Last Updated: 20-May-2022