The Scottish Medicines Consortium (SMC) has today accepted mercaptamine (Procysbi) for use within NHSScotland, following a third resubmission assessed under the orphan equivalent medicine process. This landmark decision marks a pivotal moment for people living with nephropathic cystinosis and their families, as it introduces long-awaited choice in primary treatment in Scotland for the first time. 

Procysbi, a 12-hourly delayed-release formulation of mercaptamine, offers an alternative to the currently available 6-hourly immediate-release cysteamine, known as Cystagon, which has been the sole treatment option for decades. The approval means patients and carers can now explore whether this formulation better suits their individual circumstances, lifestyles, and tolerability needs. 

Lesley Greene, Founder of Metabolic Support UK, reflected on the journey of cystinosis treatment and the significance of this decision, saying:

“When our daughter Jen was diagnosed with nephropathic cystinosis in 1978, we were told there was only maintenance treatment and the outlook was bleak. With help from the British Kidney Patients Association, we were directed to the dedicated paediatric nephrologist Dr Mike Winterbourne at Birmingham Children’s Hospital. His support led to Jen starting cysteamine treatment every four hours, a raw formulation with an unpleasant smell and side effects, but one that gradually brought her cystine levels down. This was in November 1981, just as we were starting the Research Trust for Metabolic Diseases in Children (RTMDC), now Metabolic Support UK.  

As Vice Chair of the Committee for Orphan Medicinal Products, I later saw how a lived experience statement from one of our members contributed to Procysbi’s approval by the European Medicines Agency. Peter, Beki and I are so proud that our Jen was a “pioneer” of Cystinosis treatment from its beginning and that the involvement of Metabolic Support UK with the SMC process has ensured the benefits of Procysbi can be experienced by those with Cystinosis in Scotland with better compliance and less treatment burden, ensuring an overall better quality of life. Thank you to everyone involved in this positive outcome.” 

Alex Hutchison, Trustee at Cystinosis Foundation UK said:

“This is a transformative moment for our community. For years, Scottish patients have had no choice in how their condition is managed. The acceptance of Procysbi not only validates the lived experience of those who advocated for its inclusion but also empowers families to make treatment decisions that reflect their realities. We can only hope that this helps neighbouring countries in gaining acceptance for use in their area, given that the Republic of Ireland, Wales and now Scotland’s governance bodies have all approved usage.” 

Laura Smith van Carroll, Head of Insight & Advocacy at Metabolic Support UK, commented:

“As an organisation founded by a family whose child was diagnosed with cystinosis, we understand firsthand the challenges that come with managing this rare and complex condition. The approval of Procysbi in Scotland marks a significant milestone for the cystinosis community, offering treatment choice, as well as the potential for improved quality of life of both those living with and caring for. We would like to thank everyone who participated in and helped disseminate the cystinosis survey, which was instrumental in providing SMC with clear, reliable evidence of the lived experience.” 

Alison Railton, Director of Policy and Public Affairs at Kidney Research UK said:

“This is great news for people living with this rare disease and their families. Having access to this treatment could make a meaningful difference, particularly for children and their parents. The twice-daily dosing means families no longer need to wake during the night, supporting a more consistent night’s sleep.“We believe everyone living with cystinosis should have access to the most effective treatments available to prevent them from developing kidney disease and eventually needing dialysis or a kidney transplant.” 

The decision follows a long SMC process covering a total of 4 submissions over a period of 8 years.  

For people living with nephropathic cystinosis, this approval means the possibility of improved adherence, reduced side effects, and a treatment schedule that may better align with daily life – particularly for children, young people, and working adults whose routines are disrupted by the current demanding dosing regimen. 

The acceptance of Procysbi is a testament to the persistence of patient advocates, clinicians, and researchers who have worked tirelessly to ensure that choice, dignity, and quality of life are central to cystinosis care in Scotland. 

Metabolic Support UK partnered with Cystinosis Foundation UK and Kidney Research UK to collaboratively write a Patient Group submission, and to prepare for and contribute to the Patient And Clinician Engagement (PACE) meeting. We extend our heartfelt thanks to the two patient and carer voices who attended the PACE meeting; their stories made a profound difference to this outcome. 

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