OBJECTIVES: To seek insight and validation on the treatment and management of dRTA for the purpose of supporting reimbursement submissions.

METHODS:

Distal renal tubular acidosis (dRTA) is a rare disorder of impaired net acid secretion by the distal tubule characterised by hyperchloraemic metabolic acidosis. It can be acquired or inherited, and if left untreated or poorly treated, can be severely debilitating.

The research was conducted from September to October 2020.

Recruitment was targeted at expert clinicians treating dRTA. 11 nephrologists participated in stage 1 of this Delphi research. Individual telephone discussions were conducted with adult and paediatric clinicians from England, Ireland, Scotland, and Wales during September and October 2020.

The objective of the panel workshop on Thursday 22nd October 2020 was to refine the findings and seek consensus where this was lacking with the support of a urologist.

The panel represents approximately 204 patients (estimated 179 adults and 25 children). This report presents an anonymised and consolidated summary

RESULTS:

Treatment and compliance

• Majority of patients are prescribed bicarbonate or citrate
• Advisors agreed, using the split of treatments described in study B21CS is appropriate for the model
• The estimated average percentage of patients who are fully compliant with their treatment was 37%
• Advisors strongly associate the burden of treatment with the volume and frequency of medication needed

Modelling assumptions and pathways

• Treatment goals are to correct biochemistry, normalisation of acid-based balance (plasma and urine pH), and prevent disease consequences
• Healthcare resource use depends on disease control and compliance
• It is acceptable to assume that disease control stabilises post-24 months if the patient is compliant with alkali therapy

CONCLUSIONS:

Patients with dRTA are a rare population with an unmet need to manage their disease.