FDA setback for AstraZeneca's hyperkalemia drug candidate ZS-9

AstraZeneca (LSE: AZN) today announced that the US Food and Drug Administration has issued a Complete Response Letter (CRL) regarding the New Drug Application for sodium zirconium cyclosilicate (ZS-9), the investigational drug being developed for the treatment of hyperkalemia (high potassium level in the blood serum) by ZS Pharma, a wholly-owned subsidiary.

The CRL refers to observations arising from a pre-approval manufacturing inspection. The FDA also acknowledged receipt of recently-submitted data which it has yet to review. The CRL does not require the generation of new clinical data. AstraZeneca and ZS Pharma are evaluating the content of the CRL and will work closely with the FDA to determine the appropriate next steps for the NDA.

Anglo-Swedish pharma major AstraZeneca remains committed to the development of sodium zirconium cyclosilicate as a treatment option for patients with hyperkalemia. Interactions are ongoing with other health authorities in the European Union and Australia, where sodium zirconium cyclosilicate is currently under separate regulatory review.