AstraZeneca blood drug dealt fresh blow by US regulator

AstraZeneca has been dealt a fresh blow by the US Food and Drug Administration in its efforts to win approval for a core drug that treats hyperkalaemia – a condition where potassium levels in the blood are too high.

The drugmaker said it had been issued with a so-called complete response letter – a formal rejection of approval for a new drug application in its present form – by the FDA for its ZS-9 drug.

The FDA rejection is the second in less than a year for AstraZeneca’s hyperkalaemia drug after it issued its first CRL in May 2016. The pharma group then said in October that it would revise its application and try again.

A spokesperson for AstraZeneca said: “As part of the FDA review an inspection took place of the ZS-9 manufacturing site in Texas US, and today’s CRL follows that inspection. The CRL does not require the generation of any new clinical data.”

The company said in a statement:

AstraZeneca and ZS Pharma are committed to working with the FDA to resolve the remaining matters under review as soon as possible.

AstraZeneca remains dedicated to developing and commercialising sodium zirconium cyclosilicate for patients with hyperkalaemia, and is confident in the profile of this potential medicine.

The decisions have come as a blow for AstraZeneca, which paid $2.7bn at the end of 2015 to snap up ZS Pharma, mainly to gain access to the hyperkalaemia drug, which the pharma group believes has huge potential.

The acquisition had been a gamble for the drugmaker that ZS-9 would win the green light from regulators, as it estimated that potential peak global sales for the drug would exceed $1bn.

However, the drugmaker has had better news from Europe on its ZS-9 drug, which was given a “positive opinion” by the Committee for Medicinal Products for Human Use in the European Union in February.