AstraZeneca, ZS Pharma overcome manufacturing issues to get potential blockbuster back on track

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AstraZeneca says potential blockbuster hyperkalemia drug ZS-9 is back on track after the FDA rejected it in 2016.

AstraZeneca said its potential blockbuster hyperkalemia drug ZS-9 is back on track after the FDA rejected it in 2016 due to manufacturing issues at its Texas facility.

A decision by the U.S. regulatory agency on the drug is expected in the first half of 2018, the company said in its 2017 year-end earnings report. During a conference call with analysts, the company said there was “encouraging news for ZS-9 in both the U.S. and the EU.”

In the period reported, the company said the FDA had “accepted the Class II regulatory resubmission for ZS-9” in the wake of AstraZeneca’s rectifying deficiencies at the manufacturing facility. Additionally, it said EU regulators (the Committee for Medicinal Products for Human Use) reiterated their recommendation granting marketing authorization for the drug in Europe. That agency had previously suspended its recommendation over the same issues.

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The drug is designed to treat hyperkalemia, a disease in which dangerously high potassium levels threaten kidney and heart function. AstraZeneca has forecast global peak sales for ZS-9 in excess of $1 billion a year. Some analysts have pegged the hyperkalemia treatment market to be worth more than $6 billion.

AstraZeneca shelled out $2.7 billion for ZS Pharma in 2015 to get access to the drug, but the FDA rejected its application twice because of manufacturing issues at the ZS Pharma manufacturing plant in Texas. An 11-page Form 483 included five observations over concerns ranging from incomplete validation records to particulates in some samples. Audit trails were missing for some equipment, and there were problems with scale-up, with five out-of-spec reports issued in four months, all illustrating the difficulty that ZS Pharma was having getting the API to meet its criteria.

At the time it said it would put the full power of its global manufacturing experience to resolve the issues at the facility.

If approved, AstraZeneca’s drug will go head-to-head with Relypsa’s hyperkalemia treatment Veltassa, which was approved in late 2015.