- AstraZeneca's drug for people with too much potassium in their blood is facing yet another detour on its road to U.S. approval, this time for manufacturing concerns.
- The London-based company revealed on Friday the Food and Drug Administration had issued a complete response letter (CRL) for ZS-9 (sodium zirconium cyclosilicate) following an inspection of a facility producing the drug.
- While few details were given in that statement, AstraZeneca did say the FDA isn't seeking more data on ZS-9 — a relatively positive sign, as it implies that issues with manufacturing equipment or protocols are stalling an approval decision, rather than worries about the drug's safety or efficacy.
ZS-9 aims to treat hyperkalemia, a disorder characterized by high potassium levels in the blood that in turn can harm the heart. Hyperkalemia is strongly associated with chronic kidney disease (CDK), which affects about 10% of the world's population. Some estimates hold that up to 50% of that population have hyperkalemia, representing an enormous pool of patients for drugmakers to tap into.
Surprisingly, few marketed products specifically target the disorder. The main contender is Relypsa's Veltassa (patiromer), which gained FDA approval in October 2015. Less than a year later, Swiss pharma Galenica Group acquired Relypsa for access to the drug in a deal worth about $1.5 billion.
At the time, analysts expected the drug could serve a patient population of 2.4 million in the U.S. and reach peak annual sales of about $1 billion. In the first half of 2016, however, the drug brought in just $2.7 million in net revenue, according to Relypsa's most recent 10-Q filing with the Securities and Exchange Commission.
AstraZeneca announced its acquisition of ZS Pharma, which gave it control of ZS-9, in late 2015 as well, though for a much higher price tag of $2.7 billion. The big medicines maker called the drug a "potential best-in-class treatment," and anticipated it would help boost the company's cardiovascular and metabolic disease portfolio.
But manufacturing failures have gummed up the drug's approval prospects since the first half of 2016. AstraZeneca received another CRL last May, for example, related to "observations arising from a pre-approval manufacturing inspection," according to a statement.
In any case, investors didn't seem to react too drastically to the news. AstraZeneca's stock was up less than two-tenths of a percent in Friday morning trading.
AstraZeneca did not respond to request for additional details regarding the most recent CRL.