US FDA rejects Nicox's topical Zyrtec rival over concerns about API supplier

By Gareth Macdonald

- Last updated on GMT


Related tags Pharmaceutical drug

The US FDA has rejected an eye drug developed by Nicox SA as a result of manufacturing problems at the firm’s API supplier.

Nicox said it received a complete response letter (CRL) for AC-170 today, explaining the US regulator’s concerns pertain “solely to a GMP inspection at a third party facility producing the active pharmaceutical ingredient (API) cetirizine​.”

The French drug firm made clear the US Food and Drug Administration (FDA) has not requested additional preclinical or clinical trials. It also said the “CRL did not include any concerns related to the finished product manufacturing facility​.”

Nicox said it had contacted its suppliers to assess the timeline for the API manufacturer to address the FDA's concerns.

It added that: "Once these have been addressed, Nicox will then resubmit the AC-170 NDA​."

Nicox spokesman Nicolas Merigeau told us "the identity of the manufacturers concerned is confidential.​"

AC-170 is a formulation of cetirizine, the active ingredient in GSK and UCB's Zyrtec, that has been developed for topical application for the treatment of ocular itching associated with allergic conjunctivitis.


A delay to the approval of AC-170 will have implications for ex-shareholders of Aciex Therapeutics, which developed the drug. Aciex became a wholly-owned subsidiary of Nicox in 2014 and was subsequently renamed Nicox Ophthalmics.

If AC-170 is approved in the US before December 1 Nicox will have to pay ex-Aciex shareholders $35m (€31m) in shares. If the drug is approved after this date the payment drops to $10m in shares. 

API supply issues

The CRL is not the first API supplier related problem Nicox has encountered this year.

In July the firm said it had been informed by its partner Bausch + Lomb - a subsidiary of Valeant – had been sent a CRL concerning the production of latanoprostene bunod, the API in a developmental intraocular pressure treatment for glaucoma patients.

According to a Valeant statement​, the Bausch + Lomb letter related to a cGMP inspection at the firm's manufacturing facility in Tampa, Florida where deficiencies were identified by the FDA.

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