PTC confirmed its receipt of a complete response letter (CRL) yesterday, explaining the agency had not been convinced Translarna is an effective treatment for nonsense mutation dystrophinopathies.
CEO Stuart Peltz, said, "We believe that this decision fails to consider the benefit-risk of ataluren and the high unmet medical need. Therefore, we plan to file a formal dispute resolution request next week."
The Food and Drug Administration’s (FDA) decision was expected.
In September, an agency advisory committee told PTC “no positive results from any prospectively planned analyses that are persuasive have been provided with this application.”
In the CRL the FDA also asked for manufacturing information according to PTC, which said, “The letter also mentioned other nonclinical and CMC matters that PTC is in the process of addressing.”
A PTC spokeswoman told us the CMC matters refer to "product specifications" but did not provide additional information.
The only mention of manufacturing in the September briefing document relates to reviewers concerns about the methods PTC used to assess Translarna‘s dissolution characteristics.
The reviewers wrote that, “The provided data did not show that the proposed method is able to detect the changes in granule sizes.
“The proposed in vitro dissolution method should have discriminatory capability with regard to the Critical Material Attributes (CMAs, such as granule size) or Critical Process Parameters (CPPs, such as milling method)” they said.
The FDA's decision contrasts with the view on the other side of the Atlantic.
The European Commission approved Translarna Commission for the treatment of nmDMD in ambulatory patients aged at least five years on a conditional basis in 2014.
Translarna‘s approval was renewed in January this year in line with a recommendation by a European Medicines Agency (EMA) review committee.
An EMA spokesman told us "We are aware of the FDA’s position on Translarna, but would not comment on scientific assessments carried out by other jurisdictions."