FDA staff reviewers last week expressed concerns about the efficacy of Clovis Oncology's lung cancer drug rociletinib, ahead of an advisory committee vote this week on whether to recommend approval for the drug.
Clovis is developing rociletinib for second-line treatment of non-small cell lung cancer in a sub-set of patients whose cancers express a specific mutation. Rociletinib received priority review status from the FDA in October 2015 and has also been granted accelerated assessment by the European Medicines Agency.
The reviewers questioned the reliance on unconfirmed responses in the drug's efficacy data and highlighted safety concerns, including drug-related hyperglycemia and QTc prolongation leading to Torsades de pointes.
Rociletinib response rates are also lower than AstraZeneca's Tagrisso, which would be the drug's major competitor if it makes it to market.
Last year, Clovis was hopeful an early approval would be forthcoming and that it would have a competitive advantage in the marketplace, especially given the unmet medical needs that still exist for treatment of NSCLC.
However, half a year later, things look much bleaker for Clovis' prospects. Tagrisso gained approval in November 2015 based on a sound efficacy profile, inducing a 59% response rate in clinical trials. And meanwhile, Clovis's efficacy data has generated from skepticism from experts, who have their doubts about the reliability of Clovis's unconfirmed trial responses.
Reviewers last week also indicated the drug's safety issues could require a "black box" warning for heart risks if the drug is approved.
Clovis already had to submit more data on rociletinib to the FDA in November, extending the review process by a month, according to Reuters.
Tuesday's advisory committee meeting should give a good indication of how the reviewer's criticisms will be interpreted. The FDA doesn't always follow the advisory committee's recommendations, but usually does.