[2] A new drug application was filed with the United States Food and Drug Administration based on these trials, and was rejected due to failure to show non-inferiority and due to safety concerns, especially drug-induced QT prolongation.

[10] A parallel application for marketing approval to the European Medicines Agency was withdrawn in 2009; in the announcement of the withdrawal, the EMA said that there was insufficient data from clinical studies to justify the dosage proposed by the company and that resistance to the drug had already been seen in the clinical trial data.

[14] Acino sold the rights to iclaprim, its data and regulatory filings, and manufactured drug to a group called Life Sciences Management Group of Bethesda, Maryland, in September 2013 and that company assigned its rights to a company called Nuprim,[7]: F-32  which had been formed by the former chief executive officer, chief science officer, and US agent of Arpida in 2014.

[7]: iv  In 2015, the FDA granted qualified infectious disease product status for iclaprim.

[10] In September 2017, the FDA granted orphan drug status to iclaprim for the treatment of Staphylococcus aureus lung infections in people with cystic fibrosis.