NRx reports positive FDA feedback on preservative-free ketamine filings
NRx said the FDA issued a positive review letter on its preservative-free ketamine ANDA, requesting only minor administrative changes. The company also received FDA guidance outlining a path to an NDA for NRX-100 using clinical trial data and real-world evidence.
NRx Pharmaceuticals said it received a positive Discipline Review Letter from the FDA Office of Generic Drugs on its preservative-free ketamine ANDA and completed a supportive meeting with Generic Drug Leadership. The letter requests only administrative changes and updates to prior stability data, all of which are identified as “Minor,” and FDA leadership expressed support for addressing the remaining aspects of the current ANDA application within the current review cycle that targets approval in Summer 2026.
The Discipline Review Letter entitled “Quality” covers the areas of Drug Substance, Drug Product, Manufacturing, and Microbiology. The positive review letter follows the previously announced favorable bioequivalence determination from the FDA Office of Generic Drugs on March 17, 2026, and represents a separate review discipline within the ANDA process.
NRx said the national priority around expediting approval of ketamine, now documented in the President’s April 16, 2026 Executive Order, was recognized by FDA leadership. The Executive Order calls for expedited approval of drugs to treat severe depression and suicidality, and the company said the approval of the preservative-free ketamine ANDA is particularly important because of supply shortages documented by physicians who seek to obtain ketamine for use in the clinic setting.
NRx said its presentation of ketamine differs from existing products in that it does not contain Benzethonium Chloride. The company said this preservative is no longer allowed to be included in new drugs and according to FDA policy cannot even be included in hand cleansers and topical antiseptics.
The company also said it completed a Type C guidance meeting with the FDA and received oral feedback outlining a path to filing a New Drug Application for NRX-100. The FDA indicated that existing clinical trial data, combined with Real World Evidence from more than 65,000 patients, could provide Substantial Evidence of Effectiveness under the drug’s Fast Track Designation, and the agency advised that no additional nonclinical data or bridging studies would be required to support the NDA.
Based on that guidance, NRx plans to seek a broader indication for NRX-100 to serve patients with treatment-resistant depression who may have suicidality, rather than limiting the application to those with suicidality alone. The company said it will work with the FDA to finalize the statistical analysis protocol for the Real-World Evidence dataset.
NRx said ketamine is identified as medically necessary by the U.S. Department of Veterans Affairs for the treatment of suicidality and treatment-resistant depression. The company is developing NRX-100, preservative-free intravenous ketamine, and said NRX-100 has been awarded Fast Track Designation for the treatment of Suicidal ideation in Depression, including Bipolar Depression. NRx also said it has filed an Abbreviated New Drug Application and initiated a New Drug Application filing for NRX-100 for the treatment of suicidal ideation in patients with depression, including bipolar depression.