FDA Grants N-Methanocarbathymidine Orphan Drug Designation

N-Methanocarbathymidine,a novel thymidine analog antiviral being developed by N&N Pharmaceuticals Inc.,has now been granted Orphan Drug Designation by the FDA.

N-Methanocarbathymidine (N-MCT) is a novel antiviral drug being developed by N&N Pharmaceuticals Inc. (N&N) for the treatment of neonatal herpes simplex.  N-MCT is a thymidine analog with potent activity against herpes simplex virus types 1 (HSV-1) and 2 (HSV-2).1 N-MCT has now been granted Orphan Drug Designation by The US Food and Drug Administration (FDA).2

A phase I clinical trial of N-MCT (ClinicalTrials.gov Identifier: NCT02778386) is underway to determine the safety and tolerability of N-MCT, evaluating a dose range of 200mg – 1200mg in healthy male and non-pregnant, non-lactating female study participants.3 Primary outcome measures include type, incidence, and severity of observed adverse events in the first 7 days after drug exposure. Secondary outcome measures include pharmacokinetics of N-MCT, including plasma and urine concentrations at several time points after oral administration.

“We have seen a high spectrum of activity of this drug in multiple viral diseases. N-MCT has shown significant activity in shingles, genital herpes, neonatal herpes and in small pox,” said Aquilur Rahman, PhD, President and CEO of N&N. He added that the company will “pursue shingles as the first indication for N-MCT.”

“In pre-clinical studies with shingle models, N-MCT has shown significantly more pronounced antiviral activity than any other known commercially available drug on the market,” said Dr Rahman.

The Orphan Drug Designation of N-MCT provides N&N “certain benefits and incentives; including a period of marketing exclusivity, potential tax credits for certain activities and other assistance to develop effective therapy for the lethal diseases,” said Naveed Rahman, Director of Business Development for N&N.


NCT02778386 is funded by N&N Pharmaceuticals, the manufacturer of N-MCT.

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  1. Zalah L, Huleihel M, Manor E, et al. Metabolic pathways of N-methanocarbathymidine, a novel antiviral agent, in native and herpes simplex virus type 1 infected Vero cells. Antiviral Res. 2002;55(1):63-75.
  2. N-Methanocarbathymidine Granted Orphan Drug Designation in the US. PR Newswire. Available at:http://www.prnewswire.com/news-releases/n-methanocarbathymidine-granted-orphan-drug-designation-in-the-us-300334437.html. September 27, 2016. Accessed October 3, 2016.
  3. N&N Pharmaceuticals Inc. Commences Clinical Trials on its Novel Antiviral Drug. PR Newswire. Available at:http://www.prnewswire.com/news-releases/nn-pharmaceuticals-inc-commences-clinical-trials-on-its-novel-antiviral-drug-300254173.html. April 20, 2016. Accessed October 3, 2016.