Rubitecan (INN, marketing name Orathecin) is an oral topoisomerase inhibitor, developed by SuperGen (now Astex Pharmaceuticals, Inc.; a member of the Otsuka Group).

On January 27, 2004, SuperGen announced that it has completed the submission of an NDA for rubitecan to the US FDA,[2] and was accepted for filing in March 2004.

[3] In January 2005, and under the direction of then-CEO James Manuso, SuperGen withdrew the NDA for rubitecan, based on feedback indicating that the current data package would not be sufficient to gain US approval,[4] and in January 2006, the Marketing Authorization Application (MAA) filed with the European Medicines Agency (EMA) was also withdrawn.

One major problem is the lack of oral bioavailability due to low permeability and poor water solubility.

One study shows 9-NC-SD through Soluplus1-based solid dispersion system is a much more effective delivery method than free 9-NC.