Decitabine: 2'-deoxy-5-azacytidine, Aza dC, DAC, dezocitidine, NSC 127716.

Abstract

Decitabine [NSC 127716, DAC, dezocitidine, Aza dC, 2'-deoxy-5-azacytidine] is a deoxycytidine and cytarabine derivative with potent antileukaemic activity, which was originated by Pharmachemie. This antimetabolite is able to induce in vitro gene activation and cellular differentiation by a mechanism involving DNA hypomethylation. SuperGen acquired worldwide rights to decitabine from Pharmachemie in the third quarter of 1999 for 4 million US dollars worth of SuperGen shares and income from manufacture upon the launch of decitabine. SuperGen announced in May 2000 that it had entered a Cooperative Research and Development Agreement (CRADA) with the US National Cancer Institute (NCI). SuperGen will supply decitabine to the NCI, which will initiate and sponsor clinical trials in patients with solid tumours and haematological malignancies. The NCI will also conduct studies on decitabine's mechanism of action. In 2002, the US FDA has granted decitabine orphan drug status for the treatment of myelodysplastic syndromes and sickle cell anaemia. In February 2003, the European Commission granted orphan drug status to decitabine for myelodysplastic syndrome. Decitabine has also received orphan drug status in the US as a host-protective agent in the treatment of AML. Decitabine has been studied in solid tumours as well as in different types of leukaemia. In several phase II studies it has been shown to have very limited efficacy against solid tumours. However, decitabine has shown better activity in the treatment of haematological malignancies such as acute myeloid leukaemia (AML), chronic myeloid leukaemia (CML) and myelodysplastic syndrome (preleukaemia). In March 2001, SuperGen announced that it had begun patient enrolment into its pivotal open-label phase III trial of decitabine in advanced myelodysplastic syndrome patients. The study, which will compare decitabine with standard care therapy, will be conducted at 15 medical centres in the US and will enrol a total of 160 patients. In March 2003, SuperGen announced that patient enrolment was complete. The study, which will compare decitabine with standard care therapy, will be conducted at 22 medical centres in the US and will enrol a total of 160 patients. A European pivotal trial is also underway for the same indication, and is aiming to enrol 220 patients. A phase I/II trial of 8 patients, designed to establish safety and efficacy in the treatment of sickle cell anaemia, has been completed at the University of Illinois, USA. Plans for additional studies of decitabine as a treatment for sickle cell anaemia are underway. Decitabine is also undergoing phase II clinical trials in Canada, for the treatment of non-small cell lung cancer, and in the US for chronic myeloid leukaemia and prostate cancer. Glasgow University in Scotland has conducted preclinical trials in chemotherapy-resistant ovarian and colon cancers. The results suggest that decitabine administration may reverse chemotherapy resistance in these cancers. SuperGen was issued a US patent (No. 6 191 119) in 2001 covering the use of decitabine in combination with rubitecan and antibiotic agents, including doxorubicin.