A historical perspective on the development of the cytarabine (7days) and daunorubicin (3days) treatment regimen for acute myelogenous leukemia: 2013 the 40th anniversary of 7+3.

This paper reviews the development of therapy for acute myelogenous leukemia that in 1973 led to the regimen of 7days of continuous intravenous arabinosylcytosine (cytarabine) and the first 3 concurrent days of intravenous daunorubicin, given the nickname "7+3." The state of leukemia treatment in the 1950s, 1960s and early 1970s is reviewed, the discovery of the two drugs in question described, and the introduction of clinical trials to reach an optimal regimen for their use delineated. During the 1950s, following World War Two and after a period of civil reconstitution, a national effort, facilitated by the U.S. Congress and federal investments in the National Cancer Institute, was initiated to enhance cancer therapy in the United States. The development of mouse models of leukemia and advances in understanding the structure and function of DNA and RNA and the process of cell proliferation provided new targets for drug development and new concepts for their use. The year, 2013, marks the 40th year that this protocol, 7+3, is the method of induction of remission for most patients with acute myelogenous leukemia. Its inadequacies also are made clear. Many patients with the disease die soon after diagnosis, and patients who have more unfavorable oncogenetic subtypes, intrinsically drug resistant cells, and greater intolerance to therapy make up the vast majority of the affected and few are cured. It is evident to all that new paradigms are needed if acute myelogenous leukemia is to be subdued in most patients with the disease.