Limitations for the use of medications usually includes several issues like efficacy, adverse events and also cost and availability. Nowadays several drugs can be administered at a “low dose” without therapeutic disadvantage, examples of this are: thalidomide (100 mg per day), dasatinib (50 mg per day), nivolumab 40 mg and even all-trans retinoic acid at 20-25 mg/m2 per day. It is also important to note that low dose venetoclax in combination with azoles is another new option in several diseases like CLL, NHL and AML. But in my opinion, a history of success in the world of low-dose drugs is rituximab, this antibody is usually administered at the dose of 375/m2 on its number one indication: non-Hodgkin lymphoma. However, in the setting of hematological autoimmune disease 100 mg per week for 4-6 weeks is now commonly employed in several conditions like immune thrombocytopenia, autoimmune hemolytic anemia, and thrombotic thrombocytopenic purpura. This alternative seems to be very effective, with a lower cost. Multiple articles describing positive results have been published from China, Italy, and Mexico among others. It is noteworthy that the American Society of Hematology’s ITP guidelines (2019) suggest, in a hallmark, that rituximab could be used in newly diagnosed ITP patients “if a rapid and sustained response is considered important”. Low dose drugs is a field of research that is very important for low and middle income countries. Every effort to reduce costs in the treatment of hematological diseases, without losing response, are very welcome all over the world.
David Gómez-Almaguer MD
ISH Chair of Council