Thalidomide treatment in myelofibrosis with myeloid metaplasia.
Myelofibrosis with myeloid metaplasia (MMM) is uniquely characterized by macroscopic bone marrow stromal changes that are believed to be both reactive and cytokine mediated. Furthermore, a prognostically detrimental increase in bone marrow angiogenesis has recently been demonstrated. These observations suggest a potential therapeutic role for agents that are inhibitory to angiogenesis as well as cytokines that are pathogenetically implicated in MMM. In a prospective study of 15 patients with MMM, thalidomide treatment, starting at a dose of 200 mg/d, resulted in increased platelet counts (12 of 15 patients), increased haemoglobin level (3 of 15), a modest decrease in spleen size (3 of 12), increased bone marrow megakaryopoiesis (5 of 9) and decreased bone marrow angiogenesis (2 of 9). Undesirable haematological effects included pericardial extramedullary haematopoiesis in one patient, marked leucocytosis in two patients and extreme thrombocytosis in three patients. The thrombocytosis occurred in both patients with post-thrombocythaemic myeloid metaplasia (PTMM) and was also associated with higher baseline levels of circulating CD34+ cells. Previously described toxicities of thalidomide were seen in the majority of patients and dose escalation to 400 mg/d was permitted in only two patients. In contrast, toxicity-related dose reductions to 50 mg/d did not appear to lessen drug efficacy. We conclude that thalidomide has both beneficial and potentially adverse biological activity in MMM. A lower dose of the drug might be more tolerable without compromising therapeutic value. Patients with PTMM and/or markedly increased circulating CD34+ cell counts might be susceptible to thalidomide-induced thrombocytosis.
Elliott
Michelle A
MA
Division of Hematology and Internal Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA. elliott.michelle@mayo.edu
Mesa
Ruben A
RA
Li
Chin-Yang
CY
Hook
C Christopher
CC
Ansell
Stephen M
SM
Levitt
Ralph M
RM
Geyer
Susan M
SM
Tefferi
Ayalew
A
D000328:Adult; D000368:Aged; D004334:Drug Administration Schedule; D005260:Female; D006411:Hematopoiesis, Extramedullary; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010490:Pericardial Effusion / Q000139:chemically induced; D055728:Primary Myelofibrosis / Q000150:complications* / Q000188:drug therapy*; D013792:Thalidomide / Q000009:adverse effects / Q000627:therapeutic use*; D013922:Thrombocytosis / Q000139:chemically induced
D007166:Immunosuppressive Agents; D013792:Thalidomide