The antileukaemic activity of 5-Aza-2 deoxycytidine (Aza-dC) in patients with relapsed and resistant leukaemia.
In the present study we demonstrate that Aza-dC in combination with Amsacrine has major antileukaemic properties in patients who have not already received extensive Ara-C therapy. Eight out of 11 patients in their first relapse of acute leukaemia achieved complete remission. Cross resistance between Ara-C and Aza-dC was revealed by the lack of antileukaemic activity in five patients with with Ara-C resistant leukaemia. Combination therapy with Aza-dC/Ams-acrine induced a considerable period of a granulocytopenia (28-35 days), while the toxic effect on erythro- and megakaryopoiesis was comparable to that reported for high dose Ara-C/Amsacrine chemotherapy. Remarkable is the long disappearance time for leukaemic blast cells in bone marrow, i.e. 3-5 weeks in some cases. Analysis of cell membrane markers showed a loss of the early differentiation antigens CD34 and CD33 from leukaemic bone marrow cells after 7 days of Aza-dC treatment, which is suggestive of leukaemic cell differentiation. In the small group of patients tested for DNA hypomethylation no association existed between the degree of hypomethylation and clinical response. Non-haematologic side effects were considerable in patients receiving the highest dosages of Aza-dC and consisted of severe, although usually reversible, gastrointestinal and neurological complications. In comparison with Ara-C, Aza-dC causes less nausea and vomiting and is therefore better tolerated.
Richel
D J
DJ
Department of Haematology, University Medical Centre, Leiden, The Netherlands.
Colly
L P
LP
Kluin-Nelemans
J C
JC
Willemze
R
R
D000208:Acute Disease; D000328:Adult; D000677:Amsacrine / Q000008:administration & dosage; D015703:Antigens, CD / Q000032:analysis; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D001374:Azacitidine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D001853:Bone Marrow / Q000473:pathology; D000077209:Decitabine; D004351:Drug Resistance; D005260:Female; D006801:Humans; D007938:Leukemia / Q000188:drug therapy* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012008:Recurrence
D015703:Antigens, CD; D000970:Antineoplastic Agents; D000677:Amsacrine; D000077209:Decitabine; D001374:Azacitidine