AUTOGRAFTING IN CHRONIC MYELOID-LEUKEMIA WITH CULTURED MARROW - UPDATE OF THE VANCOUVER STUDY

When chronic myeloid leukemia (CML) marrow is set up in long-term culture (LTC), Philadelphia chromosome (Ph)-positive (Ph+) cells typically decline and Ph-negative (Ph-) hematopoietic cells often become detectable. In 1987, we initiated a study to evaluate the feasibility of using 10-day cultured marrow autografts to allow intensive treatment of CML. Patients were selected on the basis of a previous assessment of the frequencies of normal and leukemic LTC-initiating cells (LTC-IC) remaining in their marrow after 10 days of LTC. Of the 87 patients evaluated, 36 (41%) were considered eligible, and 22 (15 in first chronic phase [CP], Group 1; and 7 with more advanced disease, Group 2) were autografted with 10-day cultured marrow after intensive therapy. Satisfactory hematological recovery occurred in 16 patients, and of these, only Ph cells were detected in 13 (nine in Group 1), with 76-94% Ph- cells in the other three (two in Group 1). Ph+ cells reappeared between 4 and 36 months post-autograft in all but one of the 13 patients in whom complete (morphological and cytogenetic) remission had been achieved; the remaining patient died in remission. Nine of these twelve patients were then treated with alpha-interferon (IFN-alpha) 1-3 x 10(6) units/m2, 3-7 days/week; four returned to complete remission, three developed increasing numbers of Ph+ cells, and two are still too early to evaluate. Fifteen patients (12 in Group 1) remain alive and well, nine in hematological remission (eight in Group 1), 9 to 64 months (median 28) post-autograft. Another patient (Group 1) remains alive 30 months post-autograft but has developed blast phase disease. Four patients (all in Group 1) continue in complete remission after treatment with IFN-alpha. These results establish the feasibility of using cultured marrow autografts for the treatment of CML.