Second transplants for patients with chronic myeloid leukaemia in relapse after original transplant with T-depleted donor marrow: feasibility of using busulphan alone for re-conditioning.

Summary. Between July 1986 and March 1991, 16 patients who had relapsed after T-lymphocyte depleted bone marrow transplantation (BMT) for chronic myeloid leukaemia (CML) received a second transplant using unmanipulated marrow cells from the same HLA-identical sibling donor. The median numbers of days from first BMT to haematological relapse and to second BMT were 557 (range 273–1543) and 1211 (range 476–2310) respectively. 11 patients were in uncomplicated chronic phase at time of second BMT, and five had more advanced disease. As conditioning for second BMT, eight patients received various combinations of cytotoxic drugs, and eight received high-dose busulphan alone. Eight (50%) patients survive at a median of 424 d post-second BMT (range 158–1789) and all are free of leukaemia by conventional criteria: five had been conditioned with high-dose busulphan alone. Causes of death in the eight patients who died included relapse (n= 2), graft-versus-host disease (n= 2). interstitial pneumonias (n= 2), and infection (n= 2). We conclude that patients relapsing into chronic phase after BMT with T-lymphocyte depleted donor marrow may be offered the option of second BMT with unmanipulated marrow from the original donor. Conditioning with high-dose busulphan alone may be safer than use of more intensive schedules.