Treatment of chronic myelogenous leukaemia with interferons [IFN]

ABSTRACT

The aim of this work was to evaluate the safety and efficacy of recombinant alpha-2 IFN alone or with Hydroxyura [H.U.] in the treatment of patients wit chronic phase Philadelphia positive [PH + Ve] CML. Between November 1990 and December 1991 inclusive 8 previously untreated patients with PH + Ve chronic phase of CML were allocated to receive either IFN alone [group A] or IFN + H.U. [group B]. The two groups were comparable as regards number of patients [4], age, sex, presenting symptoms, peroformance status, peripheral blood A patients was 215x10 /L versus 239x10 /L for group B. The mean follow- up period for group A and B were 32 and 20.5 months respectively. All patients [8/8] went into complete hematologic remission [CHR]. However, time to attain CHR was much shorter in group B [mean 2.6 months] than in group A [mean 6.6 months]. Complete cytogenetic remission [CCR] was documented in 3/4 patients of group A and in 2/4 patients of group B. However, 3 of these 5 patients in CCR has residual palpable spleen the nature of which was not histopathologically confirmed, but ultrasonographic findings of bilharziasis were evident. All patients [8/8] showed hematologic relapse after a mean period of 2 months [range 1-3] of cessation of maintenance IFN. Only one of these relapsed patients [1/8] was retreated with IFN alone for 3 months during which he attained a second CHR and CCR but he relapsed within 6 months of cessation of IFN. No life threatening complication was recoreded although a variable degrees of musculoskeletal pains were recorded. In conclusion, alpha 2-IFN is an effective safe treatment of chronic phase PH + Ve CML patients and is capable of inducing CCR. Achieving a second CCR by alpha 2-IFN is possible i.e lack of drug resistance and the addition of H.U. to alpha 2-IFN during induction can reduce time to CHR by about 4 months. Reappearance of PH [+] ve cells shortly after cessation of maintenance alpha 2-IFN may indicate the need of its prolongation and the importance of confirming complete remission at molecular level