813 Treatment of PH+ chronic myelogenous leukemia (CML) with interferon alfa 2B R(IFN)

In 1988 and 1990 2 randomized IFN-based (Intron A, Schering Plough) pilot trials on CML were activated. The first trial (20 untreated pts, 18 evaluated, follow-up 56 months range 10–80) compared IFN versus IFN + cytoreductive chemotherapy to evaluate time to hematological/cytogenetic responses (HR, CR), event -free/overall survivals (EFS, OS); all pts received IFN for maintenance. Except for slight advantage in time to HR ( P  = NS) in low risk pts (compared to intermediate/high risk), no difference was observed between arms in CR/EFS/OS. Two low risks pts (1 from each arm) are currently BCR-ABL (–) (PCR) at 50/61 mos f-up. The second trial (23 untreated pts, 20 evaluated, f-up 44 mos range 7–59) compared 5 versus 3 days-a-week IFN maintenance after daily IFN until HR, to evaluate the impact on CR, EFS, OS. Four low risk pts (3 with IFN 5 days-a-week) remain BCR-ABL (–) at 22, 39, 45, 49 mos f-up (2 pts no current therapy). Six hematological relapses (3 in each arm) occurred in 2 intermediate, 4 high risk pts. Pts at low risk under IFN 5 days-a-week showed better CR and survived longer (median survival not achieved at 42 mos f-up), than intermediate/high risk pts. Side effects and toxicity did not limit therapy with IFN. According to these data, IFN at higher doses during induction/maintenance induces sustained HR and CR in low risk Ph+ CML pts. On this basis, in 1993 a new stratified multicentric (GATLA) trial (IFN at higher dose plus more intensive chemotherapy for induction/maintenance) was activated.