W. Gaßmann

Chronic myeloid leukemia (CML)-study IV was designed to explore whether treatment with imatinib (IM) at 400 mg/day (n=400) could be optimized by doubling the dose (n=420), adding interferon (IFN) (n=430) or cytarabine (n=158) or using IM after IFN-failure (n=128). From July 2002 to March 2012, 1551 newly diagnosed patients in chronic phase were randomized into a 5-arm study. The study was powered to detect a survival difference of 5% at 5 years. After a median observation time of 9.5 years, 10-year overall survival was 82%, 10-year progression-free survival was 80% and 10-year relative survival was 92%. Survival between IM400 mg and any experimental arm was not different. In a multivariate analysis, risk group, major-route chromosomal aberrations, comorbidities, smoking and treatment center (academic vs other) influenced survival significantly, but not any form of treatment optimization. Patients reaching the molecular response milestones at 3, 6 and 12 months had a significant survival advantage. For responders, monotherapy with IM400 mg provides a close to normal life expectancy independent of the time to response. Survival is more determined by patients' and disease factors than by initial treatment selection. Although improvements are also needed for refractory disease, more life-time can currently be gained by carefully addressing non-CML determinants of survival.

Early intensification of chemotherapy with high-dose cytarabine either in the postremission or remission induction phase has recently been shown to improve long-term relapse-free survival (RFS) in patients with acute myeloid leukemia (AML). Comparable results have been produced with the double induction strategy. The present trial evaluated the contribution of high-dose versus standard-dose cytarabine to this strategy. Between March 1985 and November 1992, 725 eligible patients 16 to 60 years of age with newly diagnosed primary AML entered the trial. Before treatment started, patients were randomized between two versions of double induction: 2 courses of standard-dose cytarabine (ara-C) with daunorubicin and 6-thioguanine (TAD) were compared with 1 course of TAD followed by high-dose cytarabine (3 g/m2 every 12 hours for 6 times) with mitoxantrone (HAM). Second courses started on day 21 before remission criteria were reached, regardless of the presence or absence of blast cells in the bone marrow. Patients in remission received consolidation by TAD and monthly maintenance with reduced TAD courses for 3 years. The complete remission (CR) rate in the TAD-TAD compared with the TAD-HAM arm was 65% versus 71% (not significant [NS]), and the early and hypoplastic death rate was 18% versus 14% (NS). The corresponding RFS after 5 years was 29% versus 35% (NS). An explorative analysis identified a subgroup of 286 patients with a poor prognosis representing 39% of the entire population; they included patients with more than 40% residual blasts in the day-16 bone marrow, patients with unfavorable karyotype, and those with high levels of serum lactate dehydrogenase. Their CR rate was 65% versus 49% (p =.004) in favor of TAD-HAM and was associated with a superior event-free survival (median, 7 v 3 months; 5 years, 17% v 12%; P =.012) and overall survival (median, 13 v 8 months; 5 years, 24% v 18%; P =.009). This suggests that the incorporation of high-dose cytarabine with mitoxantrone may contribute a specific benefit to poor-risk patients that, however, requires further substantiation. Double induction, followed by consolidation and maintenance, proved a safe and effective strategy and a new way of delivering early intensification treatment for AML.

A total of 68 adult patients with B-cell acute lymphoblastic leukemia (B-ALL) were treated in three consecutive adult multicenter ALL studies. The diagnosis of B-ALL was confirmed by L3 morphology and/or by surface immunoglobulin (Slg) expression with > 25% blast cell infiltration in the bone marrow (BM). They were characterized by male predominance (78%) and a median age of 34 years (15 to 65 y) with only 9% adolescents (15 to 20 y), but 28% elderly patients (50 to 65 y). The patients received either a conventional (N = 9) ALL treatment regimen (ALL study 01/81) or protocols adapted from childhood B-ALL with six short, intensive 5-day cycles, alternately A and B. In study B-NHL83 (N = 24) cycle A consisted of fractionated doses of cyclophosphamide 200 mg/m2 for 5 days, intermediate-dose methotrexate (IdM) 500 mg/m2 (24 hours), in addition to cytarabine (AraC), teniposide (VM26) and prednisone. Cycle B was similar except that AraC and VM26 were replaced by doxorubicin. Major changes in study B-NHL86 (N = 35) were replacement of cyclophosphamide by ifosphamide 800 mg/m2 for 5 days, an increase of IdM to high-dose, 1,500 mg/m2 (HdM) and the addition of vincristine. A cytoreductive pretreatment with cyclophosphamide 200 mg/m2, and prednisone 60 mg/m2, each for 5 days was recommended in study B-NHL83 for patients with high white blood cell (WBC) count (> 2,500/m2) or large tumor burden and was obligatory for all patients in study B-NHL86. Central nervous system (CNS) prophylaxis/treatment consisted of intrathecal methotrexate (MTX) therapy, later extended to the triple combination of MTX, AraC, and dexamethasone, and a CNS irradiation (24 Gy) after the second cycle. Compared with the ALL 01/81 study where all the patients died, results obtained with the pediatric protocols B-NHL83 and B-NHL86 were greatly improved. The complete remission (CR) rates increased from 44% to 63% and 74%, the probability of leukemia free survival (LFS) from 0% to 50% and 71% (P = .04), and the overall survival rates from 0% to 49% and 51% (P = .001). Toxicity, mostly hematotoxicity and mucositis, was severe but manageable. In both studies B-NHL83 and B-NHL86, almost all relapses occurred within 1 year. The time to relapse was different for BM, 92 days, and for isolated CNS and combined BM and CNS relapses, 190 days (P = .08). The overall CNS relapses changed from 50% to 57% and 17%, most probably attributable to the high-dose MTX and the triple intrathecal therapy. LFS in studies B-NHL83 and B-NHL86 was significantly influenced by the initial WBC count < or > 50,000/microL, LFS 71% versus 29% (P = .003) and hemoglobin value > or < 8 g/dL, LFS 67% versus 27% (P = .02). Initial CNS involvement had no adverse impact on the outcome. Elderly B-ALL patients (> 50 years) also benefited from this treatment with a CR rate of 56% and a LFS of 56%. It is concluded that this short intensive therapy with six cycles is effective in adult B-ALL. HdM and fractionated higher doses of cyclophosphamide or ifosphamide seem the two major components of treatment.

Risk assessment in acute myeloid leukemia (AML) using pretreatment characteristics may be improved by incorporating parameters of early response to therapy. In the 1992 trial of the German AML Cooperative Group (AMLCG), the amount of residual leukemic blasts in bone marrow was assessed one week after the first induction course (day 16 blasts). A total of 449 patients 16 to 76 years of age (median, 53 years) with de novo AML entered the trial and were evaluable. Treatment included TAD/HAM (thioguanine, cytosine arabinoside, and daunorubicin/high-dose cytosine arabinoside and mitoxantrone) double induction, TAD consolidation, and randomly either maintenance therapy or S-HAM consolidation. Cytogenetics were favorable, intermediate, unfavorable and not available in 10.0%, 48.3%, 13.1%, and 28.5%, respectively. Day 16 blasts ranged from 0% to 100% (median, 5%, mean +/- SD, 18.6 +/- 28.5%). Complete remission (CR) rate was 72.6%, 17.6% had persistent leukemia (PL), and 9.8% succumbed to hypoplastic death. Median overall survival (OS), event-free survival (EFS), and relapse-free survival (RFS) were 18, 9, and 15 months with 28.4%, 21.6%, and 30.1% at 5 years, respectively. As a continuous variable, day 16 blasts were related to CR rate (P < 0.0001), PL rate (P < 0.0001), OS (P < 0.0001), EFS (P < 0.0001), and RFS (P = 0.0049). Multivariate analyses identified the following parameters to be associated with the respective end points. CR rate: day 16 blasts (P <.0001), age (P =.0036), and LDH (P =.0072); OS: unfavorable cytogenetics (P <.0001), day 16 blasts (P <.0001), age (P <.0001), and LDH (P =.0040); EFS: unfavorable cytogenetics (P <.0001), LDH (P <.0001), day 16 blasts (P <.0001), and age (P =.0061); RFS: unfavorable cytogenetics (P <.0001), LDH (P <.0001), and day 16 blasts (P =.0359). The prognostic significance of day 16 blasts is independent of pretherapeutic parameters and predicts outcome even in patients achieving a CR.

We studied the influence of comorbidities on remission rate and overall survival (OS) in patients with chronic myeloid leukemia (CML). Participants of the CML Study IV, a randomized 5-arm trial designed to optimize imatinib therapy, were analyzed for comorbidities at diagnosis using the Charlson Comorbidity Index (CCI); 511 indexed comorbidities were reported in 1519 CML patients. Age was an additional risk factor in 863 patients. Resulting CCI scores were as follows: CCI 2, n = 589; CCI 3 or 4, n = 599; CCI 5 or 6, n = 229; and CCI ≥ 7, n = 102. No differences in cumulative incidences of accelerated phase, blast crisis, or remission rates were observed between patients in the different CCI groups. Higher CCI was significantly associated with lower OS probabilities. The 8-year OS probabilities were 93.6%, 89.4%, 77.6%, and 46.4% for patients with CCI 2, 3 to 4, 5 to 6, and ≥7, respectively. In multivariate analysis, CCI was the most powerful predictor of OS, which was still valid after removal of its age-related components. Comorbidities have no impact on treatment success but do have a negative effect on OS, indicating that survival of patients with CML is determined more by comorbidities than by CML itself. OS may therefore be inappropriate as an outcome measure for specific CML treatments. The trial was registered at www.clinicaltrials.gov as #NCT00055874.