Susan M. Richards

Assessment of fludarabine plus cyclophosphamide for patients with chronic lymphocytic leukaemia (the LRF CLL4 Trial): a randomised controlled trial

BACKGROUND Previous studies of patients with chronic lymphocytic leukaemia reported high response rates to fludarabine combined with cyclophosphamide. We aimed to establish whether this treatment combination provided greater survival benefit than did chlorambucil or fludarabine. METHODS 777 patients with chronic lymphocytic leukaemia requiring treatment were randomly assigned to fludarabine (n=194) or fludarabine plus cyclophosphamide (196) for six courses, or chlorambucil (387) for 12 courses. The primary endpoint was overall survival, with secondary endpoints of response rates, progression-free survival, toxic effects, and quality of life. Analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number NCT 58585610. FINDINGS There was no significant difference in overall survival between patients given fludarabine plus cyclophosphamide, fludarabine, or chlorambucil. Complete and overall response rates were better with fludarabine plus cyclophosphamide than with fludarabine (complete response rate 38%vs 15%, respectively; overall response rate 94%vs 80%, respectively; p<0.0001 for both comparisons), which were in turn better than with chlorambucil (complete response rate 7%, overall response rate 72%; p=0.006 and 0.04, respectively). Progression-free survival at 5 years was significantly better with fludarabine plus cyclophosphamide (36%) than with fludarabine (10%) or chlorambucil (10%; p<0.00005). Fludarabine plus cyclophosphamide was the best combination for all ages, including patients older than 70 years, and in prognostic groups defined by immunoglobulin heavy chain gene (V(H)) mutation status and cytogenetics, which were tested in 533 and 579 cases, respectively. Patients had more neutropenia and days in hospital with fludarabine plus cyclophosphamide, or fludarabine, than with chlorambucil. There was less haemolytic anaemia with fludarabine plus cyclophosphamide (5%) than with fludarabine (11%) or chlorambucil (12%). Quality of life was better for responders, but preliminary analyses showed no significant difference between treatments. A meta-analysis of these data and those of two published phase III trials showed a consistent benefit for the fludarabine plus cyclophosphamide regimen in terms of progression-free survival. INTERPRETATION Fludarabine plus cyclophosphamide should now become the standard treatment for chronic lymphocytic leukaemia and the basis for new protocols that incorporate monoclonal antibodies.

UK Medical Research Council randomised, multicentre trial of interferon-αn1 for chronic myeloid leukaemia: improved survival irrespective of cytogenetic response

Interferon-alpha may be better than cytotoxic drugs in the long-term management of patients with chronic myeloid leukaemia (CML) in chronic phase. To test this possibility 587 patients with CML in chronic phase were randomly allocated to receive lymphoblastoid cell-line interferon-alpha n1 (IFN-alpha, n = 293) or chemotherapy with busulphan or hydroxyurea (no IFN-alpha, n = 294) as maintenance after initial induction treatment with cytotoxic drugs. There was a significant survival benefit for patients in the IFN-alpha arm when analysed on the basis of intention to treat (2p = 0.0009). The median survival for those allocated IFN-alpha was 61 months and no IFN-alpha was 41 months. Out of 269 patients with Philadelphia-positive CML in the IFN-alpha arm with at least 6 months follow-up, 211 were evaluable for haematological response: 145 (68%) achieved good responses (A+ or A type), 37 (18%) had partial responses (B type) and 29 (14%) had poor responses (C type). Patients with types A and B responses had a better survival than those in the no IFN-alpha arm; patients with type C responses had survival equivalent to the no IFN-alpha arm. Of these 269 patients, 26 of whom had not started IFN-alpha, 59 (22%) achieved a significant degree of cytogenetic response but 210 (78%) did not have a response. Cytogenetic responders survived significantly longer than non-responders and even non-responders survived longer than patients in the no IFN-alpha arm. Since cytogenetic non-responders had worse than average prognostic features, they may also benefit from IFN-alpha therapy. We conclude that treatment with IFN-alpha prolongs the survival of patients with CML; benefits of IFN-alpha are not confined to cytogenetic responders but may extend to most, if not all patients receiving IFN-alpha treatment; and cytogenetic response to IFN-alpha treatment identifies patients with a relatively good prognosis.

Intensification of treatment and survival in all children with lymphoblastic leukaemia: results of UK Medical Research Council trial UKALL X

The UK Medical Research Council trial MRC UKALL X was designed to investigate the benefit of one or two courses of additional intensification therapy in children with acute lymphoblastic leukaemia receiving standard treatment. From 1985 to 1990 1612 children, comprising more than 90% of eligible cases in the UK, were treated with intensive induction therapy, central nervous system directed therapy with cranial irradiation and intrathecal methotrexate, and continuing treatment for 2 years. 1171 children were randomised to receive additional intensification therapy at 5 weeks, 20 weeks, both, or neither. At follow-up of at least 3 years disease-free survival for all children at 5 years was 62% (95% confidence interval [Cl] 60.0-64.4), a significant improvement over the 56% (53.0-59.6) found in the preceding MRC UKALL trial. The 5-year disease-free survival was 71% (65.5-76.1) for children randomised to two blocks of intensification therapy, this being significantly better than the 62% (56.6-68.0), 61% (55.7-67.1), and 57% (50.9-62.7) rates for the groups randomised to one intensification block at 5 weeks, one at 20 weeks, and no intensification, respectively. The benefits of intensification therapy were seen irrespective of clinical factors known to influence outcome such as age, sex, and initial leucocyte count. We conclude that the addition of two courses of intensification therapy has produced a 14% improvement in disease-free survival and an 11% improvement in overall survival for the randomised patients. This additional treatment is of benefit to all children with acute lymphoblastic leukaemia, even those traditionally deemed at lower risk of relapse.

Benefit of dexamethasone compared with prednisolone for childhood acute lymphoblastic leukaemia: results of the UK Medical Research Council ALL97 randomized trial

Corticosteroids are an essential component of treatment for acute lymphoblastic leukaemia (ALL). Prednisolone is the most commonly used steroid, particularly in the maintenance phase of therapy. There is increasing evidence that, even in equipotent dosage for glucocorticoid effect, dexamethasone has enhanced lymphoblast cytotoxicity and penetration of the central nervous system (CNS) compared with prednisolone. Substitution of dexamethasone for prednisolone in the treatment of ALL might, therefore, result in improved event‐free and overall survival. Children with newly diagnosed ALL were randomly assigned to receive either dexamethasone or prednisolone in the induction, consolidation (all received dexamethasone in intensification) and continuation phases of treatment. Among 1603 eligible randomized patients, those receiving dexamethasone had half the risk of isolated CNS relapse (P = 0·0007). Event‐free survival was significantly improved with dexamethasone (84·2% vs. 75·6% at 5 years; P = 0·01), with no evidence of differing effects in any subgroup of patients. The use of 6·5 mg/m2 dexamethasone throughout treatment for ALL led to a significant decrease in the risk of relapse for all risk‐groups of patients and, despite the increased toxicity, should now be regarded as part of standard therapy for childhood ALL.

Prognostic factors in chronic lymphocytic leukaemia: the importance of age, sex and response to treatment in survival

Summary. We report the analysis of prognostic factors in a cohort of 660 patients entered in the first Medical Research Council trial in chronic lymphocytic leukaemia (CLL) between 1978 and 1984. The majority (94%) of patients were aged 50 or over and the number of men (M) was almost twice that of women (F) with an M: F ratio of 1·8: 1. The M: F ratio was lower, 1·5:1, in patients aged 70 or over. Stage A CLL was the most common, and stage C the least common, among women of all ages, in contrast to men for whom stage A only predominated in the older age group. As the majority of CLL patients are elderly we have examined the causes of death in great detail. 29% of deaths were unrelated to CLL, mainly other cancers (12%) and cardiovascular complications (16%). The majority of deaths in patients presenting with stages B and C were from CLL‐related causes, whilst almost half of the deaths in patients presenting with stage A were not obviously related to CLL. Univariate analysis disclosed that the A, B, C staging system was the most important factor considered; stratified and multivariate analysis showed that age and response to treatment were the main prognostic factors after stage. Women always fared better than men and this was independent of stage and age. This and other features documented in the trial suggest a major biological difference between the sexes which has not been widely recognized. The significant influence of treatment response on patients’ survival suggests that the search for better treatments in CLL may be rewarding. The improved median survival of stage C patients recorded in this trial, 41 months, compares favourably with previous reports and may have resulted from better treatment.

Prospective outcome data on 267 unselected adult patients with Philadelphia chromosome–positive acute lymphoblastic leukemia confirms superiority of allogeneic transplantation over chemotherapy in the pre-imatinib era: results from the International ALL Trial MRC UKALLXII/ECOG2993

Prospective data on the value of allogeneic hematopoietic stem cell transplantation (alloHSCT) in Philadelphia chromosome-positive (Ph(+)) acute lymphoblastic leukemia (ALL) are limited. The UKALLXII/ECOG 2993 study evaluated the outcome of assigning alloHSCT with a sibling (sib) or matched unrelated donor (MUD) to patients younger than 55 years of age achieving complete remission (CR). The CR rate of 267 patients, median age 40, was 82%. Twenty-eight percent of patients proceeded to alloHSCT in first CR. Age older than 55 years or a pre-HSCT event were the most common reasons for failure to progress to alloHSCT. At 5 years, overall survival (OS) was 44% after sib alloHSCT, 36% after MUD alloHSCT, and 19% after chemotherapy. After adjustment for sex, age, and white blood count and excluding chemotherapy-treated patients who relapsed or died before the median time to alloHSCT, only relapse-free survival remained significantly superior in the alloHSCT group (odds ratio 0.31, 95% confidence interval 0.16-0.61). An intention-to-treat analysis, using the availability or not of a matched sibling donor, showed 5-year OS to be nonsignificantly better at 34% with a donor versus 25% with no donor. This prospective trial in adult Ph(+) ALL indicates a modest but significant benefit to alloHSCT. This trial has been registered with clinicaltrials.gov under identifier NCT00002514 and as ISRCTN77346223.

T-cell acute lymphoblastic leukemia in adults: clinical features, immunophenotype, cytogenetics, and outcome from the large randomized prospective trial (UKALL XII/ECOG 2993)

The biology and outcome of adult T-cell acute lymphoblastic leukemia are poorly understood. We present here the clinical and biologic features of 356 patients treated uniformly on the prospective trial (UKALL XII/ECOG 2993) with the aim of describing the outcome and identifying prognostic factors. Complete remission was obtained in 94% of patients, and 48% survived 5 years. Positivity of blasts for CD1a and lack of expression of CD13 were associated with better survival (P = .01 and < .001, respectively). NOTCH1 and CDKN2A mutations were seen in 61% and 42% of those tested. Complex cytogenetic abnormalities were associated with poorer survival (19% vs 51% at 5 years, P = .006). Central nervous system involvement at diagnosis did not affect survival (47% vs 48%, P = not significant). For 99 patients randomized between autograft and chemotherapy, 5-year survival was 51% in each arm. Patients with a matched sibling donor had superior 5-year survival to those without donors (61% vs 46%, chi(2), P = .02); this was the result of less relapse (25% vs 51% at 5 years, P < .001). Only 8 of 123 relapsed patients survive. This study provides a baseline for trials of new drugs, such as nelarabine, and may allow risk-adapted therapy in patients with poor-prognosis T-cell ALL.

The impact of age on outcome in lymphoblastic leukaemia; MRC UKALL X and XA compared : a report from the MRC paediatric and adult working parties

The purpose of the study was to examine the influence of age on outcome in a large cohort of children and adults with lymphoblastic leukaemia who were treated on two similar trials. Factors influencing outcome were examined in 2204 patients aged over 1 year treated between 1985 and 1992 on the parallel Medical Research Council Trials UKALL X and Xa, for children and adults, respectively. There was a progressive worsening in survival with increasing age from 85% (95% CI 83–87) at 5 years for children aged 1–9 to 24% (CI 17–31) for patients over 40. Induction failures, deaths in remission and bone marrow relapses increased significantly with age. Analysis of clinical and biological features showed dominance of early B-ALL in childhood and increasing incidence of the Ph′ chromosome with age. Over 80% of eligible children, but a much lower proportion of adults especially those over 40, was entered. Compliance was stricter in the paediatric trial but most deviations in adults involved giving more treatment. Analysis of results in a proportional hazards model confirmed the overwhelming independent influence of age; with all other factors equal a 10 year old had half the risk of treatment failure of a 20 year old and a 44 year old double the risk. Selective entry to therapeutic trials and increased treatment-related toxicity are features of adult ALL but age itself remains a dominant prognostic factor. While improved supportive care and refinements of conventional therapy may have some effect on prognosis, new understandings and treatment approaches to adult ALL are needed.

Cytogenetics and prognosis in childhood lymphoblastic leukaemia: results of MRC UKALL X

We have analysed the prognostic influence of cytogenetic findings at diagnosis in a group of 502 children with acute lymphoblastic leukaemia (ALL), treated on MRC UKALL X, in whom clonal cytogenetic abnormalities were detected at diagnosis. Despite the overall improvement in outcome in children treated on this protocol compared with previous trials, some cytogenetically‐defined groups were still associated with a poor outcome and ploidy retained some prognostic significance. Patients with high hyperdiploid ALL (39% of those with clonal abnormalities) had a favourable outcome with event free survival of 71% at 5 years. Those with near haploidy (1%), hypodiploidy (9%) and low hyperdiploidy (16.5%) had a relatively poor prognosis with event‐free survival at 5 years of 17%, 42% and 49% respectively. Only two of 12 children with Ph‐positive leukaemia are alive in remission and abnormalities of chromosome 11q23 were also associated with a high risk of treatment failure. In contrast, the t(1;19) was associated with improved event‐free survival of 87.5% at 5 years. A number of other non‐random abnormalities were identified with no clear prognostic significance.

Three distinct subgroups of hypodiploidy in acute lymphoblastic leukaemia

This study of children and adults with acute lymphoblastic leukaemia (ALL) is the largest series of patients with hypodiploidy (<46 chromosomes) yet reported. The incidence of 5% was independent of age. Patients were subdivided by the number of chromosomes; near‐haploidy (23–29 chromosomes), low hypodiploidy (33–39 chromosomes) and high hypodiploidy (42–45 chromosomes). The near‐haploid and low hypodiploid groups were characterized by their chromosomal gains and a doubled hyperdiploid population. Structural abnormalities were more frequent in the low hypodiploid group. Near‐haploidy was restricted to children of median age 7 years (range 2–15) whereas low hypodiploidy occurred in an older group of median age 15 years (range 9–54). Patients with 42–45 chromosomes were characterized by complex karyotypes involving chromosomes 7, 9 and 12. The features shared by the few patients with 42–44 chromosomes and the large number with 45 justified their inclusion in the same group. Survival analysis showed a poor outcome for the near‐haploid and low hypodiploid groups compared to those with 42–45 chromosomes. Thus cytogenetics, or at least a clear definition of the modal chromosome number, is essential at diagnosis in order to stratify patients with hypodiploidy into the appropriate risk group for treatment.