International reference analysis of outcomes in adults with B-precursor Ph-negative relapsed/refractory acute lymphoblastic leukemia

Abstract

A dults with relapsed/refractory acute lymphoblastic leukemia have an unfavourable prognosis, which is influenced by disease and patient characteristics. To further evaluate these characteristics, a retrospective analysis of 1,706 adult patients with Ph-negative relapsed/refractory B-precursor acute lymphoblastic leukemia diagnosed between 1990-2013 was conducted using data reflecting the standard of care from 11 study groups and large centers in Europe and the United States. Outcomes included complete remission, overall survival, and realization of stem cell transplantation after salvage treatment. The overall complete remission rate after first salvage was 40%, ranging from 35%-41% across disease status categories (primary refractory, relapsed with or without prior transplant), and was lower after second (21%) and third or greater (11%) salvage. The overall complete remission rate was higher for patients diagnosed from 2005 onward (45%, 95% CI: 39%-50%). One-and three-year survival rates after first, second, and third or greater salvage were 26% and 11%, 18% and 6%, and 15% and 4%, respectively, and rates were 2%-5% higher among patients diagnosed from 2005. Prognostic factors included younger age, longer duration of first remission, and lower white blood cell counts at primary diagnosis. This large dataset can provide detailed reference outcomes for patients with relapsed/refractory Ph-negative B-precursor acute lymphoblastic leukemia. clinicaltrials.gov identifier: 02003612 IntroductionOverall prognosis among adult acute lymphoblastic leukemia (ALL) patients has improved by optimisation of front-line therapy, 1 but outcomes remain poor for patients who relapse or are refractory to initial treatment. Reported rates of complete remission (CR) after salvage treatment range from 18%-45%, and median survival times range from 2-8 months, with less than 10% survival after 5 years in most studies.2-7 Achievement of CR and subsequent HSCT is the only curative option in relapsed adult ALL; 2,3,6 however, this can only be achieved in a subgroup For these reasons, new treatment options are needed for adult patients with relapsed/refractory (r/r) ALL, and a number of promising compounds are currently under clinical evaluation. 8,9 The rarity of adult r/r ALL, 10 combined with the very poor outcomes and non-standardised approaches of salvage therapies, make it difficult to conduct randomised trials of new compounds. Approvals of new treatments are therefore often based on evidence from phase 2 single-arm trials. 11-14To attain a more precise estimate of clinical practice outcomes in adult r/r ALL, and to evaluate important patient subgroups, we pooled data from major national study groups and large individual sites treating adult ALL from Europe and the United States to create the most extensive clinical dataset available in this population.The analysis aimed to describe patient characteristics and outcome parameters (achievement of CR, overall survival [OS] and realization of allogeneic HSCT) among adult patients with P...

Tisagenlecleucel-T for the treatment of acute lymphocytic leukemia

“…In the relapse setting, allogeneic HSCT remains the best curative option. However, it can only be performed in a subgroup of patients [14] who have reached a CR status with preferably MDR-negativity [15]. Thus, innovative therapeutic options are needed in this situation.…”

Updates in Adult Acute Lymphoblastic Leukemia—Current Status of Antigen-targeted Treatments and Immunotherapy

“…4,5,8 A retrospective analysis of 1,706 adult patients with Philadelphia chromosome-negative R/R BCP-ALL from 11 study groups and large centers was recently conducted in order to provide detailed reference outcomes for this patient population. 10 The overall CR rate after first salvage was 40%, ranging from 35-41% across disease status categories (primary refractory, relapsed with or without prior transplant), and was lower after second (21%) or further (11%) salvage. The 3-year survival rates range from 2-5%.…”

Inclusion and response criteria for clinical trials in relapsed/refractory acute lymphoblastic leukemia and usefulness of historical control trials

“…The response rates in our historical study varied between 11% to 41%, depending on the line of salvage and type of relapse. 20 This observation is very important for the appropriate interpretation of trials with new compounds, because outcomes may vary depending on the type of relapses included in the trials, e.g., poorer results in trials with a high proportion of early, refractory relapses or relapses after transplant. We consider the bias of selected relapse categories in pivotal clinical trials far more important than the bias induced by slightly different thresholds for bone marrow involvement or general inclusion or exclusion criteria.…”