The role of hematopoietic cell transplantation in adult ALL: clinical equipoise persists

Economic evaluation of rituximab in addition to standard of care chemotherapy for adult patients with acute lymphoblastic leukemia

AIMS

Acute lymphoblastic leukemia (ALL) is an aggressive form of leukemia with a poor prognosis in adult patients. The addition of the monoclonal antibody rituximab to standard chemotherapy has been shown to improve survival in adults with ALL. However, it is unknown whether the addition of rituximab is cost-effective. The objective was to determine the economic impact of rituximab in addition to standard of care (SOC) chemotherapy vs SOC alone in newly-diagnosed Philadelphia chromosome-negative, CD20-positive, B-cell precursor ALL.

METHODS

A decision analytic model was constructed, based upon the Canadian healthcare system. It included the following health states over a lifetime horizon (max ≈60 years): event-free survival (EFS), relapsed/resistant disease, cure, and death. SOC was either hyper-CVAD or the Dana Farber Cancer Institute (DFCI) ALL consortium. EFS, overall survival, and serious adverse event (SAE) rates were derived from a large randomized controlled trial. Costs of the model included: first-line treatment and administration, disease management, second-line and third-line treatment and administration, palliative care, and SAE-related treatments. Inputs were sourced from provincial and national public data, the literature, and cancer agency input.

RESULTS

Quality-adjusted life-years (QALYs) increased by 2.20 QALYs with rituximab in addition to SOC. The resulting mean Incremental Cost-Effectiveness Ratio (ICER) was C$21,828/QALY. At a willingness-to-pay threshold of C$100,000/QALY, the probability of being cost-effective was 98%. Decision outcomes were robust to the probabilistic and deterministic sensitivity analyses, including the SOC backbone as either hyper-CVAD or DFCI.

LIMITATIONS

The results of this analysis are limited by generalizability of the chemotherapy backbone to Canadian practice.

CONCLUSIONS

For adults with ALL, rituximab in addition to SOC was found to be a cost-effective intervention, compared to SOC alone. The addition of rituximab is associated with increased life years and increased QALYs at a reasonable incremental cost.

Allogeneic stem cell transplantation in acute lymphoblastic leukemia patients older than 60 years: a survey from the acute leukemia working party of EBMT

Hematopoietic stem cell transplantation (HSCT) is being increasingly explored as a treatment modality for older patients with acute lymphoblastic leukemia (ALL). Yet, concerns regarding the long term outcome of transplantation in older patients limit the wide spread applicability of this approach. In this analysis we set out to determine the outcome of ALL patients over the age of 60 who underwent reduced intensity HSCT. Herein, we present the experience of the acute leukemia working party (ALWP) of the EBMT in this age group. We analyzed a cohort of 142 patients transplanted in first remission with a median age of 62 (range 60–76 years) and a median follow-up period of 36 months post-transplant. At 3 years, overall survival (OS) and leukemia-free survival were 42% and 35%, respectively. Multivariate analyses identified cytomegalovirus (CMV) donor-recipient matching (CMV D+/R+) to be significantly associated with inferior OS. Patients transplanted from unrelated donors experienced increased grade II-IV acute graft versus host disease compared to those receiving grafts from matched related donors [Hazard ratio (HR) of 3.7, 95% confidence interval (CI), 1.75–7.8; p = 0.0005). Outcome was not impacted by Philadelphia chromosome status. A select subset of older ALL patients will benefit from extended survival and a disease free state following HSCT.

Haploidentical transplantation compared with matched sibling and unrelated donor transplantation for adults with standard-risk acute lymphoblastic leukaemia in first complete remission

We retrospectively investigated outcomes of haploidentical donor (HID) transplant for adults with standard-risk acute lymphoblastic leukaemia (ALL) in first complete remission (CR1) compared with human leucocyte antigen (HLA)-matched sibling donor (MSD) and HLA-matched unrelated donor (MUD) transplants. A total of 348 adult patients were enrolled, including 127 HID, 144 MSD and 77 MUD recipients. The cumulative incidence of grade II-IV acute graft-versus-host disease (aGVHD) was 39·5%, 24·0% and 40·3% for HID, MSD and MUD, respectively (P = 0·020). However, there was no difference in grade III-IV aGVHD (11·4%, 7·7%, 13·5%, respectively, P = 0·468). The 5-year cumulative transplant-related mortality was 16·4%, 11·6% and 19·6% (P = 0·162), the 5-year relapse rate post-transplantation was 14·8%, 21·1% and 16·7% (P = 0·231), the 5-year overall survival was 70·1%, 73·7% and 69·8% (P = 0·525), and the 5-year disease-free survival was 68·7%, 67·3% and 63·7%, respectively (P = 0·606). Furthermore, the 3-year GVHD-free, relapse-free survival was not different (50·8%, 54·9% and 52·2%, respectively, P = 0·847). Our results indicate that the outcomes of HID transplants are equivalent to those of MSD and MUD, and that HID transplantation is a valid alternative for standard-risk adults with ALL in CR1 who lack matched donors.

Pediatric-inspired therapy compared to allografting for Philadelphia chromosome-negative adult ALL in first complete remission

For adults with Philadelphia chromosome-negative (Ph-) acute lymphoblastic leukemia (ALL) in first complete remission (CR1), allogeneic hematopoietic cell transplantation (HCT) is an established curative strategy. However, pediatric-inspired chemotherapy may also offer durable leukemia-free survival in the absence of HCT. We compared 422 HCT recipients aged 18-50 years with Ph-ALL in CR1 reported to the CIBMTR with an age-matched concurrent cohort of 108 Ph- ALL CR1 patients who received a Dana-Farber Consortium pediatric-inspired non-HCT regimen. At 4 years of follow-up, incidence of relapse after HCT was 24% (95% CI 19-28) versus 23% (95% CI 15-32) for the non-HCT (chemo) cohort (P=0.97). Treatment-related mortality (TRM) was higher in the HCT cohort [HCT 37% (95% CI 31-42) versus chemo 6% (95% CI 3-12), P<0.0001]. DFS in the HCT cohort was 40% (95% CI 35-45) versus 71% (95% CI 60-79) for chemo, P<0.0001. Similarly, OS favored chemo [HCT 45% (95% CI 40-50)] versus chemo 73% [(95% CI 63-81), P<0.0001]. In multivariable analysis, the sole factor predictive of shorter OS was the administration of HCT [hazard ratio 3.12 (1.99-4.90), P<0.0001]. For younger adults with Ph- ALL, pediatric-inspired chemotherapy had lower TRM, no increase in relapse, and superior overall survival compared to HCT. Am. J. Hematol. 91:322-329, 2016. © 2015 Wiley Periodicals, Inc.

Haploidentical hematopoietic SCT may be superior to conventional consolidation/maintenance chemotherapy as post-remission therapy for high-risk adult ALL

Only 30% of high-risk adult ALL patients in their first complete remission (CR1) are able to receive an HLA-matched sibling stem cell transplant. The role of haploidentical hematopoietic SCT (haplo-HSCT) in post-remission therapy is not well established. Recently, we developed a novel protocol for unmanipulated haploidentical transplantation. In this study, we compared haplo-HSCT with conventional consolidation and maintenance chemotherapy in adult high-risk ALL patients. Between January 2000 and December 2012, 104 patients received conventional chemotherapy and 79 patients received haplo-HSCT. Patients who underwent haplo-HSCT had significantly improved 3-year OS (72.5% vs 26.6%; P<0.001), 3-year disease-free survival (DFS) (63.9% vs 21.1%; P<0.001) and 3-year relapse (18.7% vs 60.5%; P<0.001) rates. The non-relapse mortality (NRM) rate was not different between patients treated with haplo-HSCT vs chemotherapy (19.2% vs 14.4%; P=0.80). In multivariate analysis, the only factor associated with improved OS, better DFS and low risk of relapse was haplo-HSCT. The only factor associated with high NRM was enrollment before 2006. In conclusion, haplo-HSCT may be an option for adults with high-risk ALL in CR1 who do not have an HLA-matched donor.