Outcomes of Patients With Acute Myeloid Leukemia Who Relapse After 5 Years of Complete Remission

Efficacy and safety of mitoxantrone, etoposide, and cytarabine for treatment of relapsed or refractory acute myeloid leukemia

BACKGROUND/RATIONALE

Most patients with acute myeloid leukemia (AML) develop relapsed or refractory (R/R) disease after receiving initial induction chemotherapy. Salvage chemotherapy followed by allogeneic hematopoietic stem cell transplantation (alloHSCT) is the only curative therapy for R/R AML. Mitoxantrone, etoposide, and cytarabine (MEC) is the current standard of care salvage regimen for R/R AML at Cleveland Clinic. The primary objective was to determine the overall remission rate (ORR: defined as patients achieving complete remission (CR) or complete remission with incomplete hematologic recovery (CRi)) in R/R AML patients who received MEC.

METHODS

Adult patients with R/R AML treated with MEC between July 1, 2014 and September 30, 2022 were included. ORR and its association with baseline characteristics were determined. Secondary outcomes included overall survival (OS), event-free survival (EFS), relapse-free survival (RFS), and safety.

RESULTS

Sixty patients were evaluated. The ORR was 51.7% (33.3% CR and 18.3% CRi). The median time from receipt of MEC to CR/CRi was 7.7 weeks. Patients with bone marrow blasts ≤20% and peripheral blood blasts ≤30% at MEC initiation were more than twice as likely to achieve CR/CRi compared to those with a higher blast burden. The median OS was 6.3 months. Twenty-four (40.0%) patients proceeded to alloHSCT. Twenty-one (35.0%) patients were transferred to the intensive care unit (ICU) during their admission.

CONCLUSIONS

MEC is an effective salvage regimen for patients with R/R AML, especially among those with low disease burden at initiation. Febrile neutropenia, infections, and severe oral mucositis were common with MEC administration.

Late relapse after hematopoietic stem cell transplantation for acute leukemia: a retrospective study by SFGM-TC

Late relapse (LR) after allogeneic hematopoietic stem cell transplantation (AHSCT) for acute leukemia is a rare event (nearly 4.5%) and raises the questions of prognosis and outcome after salvage therapy. We performed a retrospective multicentric study between January 1, 2010, and December 31, 2016, using data from the French national retrospective register ProMISe provided by the SFGM-TC (French Society for Bone Marrow Transplantation and Cellular Therapy). We included patients presenting with LR, defined as a relapse occurring at least 2 years after AHSCT. We used the Cox model to identify prognosis factors associated with LR. During the study period, a total of 7582 AHSCTs were performed in 29 centers, and 33.8% of patients relapsed. Among them, 319 (12.4%) were considered to have LR, representing an incidence of 4.2% for the entire cohort. The full dataset was available for 290 patients, including 250 (86.2%) with acute myeloid leukemia and 40 (13.8%) with acute lymphoid leukemia. The median interval from AHSCT to LR was 38.2 months (interquartile range [IQR], 29.2 to 49.7 months), and 27.2% of the patients had extramedullary involvement at LR (17.2% exclusively and 10% associated with medullary involvement). One-third of the patients had persistent full donor chimerism at LR. Median overall survival (OS) after LR was 19.9 months (IQR, 5.6 to 46.4 months). The most common salvage therapy was induction regimen (55.5%), with complete remission (CR) obtained in 50.7% of cases. Ninety-four patients (38.5%) underwent a second AHSCT, with a median OS of 20.4 months (IQR, 7.1 to 49.1 months). Nonrelapse mortality after second AHSCT was 18.2%. The Cox model identified the following factors as associated with delay of LR: disease status not in first CR at first HSCT (odds ratio [OR], 1.31; 95% confidence interval [CI], 1.04 to 1.64; P = .02) and the use of post-transplantation cyclophosphamide (OR, 2.23; 95% CI, 1.21 to 4.14; P = .01). Chronic GVHD appeared to be a protective factor (OR, .64; 95% CI, .42 to .96; P = .04). The prognosis of LR is better than in early relapse, with a median OS after LR of 19.9 months. Salvage therapy associated with a second AHSCT improves outcome and is feasible, without creating excess toxicity.

Cost-Effectiveness Analysis of Venetoclax in Combination with Azacitidine Versus Azacitidine Monotherapy in Patients with Acute Myeloid Leukemia Who are Ineligible for Intensive Chemotherapy: From a US Third Party Payer Perspective

OBJECTIVES

Using individual patient-level data from the phase 3 VIALE-A trial, this study assessed the cost-effectiveness of venetoclax in combination with azacitidine compared with azacitidine monotherapy for patients newly diagnosed with acute myeloid leukemia (AML) who are ineligible for intensive chemotherapy, from a United States (US) third-party payer perspective.

METHODS

A partitioned survival model with a 28-day cycle and three health states (event-free survival (EFS), progressive/relapsed disease, and death) was developed to estimate costs and effectiveness of venetoclax + azacitidine versus azacitidine over a lifetime (25-year) horizon. Efficacy inputs (overall survival (OS), EFS, and complete remission (CR)/CR with incomplete marrow recovery (CRi) rate) were estimated using VIALE-A data. Best-fit parametric models per Akaike Information Criterion were used to extrapolate OS until reaching EFS and extrapolate EFS until Year 5. Within EFS, the time spent in CR/CRi was estimated by applying the CR/CRi rate to the EFS curve. Past Year 5, patients still in EFS were considered cured and to have the same mortality as the US general population. Mean time on treatment (ToT) for both regimens was based on the time observed in VIALE-A. Costs of drug acquisition, drug administration (initial and subsequent treatments), subsequent stem cell transplant procedures, adverse events (AEs), and healthcare resource utilization (HRU) associated with health states were obtained from the literature/public data and inflated to 2021 US dollars. Health state utilities were estimated using EuroQol-5 dimension-5 level data from VIALE-A; AE disutilities were obtained from the literature. Incremental cost-effectiveness ratios (ICERs) per life-year (LY) and quality-adjusted life-year (QALY) gained were estimated. Deterministic sensitivity analyses (DSA), scenario analyses, and probabilistic sensitivity analyses (PSA) were also performed.

RESULTS

Over a lifetime horizon, venetoclax + azacitidine versus azacitidine led to gains of 1.89 LYs (2.99 vs. 1.10, respectively) and 1.45 QALYs (2.30 vs. 0.84, respectively). Patients receiving venetoclax + azacitidine incurred higher total lifetime costs ($250,486 vs. $110,034 (azacitidine)). The ICERs for venetoclax + azacitidine versus azacitidine were estimated at $74,141 per LY and $96,579 per QALY gained. Results from the DSA and scenario analyses supported the base-case findings, with ICERs ranging from $60,718 to $138,554 per QALY gained. The results were most sensitive to varying the parameters for the venetoclax + azacitidine base-case EFS parametric function (Gompertz), followed by alternative approaches for ToT estimation, treatment costs of venetoclax + azacitidine, standard mortality rate value and ToT estimation, alternative sources to inform HRU, different cure modeling assumptions, and the parameters for the venetoclax + azacitidine base-case OS parametric function (log-normal). Results from the PSA showed that, compared with azacitidine, venetoclax + azacitidine was cost-effective in 99.9% of cases at a willingness-to-pay threshold of $150,000 per QALY.

CONCLUSIONS

This analysis suggests that venetoclax + azacitidine offers a cost-effective strategy in the treatment of patients with newly diagnosed AML who are ineligible for intensive chemotherapy from a US third-party payer perspective.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02993523. Date of registration: 15 December 2016.