Rates of complete diagnostic testing for patients with acute myeloid leukemia

Real-world genomic testing and treatment patterns of newly diagnosed adult acute myeloid leukemia patients within a comprehensive health system

BACKGROUND

We evaluated the frequency of genomic testing and treatment patterns by age category in patients with newly diagnosed (ND) acute myeloid leukemia (AML) treated in both academic- and community-based health systems within a single Midwestern State.

METHODS

Retrospective analysis of data from the Indiana University Health System Enterprise Data Warehouse and two local cancer registries, of 629 patients aged ≥18 years with ND AML during 2011-2018. Primary outcome variables were, proportion of patients with genomic analysis and frequency of mutations. Chemotherapy was categorized as "standard induction" or "other chemotherapy"/targeted therapy, and hypomethylating agents.

RESULTS

Overall, 13% of ND AML patients between 2011 and 2018 had evidence of a genomic sequencing report with a demonstrated increase to 37% since 2016. Genomic testing was more likely performed in patients: aged ≤60 years than >60 years (45% vs. 30%; p = 0.03), treated in academic versus community hospitals (44% vs. 26%; p = 0.01), and in chemotherapy recipients than non-therapy recipients (46% vs. 19%; p < 0.001). Most common mutations were ASXL1, NPM1, and FLT3. Patients ≥75 years had highest proportion (46%) of multiple (≥3) mutations. Overall, 31.2% of patients with AML did not receive any therapy for their disease. This subgroup was older than chemotherapy recipients (mean age: 71.4 vs. 55.7 years, p < 0.001), and was highest (66.2%) in patients ≥75 years.

CONCLUSIONS

Our results highlight the unmet medical need to increase access to genomic testing to afford treatment options, particularly to older AML patients in the real-world setting, in this new era of targeted therapies.

Practice patterns and outcomes for adults with acute myeloid leukemia receiving care in community vs academic settings

Consistent with observations in other disease settings, retrospective studies have indicated that treatment outcomes for adults with acute myeloid leukemia (AML) are better in higher- vs lower-volume hospitals and academic vs nonacademic centers, with greatest benefits noted in acute promyelocytic leukemia. Younger age, more frequent receipt of chemotherapy and hematopoietic cell transplantation, and differences in comorbidities and socioeconomic factors may partially account for these differences. With new therapeutic options including oral small molecule inhibitors and parenteral drugs suitable for outpatient administration, there is increasing interest from patients and physicians in treating AML in the community setting and avoiding referral to academic centers. This may be particularly true for older adults, for whom treatment rates in the community have historically been low, and for those with comorbidities, because treatment benefits are estimated to be low, and thus travel to academic centers is perceived as especially burdensome. How the volume-outcome relationship is affected by the shift of the treatment landscape in AML over the last few years is unknown. Additionally, improvements in supportive care (transfusion support, broad-spectrum oral antimicrobials), resulting in gradually decreasing early death rates over time, and the growing focus on the impact of AML therapy on quality of life and treatment cost concerns further fuel the larger trend toward an increasing proportion of care delivered in the outpatient setting. Here, we examine whether the current shift of administering chemotherapy and supportive care to the outpatient setting can be translated to the community setting without compromising patient outcomes.

Diagnostic and molecular testing patterns in patients with newly diagnosed acute myeloid leukemia in the Connect® MDS/AML Disease Registry

Diagnostic and molecular genetic testing are key in advancing the treatment of acute myeloid leukemia (AML), yet little is known about testing patterns outside of clinical trials, especially in older patients. We analyzed diagnostic and molecular testing patterns over time in 565 patients aged ≥ 55 years with newly diagnosed AML enrolled in the Connect® MDS/AML Disease Registry (NCT01688011) in the United States. Diagnostic data were recorded at enrolment and compared with published guidelines. The percentage of bone marrow blasts was reported for 82.1% of patients, and cellularity was the most commonly reported bone marrow morphological feature. Flow cytometry, karyotyping, molecular testing, and fluorescence in situ hybridization were performed in 98.8%, 95.4%, 75.9%, and 75.7% of patients, respectively. Molecular testing was done more frequently at academic than community/government sites (84.3% vs 70.2%; P < .001). Enrolment to the Registry after 2016 was significantly associated with molecular testing at academic sites (odds ratio [OR] 2.59; P = .023) and at community/government sites (OR 4.85; P < .001) in logistic regression analyses. Better understanding of practice patterns may identify unmet needs and inform institutional protocols regarding the diagnosis of patients with AML.

Targeting FLT3 mutations in AML: review of current knowledge and evidence

Genomic investigations of acute myeloid leukemia (AML) have demonstrated that several genes are recurrently mutated, leading to new genomic classifications, predictive biomarkers, and new therapeutic targets. Mutations of the FMS-like tyrosine kinase 3 (FLT3) gene occur in approximately 30% of all AML cases, with the internal tandem duplication (ITD) representing the most common type of FLT3 mutation (FLT3-ITD; approximately 25% of all AML cases). FLT3-ITD is a common driver mutation that presents with a high leukemic burden and confers a poor prognosis in patients with AML. The prognostic value of a FLT3 mutation in the tyrosine kinase domain (FLT3-TKD), which has a lower incidence in AML (approximately 7-10% of all cases), is uncertain. Accumulating evidence demonstrates that FLT3 mutational status evolves throughout the disease continuum. This so-called clonal evolution, together with the identification of FLT3-ITD as a negative prognostic marker, serves to highlight the importance of FLT3-ITD testing at diagnosis and again at relapse. Earlier identification of FLT3 mutations will help provide a better understanding of the patient's disease and enable targeted treatment that may help patients achieve longer and more durable remissions. First-generation FLT3 inhibitors developed for clinical use are broad-spectrum, multikinase inhibitors; however, next-generation FLT3 inhibitors are more specific, more potent, and have fewer toxicities associated with off-target effects. Primary and secondary acquired resistance to FLT3 inhibitors remains a challenge and provides a rationale for combining FLT3 inhibitors with other therapies, both conventional and investigational. This review focuses on the pathological and prognostic role of FLT3 mutations in AML, clinical classification of the disease, recent progress with next-generation FLT3 inhibitors, and mechanisms of resistance to FLT3 inhibitors.