NPM1-mutated myeloid neoplasms are a unique entity not defined by bone marrow blast percentage.

INTRODUCTION: NPM1-mutated (NPM1mut) myeloid neoplasms (MNs) with <20% bone marrow (BM) blasts (NPM1mut MNs<20) are uncommon, and their classification remains inconsistent. METHODS: The clinicopathologic features of 54 patients with NPM1mut MNs <20 were evaluated and compared with wild-type NPM1 MNs <20 and NPM1mut MNs≥20, respectively. RESULTS: NPM1mut MNs had similar features regardless of blast percentage, except for higher IDH2 (29% vs 7%, p = .023) and FLT3 (70% vs 11%, p < .001) frequency in patients with ≥20% BM blasts. Thirty-three (61%) patients with NPM1mut MNs <20 received low-intensity chemotherapy (LIC) and 12 (22%) received intensive chemotherapy (IC). Higher complete remission rates (75% vs 27%, p = .006) and median overall survival (mOS) (not reached vs 30.4 months, p = .06) were observed with IC compared to LIC. Young patients (age <60 years) did not reach mOS either when treated with LIC or IC. Stem cell transplant was associated with increased survival only in patients treated with LIC (HR, 0.24; p = .025). No differences in mOS were observed by BM blast strata (32.2 months, not reached and 46.9 months for <10%, 10%-19%, and ≥20% blasts, p = .700) regardless of treatment modality (LIC: p = .900; IC: p = .360). Twenty-three patients (43%) with NPM1mut MNs <20 had marrow blast progression to ≥20%. CONCLUSIONS: Overall, NPM1mut MNs define a unique entity independent of BM blast percentage.

Combination therapy with novel agents for acute myeloid leukaemia: Insights into treatment of a heterogenous disease.

The treatment landscape of acute myeloid leukaemia (AML) is evolving rapidly. Venetoclax in combination with intensive chemotherapy or doublets or triplets with targeted or immune therapies is the focus of numerous ongoing trials. The development of mutation-targeted therapies has greatly enhanced the treatment armamentarium, with FLT3 inhibitors and isocitrate dehydrogenase inhibitors improving outcomes in frontline and relapsed/refractory (RR) AML, and menin inhibitors showing efficacy in RR NPM1mut and KMT2A-rearranged AML. With so many new drugs approved, the number of potential combinatorial approaches to leverage the maximal benefit of these agents has increased dramatically, while at the same time introducing clinical challenges, such as key preclinical and clinical data supporting the development of combinatorial therapy, how to optimally combine or sequence these novel agents, how to optimise dose and duration to maintain safety while enhancing efficacy, the optimal duration of therapy and the role of measurable residual disease in decision-making in both intensive and low-intensity therapy settings. In this review, we will outline the evidence leading to the approval of key agents in AML, their on-label current approvals and how they may be optimally combined in a safe and deliverable fashion to further improve outcomes in AML.

Outcomes and genetic dynamics of acute myeloid leukemia at first relapse.

Patients with relapsed acute myeloid leukemia (rAML) experience dismal outcomes. We performed a comprehensive analysis of patients with rAML to determine the genetic dynamics and survival predictive factors. We analyzed 875 patients with newly diagnosed AML who received intensive treatment (IT) or low-intensity treatment (LIT). Of these patients, 197 experienced subsequent rAML. Data was available for 164 patients, with a median time from CR/CRi to relapse of 6.5 months. Thirty-five of the 164 patients (21%) experienced relapse after allogeneic hematopoietic stem cell transplantation (alloSCT). At relapse mutations in genes involved in pathway signaling tended to disappear, whereas clonal hematopoiesis-related mutations or TP53 tended to persist. Patients with normal karyotypes tended to acquire cytogenetic abnormalities at relapse. Patients treated with IT had a higher emergence rate of TP53 mutations (16%), compared to patients treated with LIT (1%, P = 0.009). The overall response rates were 38% and 35% for patients treated with salvage IT or LIT, respectively. Seventeen patients (10%) underwent alloSCT after salvage therapy. The median overall survival (OS) duration after relapse was 5.3 months, with a 1-year OS rate of 17.6%. Complex karyotype (hazard ratio [HR] = 2.14, P < 0.001), a KMT2A rearrangement (HR = 3.52, P = 0.011), time in remission < 12 months (HR = 1.71, P = 0.011), and an elevated white blood cell count at relapse (HR = 2.38, P = 0.005) were independent risk factors for OS duration. More effective frontline and maintenance therapies are warranted to prevent rAML.

Results of ponatinib as frontline therapy for chronic myeloid leukemia in chronic phase.

BACKGROUND: Ponatinib is a third-generation BCR::ABL1 tyrosine kinase inhibitor (TKI) with robust activity in Philadelphia chromosome-positive leukemias. Herein, we report the long-term follow-up of the phase 2 trial of ponatinib in chronic myeloid leukemia in chronic phase. METHODS: Patients received ponatinib 30 to 45 mg/day. The primary end point was the rate of 6-month complete cytogenetic response (CCyR). The study was held in June 2014 because of the risk of cardiovascular toxicity, requiring patients to change TKI. RESULTS: Fifty-one patients were treated with ponatinib (median dose, 45 mg/day). Median age was 48 years (range, 21-75); 30 (59%) had baseline cardiovascular comorbidities. Median treatment duration was 13 months (range, 2-25). Fourteen patients (28%) discontinued ponatinib because of toxicities, 36 (71%) after the Food and Drug Administration warning/study closure, and one for noncompliance. Dasatinib was the most frequently chosen second-line TKI (n = 34; 66%). Among 46 patients evaluable at 6 months, 44 (96%) achieved CCyR, 37 (80%) major molecular response, 28 (61%) MR4, and 21 (46%) MR4.5. The cumulative 6-month rates of CCyR, major molecular response, MR4, and MR4.5 were 96%, 78%, 50%, and 36%, respectively. Durable MR4 ≥24 or ≥60 months was observed in 67% and 51% of patients, respectively. The 24-month event-free survival rate was 97%. After a median follow-up of 128 months, the 10-year overall survival rate was 90%. Eight patients (16%) had serious grade 2 to 3 cardiovascular adverse events, leading to permanent discontinuation in five (10%). CONCLUSION: Ponatinib yielded high cytogenetic and molecular responses in newly diagnosed chronic myeloid leukemia in chronic phase. Its use in the frontline setting is hindered by arterio-/vaso-occlusive and other severe toxicities.

Phase 1 Study of CK0801 in Treatment of Bone Marrow Failure Syndromes.

BACKGROUND: An inflammatory bone marrow microenvironment contributes to acquired bone marrow failure syndromes. CK0801, an allogeneic T regulatory (Treg) cell therapy product, can potentially interrupt this continuous loop of inflammation and restore hematopoiesis. METHODS: In this phase 1 dose-escalation study of CK0801 Treg cells, we enrolled patients with bone marrow failure syndromes with suboptimal response to their prior therapy to determine the safety and efficacy of this treatment for bone marrow failure syndromes. RESULTS: We enrolled nine patients with a median age of 57 years (range, 19 to 74) with an underlying diagnosis of aplastic anemia (n=4), myelofibrosis (n=4), or hypoplastic myelodysplasia (n=1). Patients had a median of three prior therapies for a bone marrow failure syndrome. Starting dose levels of CK0801 were 1 × 106 (n=3), 3 × 106 (n=3), and 10 × 106 (n=3) cells per kg of ideal body weight. No lymphodepletion was administered. CK0801 was administered in the outpatient setting with no infusion reactions, no grade 3 or 4 severe adverse reactions, and no dose-limiting toxicity. At 12 months, CK0801 induced objective responses in three of four patients with myelofibrosis (two had symptom response, one had anemia response, and one had stable disease) and three of four patients with aplastic anemia (three had partial response). Three of four transfusion-dependent patients at baseline achieved transfusion independence. Although the duration of observation was limited at 0.9 to 12 months, there were no observed increases in infections, no transformations to leukemia, and no deaths. CONCLUSIONS: In previously treated patients, CK0801 demonstrated no dose-limiting toxicity and showed evidence of efficacy, providing proof of concept for targeting inflammation as a therapy for bone marrow failure. (Funded by Cellenkos Inc.; Clinicaltrials.gov number, NCT03773393.).

Asciminib in Newly Diagnosed Chronic Myeloid Leukemia.

BACKGROUND: Patients with newly diagnosed chronic myeloid leukemia (CML) need long-term therapy with high efficacy and safety. Asciminib, a BCR::ABL1 inhibitor specifically targeting the ABL myristoyl pocket, may offer better efficacy and safety and fewer side effects than currently available frontline ATP-competitive tyrosine kinase inhibitors (TKIs). METHODS: In a phase 3 trial, patients with newly diagnosed CML were randomly assigned in a 1:1 ratio to receive either asciminib (80 mg once daily) or an investigator-selected TKI, with randomization stratified by European Treatment and Outcome Study long-term survival score category (low, intermediate, or high risk) and by TKI selected by investigators before randomization (including imatinib and second-generation TKIs). The primary end points were major molecular response (defined as BCR::ABL1 transcript levels ≤0.1% on the International Scale [IS]) at week 48, for comparisons between asciminib and investigator-selected TKIs and between asciminib and investigator-selected TKIs in the prerandomization-selected imatinib stratum. RESULTS: A total of 201 patients were assigned to receive asciminib and 204 to receive investigator-selected TKIs. The median follow-up was 16.3 months in the asciminib group and 15.7 months in the investigator-selected TKI group. A major molecular response at week 48 occurred in 67.7% of patients in the asciminib group, as compared with 49.0% in the investigator-selected TKI group (difference, 18.9 percentage points; 95% confidence interval [CI], 9.6 to 28.2; adjusted two-sided P<0.001]), and in 69.3% of patients in the asciminib group as compared with 40.2% in the imatinib group within the imatinib stratum (difference, 29.6 percentage points; 95% CI, 16.9 to 42.2; adjusted two-sided P<0.001). The percentage of patients with a major molecular response at week 48 was 66.0% with asciminib and 57.8% with TKIs in the second-generation TKI stratum (difference, 8.2 percentage points; 95% CI, -5.1 to 21.5). Adverse events of grade 3 or higher and events leading to discontinuation of the trial regimen were less frequent with asciminib (38.0% and 4.5%, respectively) than with imatinib (44.4% and 11.1%) and second-generation TKIs (54.9% and 9.8%). CONCLUSIONS: In this trial comparing asciminib with investigator-selected TKIs and imatinib, asciminib showed superior efficacy and a favorable safety profile in patients with newly diagnosed chronic-phase CML. Direct comparison between asciminib and second-generation TKIs was not a primary objective. (Funded by Novartis; ASC4FIRST ClinicalTrials.gov number, NCT04971226).

Characteristics and outcomes of acute myeloid leukaemia patients with baseline CD7 expression.

Targeted therapy development for acute myeloid leukaemia (AML) requires an understanding of specific expression profiles. We collected flow cytometry data on 901 AML patients and recorded aberrant CD7 expression on leukaemic blasts. 263 (29.2%) had blasts positive for CD7. CD7+ AML was more likely to be adverse risk (64.6% vs. 55.6%, p = 0.0074) and less likely to be favourable risk (15.2% vs. 24.1%, p = 0.0074) by European LeukemiaNet 2022 criteria. Overall survival was inferior (11.9 [95% CI, 9.7-15.9] vs. 19.0 months [95% CI, 16.1-23.0], p = 0.0174). At relapse, 30.4% lost and 19.0% gained CD7, suggesting moderate instability over time.

Combination of dasatinib and venetoclax in newly diagnosed chronic phase chronic myeloid leukemia.

BACKGROUND: The dual inhibition of the BCR::ABL1 tyrosine kinase and BCL-2 could potentially deepen the response rates of chronic myeloid leukemia in chronic phase (CML-CP). This study evaluated the safety and efficacy of the combination of dasatinib and venetoclax. METHODS: In this phase 2 trial, patients with CML-CP or accelerated phase (clonal evolution) received dasatinib 50 mg/day for three courses; venetoclax was added in course 4 for 3 years. The initial venetoclax dose was 200 mg/day continuously but reduced later to 200 mg/day for 14 days, and to 100 mg/day for 7 days per course once a molecular response (MR)4.5 was achieved. After 3 years of combination, patients were maintained on single-agent dasatinib. The primary end point was the rate of major molecular response (MMR) by 12 months of combination. RESULTS: Sixty-five patients were treated. Their median age was 46 years (range, 23-73). By 12 months of combination, the MMR, MR4, and MR4.5 rates were 86%, 53%, and 45%, respectively. After a median follow-up of 42 months, the 4-year event-free and overall survival rates were 96% and 100%, respectively. Outcomes with the combination were comparable to historical outcomes with single-agent dasatinib (cumulative 12-months MMR rate of 79% with both strategies). The incidence of grade 3-4 neutropenia was 22% with the combination and 11% with single-agent dasatinib (p < .001). CONCLUSIONS: Treatment with dasatinib and venetoclax was safe and effective in CML-CP. The cumulative response rates with the combination were similar to those with single-agent dasatinib. Further follow-up is needed to evaluate the rates of durable deep molecular response and treatment-free remission.

Failure of treatment-free remission after a prolonged deep molecular response in patients with chronic myeloid leukemia.

Patients with chronic myeloid leukemia in chronic phase (CML-CP) can have a normal life expectancy when treated with the BCR::ABL1 tyrosine kinase inhibitors. In recent years, treatment discontinuation and treatment-free remission (TFR) emerged as the new goal of therapy in patients with CML-CP. Deep and sustained molecular remissions for more than 3 to 5 years are associated with higher chances of a successful TFR. However, although uncommon, some patients may still experience molecular or hematological relapse after treatment discontinuation, even after a prolonged duration of remission. In this case series, we report the outcome of four patients with CML-CP who were treated with tyrosine kinase inhibitors and achieved a deep molecular response for ≥8 years, but eventually experienced disease relapse after treatment discontinuation. We discuss the importance of regular monitoring after treatment discontinuation as well as future strategies to increase the chances of TFR in patients with CML-CP.

Oral decitabine plus cedazuridine and venetoclax in patients with higher-risk myelodysplastic syndromes or chronic myelomonocytic leukaemia: a single-centre, phase 1/2 study.

BACKGROUND: Hypomethylating agents are approved in higher-riskmyelodysplastic syndromes. The combination of a hypomethylating agent with venetoclax is standard of care in acute myeloid leukaemia. We investigated the safety and activity of the first totally oral combination of decitabine plus cedazuridine and venetoclax in patients with higher-risk-myelodysplastic syndromes and chronic myelomonocytic leukaemia. METHODS: We did a single-centre, dose-escalation and dose-expansion, phase 1/2, clinical trial. Patients with treatment-naive higher-risk-myelodysplastic syndromes or chronic myelomonocytic leukaemia (risk level categorised as intermediate-2 or higher by the International Prognostic Scoring System) with excess blasts (>5%). Treatment consisted of oral decitabine 35 mg plus cedazuridine 100 mg on days 1-5 and venetoclax (variable doses of 100-400 mg, day 1 to 14, 28-day cycle). The primary outcomes were safety for the phase 1 part and the overall response for the phase 2 part of the study. The trial is ongoing and this analysis was not prespecified. This study is registered with ClinicalTrials.gov, NCT04655755, and is currently enrolling participants. FINDINGS: Between Jan 21, 2021, and Jan 20, 2023, we enrolled 39 patients (nine in phase 1 and 30 in phase 2). The median age was 71 years (range 27-94), 28 (72%) patients were male, and 11 (28%) were female. The maximum tolerated dose was not reached, and the recommended phase 2 dose was established as oral decitabine 35 mg plus cedazuridine 100 mg for 5 days and venetoclax (400 mg) for 14 days. The most common grade 3-4 adverse events were thrombocytopenia (33 [85%] of 39), neutropenia (29 [74%]), and febrile neutropenia (eight [21%]). Four non-treatment-related deaths occurred on the study drugs due to sepsis (n=2), lung infection (n=1), and undetermined cause (n=1). The median follow-up time was 10·8 months (IQR 5·6-16·4). The overall response rate was 95% (95% CI 83-99; 37/39). 19 (49%) patients proceeded to hematopoietic stem-cell transplantation. INTERPRETATION: This early analysis suggests that the combination of oral decitabine plus cedazuridine with venetoclax for higher-risk-myelodysplastic syndromes and chronic myelomonocytic leukaemia is safe in most patients, with encouraging activity. Longer follow-up will be needed to confirm these data. FUNDING: MD Anderson Cancer Center, MDS/AML Moon Shot, Genentech/AbbVie, and Astex Pharmaceuticals.

Targetable genetic abnormalities in patients with acute myeloblastic leukemia across age groups.

Incidence of potential targetable genetic abnormalities by age in AML.

Ivosidenib significantly reduces triazole levels in patients with acute myeloid leukemia and myelodysplastic syndrome.

BACKGROUND: Ivosidenib is primarily metabolized by CYP3A4; however, it induces CYP450 isozymes, including CYP3A4 and CYP2C9, whereas it inhibits drug transporters, including P-glycoprotein. Patients with acute myeloid leukemia are at risk of invasive fungal infections, and therefore posaconazole and voriconazole are commonly used in this population. Voriconazole is a substrate of CYP2C9, CYP2C19, and CYP3A4; therefore, concomitant ivosidenib may result in decreased serum concentrations. Although posaconazole is a substrate of P-glycoprotein, it is metabolized primarily via UDP glucuronidation; thus, the impact of ivosidenib on posaconazole exposure is unknown. METHODS: Patients treated with ivosidenib and concomitant triazole with at least one serum trough level were included. Subtherapeutic levels were defined as posaconazole <700 ng/mL and voriconazole <1.0 µg/mL. The incidences of breakthrough invasive fungal infections and QTc prolongation were identified at least 5 days after initiation of ivosidenib with concomitant triazole. RESULTS: Seventy-eight serum triazole levels from 31 patients receiving ivosidenib-containing therapy and concomitant triazole were evaluated. Of the 78 concomitant levels, 47 (60%) were subtherapeutic (posaconazole: n = 20 of 43 [47%]; voriconazole: n = 27 of 35 [77%]). Compared to levels drawn while patients were off ivosidenib, median triazole serum levels during concomitant ivosidenib were significantly reduced. There was no apparent increase in incidence of grade 3 QTc prolongation with concomitant azole antifungal and ivosidenib 500 mg daily. CONCLUSIONS: This study demonstrated that concomitant ivosidenib significantly reduced posaconazole and voriconazole levels. Voriconazole should be avoided, empiric high-dose posaconazole (>300 mg/day) may be considered, and therapeutic drug monitoring is recommended in all patients receiving concomitant ivosidenib.

Azacitidine, Venetoclax, and Gilteritinib in Newly Diagnosed and Relapsed or Refractory FLT3-Mutated AML.

PURPOSE: Azacitidine plus venetoclax is a standard of care for patients with newly diagnosed AML who are unfit for intensive chemotherapy. However, FLT3 mutations are a common mechanism of resistance to this regimen. The addition of gilteritinib, an oral FLT3 inhibitor, to azacitidine and venetoclax may improve outcomes in patients with FLT3-mutated AML. METHODS: This phase I/II study evaluated azacitidine, venetoclax, and gilteritinib in two cohorts: patients with (1) newly diagnosed FLT3-mutated AML who were unfit for intensive chemotherapy or (2) relapsed/refractory FLT3-mutated AML (ClinicalTrials.gov identifier: NCT04140487). The primary end points were the maximum tolerated dose of gilteritinib (phase I) and the combined complete remission (CR)/CR with incomplete hematologic recovery (CRi) rate (phase II). RESULTS: Fifty-two patients were enrolled (frontline [n = 30]; relapsed/refractory [n = 22]). The recommended phase II dose was gilteritinib 80 mg once daily in combination with azacitidine and venetoclax. In the frontline cohort, the median age was 71 years and 73% of patients had an FLT3-internal tandem duplication (ITD) mutation. The CR/CRi rate was 96% (CR, 90%; CRi, 6%). Sixty-five percent of evaluable patients achieved FLT3-ITD measurable residual disease <5 × 10-5 within four cycles. With a median follow-up of 19.3 months, the median relapse-free survival (RFS) and overall survival (OS) have not been reached and the 18-month RFS and OS rates are 71% and 72%, respectively. In the relapsed/refractory cohort, the CR/CRi rate was 27%; nine additional patients (41%) achieved a morphologic leukemia-free state. The most common grade 3 or higher nonhematologic adverse events were infection (62%) and febrile neutropenia (38%), which were more frequent in the relapsed/refractory cohort. CONCLUSION: The combination of azacitidine, venetoclax, and gilteritinib resulted in high rates of CR/CRi, deep FLT3 molecular responses, and encouraging survival in newly diagnosed FLT3-mutated AML. Myelosuppression was manageable with mitigative dosing strategies.