Concurrent versus sequential or no triazole anti-fungal therapy in patients undergoing 7 + 3 plus midostaurin induction for FLT-3 acute myelogenous leukemia.

INTRODUCTION: Midostaurin is a multikinase inhibitor approved for the treatment of adult patients with newly diagnosed FMS-like tyrosine kinase 3 mutated (FLT3m) acute myeloid leukemia (AML). Azole antifungal medications are commonly used in AML and are known to interact with anti-cancer drugs such as midostaurin through the CYP3A pathway. However, there are no midostaurin related dose modifications recommended with strong CYP3A inhibitors. METHODS: We retrospectively reviewed 40 patients between 2017-2022 and compared efficacy and safety outcomes in patients who received azole antifungals concurrently to those who did not receive an azole or received it sequentially to midostaurin for treatment of FLT3m AML. RESULTS: Median age of both groups was approximately 55 years and 70% of patients harbored FLT-3 internal tandem duplication mutations. Most patients in the concurrent arm were on either posaconazole (33%) or isavuconazole (50%) for antifungal prophylaxis and micafungin (72%) for the sequential/no azole arm. Overall CR/CRi rate with concurrent versus sequential/no azole were 72% and 77%, and non-hematologic grade 3 toxicities were 22% and 40% (p = 0.21), respectively. Rates of dose reductions (6% vs. 0%, p = 0.26) and held doses (17% vs. 14%, p = 0.79) were not different between concurrent and sequential/no azole. There were no differences in the rates of new fungal infection during induction between the two groups. CONCLUSION: Azoles given concurrently or sequentially with midostaurin were found to be equally safe and effective in the treatment of newly diagnosed FLT3 AML. Additional confirmatory studies are needed due to our limited sample size.

CDK9 inhibition induces epigenetic reprogramming revealing strategies to circumvent resistance in lymphoma.

Diffuse large B-cell lymphoma (DLBCL) exhibits significant genetic heterogeneity which contributes to drug resistance, necessitating development of novel therapeutic approaches. Pharmacological inhibitors of cyclin-dependent kinases (CDK) demonstrated pre-clinical activity in DLBCL, however many stalled in clinical development. Here we show that AZD4573, a selective inhibitor of CDK9, restricted growth of DLBCL cells. CDK9 inhibition (CDK9i) resulted in rapid changes in the transcriptome and proteome, with downmodulation of multiple oncoproteins (eg, MYC, Mcl-1, JunB, PIM3) and deregulation of phosphoinotiside-3 kinase (PI3K) and senescence pathways. Following initial transcriptional repression due to RNAPII pausing, we observed transcriptional recovery of several oncogenes, including MYC and PIM3. ATAC-Seq and ChIP-Seq experiments revealed that CDK9i induced epigenetic remodeling with bi-directional changes in chromatin accessibility, suppressed promoter activation and led to sustained reprograming of the super-enhancer landscape. A CRISPR library screen suggested that SE-associated genes in the Mediator complex, as well as AKT1, confer resistance to CDK9i. Consistent with this, sgRNA-mediated knockout of MED12 sensitized cells to CDK9i. Informed by our mechanistic findings, we combined AZD4573 with either PIM kinase or PI3K inhibitors. Both combinations decreased proliferation and induced apoptosis in DLBCL and primary lymphoma cells in vitro as well as resulted in delayed tumor progression and extended survival of mice xenografted with DLBCL in vivo. Thus, CDK9i induces reprogramming of the epigenetic landscape, and super-enhancer driven recovery of select oncogenes may contribute to resistance to CDK9i. PIM and PI3K represent potential targets to circumvent resistance to CDK9i in the heterogeneous landscape of DLBCL.

Hematopoietic stem cell donor vaccination with cytomegalovirus triplex augments frequencies of functional and durable cytomegalovirus-specific T cells in the recipient: A novel strategy to limit antiviral prophylaxis.

To enhance protective cytomegalovirus (CMV)-specific T cells in immunosuppressed recipients of an allogeneic hematopoietic cell transplant (HCT), we evaluated post-HCT impact of vaccinating healthy HCT donors with Triplex. Triplex is a viral vectored recombinant vaccine expressing three immunodominant CMV antigens. The vector is modified vaccinia Ankara (MVA), an attenuated, non-replicating poxvirus derived from the vaccinia virus strain Ankara. It demonstrated tolerability and immunogenicity in healthy adults and HCT recipients, in whom it also reduced CMV reactivation. Here, we report feasibility, safety, and immunological outcomes of a pilot phase 1 trial (NCT03560752 at ClinicalTrials.gov) including 17 CMV-seropositive recipients who received an HCT from a matched related donor (MRD) vaccinated with 5.1 × 108 pfu/ml of Triplex before cell harvest (median 15, range 11-28 days). Donor and recipient pairs who committed to participation in the trial resulted in exceptional adherence to the protocol. Triplex was well-tolerated with limited adverse events in donors and recipients, who all engrafted with full donor chimerism. On day 28 post-HCT, levels of functional vaccinia- and CMV-specific CD137+ CD8+ T cells were significantly higher (p < .0001 and p = .0174, respectively) in recipients of Triplex vaccinated MRD than unvaccinated MRD (control cohort). Predominantly, central and effector memory CMV-specific T-cell responses continued to steadily expand through 1-year follow-up. CMV viremia requiring antivirals developed in three recipients (18%). In summary, this novel approach represents a promising strategy applicable to different HCT settings for limiting the use of antiviral prophylaxis, which can impair and delay CMV-specific immunity, leading to CMV reactivation requiring treatment.

High response rates and transition to transplant after novel targeted and cellular therapies in adults with relapsed/refractory acute lymphoblastic leukemia with Philadelphia-like fusions.

Philadelphia (Ph)-like acute lymphoblastic leukemia (ALL) is associated with a poor response to standard chemotherapy. However, outcomes with novel antibody and cellular therapies in relapsed/refractory (r/r) Ph-like ALL are largely unknown. We conducted a single-center retrospective analysis of adult patients (n = 96) with r/r B-ALL and fusions associated with Ph-like who received novel salvage therapies. Patients were treated with 149 individual novel regimens (blinatumomab = 83, inotuzumab ozogamicin [InO] = 36, and CD19CAR T cells = 30). The median age at first novel salvage therapy was 36 years (range; 18-71). Ph-like fusions were IGH::CRLF2 (n = 48), P2RY8::CRLF2 (n = 26), JAK2 (n = 9), ABL-class (n = 8), EPOR::IGH (n = 4) and ETV6::NTRK2 (n = 1). CD19CAR T cells were administered later in the course of therapy compared to blinatumomab and InO (p < .001) and more frequently in recipients who relapsed after allogeneic hematopoietic cell transplantation (alloHCT) (p = .002). Blinatumomab was administered at an older age compared to InO and CAR T-cells (p = .004). The complete remission (CR)/CR with incomplete hematologic recovery (CRi) rates were 63%, 72%, and 90% following blinatumomab, InO and CD19CAR, respectively, among which 50%, 50%, and 44% of responders underwent consolidation with alloHCT, respectively. In multivariable analysis, the type of novel therapy (p = .044) and pretreatment marrow blasts (p = .006) predicted the CR/CRi rate, while the Ph-like fusion subtype (p = .016), pretreatment marrow blasts (p = .022) and post-response consolidation with alloHCT (p < .001) influenced event-free survival. In conclusion, novel therapies are effective in inducing high remission rates in patients with r/r Ph-like ALL and successfully transitioning the responders to alloHCT.

Extramedullary disease relapse and progression after blinatumomab therapy for treatment of acute lymphoblastic leukemia.

BACKGROUND: Blinatumomab has demonstrated encouraging activity in relapsed/refractory (r/r) and minimal residual disease-positive (MRD+) acute lymphoblastic leukemia (ALL). Extramedullary disease (EMD) relapse or relapse with CD19- disease has been observed after blinatumomab therapy in patients with r/r or MRD+ ALL. However, the pathophysiology and risk factors of treatment failure are not fully understood. METHODS: This study retrospectively reviewed the outcomes of adult patients with B-cell ALL treated with blinatumomab (n = 132) for either r/r (n = 103) or MRD+ disease (n = 29) at the authors' center (2013-2021) and analyzed factors associated with treatment response and EMD failure. RESULTS: The overall response rate was 64%. A lower marrow blast burden before blinatumomab (P = .049) and no history of previous EMD (P = .019) were significantly associated with a higher response. Among the patients who responded to blinatumomab, 56% underwent consolidation with allogeneic transplantation. Blinatumomab failure was observed in 89 patients; 43% of these patients (n = 38) either progressed or relapsed at extramedullary sites. A history of extramedullary involvement (53% vs 24%; P = .005) and retention of CD19 expression at the time of relapse/progression (97% vs 74%; P = .012) were associated with a higher risk for extramedullary failure. Central nervous system (CNS) failure after blinatumomab was encountered in 39% of the patients with EMD. CONCLUSIONS: A history of EMD predicted an inferior response to blinatumomab therapy with a higher risk for relapse/progression at extramedullary sites (particularly CNS). Consolidation with allogenic transplantation in patients who primarily responded to blinatumomab did not abrogate the risk of extramedullary relapse. The incorporation of extramedullary assessment and the intensification of CNS prophylaxis may help in addressing extramedullary failure. LAY SUMMARY: Extramedullary failure is common during blinatumomab therapy for relapsed/refractory acute lymphoblastic leukemia. A history of extramedullary disease predicts an inferior response to blinatumomab therapy and a higher risk for relapse/progression at extramedullary sites. Most extramedullary failure cases retain CD19 expression.

Venetoclax in combination with nucleoside analogs in acute myelogenous leukemia.

PURPOSE OF REVIEW: Venetoclax in combination with nucleoside analogs such as hypomethylating agents (HMA) and low-dose cytarabine (LDAC) has led to unprecedented response and survival outcomes in patients with acute myeloid leukemia (AML). This has spurred the development of regimens combining venetoclax with other nucleoside analogs with distinct mechanisms of action. Here, we review older and newer nucleoside analogs, the rationale for their combination with venetoclax, and clinical evidence for the combination when available. RECENT FINDINGS: Venetoclax with HMA prolonged survival in a phase 3 study. Additionally, biologic correlates of response and resistance to venetoclax with HMA have been identified. The addition of venetoclax to standard intensive regimens containing higher doses of cytarabine and purine nucleoside analogs are safe and induce very high rates of remission and measurable residual disease negativity (MRD) negativity in newly diagnosed and relapsed/refractory AML. Investigational nucleoside analogs aim to improve upon the safety, bioavailability, or efficacy of approved venetoclax combinations and are currently being evaluated in clinical studies. SUMMARY: The development of venetoclax with HMA has transformed care for elderly adults with AML and opened the door for novel combinations of venetoclax with other nucleoside analogs. Further clinical studies are needed to see if these novel combinations further improve outcomes in AML particularly for patients with high-risk disease.

Current and Emerging Therapies for Acute Myeloid Leukemia.

Acute myeloid leukemia (AML) is predominantly a disease of older adults and the majority of affected patients succumb to the disease. After decades of slow progress, the last 5 years have witnessed remarkable progress in AML therapy with the approval of multiple highly active and well-tolerated novel therapies. Notable among these are agents targeting driver mutations including FLT3, IDH1/2 as well as the Bcl-2 inhibitor venetoclax. The combination of hypomethylating agents with venetoclax is highly active in AML and has become the standard of care for older patients as well as those with comorbidities. As a result of these advances, a larger proportion of AML patients now achieve complete remissions enabling them to undergo allogeneic hematopoietic cell transplantation with curative intent. Progress is also being made in the field of monoclonal antibodies targeting leukemia antigens and other immunotherapies and many such agents are currently under active investigation.

Sizes, ratios, approximations: On what and how the ANS represents.

Clarke and Beck propose that the approximate number system (ANS) represents rational numbers. The evidence cited supports only the view that it represents ratios (and positive integers). Rational numbers are extensive magnitudes (i.e., sizes), whereas ratios are intensities. It is also argued that WHAT a system represents and HOW it does so are not as independent of one another as the authors assume.

Which are the most promising targets for minimal residual disease-directed therapy in acute myeloid leukemia prior to allogeneic stem cell transplant?

Minimal residual disease has emerged as an important prognostic factor for relapse and survival in acute myeloid leukemia. Eradication of minimal residual disease may increase the number of patients with long-term survival; however, to date, strategies that specifically target minimal residual disease are limited. Consensus guidelines on minimal residual disease detection by immunophenotypic and molecular methods are an essential initial step for clinical trials evaluating minimal residual disease. Here, we review promising targets of minimal residual disease prior to allogeneic stem cell transplantation. Specifically, the focus of this review is on the rationale and clinical development of therapies targeting: oncogenic driver mutations, apoptosis, methylation, and leukemic immune targets. We review the progress made in the clinical development of therapies against each target and the challenges that lie ahead.

Treatment of relapsed or refractory FLT-3 acute myelogenous leukemia with a triplet regimen of hypomethylating agent, venetoclax, and gilteritinib.

Relapsed or refractory (R/R) acute myeloid leukemia (AML) with FMS-like tyrosine kinase 3 (FLT3) mutations remains a difficult and hard to treat entity. Gilteritinib is a potent oral FLT-3 inhibitor that improves overall survival in R/R AML, but studies are limited in combining gilteritinib with a hypomethylating agent and venetoclax treatment backbone (HMA-VEN-GILT). Here we report our experience with HMA-VEN-GILT for 22 R/R FLT3 AML patients. HMA-VEN-GILT yielded an ORR of 77.3% (17/22), CR 4.5% (1/22), CRi 13.6% (3/22), MLFS 59.1% (13/22). Median follow-up was 10.4 months with a relapse rate of 29.4% (5/17), median time to relapse of 69 days (range 35-298 days), 6-month overall survival of 84%, and median OS of 10.1 months. Additionally, 36.4% (8/22) of patients proceeded to hematopoietic stem cell transplant. In conclusion, HMA-VEN-GILT for the treatment of R/R FLT3 AML is feasible and can be used as a bridge to allogeneic transplantation.

Hypomethylating agents plus venetoclax compared with intensive induction chemotherapy regimens in molecularly defined secondary AML.

Molecularly defined secondary acute myeloid leukemia is associated with a prior myeloid neoplasm and confers a worse prognosis. We compared outcomes of molecularly defined secondary AML patients (n = 395) treated with daunorubicin and cytarabine (7 + 3, n = 167), liposomal daunorubicin and cytarabine (CPX-351, n = 66) or hypomethylating agents (HMA) + venetoclax (VEN) (n = 162). Median overall survival (OS) was comparable between treatment groups among patients aged >60 years. In a multivariable model HMA + VEN vs. 7 + 3 was associated with better OS (hazard ratio [HR] 0.64 [95% confidence interval (CI) 0.42-0.98, p = 0.041]), whereas CPX-351 vs. 7 + 3 was not (HR 0.79 [CI 95% 0.50-1.25, p = 0.31]). Allogeneic hematopoietic stem cell transplantation, BCOR and IDH mutations were associated with improved OS; older age, prior myeloid disease, NRAS/KRAS mutations, EZH2 mutation, and monosomal karyotype were associated with worse OS. When analyzed in each treatment separately, the IDH co-mutations benefit was seen with 7 + 3 and the detrimental effect of NRAS/KRAS co-mutations with HMA + VEN and CPX-351. In pairwise comparisons adjusted for age, HMA + VEN was associated with improved OS vs. 7 + 3 in patients with SF3B1 mutation and improved OS vs. CPX-351 in those with RNA splicing factor mutations. In molecularly defined secondary AML treatment with HMA + VEN might be preferred but could further be guided by co-mutations.

Comparing transplant outcomes in ALL patients after myeloablative conditioning in mismatch-related or unrelated donor settings.

The optimal myeloablative conditioning regimen for ALL patients undergoing hematopoietic cell transplant (HCT) with an alternative donor is unknown. We analyzed HCT outcomes ALL patients (n = 269) who underwent HCT at our center from 2010 to 2020 in complete remission (CR) after FTBI-etoposide and CNI-based GvHD prophylaxis for matched donor HCT (ETOP-package; n = 196) or FTBI-Fludarabine and post-transplant cyclophosphamide (PTCy)-based prophylaxis for HLA- mismatched (related or unrelated) donors (FLU-package; n = 64). Patients in FLU-package showed a significant delay in engraftment (p < 0.001) and lower cumulative incidence (CI) of any and extensive chronic GVHD (p = 0.009 and 0.001, respectively). At the median follow up of 4.6 years (range 1-12 years); non-relapse mortality, overall or leukemia-free survival and GVHD-free/relapse-free survival were not significantly impacted by the choice of conditioning. However, in patients at CR2 or with measurable residual disease (MRD+), there was a trend towards higher relapse after FLU-package (p = 0.08 and p = 0.07, respectively), while patients at CR1 regardless of MRD status had similar outcomes despite the package/donor type (p = 0.9 and 0.7, respectively). Our data suggests that FLU-package for alternative donors offers comparable outcomes to ETOP-package for matched donor HCT to treat ALL. Disease status and depth of remission at HCT were independent predictors for better outcomes.

Total Body Irradiation and Fludarabine with Post-Transplantation Cyclophosphamide for Mismatched Related or Unrelated Donor Hematopoietic Cell Transplantation.

Allogeneic hematopoietic cell transplantation (HCT) remains the sole curative treatment for most patients with hematologic malignancies. A well-matched donor (related or unrelated) remains the preferred donor for patients undergoing allogeneic HCT; however, a large number of patients rely on alternative donor choices of mismatched related (haploidentical) or unrelated donors to access HCT. In this retrospective study, we investigated outcomes of patients who underwent mismatched donor (related or unrelated) HCT with a radiation-based myeloablative conditioning MAC regimen in combination with fludarabine, and post-transplantation cyclophosphamide (PTCy) as higher-intensity graft-versus-host disease (GVHD) prophylaxis. We retrospectively assessed HCT outcomes in 155 patients who underwent mismatched donor HCT (related/haploidentical versus unrelated [MMUD]) with fractionated-total body irradiation (fTBI) plus fludarabine and PTCy as GVHD prophylaxis at City of Hope from 2015 to 2021. Diagnoses included acute lymphoblastic leukemia (46.5%), acute myelogenous leukemia (36.1%), and myelodysplastic syndrome (6.5%). The median age at HCT was 38 years, and 126 patients (81.3%) were an ethnic minority. The Hematopoietic Stem Cell Transplantation Comorbidity Index was ≥3 in 36.1% of the patients, and 29% had a Disease Risk Index (DRI) of high/very high. The donor type was haploidentical in 67.1% of cases and MMUD in 32.9%. At 2 years post-HCT, disease-free survival (DFS) was 75.4% and overall survival (OS) was 80.6% for all subjects. Donor type did not impact OS (hazard ratio [HR], .72; 95% confidence interval [CI], .35 to 1.49; P = .37) and DFS (HR, .78; 95% CI, .41 to 1.48; P = .44), but younger donors was associated with less grade III-IV acute GVHD (HR, 6.60; 95% CI, 1.80 to 24.19; P = .004) and less moderate or severe chronic GVHD (HR, 3.53; 95% CI, 1.70 to 7.34; P < .001), with a trend toward better survival (P = .099). The use of an MMUD was associated with significantly faster neutrophil recovery (median, 15 days versus 16 days; P = .014) and platelet recovery (median, 18 days versus 24 days; P = .029); however, there was no difference in GVHD outcomes between the haploidentical donor and MMUD groups. Nonrelapse mortality (HR, .86; 95% CI, .34 to 2.20; P = .76) and relapse risk (HR, .78; 95% CI, .33 to 1.85; P = .57) were comparable in the 2 groups. Patient age <40 years and low-intermediate DRI showed a DFS benefit (P = .004 and .029, respectively). High or very high DRI was the only predictor of increased relapse (HR, 2.89; 95% CI, 1.32 to 6.34; P = .008). In conclusion, fludarabine/fTBI with PTCy was well-tolerated in mismatched donor HCT, regardless of donor relationship to the patient, provided promising results, and increased access to HCT for patients without a matched donor, especially patients from ethnic minorities and patients of mixed race.

Intensive Induction Chemotherapy versus Hypomethylating Agents in Combination with Venetoclax in NPM1-mutant AML.

While intensive induction chemotherapy (IC) remains the standard of care for younger patients with acute myeloid leukemia (AML), data from older patients shows that hypomethylating agents + venetoclax (HMA/VEN) can lead to durable remissions among patients with NPM1 mutations. Whether IC or HMA/VEN is superior in patients ≥60 years-old with NPM1-mutant AML is unknown. To compare IC and HMA/VEN, we performed an international, multicenter retrospective cohort study of patients with newly diagnosed, NPM1-mutant AML.We included 221 patients (147 IC, 74 HMA/VEN) with previously untreated NPM1-mutant AML. Composite complete remission (cCR; defined as CR + CR with incomplete count recovery [CRi]) rate was similar for IC and HMA/VEN (cCR: 85% vs. 74%; p=0.067). While OS was favorable with IC in unselected patients compared to HMA/VEN (24-month OS 59% [95% CI: 52-69%] vs. 38% [95% CI 27-55%]; p=0.013), it was not statistically different among patients 60-75 years-old (60% [95% CI 52-70%] vs. 44% [95% CI 29-66%]; p=0.069) and patients who received an allogeneic stem cell transplant (70% [95% CI: 58-85%] vs. 66% [95% CI: 44-100%]; p=0.56). Subgroup analyses suggested that patients with normal cytogenetics (24-month OS with IC 65% [95% 56-74%] vs. 40% [95% CI: 26-60%] with HMA/VEN; p=0.009) and without FLT3-ITD mutations might benefit from IC compared with HMA/VEN (24-month OS: 68% [95% CI: 59-79%] vs. 43% [95% CI: 29-63%]; p=0.008). In multivariable analysis, OS was not statistically different for patients treated with IC and HMA/VEN (hazard ratio for death HMA/VEN vs. IC: 0.71; 95% CI: 0.40-1.27; p=0.25).

Coordinate loss of a microRNA and protein-coding gene cooperate in the pathogenesis of 5q- syndrome.

Large chromosomal deletions are among the most common molecular abnormalities in cancer, yet the identification of relevant genes has proven difficult. The 5q- syndrome, a subtype of myelodysplastic syndrome (MDS), is a chromosomal deletion syndrome characterized by anemia and thrombocytosis. Although we have previously shown that hemizygous loss of RPS14 recapitulates the failed erythroid differentiation seen in 5q- syndrome, it does not affect thrombocytosis. Here we show that a microRNA located in the common deletion region of 5q- syndrome, miR-145, affects megakaryocyte and erythroid differentiation. We find that miR-145 functions through repression of Fli-1, a megakaryocyte and erythroid regulatory transcription factor. Patients with del(5q) MDS have decreased expression of miR-145 and increased expression of Fli-1. Overexpression of miR-145 or inhibition of Fli-1 decreases the production of megakaryocytic cells relative to erythroid cells, whereas inhibition of miR-145 or overexpression of Fli-1 has a reciprocal effect. Moreover, combined loss of miR-145 and RPS14 cooperates to alter erythroid-megakaryocytic differentiation in a manner similar to the 5q- syndrome. Taken together, these findings demonstrate that coordinate deletion of a miRNA and a protein-coding gene contributes to the phenotype of a human malignancy, the 5q- syndrome.