Long-term follow-up of VIALE-A: Venetoclax and azacitidine in chemotherapy-ineligible untreated acute myeloid leukemia

Venetoclax-azacitidine is approved for treatment of patients with newly diagnosed acute myeloid leukemia (AML) ineligible for intensive chemotherapy based on the interim overall survival (OS) analysis of the VIALE-A study (NCT02993523). Here, long-term follow-up is presented to address survival benefit and long-term outcomes with venetoclax-azacitidine. Patients with newly diagnosed AML who were ineligible for intensive chemotherapy were randomized 2:1 to receive venetoclax-azacitidine or placebo-azacitidine. OS was the primary endpoint; complete remission with/without blood count recovery (CR/CRi) was a key secondary endpoint. This final analysis was conducted when 100% of the predefined 360 OS events occurred. In VIALE-A, 431 patients were enrolled to venetoclax-azacitidine (n = 286) or placebo-azacitidine (n = 145). At 43.2 months median follow-up, median OS was 14.7 months (95% confidence interval [CI], 12.1-18.7) with venetoclax-azacitidine, and 9.6 months (95% CI, 7.4-12.7) with placebo-azacitidine (hazard ratio, 0.58 [95% CI, 0.47-0.72], p < .001); the estimated 24-month OS rate was 37.5% and 16.9%, respectively. Median OS for patients with IDH1/2 mutations and those with measurable residual disease responses was reached in this final analysis. CR/CRi rate was similar to interim analysis. Any-grade hematologic and gastrointestinal adverse events were most common in venetoclax-azacitidine and placebo-azacitidine arms, including thrombocytopenia (47% and 42%) and neutropenia (43% and 29%). No new safety signals were identified. Long-term efficacy and safety confirm venetoclax-azacitidine is an improvement in standard-of-care for patients with AML who are not eligible for intensive chemotherapy because of advanced age or comorbidities.

Therapy-related acute lymphoblastic leukaemia in women with antecedent breast cancer

Therapy-related acute lymphoblastic leukaemia (tr-ALL) is a disease entity attributed to previous exposure to chemotherapy and/or radiation for antecedent malignancy. There is observed female predominance for tr-ALL, likely due to high prevalence and excellent curable rate for non-metastatic breast cancer as well as the frequent use of carcinogenic agents as part of adjuvant therapy. Here, we reviewed 37 women with diagnosis of ALL following breast cancer treatment with focus on cytogenetic categorization. Philadelphia chromosome positivity (Ph+), KMT2A alterations and other cytogenetic change groups were observed in 32%, 22% and 46% of patients respectively. Median overall survival (OS) and relapse-free survival (RFS) were 19.4 and 12.9 months, overall while both OS and RFS were superior in tr-ALL with Ph+ disease compared to KMT2Ar and other cytogenetics respectively. Seventeen (45.9%) patients underwent consolidative allogeneic haematopoietic cell transplantation (alloHCT) in CR1 out of which 4 (24%) relapsed following transplant. Both OS and RFS were superior in the KMT2Ar cytogenetics group following alloHCT. Ph chromosome represents the largest genetic entity of tr-ALL following breast cancer therapy, and it may be associated with superior survival outcomes while KMT2Ar may be associated with poorer outcomes that can perhaps be mitigated by alloHSCT.

Oral Iptacopan Monotherapy in Paroxysmal Nocturnal Hemoglobinuria

BACKGROUND

Persistent hemolytic anemia and a lack of oral treatments are challenges for patients with paroxysmal nocturnal hemoglobinuria who have received anti-C5 therapy or have not received complement inhibitors. Iptacopan, a first-in-class oral factor B inhibitor, has been shown to improve hemoglobin levels in these patients.

METHODS

In two phase 3 trials, we assessed iptacopan monotherapy over a 24-week period in patients with hemoglobin levels of less than 10 g per deciliter. In the first, anti-C5-treated patients were randomly assigned to switch to iptacopan or to continue anti-C5 therapy. In the second, single-group trial, patients who had not received complement inhibitors and who had lactate dehydrogenase (LDH) levels more than 1.5 times the upper limit of the normal range received iptacopan. The two primary end points in the first trial were an increase in the hemoglobin level of at least 2 g per deciliter from baseline and a hemoglobin level of at least 12 g per deciliter, each without red-cell transfusion; the primary end point for the second trial was an increase in hemoglobin level of at least 2 g per deciliter from baseline without red-cell transfusion.

RESULTS

In the first trial, 51 of the 60 patients who received iptacopan had an increase in the hemoglobin level of at least 2 g per deciliter from baseline, and 42 had a hemoglobin level of at least 12 g per deciliter, each without transfusion; none of the 35 anti-C5-treated patients attained the end-point levels. In the second trial, 31 of 33 patients had an increase in the hemoglobin level of at least 2 g per deciliter from baseline without red-cell transfusion. In the first trial, 59 of the 62 patients who received iptacopan and 14 of the 35 anti-C5-treated patients did not require or receive transfusion; in the second trial, no patients required or received transfusion. Treatment with iptacopan increased hemoglobin levels, reduced fatigue, reduced reticulocyte and bilirubin levels, and resulted in mean LDH levels that were less than 1.5 times the upper limit of the normal range. Headache was the most frequent adverse event with iptacopan.

CONCLUSIONS

Iptacopan treatment improved hematologic and clinical outcomes in anti-C5-treated patients with persistent anemia - in whom iptacopan showed superiority to anti-C5 therapy - and in patients who had not received complement inhibitors. (Funded by Novartis; APPLY-PNH ClinicalTrials.gov number, NCT04558918; APPOINT-PNH ClinicalTrials.gov number, NCT04820530.).

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.

A phase 1 trial of 8-chloro-adenosine in relapsed/refractory acute myeloid leukemia: An evaluation of safety and pharmacokinetics

BACKGROUND

This study evaluated the safety, pharmacokinetics (PK), and pharmacodynamics (PD) of 8-chloro-adenosine (8-Cl-Ado) in patients with relapsed/refractory acute myeloid leukemia (AML).

METHODS

8-Cl-Ado was administered daily for 5 days; the starting dose was 100 mg/m2 , the highest dose tested was 800 mg/m2 . The end points were toxicity, disease response, and PK/PD measurements.

RESULTS

The predominant nonhematologic toxicity was cardiac with grade ≥3 toxicity. Plasma PK in all patients suggested heterogeneity among patients, yet, some dose-dependency for the accumulation of 8-Cl-Ado. Two 8-Cl-Ado metabolites accumulated at similar levels to 8-Cl-Ado. Cellular PK in eight patients indicated accumulation of 8-Cl-ATP, which was associated with AML blast cytoreduction in peripheral blood. The authors determined the RP2D of 8-Cl-Ado to be 400 mg/m2 .

CONCLUSIONS

Given the cardiac adverse events observed, patients require monitoring for arrhythmias and QT interval during infusion. Although peripheral blood cytoreduction was observed, responses were transient, suggesting combination strategies will be required.

Optimizing CAR-T cell therapy in adults with B-cell acute lymphoblastic leukemia

Chimeric antigen receptor T-cell (CAR-T) therapy has demonstrated unprecedented success in the treatment of various hematologic malignancies including relapsed or refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL). Currently, there are two FDA-approved CD19-directed CAR-T cell products for the treatment of adults with R/R B-ALL. Despite high remission rates following CD19 CAR-T cell therapy in R/R B-ALL, remission durability remains limited in most adult patients, with relapse observed frequently in the absence of additional consolidation therapy. Furthermore, the burden of CAR-T cell toxicity remains significant in adults with R/R B-ALL and further limits the wide utilization of this effective therapy. In this review, we discuss patient and disease factors that are linked to CAR-T cell therapy outcomes in R/R B-ALL and strategies to optimize durability of response to reduce relapse and mitigate toxicity in the adult population. We additionally discuss future approaches being explored to maximize the benefit of CAR-T in adults with B-ALL.

Patterns of interventions for central venous catheter-associated deep vein thrombosis and outcomes in cancer patients

PURPOSE

This letter evaluated the impact of different management strategies, specifically the presence or absence of therapeutic anticoagulation, on clinical outcomes for central venous catheter (CVC)-associated deep vein thrombosis (DVT) in cancer patients.

METHODS

One-hundred ninety-eight adult cancer patients with a confirmed CVC-associated DVT diagnosis from February 2013 and February 2021 were included.

RESULTS

Incidence of symptomatic recurrent venous thromboembolism (VTE) was similar between patients who received therapeutic anticoagulation and those who did not (14% vs 16%, p = 0.807). In addition, therapeutic anticoagulation did not significantly alter the incidence of grade 3 and above bleeding events despite most patients having hematologic malignancies (9% vs 8%, p = 0.826).

CONCLUSION AND RELEVANCE

Therapeutic anticoagulation was not associated with a reduction in the incidence of recurrent VTE or increase the incidence of bleeding in adult cancer patients following a CVC-associated DVT diagnosis.

Sabatolimab plus hypomethylating agents in previously untreated patients with higher-risk myelodysplastic syndromes (STIMULUS-MDS1): a randomised, double-blind, placebo-controlled, phase 2 trial

BACKGROUND

Sabatolimab is an immunotherapy targeting T-cell immunoglobulin domain and mucin domain-3 (TIM-3), an immuno-myeloid regulator expressed on immune cells and leukaemic stem cells. In this trial, we compared the efficacy and safety of sabatolimab plus hypomethylating agent with placebo plus hypomethylating agents in previously untreated patients with higher-risk myelodysplastic syndromes.

METHODS

STIMULUS-MDS1 was a multicentre, randomised, double-blind, placebo-controlled, phase 2 study done at 54 investigational sites in 17 countries. Adult patients (aged ≥18 years) with intermediate-risk, high-risk, and very high-risk myelodysplastic syndromes (according to Revised International Prognostic Scoring System criteria) who had not received previous treatment were included. Patients were randomly assigned (1:1) to intravenous sabatolimab (400 mg on day 8 and 22) or placebo plus a hypomethylating agent (intravenous decitabine 20 mg/m2 on day 1-5 or intravenous or subcutaneous azacitidine 75 mg/m2 on day 1-7 or day 1-5 and day 8 and 9) every 28 days until treatment discontinuation. The two primary endpoints were complete response rate and progression-free survival, assessed in the full analysis set, which included all randomly assigned patients. Complete response was analysed, as prespecified, 7 months after the last patient was randomly assigned. All other analyses presented, including progression-free survival, were done at the final data cutoff prespecified via a protocol amendment on Sept 2, 2021. Safety was assessed in in all patients who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov, NCT03946670, and is ongoing.

FINDINGS

Between July 29, 2019, and Aug 10, 2020, 127 patients were randomly assigned to sabatolimab plus a hypomethylating agent group (sabatolimab group; n=65) or placebo plus a hypomethylating agent (placebo group; n=62). The median age of participants was 73 years (IQR 69-77), of whom 86 (68%) of 127 patients were male and 77 (61%) were White. The primary endpoints were not met. Complete response (cutoff date of March 10, 2021) was achieved in 14 (22%; 95% CI 12·3-33·5) of 65 patients in the sabatolimab group vs 11 (18%; 9·2-29·5) of 62 patients in the placebo group (p=0·77). At the cutoff date of the final analysis (March 1, 2022), median follow-up for progression-free survival was 17·8 months (IQR 16·6-19·4) in the sabatolimab group and 19·2 months (17·7-22·3) in the placebo group, and the median progression-free survival was 11·1 months (95% CI 7·6-17·6) in the sabatolimab group vs 8·5 months (6·9-11·3) in the placebo group (hazard ratio 0·75 [95% CI 0·48-1·17]; p=0·1022). The most common adverse events of any grade were neutropenia (35 [56%] of 62 patients in the sabatolimab group vs 43 [68%] of 63 patients in the placebo group), thrombocytopenia (30 [48%] vs 32 [51%]), constipation (29 [47%] vs 24 [38%]), diarrhoea (27 [44%] vs 14 [22%]), anaemia (22 [35%] vs 34 [54%]), febrile neutropenia (22 [35%] vs 15 [24%]), and leukopenia (15 [24%] vs 20 [32%]). One patient developed a serious potential treatment-related immune-mediated adverse event in the sabatolimab group. There was one treatment-related death in the sabatolimab group due to pneumonitis.

INTERPRETATION

The addition of sabatolimab to hypomethylating agents in this study did not result in a significant improvement in complete response rates or progression-free survival. Sabatolimab had a manageable safety in most patients with higher-risk myelodysplastic syndromes. A randomised phase 3 trial is ongoing to assess the potential benefit of sabatolimab plus azacitidine on overall survival in this setting.

FUNDING

Novartis Pharmaceuticals.

CPX-351 in FLT3-mutated acute myeloid leukemia

CPX-351, a dual-drug liposomal encapsulation of daunorubicin and cytarabine in a 1:5 molar ratio, is approved for the treatment of newly diagnosed therapy-related acute myeloid leukemia (AML) or AML with myelodysplasia-related changes. In a pivotal phase III trial, CPX-351 significantly improved overall survival compared with standard-of-care 7 + 3 chemotherapy (7 days cytarabine; 3 days daunorubicin) in adults aged 60-75 years with newly diagnosed high-risk or secondary AML (median = 9.56 months vs. 5.95 months; hazard ratio = 0.69; 95% confidence interval = 0.52-0.90; p = 0.003). Approximately 30% of patients with newly diagnosed AML have mutations in the FLT3 gene, which may be associated with poor outcomes. Here, we review the current in vitro, clinical, and real-world evidence on the use of CPX-351 in patients with AML and mutations in FLT3. Additionally, we review preliminary data from clinical trials and patient case reports that suggest the combination of CPX-351 with FLT3 inhibitors may represent another treatment option for patients with FLT3 mutation-positive AML.

WT1-mutated acute myeloid leukemia is sensitive to fludarabine-based chemotherapy and conditioning regimens

We conducted a retrospective analysis of WT1-mutated acute myeloid leukemia (AML) patients who underwent allogeneic stem cell transplant. Thirty-seven patients with WT1-mutated AML were identified. Primary induction failure (40%) and early relapse rate (18%) after idarubicin/cytarabine (7 + 3) chemotherapy were observed. All patients with induction failure subsequently achieved CR with additional chemotherapy. There was no significant difference between outcomes after myeloablative vs. reduced intensity (Fludarabine/Melphalan [Flu/Mel]) conditioning regimens. RFS but not OS was significantly better in patients who received FLAG-IDA prior to transplant and/or a fludarabine-containing conditioning. In an independent ex vivo study, WT1-mutated AML samples exhibited greater sensitivity to fludarabine (p = 0.026) and melphalan (p = 0.0005) than non-WT1-mutated AML samples while there was no difference between sensitivity to cytarabine. Our data favor using a fludarabine-based induction for AML with WT1 mutation instead of 7 + 3. Fludarabine conditioning regimens for alloHCT showed better RFS but not OS.

Thrombopoietin Receptor Agonists for Thrombocytopenia Secondary to HER2-Targeted Antibody Drug Conjugates

Trastuzumab emtansine and trastuzumab deruxtecan are widely used in breast cancer and other solid tumor malignancies. Thrombocytopenia is a common adverse event associated with the use of these agents that can lead to a treatment delay, reduction in dose intensity, and discontinuation. The role of thrombopoietin receptor agonists (TPO-RA) remains unknown in this setting. We report a case series of 6 individuals with breast cancer that experienced dose-reductions and therapy delays due to thrombocytopenia secondary to trastuzumab emtansine or trastuzumab deruxtecan therapy and received intervention with TPO-RA. All 6 were able to resume therapy with TPO-RA support.

HER2-targeted antibody-drug conjugates for breast cancer: ancestry and dose adjustment for thrombocytopenia

BACKGROUND

Thrombocytopenia is a common adverse event on HER2-targeted therapies, fam-trastuzumab deruxtecan (T-DXd) and ado-trastuzumab emtansine (T-DM1). A reported association of Asian ancestry with this event merits investigation to rule out potential confounding.

METHODS

Subjects in this retrospective cohort were female patients with HER2 positive breast cancer, of Asian or non-Hispanic White ancestry, who initiated T-DM1 or T-DXd from January 2017 through October 2021. Follow-up closed in January 2022. Primary endpoint was dose adjustment for thrombocytopenia. Competing endpoints were discontinuation of drug for other toxicity, disease progression, or for completion of prescribed cycles. The association between Asian ancestry and thrombocytopenia-related dose adjustment was tested at p < 0.01 in a proportional hazards model for the sub-distributions of 4 (primary and competing) endpoints. Covariates examined as potential confounders were age, metastatic disease, specific HER2-targeted drug, and prior drug switching for toxicity.

RESULTS

Among 181 subjects, 48 reported Asian ancestry. Incidence of dose adjustment for thrombocytopenia was higher in patients with Asian ancestry and among patients switched to T-DXd after experiencing thrombocytopenia on T-DM1. Independent of specific drug and prior drug switching, Asian ancestry was associated with dose adjustment for thrombocytopenia (hazards ratio 2.95, 95% confidence interval 1.41-6.18) but not with competing endpoints. Among participants of Asian ancestry, the ancestral origin was usually China or the Philippines (where Chinese ancestry is common).

CONCLUSIONS

The association between Asian ancestry and thrombocytopenia on HER2-targeted therapy is independent of age, metastatic disease, drug, and history of similar toxicity. This association may have a genetic basis linked to Chinese ancestry.

Positioning blinatumomab in the frontline of adult B-cell acute lymphoblastic leukemia treatment

Blinatumomab is a bispecific T cell engager that has shown efficacy in relapsed/refractory Philadelphia chromosome (Ph)-positive and Ph-negative acute lymphoblastic leukemia (ALL). Considering its favorable safety and activity in advanced ALL, blinatumomab as a targeted immunotherapy is fast gaining a frontline position in the ALL treatment paradigm. There have been multiple completed and ongoing studies showing significant promise with improved response rates and survival outcomes and decreased treatment toxicity and need for multi-agent chemotherapy regimens. The early use of blinatumomab has established success in Ph-negative and Ph-positive B-ALL, and this has extended to older adults with ALL who have historically had substantially inferior outcomes compared to their pediatric and young adult counterparts. Herein we will review the current data describing the early use of blinatumomab in newly diagnosed adults with B-cell ALL and future directions.

Ph-like acute lymphoblastic leukemia in adults: understanding pathogenesis, improving outcomes, and future directions for therapy

Philadelphia (Ph)-like acute lymphoblastic leukemia (ALL) is a high-risk subgroup of B cell ALL with distinct genotypes, unified by gene expression profile similar to Ph-positive ALL, but lacking the BCR::ABL1 fusion. Ph-like ALL patients respond inadequately to conventional chemotherapy with higher rates of induction failure, persistent measurable residual disease, and lower survival rates compared to other B cell ALL subtypes. Considering Ph-like ALL's chemo-refractory nature, there is an interest in pursuing innovative therapeutic approaches to treat, including the combination of tyrosine kinase inhibitors with frontline regimens, and early introduction of novel antibody-drug conjugates and immunotherapies. Accurate diagnosis and disease-risk stratification are key to increase access for high-risk patients to allogeneic hematopoietic cell transplantation in their first complete remission. In this review, we will discuss our current knowledge of pathogenesis of Ph-like ALL, diagnostic strategies, as well as emerging data on new and current treatment strategies for this disease.

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.

Favorable Activity and Safety Profile of Memory-Enriched CD19-Targeted Chimeric Antigen Receptor T-Cell Therapy in Adults with High-Risk Relapsed/Refractory ALL

PURPOSE

A phase I/II study evaluating the safety and activity of memory-enriched CD19-directed chimeric antigen receptor (CD19-CAR) T cells in adults with relapsed/refractory B-cell acute lymphoblastic leukemia (ALL).

PATIENTS AND METHODS

In phase I, we tested sequentially two cell populations for CAR transduction: (i) central memory (Tcm) or (ii) naïve, stem, and central memory (Tn/mem) T cells. The study employed an activity constrained for toxicity design to determine the recommended phase II dose (RP2D), which was tested in phase II.

RESULTS

The Tcm cohort was closed early due to lack of activity. The 200 ×106 Tn/mem-derived CD19-CAR T-cell dose was found to be safe and active, and was declared the RP2D. At RP2D, 58 participants underwent leukapheresis and 46 received CD19-CAR T cells. Median age for treated participants was 38 years (range, 22-72). Twenty-nine (63%) participants had relapsed post-allogeneic hematopoietic cell transplantation (alloHCT), 18 (39%) had Philadelphia-like (Ph-like) genotype, and 16 (35%) had extramedullary disease (EMD) at lymphodepletion (LD). Three (7%) participants had grade 3 cytokine release syndrome (CRS), and none had grade ≥ 4 CRS. Eight (17%) participants had grade ≥ 3 neurotoxicity, including one fatal cerebral edema. Forty (87%) patients achieved complete remission (CR)/CR with incomplete hematologic recovery, 2 (4%) progressed, and 4 (9%) were unevaluable for response. Among 42 response-evaluable participants, 16/17 with Ph-like ALL and 13/15 with EMD at LD responded. Twenty-one (53%) responders underwent alloHCT consolidation, which was associated with improved relapse-free survival (adjusted HR = 0.16; 95% confidence interval, 0.05-0.48; P = 0.001).

CONCLUSIONS

Tn/mem-derived CD19-CAR T cells were safe and active, including in Ph-like ALL and EMD. See related commentary by El Marabti and Abdel-Wahab, p. 694.

Clearance of bone marrow mast cells after hypomethylating agent and venetoclax for systemic mastocytosis associated with myeloid neoplasia

Systemic mastocytosis (SM) results from clonal proliferation of neoplastic mast cells that infiltrate bone marrow and other organs. A major subset of patients with SM has a clonally related myeloid neoplasm and the SM itself (SM-AMN). We evaluated the efficacy of hypomethylating agent and venetoclax (HMA-VEN) to target both the myeloid neoplasm and mast cell infiltrate in a patient with SM associated with acute myeloid leukemia arising from myelodysplastic syndrome and illustrate complete elimination of bone marrow mast cells and complete remission of MDS/AML. This case illustrates the potent activity of HMA-VEN both against the AMN as well as the associated SM.

Post-Transplantation Sinusoidal Obstruction Syndrome in Adult Patients with B Cell Acute Lymphoblastic Leukemia Treated with Pretransplantation Inotuzumab

Sinusoidal obstruction syndrome (SOS) is a potentially life-threatening complication that can be observed after allogeneic hematopoietic cell transplantation (HCT). Inotuzumab ozogamicin is an anti-CD22 monoclonal antibody-drug conjugate that has demonstrated high efficacy in relapsed/refractory (R/R) acute lymphoblastic leukemia (ALL) but is associated with an increased risk of SOS in HCT recipients. Here we aimed to examine the incidence and outcomes of SOS in 47 adult patients with R/R ALL who received inotuzumab therapy and subsequently underwent HCT at our institution. All patients received prophylactic therapy with ursodiol, and continuous low-dose heparin also was administered to patients receiving myeloablative conditioning (MAC). SOS occurred in 12 patients (26%) post-HCT, at a median onset of 11 days (range, 3 to 41 days). SOS was graded as very severe in 50% (n = 6), severe in 25% (n = 3), and mild in 25% (n = 3). All patients diagnosed with SOS received treatment with defibrotide for a median of 21 days (range, 3 to 34 days), with resolution of SOS occurring in 8 patients (67%). Mortality from SOS was 33% (n = 4) and occurred at a median of 10 days from diagnosis (range, 3 to 31 days) in patients graded as very severe (n = 3) or severe (n = 1). There were no significant differences between patients who developed SOS and those who did not develop SOS in the median time from the last dose of inotuzumab to transplantation (46 days versus 53 days; P = .37), use of an MAC regimen (42% versus 49%; P = .75), number of lines of therapy prior to inotuzumab (P = .79), median number of administered cycles of inotuzumab (2 versus 2; P = .14), or receipt of inotuzumab as the last therapy prior to HCT (67% versus 66%; P = 1.0). Sirolimus-based graft-versus-host disease (GVHD) prophylaxis was used more frequently in the SOS group (75% versus 29%; P < .01), but there was no between-group difference in the peak sirolimus level (P = .81) or the median time to peak sirolimus level (7 days versus 3.5 days; P = .39). In univariable analysis, only the use of sirolimus-based GVHD prophylaxis was significantly associated with an increased risk of SOS (hazard ratio [HR], 7.50; 95% confidence interval [CI], 1.7 to 33.6; P < .01). In the SOS group, the 100-day mortality rate was 33% (n = 4), and median overall survival (OS) post-HCT was 4.3 months (range, 0.2 to 57.2 months). In the group without SOS, the 100-day mortality rate was 14% (n = 5) and the median OS post-HCT was 10.7 months (range, .52 to 39.6 months). In this study cohort, SOS was prevalent in HCT recipients who had been treated with inotuzumab prior to transplantation, and sirolimus-based GVHD prophylaxis was a risk factor for SOS in inotuzumab recipients.

Outcomes in Patients with Poor-Risk Cytogenetics with or without TP53 Mutations Treated with Venetoclax and Azacitidine

PURPOSE

To evaluate efficacy and safety of venetoclax + azacitidine in treatment-naïve patients with acute myeloid leukemia harboring poor-risk cytogenetics and TP53mut or TP53wt.

PATIENTS AND METHODS

We analyzed data from a phase III study (NCT02993523) comparing venetoclax (400 mg orally days 1-28) + azacitidine (75 mg/m2 days 1-7) or placebo + azacitidine, and from a phase Ib study (NCT02203773) of venetoclax + azacitidine. Patients were ineligible for intensive therapy. TP53 status was analyzed centrally; cytogenetic studies were performed locally.

RESULTS

Patients (n = 127) with poor-risk cytogenetics receiving venetoclax + azacitidine (TP53wt = 50; TP53mut = 54) were compared with patients with poor-risk cytogenetics (n = 56) receiving azacitidine alone (TP53wt = 22; TP53mut = 18).For poor-risk cytogenetics + TP53wt patients, venetoclax + azacitidine versus azacitidine alone resulted in composite remission rates (CRc) of 70% versus 23%, median duration of remission (DoR) of 18.4 versus 8.5 months, and median overall survival (OS) of 23.4 versus 11.3 months, respectively. Outcomes with venetoclax + azacitidine were comparable with similarly treated patients with intermediate-risk cytogenetics and TP53wt.For poor-risk cytogenetics + TP53mut patients, venetoclax + azacitidine versus azacitidine alone resulted in CRc of 41% versus 17%, median DoR of 6.5 versus 6.7 months, and median OS of 5.2 versus 4.9 months, respectively.For poor-risk cytogenetics + TP53mut patients, predominant grade ≥3 adverse events (AE) for venetoclax + azacitidine versus azacitidine were febrile neutropenia (55%/39%), thrombocytopenia (28%/28%), neutropenia (26%/17%), anemia (13%/6%), and pneumonia (28%/33%). AEs were comparable between TP53mut and TP53wt patients.

CONCLUSIONS

In poor-risk cytogenetics + TP53mut patients, venetoclax + azacitidine improved remission rates but not DoR or OS compared with azacitidine alone. However, in poor-risk cytogenetics + TP53wt patients, venetoclax + azacitidine resulted in higher remission rates and longer DoR and OS than azacitidine alone, with outcomes comparable with similarly treated patients with intermediate-risk cytogenetics. Toxicities were similar in TP53mut and TP53wt patients. See related commentary by Green and Zeidner, p. 5235.

Total Marrow and Lymphoid Irradiation with Post-Transplantation Cyclophosphamide for Patients with AML in Remission

Graft-versus-host disease (GVHD) has remained the main cause of post-transplantation mortality and morbidity after allogeneic hematopoietic cell transplantation (alloHCT), adding significant economic burden and affecting quality of life. It would be desirable to reduce the rate of GVHD among patients in complete remission (CR) without increasing the risk of relapse. In this study, we have tested a novel conditioning regimen of total marrow and lymphoid irradiation (TMLI) at 2000 cGy, together with post-transplantation cyclophosphamide (PTCy) for patients with acute myeloid leukemia in first or second CR, to attenuate the risk of chronic GVHD by using PTCy, while using escalated targeted radiation conditioning before allografting to offset the possible increased risk of relapse. The primary objective was to evaluate the safety/feasibility of combining a TMLI transplantation conditioning regimen with a PTCy-based GVHD prophylaxis strategy, through the assessment of adverse events in terms of type, frequency, severity, attribution, time course, duration, and complications, including acute GVHD, infection, and delayed neutrophil/platelet engraftment. Secondary objectives included estimation of non-relapse mortality (NRM), overall survival (OS), relapse-free survival, acute and chronic GVHD, and GVHD-relapse-free survival (GRFS). A patient safety lead-in was first conducted to ensure there were no unexpected toxicities and was expanded on the basis of lack of dose-limiting toxicities. The patient safety lead-in segment followed 3 + 3 dose expansion/(de-)escalation rules based on observed toxicity through day 30; the starting dose of TMLI was 2000 cGy, and a de-escalation to 1800 cGy was considered. After the safety lead-in segment, an expansion cohort of up to 12 additional patients was to be studied. TMLI was administered on days -4 to 0, delivered in 200 cGy fractions twice daily. The radiation dose delivered to the liver and brain was kept at 1200 cGy. Cyclophosphamide was given on days 3 and 4 after alloHCT, 50 mg/kg each day for GVHD prevention; tacrolimus was given until day 90 and then tapered. Among 18 patients with a median age of 40 years (range 19-56), the highest grade toxicities were grade 2 Bearman bladder toxicity and stomatitis. No grade 3 or 4 Bearman toxicities or toxicity-related deaths were observed. The cumulative incidence of acute GVHD grade 2 to 4 and moderate-to-severe chronic GVHD were 11.1% and 11.9%, respectively. At a median follow up of 24.5 months, two-year estimates of OS and relapse-free survival were 86.7% and 83.3%, respectively. Disease relapse at 2 years was 16.7%. The estimates of NRM at 2 years was 0%. The GVHD/GRFS rate at 2 years was 59.3% (95% confidence interval, 28.8-80.3). This chemotherapy-free conditioning regimen, together with PTCy and tacrolimus, is safe, with no NRM. Preliminary results suggest an improved GRFS rate.

Impact of FLT3 Mutation on Outcomes after Venetoclax and Azacitidine for Patients with Treatment-Naïve Acute Myeloid Leukemia

PURPOSE

To evaluate efficacy and safety of venetoclax + azacitidine among treatment-naïve patients with FLT3-mutant acute myeloid leukemia.

PATIENTS AND METHODS

Data were pooled from patients enrolled in a phase III study (NCT02993523) that compared patients treated with venetoclax + azacitidine or placebo + azacitidine and a prior phase Ib study (NCT02203773) where patients were treated with venetoclax + azacitidine. Enrolled patients were ineligible for intensive therapy due to age ≥75 years and/or comorbidities. Patients on venetoclax + azacitidine received venetoclax 400 mg orally (days 1-28) and azacitidine (75 mg/m2; days 1-7/28-day cycle). FLT3 mutation was analyzed centrally on pretreatment bone marrow aspirates.

RESULTS

In the biomarker evaluable population, FLT3 mutation was detected in 42 (15%) and 22 (19%) patients in the venetoclax + azacitidine and azacitidine groups. Composite complete remission [CRc; complete remission (CR) + CR with incomplete hematologic recovery (CRi)] rates (venetoclax + azacitidine/azacitidine) for FLT3-mutant patients were 67%/36%, median duration of remission (DoR) was 17.3/5.0 months, and median OS was 12.5/8.6 months. The CRc rates among FLT3 wild-type patients were 67%/25%, median DoR 18.4/13.4 months, and median OS 14.7/10.1 months. In patients treated with venetoclax + azacitidine, CRc in patients with FLT3-ITD and FLT3-TKD was 63% and 77% and median OS was 9.9 and 19.2 months, and in comutated FLT3-ITD + NPM1 patients, CRc was 70%, median DoR was not reached, and median OS was 9.1 months. There were no unexpected toxicities in the venetoclax + azacitidine group.

CONCLUSIONS

When treated with venetoclax + azacitidine, patients with FLT3 mutations and FLT3 wild-type had similar outcomes. Future analyses in larger patient populations may further define the impact of venetoclax + azacitidine in patients harboring FLT3-ITD. See related commentary by Perl and Vyas, p. 2719.

Measurable Residual Disease Response and Prognosis in Treatment-Naïve Acute Myeloid Leukemia With Venetoclax and Azacitidine

PURPOSE

There is limited evidence on the clinical utility of monitoring measurable residual disease (MRD) in patients with acute myeloid leukemia treated with lower-intensity therapy. Herein, we explored the outcomes of patients treated with venetoclax and azacitidine who achieved composite complete remission (CRc; complete remission + complete remission with incomplete hematologic recovery) and MRD < 10^-3 in the VIALE-A trial.

METHODS

The patients included in this report were treated with venetoclax and azacitidine. Bone marrow aspirate samples for multiparametric flow cytometry assessments were collected for central analysis at baseline, end of cycle 1, and every three cycles thereafter. MRD-negative response was defined as < 1 residual blast per 1,000 leukocytes (< 10^-3 or 0.1%) with an estimated analytic sensitivity of 0.0037%-0.0027%. CRc, duration of remission (DoR), event-free survival (EFS), and overall survival (OS) were assessed. A multivariate Cox regression analysis identified prognostic factors associated with OS.

RESULTS

One hundred sixty-four of one hundred ninety (86%) patients with CRc were evaluable for MRD. MRD < 10^-3 was achieved by 67 of 164 (41%), and 97 of 164 (59%) had MRD ≥ 10^-3. The median DoR, EFS, and OS were not reached in patients with CRc and MRD < 10^-3, and the 12-month estimates for DoR, EFS, and OS in this group were 81.2%, 83.2%, and 94.0%. Among patients with CRc and MRD ≥ 10^-3, the median DoR, EFS, and OS were 9.7, 10.6, and 18.7 months. Multivariate analysis showed that CRc with MRD < 10^-3 was a strong predictor of OS (adjusted hazard ratio = 0.285; 95% CI, 0.159 to 0.510; P < .001).

CONCLUSION

Patients who achieved CRc and MRD < 10^-3 with venetoclax and azacitidine had longer DoR, EFS, and OS, than responding patients with MRD ≥ 10^-3.

Freeze-dried platelets are a promising alternative in bleeding thrombocytopenic patients with hematological malignancies

Thrombosomes are trehalose-stabilized, freeze-dried group O platelets with a 3-year shelf life. They can be stockpiled, rapidly reconstituted, and infused regardless of the recipient's blood type. Thrombosomes thus represent a potential alternative platelet transfusion strategy. The present study assessed the safety and potential early signals of efficacy of Thrombosomes in bleeding thrombocytopenic patients. We performed an open-label, phase 1 study of single doses of allogeneic Thrombosomes at three dose levels in three cohorts, each consisting of eight patients who had hematologic malignancies, thrombocytopenia, and bleeding. Adverse events, dose-limiting toxicities (DLTs), World Health Organization (WHO) bleeding scores, and hematology values were assessed. No DLTs were reported. The median age was 59 years (24-71). Most patients had AML (58%) or ALL (29%), followed by MDS (8%) and myeloproliferative neoplasm (4%). The WHO scores of 22 patients who were actively bleeding at a total of 27 sites at baseline either improved (n = 17 [63%]) or stabilized (n = 10 [37%]) through day 6. Twenty-four hours after infusion, 12 patients (50%) had a clinically significant platelet count increase. Of eight patients who received no platelet transfusions for 6 days after Thrombosomes infusion, 5 had a clinically significant increase in platelet count of ≥5000 platelets/μL and 2 had platelet count normalization. Thrombosomes doses up to 3.78 × 10⁸ particles/kg demonstrated safety in 24 bleeding, thrombocytopenic patients with hematological malignancies. Thrombosomes may represent an alternative to conventional platelets to treat bleeding. A phase 2 clinical trial in a similar patient population is underway.

Long-term follow-up of patients with poor-risk acute leukemia treated on a phase 2 trial undergoing intensified conditioning regimen prior to allogeneic hematopoietic cell transplantation

Patients with acute leukemia who undergo allogenic hematopoietic cell transplantation with active disease have high rates of relapse and poor overall survival (OS) post-transplant compared to patients undergoing HCT in remission. Here, we report the long-term outcomes in 32 patients who received a high-intensity conditioning regimen comprising fractionated total body irradiation (FTBI; 1200 cGy) with pharmacokinetic (PK) dosing of intravenous Busulfan (IV BU) targeted to first dose area under curve (AUC) of 700-900 µM/min and etoposide (30 mg/kg) in a prospective phase 2 clinical trial. The median age of the patients at the time of HCT was 37 years (range: 18-50) presenting with high-risk (n = 6) and relapsed/refractory(r/r) acute leukemias (n = 26). All but one patient underwent HCT using peripheral blood stem cells from matched sibling donors. At a median follow-up of 17.3 years (range 14.4-19.0), 11 patients remained alive. The disease-free survival and OS at 15 years was 34% (versus 40% at 5-years post-HCT). The 15-year cumulative incidence of relapse was 26% and non-relapse mortality (NRM) was 38% (95% CI: 21-54%) and the cumulative incidence of chronic GVHD at 15 years was 33% using a prophylactic regimen of cyclosporine A and mycophenolate mofetil. The most common life-threatening late effects were secondary malignancies, metabolic, or cardiac complications with a cumulative incidence of 6.6%, 6.6%, and 13.3%, respectively. No unusual late effects or patterns of relapse were noted on longer followed on patients treated with intensified myeloablative condition regimen. Results from this study supports continued development of intensive conditioning regimens in patients with r/r acute leukemias to improve leukemia free (LFS) and OS in this high-risk population.

Will immunotherapy lead to a breakthrough in the treatment of older adults with ALL?

Historically, older adults with B-cell acute lymphoblastic leukemia (ALL) have done poorly with chemotherapy-based treatment. Therefore, new innovative approaches are urgently needed to improve outcomes for this population. CD19-targeted immunotherapies such as blinatumomab and chimeric antigen receptor (CAR) T cell therapy have produced remarkable responses in relapsed/refractory (r/r) B-cell ALL, including clearance of minimal residual disease (MRD). Available data support the efficacy and safety of blinatumomab in older adults with advanced B-cell ALL. Therefore, its application is being extended to frontline regimens for B-cell ALL, particularly in older adults. There are several studies actively examining the role of blinatumomab alone or in combination with attenuated dosing of conventional chemotherapy or novel agents in older adults with newly diagnosed ALL and early data are encouraging. While CD19-targeted CAR (CD19CAR) T cell therapy is active in children and young adults with r/r B-cell ALL, data supporting its efficacy and safety in older adults with ALL is scarce. Furthermore, the commercially FDA approved CD19CAR T cell therapy product for r/r ALL is restricted only to patients ≤25 years of age. Although there are concerns about older adults tolerating the expected toxicities associated with CAR T cell therapy, which may be life threatening, tailored approaches for prophylactic and pre-emptive interventions combined with utilization of safer CAR T cell platforms may improve tolerability and further extend the use of this promising treatment to older patients with ALL. In this review, we will discuss the progress in immunotherapies for older adults with B-cell ALL and their potential for transforming frontline therapy for newly diagnosed patients.

Tacrolimus initial steady state level in post-transplant cyclophosphamide-based GvHD prophylaxis regimens

Post-transplant cyclophosphamide (PTCy) combined with tacrolimus (TAC) as graft-versus-host disease (GvHD) prophylaxis post-hematopoietic cell transplantation (HCT) is safe and effective. Optimal serum levels of TAC in this combination remain undetermined. We hypothesized that TAC at initial steady state (TISS) of <10 ng/mL could promote optimal transplant outcomes and prevent TAC-associated toxicities. We retrospectively analyzed a consecutive case series of 210 patients who received PTCy/TAC-based prophylaxis post-HCT from 1/2013–6/2018. Patients received HCT from haploidentical (n=172) or mismatched donors (n=38), and flat dose (FD) or weight-based dose (WBD) TAC. Twenty-four-month overall survival (OS), disease free survival (DFS), and relapse rate (RR) were 61%, 56%, and 22%, respectively, in TISS <10 ng/mL cohort (n=176), and 50%, 43%, and 35%, respectively, in TISS ≥10 ng/mL cohort (n=34) (OS, P=0.71; DFS, P=0.097; RR, P=0.031). OS, DFS, RR, non-relapse mortality, acute GvHD grade II-IV, grade III-IV or chronic GvHD by TISS were similar in multivariable analysis. TISS ≥10 ng/mL conferred increased risk of viral infection (P=0.003). More patients receiving FD vs. WBD had TISS <10 ng/mL (P=0.001). Overall, TISS <10 ng/mL early post HCT conferred similar survival outcomes and lowered risk of viral infection and toxicities compared to TISS ≥10 ng/mL.

Immunophenotype of acute lymphoblastic leukemia in minorities- analysis from the SEER database

Acute Lymphocytic Leukemia (ALL) is a malignancy that originates from immature lymphoid cells and is clinically established with flow cytometry through disease-specific markers. Variation between ethnic groups is an epidemiological aspect of ALL. Higher incidence rates have been observed in Latin American patients and ALL in Latinos carries a dismal prognosis. The cell of origin in ALL is derived from immature cells of either the B or T lineage. Most reported data among Latinos either exclusively looks at B cell precursor ALL or do not distinguish between subtypes. We used the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) database to delineate the differences in incidence rates of B-ALL and T-ALL across ethnic groups in the United States. Data from SEER-18 was used to compare incidence rates of T-ALL and B-ALL. Due to the utilization of cytogenetics and subsequent changes in ICD coding over the years examined the most recent data reported from 2002 to 2017. We compared rates in Non-Hispanic Whites (NHWs), Latinos, Blacks and Asian-Pacific Islanders (API). Age-adjusted incidence rates per 100,000 person-years were calculated. The incidence rate of B-ALL in the Latino population was consistently higher than other race/ethnicities throughout the years, ranging from 1.0 per 100,000 in 2002 to 2.5 per 100,000 in 2017. Blacks had the lowest age adjusted incidence rate (AAIR) of B-ALL overall, with rates approximately one third of those found in Latinos and the highest AAIR of T-ALL with an AAIR of 0.5 per 100,000.

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.

Genetics and Diagnostic Approach to Lymphoblastic Leukemia/Lymphoma

Our understanding of the genetics and biology of lymphoblastic leukemia/lymphoma (acute lymphoblastic leukemia, ALL) has advanced rapidly in the past decade with advances in sequencing and other molecular techniques. Besides recurrent chromosomal abnormalities detected by karyotyping or fluorescence in situ hybridization, these leukemias/lymphomas are characterized by a variety of mutations, gene rearrangements as well as copy number alterations. This is particularly true in the case of Philadelphia-like (Ph-like) ALL, a major subset which has the same gene expression signature as Philadelphia chromosome-positive ALL but lacks BCR-ABL1 translocation. Ph-like ALL is associated with a worse prognosis and hence its detection is critical. However, techniques to detect this entity are complex and are not widely available. This chapter discusses various subsets of ALL and describes our approach to the accurate classification and prognostication of these cases.

Use of high-dose mesna and hyperhydration leads to lower incidence of hemorrhagic cystitis after posttransplant cyclophosphamide-based allogeneic transplantation

Currently, there is no consensus on best practices to prevent hemorrhagic cystitis (HC) in patients receiving posttransplant cyclophosphamide (PTCy). We retrospectively reviewed 194 patients undergoing their first hematopoietic cell transplant (HCT) who received PTCy from 2014 to 2018 to describe the incidence and severity of HC, identify potential risk factors, and impact of HC on HCT outcomes. Standard HC prophylaxis was hyperhydration with forced diuresis and mesna at 320% the daily dose of PTCy. Incidence of HC was 31.4% at day +100 of HCT. Median onset of HC was 12 days with 11.5% grade 3 HC and no Grade 4 HC. Patients with chemical HC experienced earlier onset (7 days vs. 34 days, p < 0.001) with a shorter median resolution time (5 days vs. 14 days, p = 0.001) when compared to BK-associated HC. In multivariate analysis, age above 60 years (HR 4.16, p = 0.006) and myeloablative conditioning (HR 2.44, p = 0.054) were associated with higher risk for HC, but overall, HC did not affect nonrelapse mortality or overall survival. In conclusion, hyperhydration with forced diuresis combined with aggressive mesna dosing is an effective strategy in preventing severe PTCy-associated HC, subsequently preventing any negative impact on transplant outcome.

Indications for Allogeneic HCT in Adults with Acute Lymphoblastic Leukemia in First Complete Remission

OPINION STATEMENT

Acute lymphoblastic leukemia (ALL) in adults is associated with poor outcomes as compared to children when treated with chemotherapy, leading to a considerably inferior cure rate. Historically, consolidation with allogeneic hematopoietic cell transplant (alloHCT) was routinely recommended for eligible adults with ALL in first complete remission (CR1) if a donor was available, since randomized studies showed superiority over continuing chemotherapy. With the increasing use of pediatric-inspired frontline regimens in young adults with ALL and the availability of novel salvage agents for relapsed/refractory B-cell ALL that have high potential in inducing a second CR, the role of early alloHCT in the treatment paradigm for ALL needs to be reevaluated, and the decision should be individualized for each patient. Simultaneously, alloHCT has evolved considerably lately, and historical randomized studies that have proven the benefit of alloHCT in adults with ALL in CR1 did not included the increasing use of reduced intensity conditioning and haploidentical transplants, and therefore, data may not entirely apply. Nowadays, detectable minimal residual disease (MRD) is the most prognostic determinant of ALL outcome and should be a major consideration in the decision to perform alloHcT in CR1. Nonetheless, other biological and clinical factors remain relevant and can support the complex decision-making. Such factors include high-risk leukemia genetics, the type of administered chemotherapy regimen and the ability of the patient to tolerate all key components of the regimen, and the availability of effective salvage therapies that allow alloHCT to be performed in CR2 in case of relapse after chemotherapy.

Venetoclax and azacitidine combination in chemotherapy ineligible untreated patients with therapy-related myeloid neoplasms, antecedent myelodysplastic syndromes, or myelodysplastic/myeloproliferative neoplasms

7011

Background: Patients (pts) with therapy-related myeloid neoplasms (tMN), antecedent myelodysplastic syndrome, or antecedent myelodysplastic/myeloproliferative neoplasms (A-MDS/MPN) may have poor outcomes due to age and adverse genetic/karyotypic features. In the VIALE-A study, pts with tMN and A-MDS/MPN unfit for intensive chemotherapy treated with venetoclax (Ven) and azacitidine (Aza) demonstrated superior response rates and overall survival (OS) than Aza alone. Herein, the efficacy and safety of Ven+Aza among pts with tMN and A-MDS/MPN are described. Methods: Data were pooled from pts enrolled in VIALE-A (NCT02993523) comparing pts who received Ven+Aza or placebo (Pbo)+Aza and a prior phase 1b study (NCT02203773) where pts received Ven+Aza. Enrolled pts were ≥18 years, treatment-naïve with no prior exposure to hypomethylating agents, and ineligible for intensive chemotherapy. Pts on Ven+Aza received Ven 400 mg orally (days 1–28) and Aza (75 mg/m2; days 1-7/28-day cycle). Composite complete remission rate (CRc; complete remission [CR] + CR with incomplete hematologic recovery [CRi]), duration of response (DoR), and OS were assessed. Disease assessments were per modified International Working Group response criteria for AML. Results: In this pooled analysis, tMN was observed in (Ven+Aza/Pbo+Aza) 31/9 and A-MDS/MPN in 59/26 pts. Poor-risk cytogenetics were observed in 18 (58%)/6 (67%) with tMN (5 or 5q deletion [del]: 4/1 ; 7 or 7q del: 6/1 ; complex [≥ 3 clonal abnormalities]: 10/4), and 19 (32%)/13 (50%) with A-MDS/MPN (5 or 5q del: 10/5; 7 or 7q del: 6/1; complex: 14/9). TP53 mutation was observed in 5/3 pts with tMN and 8/0 pts with A-MDS/MPN. Pts with tMN received a median (Ven+Aza/Pbo+Aza) of 5/4 cycles of treatment. CRc was achieved by 19 (61%)/1 (11%). The mDoR was not reached (NR) (95% CI: 17.8, NR)/8.5 (NR, NR) months. The mOS was 16.4 (95% CI: 4.1, NR)/11.3 (0.6, 17.5) months. Pts with A-MDS/MPN received a median (Ven+Aza/Pbo+Aza) of 9/5 cycles of treatment. CRc was achieved by 39 (66%)/7 (27%) pts with mDoR of 17.3 (95% CI: 9.6, NR)/5.8 (1.1, NR) mos. The mOS was 15.9 (95% CI: 11.5, NR)/10.1 (4.7, 14.5) mos. Common grade≥3 adverse events (Ven+Aza/Pbo+Aza) were febrile neutropenia (tMN: 39%/11% and A-MDS/MPN: 36%/12%) neutropenia (tMN: 29%/33%; A-MDS/MPN: 39%31%), and thrombocytopenia (tMN: 32%/33%; A-MDS/MPN: 39%/62%). Conclusions: Ven+Aza compared to Aza monotherapy resulted in higher CRc rates with longer DoR and median OS among treatment-naïve pts with tMN and A-MDS/MPN ineligible for intensive chemotherapy. The safety profile was similar to overall pts with the Ven+Aza combination. Outcomes by cytogenetic and molecular risk-groups will be presented. Clinical trial information: NCT02993523, NCT02203773.

Measurable residual disease response in acute myeloid leukemia treated with venetoclax and azacitidine

7018

Background: In the phase 3 VIALE-A trial, rates of composite complete remission (CRc; complete remission [CR] + CR with incomplete hematologic recovery [CRi]) and measurable residual disease response (MRD<10-3) were higher in patients (pts) treated with venetoclax (Ven) + azacitidine (Aza) compared to Aza alone (23.4%/7.6%, p<0.001). There is limited evidence of the clinical significance of MRD monitoring in pts receiving low-intensity chemotherapy. Herein, we explored the outcomes of pts treated with Ven+Aza who achieved both CRc and MRD<10-3 in the VIALE-A trial (NCT02993523). Methods: Enrolled pts were ≥18 years and unfit for intensive chemotherapy. Pts received Ven 400 mg orally; days 1–28 and Aza 75 mg/m2; days 1-7/28-day cycle. Bone marrow aspirate samples for multiparametric flow cytometry assessments by integrated leukemia-associated immunophenotypes and different than normal procedures were collected for central analysis (Covance Central Laboratory Services) at baseline, end of cycle 1, and every 3 cycles thereafter. Assessments were performed independent of disease responses. MRD response was defined as <1 residual blast /1000 leukocytes (<10-3). CRc, DoR, OS, and EFS were assessed. Disease assessments were per modified International Working Group response criteria for AML. Results: 211/286 (74%) pts treated with Ven+Aza with at least one valid post-baseline MRD assessment were considered MRD evaluable; 78/211 (37%) achieved MRD<10-3 and 133/211 (63%) had MRD≥10-3. Median age (MRD<10-3/ MRD≥10-3) was 76 (range: 49-89)/77 (58-91) yrs. Pts (MRD<10-3/ MRD≥10-3) received median of 14.5 (range: 1-28) /7.0 (1-30) cycles of Ven+Aza. At median follow-up of 22.0 (range: 20.1-23.0)/20.8 (19.8-22.3) months (mos), CRc + MRD<10-3/ MRD≥10-3 was achieved by 67 (86%)/ 97 (73%); 20/67 (30%) achieved CRc + MRD<10-3 by end of cycle 1. Median DoR, OS, and EFS were not reached in pts with CRc + MRD<10-3 response (Table). The 12-mo estimates for DoR, OS, and EFS for pts with CRc + MRD<10-3response were 81.2%, 94.0%, and 83.2%, respectively. Adverse events ≥grade 3 (MRD<10-3/ MRD≥10-3) were febrile neutropenia (50%/43%), neutropenia (50%/35%), and thrombocytopenia (44%/44%), similar to the overall population. Conclusions: Pts with best response of CRc who achieved MRD<10-3 response with Ven+Aza treatment had longer DoR, OS, and EFS than pts who were CRc and MRD positive. Clinical trial information: NCT02993523. [Table: see text]