Minimal Residual Disease Negativity Rate Research Articles

Isatuximab, lenalidomide, dexamethasone and bortezomib in transplant-ineligible multiple myeloma: the randomized phase 3 BENEFIT trial.

CD38-targeting immunotherapy is approved in combination with lenalidomide and dexamethasone in patients with newly diagnosed multiple myeloma (NDMM) that are transplant ineligible (TI) and is considered the best standard of care (SOC). To improve current SOC, we evaluated the added value of weekly bortezomib (V) to isatuximab plus lenalidomide and dexamethasone (IsaRd versus Isa-VRd). This Intergroupe Francophone of Myeloma phase 3 study randomized 270 patients with NDMM that were TI, aged 65-79 years, to IsaRd versus Isa-VRd arms. The primary endpoint was a minimal residual disease (MRD) negativity rate at 10-5 by next-generation sequencing at 18 months from randomization. Key secondary endpoints included response rates, MRD assessment rates, survival and safety. The 18-month MRD negativity rates at 10-5 were reported in 35 patients (26%, 95% confidence interval (CI) 19-34) in IsaRd versus 71 (53%, 95% CI 44-61) in Isa-VRd (odds ratio for MRD negativity 3.16, 95% CI 1.89-5.28, P < 0.0001). The MRD benefit was consistent across subgroups at 10-5 and 10-6, and was already observed at month 12. The proportion of patients with complete response or better at 18 months was higher with Isa-VRd (58% versus 33%; P < 0.0001), as was the proportion of MRD negativity and complete response or better (37% versus 17%; P = 0.0003). At a median follow-up of 23.5 months, no difference was observed for survival times (immature data). The addition of weekly bortezomib did not significantly affect the relative dose intensity of IsaRd. Isa-VRd significantly increased MRD endpoints, including the 18-month negativity rate at 10-5, the primary endpoint, compared with IsaRd. This study proposes Isa-VRd as a new SOC for patients with NDMM that are TI. ClinicalTrials.gov identifier: NCT04751877 .

Effect of dose-adjusted melphalan on MRD-negativity to full dose melphalan in patients with multiple myeloma post-autologous stem cell transplant.

7557 Background: Despite significant therapeutic advancements, Multiple Myeloma (MM) remains an incurable disease. Autologous stem cell transplantation (ASCT) is a standard treatment for eligible patients, with high-dose melphalan (MEL200) as the preferred conditioning regimen. Reduced-dose melphalan (MEL140) is used for older or less fit patients. However, this was not prospectively studied and there has been ongoing debate about the efficacy of reduced dosing. This study aimed to investigate the impact of melphalan dose on minimal residual disease (MRD) negativity rates in MM patients undergoing upfront ASCT. Methods: We conducted a retrospective, single-center study involving 74 MM patients who underwent ASCT between 2018 and 2022 at UHCMC, Cleveland, OH and had MRD testing done after transplant. MRD testing was performed using the ClonoSEQ next generation sequencing platform. Results: Median age was higher in the MEL140 group compared to MEL200 (70.3 vs 59.8 years), both groups were similar in terms of sex and race distribution, BMI and KPS scores. Both groups have comparable ISS staging and high-risk cytogenetics. Similar numbers of lines of treatment prior to transplant were seen, with approximately 64% having only one line. First-line induction therapy included triplet therapy (Lenalidomide, Bortezomib, and Dexamethasone) in 73% of patients. Depth of remission at transplant was comparable between groups. MRD negativity rates at 10-5 and 10-6 were comparable between MEL140 and MEL200 groups (64% and 39% in MEL140; 61% and 41% in MEL200; p=0.8 and 0.7 respectively). Sustained MRD negativity at 10-5 over at least 12 months was also comparable (43% in MEL140; 50% in MEL200, p=0.8). After a median follow-up of 37 months, PFS was not reached for either group (p=0.69). Patients achieving MRD negativity at levels of 10-5 had a not reached median PFS, while those not achieving MRD negativity had a median PFS of 41 months (95%CI 23-NR; p=0.024). There was no significant difference in hospital stay duration, time to neutrophil engraftment, readmission rate, or infections within 100 days post-transplant between the MEL140 and MEL200 groups. Conclusions: Our real-world analysis demonstrates that MEL140 yields similar deep post-transplant remissions as MEL200, translating to improved PFS for patients achieving MRD negativity, regardless of the dose used. This is the first report to our knowledge of MRD negativity rate in patients receiving MEL140. [Table: see text]

Phase 3 randomized study of isatuximab (Isa) plus lenalidomide and dexamethasone (Rd) with bortezomib versus isard in patients with newly diagnosed transplant ineligible multiple myeloma (NDMM TI).

7501 Background: CD38 targeting immunotherapy is approved in combination with lenalidomide and dexamethasone in NDMM TI and considered the current standard of care (SOC). The best treatment combinations are important in NDMM TI, as outcomes worsen with successive line of therapy. To improve current SOC, we evaluated the added value of prolonged use of bortezomib for 18 months with reduced intensity weekly schedule to IsaRd, with the intent to demonstrate the impact of a PI in a quadruplet regimen to improve depth of response. In BENEFIT/IFM2020-05 study (NCT04751877), we investigated efficacy and safety of IsaRd vs Isa-VRd in NDMM TI. Methods: BENEFIT is a prospective, multicenter, randomized, parallel trial. Patients aged 65-79, non-frail, with NDMM TI were randomized 1:1 and stratified by age, high-risk cytogenetic and center. Isa-VRd arm received V (1.3 mg/m2 SC weekly up to c12 (c), bimonthly up to c18); both arms received Isa (10 mg/kg IV weekly and bimonthly up to c12, then monthly), R (25 mg), and d (20 mg up to c12). The primary endpoint was minimal residual disease (MRD) 10-5 negative rate (NGS) at 18 months from treatment start analyzed in ITT. Key secondary endpoints included survival times (OS, PFS, EFS, TTNT), response rates and durations, MRD endpoints, and safety (using NCI CTCAE v5.0). Results: At data cutoff date (02 Feb 2024), 270 patients (135 per arm) were recruited. Patients baseline characteristics were well balanced across arms, overall median age was 73.2 years [IQR. 71;76], 90 patients (33%) were &gt;75 years, 23 (9%) had high-risk cytogenetic (IFM score &gt;1), 181 (76%) had R-ISS2+3, and 47 (17%) had impaired renal function (eGFR &lt;60 mL/min). MRD negativity rates at 10-5 at 18 months were significantly higher in Isa-VRd arm compared to IsaRd arm (47% vs 24%, OR for negative MRD =2.96 [95%CI. 1.73 – 5.07, p&lt;0.001]. The MRD benefit was consistent across subgroups. At 21.2 months median follow-up, 33 (12%) patients had relapsed and 20 (7%) had died, and no significant difference were observed across arms, yet. The addition of weekly “light” schedule of bortezomib did not significantly affect relative dose intensity of IsaRd. Forty-four (33%) patients presented with neurological adverse events grade ≥2 in the Isa-VRd vs 27 (20%) in IsaRd arm. Conclusions: Isa-VRd significantly deepened responses including a significant increase of the MRD negative rate at 10-5 vs IsaRd. The safety profile is consistent with addition of bortezomib. This study supports Isa-VRd as a new standard of care for NDMM TI non-frail patients. Clinical trial information: NCT04751877 . [Table: see text]

Frontline treatment with zanubrutinib plus rituximab (ZR) followed by short course R-DHAOx in patients with mantle cell lymphoma (MCL): Results of the phase II CHESS clinical trial.

7062 Background: Combining Bruton’s tyrosine kinase (BTK) inhibitor and rituximab showed favourable efficacy as first-line therapy for mantle cell lymphoma (MCL). Zanubrutinib, a next-generation, highly-selective BTK inhibitor, achieved promising antitumor activity in MCL. In this multicenter phase II trial (CHESS - chemo-less), we aimed to investigate the efficacy and toxicity of zanubrutinib plus rituximab (ZR) combination, followed by short course cytarabine-based chemotherapy, then zanubrutinib maintenance as frontline therapy for MCL (NCT04624958). Methods: Previously untreated MCL patients enrolled and received induction therapy of ZR until complete response (CR) or to a maximum of 12 cycles, and followed by 4 cycles of R-DHAOx regimen (rituximab, dexamethasone, cytarabine and oxaliplatin). Patients achieving CR after chemotherapy would receive maintenance therapy with zanubrutinib for a maximum of 1 year. The primary endpoint was CR rate after induction therapy with ZR regimen. Minimal residual disease (MRD) of bone marrow and peripheral blood were evaluated by flow cytometry. Results: From Oct 2020 to Nov 2023, a total of 42 patients were enrolled and the enrollment was finished. The median age was 57 years (IQR, 51-64). Stage III-IV accounted for 92.8%, and 42.8% were intermediate or high risk simplified MIPI. Thirty-four patients (81.0%) were classic histological subtype. The median cycle of ZR was 4 (range, 2-6). As of Jan 2024, among 37/42 patients with post-treatment PET evaluation, the best CR rate of ZR regimen was 91.9% (34/37), and 94.1% (32/34) obtained CR after 2-4 cycles. The bone marrow MRD negative CR rate was 92.0% (23/25). The other 5/42 patients were still receiving ZR treatment, and PET evaluation would be performed subsequently. Among 27 patients who finished chemotherapy and were evaluable for response, only one patient experienced disease progression. With a median follow up of 11.6 months, the 1-year progression-free survival and overall survival was 90.1% and 96.7%, respectively. Two patients died due to lymphoma (n=1) and COVID-19 (n=1). Grade 3-4 adverse events on ZR regimen were neutropenia (n=3), fatigue (n=2), and aminotransferase (n=1). During chemotherapy, grade 3-4 thrombocytopenia was observed in 75.8% of patients. Conclusions: Induction treatment with ZR followed by short-course R-DHAOx chemotherapy yielded promising antitumor efficacy. This strategy might reduce the toxicity of cytarabine-based chemotherapy without weakening the therapeutic efficacy. Clinical trial information: NCT04624958 . [Table: see text]

Acalabrutinib plus venetoclax and rituximab in treatment-naive mantle cell lymphoma: 2-year safety and efficacy analysis

AbstractThis phase 1b study evaluated safety and efficacy of acalabrutinib, venetoclax, and rituximab (AVR) in treatment-naive mantle cell lymphoma (TN MCL). Patients received acalabrutinib from cycle 1 until progressive disease (PD) or undue toxicity, rituximab for 6 cycles with maintenance every other cycle through cycle 24 or until PD, and venetoclax, beginning at cycle 2, for 24 cycles. Twenty-one patients were enrolled; 95.2% completed induction (6 AVR cycles) and 47.6% continued acalabrutinib maintenance. Thirteen (61.9%) patients had grade 3-4 adverse events (AEs), most commonly neutropenia (33.3%). Seven (33.3%) patients had COVID-19 infection (6 [28.6%] serious AEs and 5 [23.8%] deaths, all among unvaccinated patients). There was no grade ≥3 atrial fibrillation, ventricular tachyarrhythmias, major hemorrhages, or tumor lysis syndrome. Overall response rate (ORR) was 100% (95% CI, 83.9-100.0) with 71.4% complete response. With median follow-up of 27.8 months, median progression-free survival (PFS) and overall survival (OS) were not reached. PFS rates at 1 and 2 years were 90.5% (95% CI, 67.0-97.5) and 63.2% (95% CI, 34.7-82.0), respectively; both were 95% after censoring COVID-19 deaths. OS rates at 1 and 2 years were 95.2% (95% CI, 70.7-99.3) and 75.2% (95% CI, 50.3-88.9), respectively; both were 100% after censoring COVID-19 deaths. Overall, 87.5% of patients with available minimal residual disease (MRD) data achieved MRD negativity (10–6; next-generation sequencing) during treatment. AVR represents a chemotherapy-free regimen for TN MCL and resulted in high ORR and high rates of MRD negativity. The trial was registered at www.ClinicalTrials.gov as #NCT02717624.

High-risk acute myeloid leukemia with DEK-NUP214 rearrangement and eyelid infiltration: a case report

Objective: This study aims to evaluate the safety and effectiveness of gilteritinib (Gilt) -based combination therapy bridging allo-HSCT for FLT3-ITD(+) R/R AML. Additionally, it aims to assess the impact of Gilt maintenance therapy on the prognosis of patients after allo-HSCT. Methods: The clinical data of 26 patients with FLT3-ITD(+) R/R AML treated at the First Affiliated Hospital of Soochow University from August 2019 to January 2023 were retrospectively analyzed. The analysis included an assessment of the composite complete remission rate (CRc), overall survival (OS) time, disease-free survival (DFS) time, and adverse events experienced by all enrolled patients. Results: A total of 26 patients with FLT3-ITD(+) R/R AML were enrolled, including 14 men and 12 women with a median age of 38 (18-65) years. A total of 18 cases were refractory, and eight cases were relapsed. The curative effect evaluation conducted between 14 and 21 days showed that the complete remission (CR) rate was 26.9% (7/26), the CR with hematology incomplete recovery was 57.7% (15/26), and the partial response (PR) rate was 7.7% (2/26). The CRc was 84.6% (22/26), and the minimal residual disease (MRD) negativity rate was 65.4%. The 12 month cumulative OS rate for all patients was 79.0%, and the 24 month cumulative OS rate was 72.0%. The median OS time was not determined. The median follow-up time was 16.0 months. Among the patients who responded to treatment, the 12 month cumulative DFS rate was 78.0%, and the 24 month cumulative DFS rate was 71.0%. The median DFS time was not determined. Patients who received allo-HSCT had a median OS time that was significantly longer than those who did not receive allo-HSCT (3.3 months, 95%CI 2.2-4.3 months, P=0.005). The median OS time of patients with or without Gilt maintenance therapy after allo-HSCT was not determined, but the OS time of patients with Gilt maintenance therapy after allo-HSCT treatment was longer than that of patients without Gilt maintenance therapy after allo-HSCT treatment (P=0.019). The FLT3-ITD mutation clearance rate in this study was 38.5%, and the median OS time of patients with FLT3-ITD mutation clearance was not determined but was significantly longer than the median OS of patients without FLT3-ITD mutation clearance (15.0 months; P=0.018). The most common grade 3 and above hematological adverse events of Gilt-based combination therapy included leukopenia (76.9%), neutropenia (76.9%), febrile neutropenia (61.5%), thrombocytopenia (69.2%), and anemia (57.7%). One patient developed differentiation syndrome during oral Gilt maintenance therapy after allo-HSCT treatment, but his condition improved after treatment. Conclusion: The Gilt-based combination therapy is highly effective in treating FLT3-ITD(+) R/R AML. It demonstrates a high CRc, MRD negativity rate, and rapid onset, leading to a significant improvement in patients' survival. Furthermore, the clearance rate of FLT3-ITD mutation is notably high. Additionally, implementing bridging allo-HSCT and Gilt maintenance therapy after allo-HSCT treatment has considerably enhances patients' survival. Closely monitoring and managing any adverse event that may occur during treatment are crucial.

Real-world evidence on treatment pattern, effectiveness, and safety of blinatumomab in Chinese patients with B-cell acute lymphoblastic leukemia

SummaryBlinatumomab is efficacious in patients with B-cell acute lymphoblastic leukemia (B-ALL), yet limited real-world data exists in this context. This retrospective study provided real-world data on the treatment pattern, effectiveness, and safety of blinatumomab in Chinese patients with newly diagnosed (ND) and relapsed/refractory (R/R) B-ALL. Patients with B-ALL who received at least one dose of blinatumomab in frontline or R/R settings between August 2021 and June 2023 were included. The primary outcome was the treatment pattern of blinatumomab. Key secondary outcomes included complete remission (CR)/CR with incomplete blood cell recovery (CRi) rate, minimal residual disease (MRD) negativity, median event-free survival (EFS), and safety. The study included 96 patients with B-ALL; 53 (55.2%) patients were in the ND group and 43 (44.8%) patients were in the R/R group. The median treatment duration was one cycle (range: 1–5). Most patients underwent chemotherapies, allo-HSCT, or experimental CAR-T following blinatumomab. The ND patients using blinatumomab induction therapy achieved 100% CR/CRi rate; 87.2% achieved MRD negativity within two cycles of blinatumomab. In R/R re-induction patients, the CR/CRi rate was 50%; MRD negativity rate was 64.2%. In R/R patients using blinatumomab for consolidation, MRD negativity rate was 90.9%. The median EFS was not reached in both ND and R/R patients; 1-year EFS rate was 90.8% (95% CI: 67%, 97%) and 55.1% (95% CI: 30%, 74%), respectively. Grade ≥ 3 adverse events were observed in 12.5% patients. Blinatumomab was found to be effective with a tolerable safety profile in real world setting.

Limited efficacy of 3 + 7 plus gemtuzumab ozogamycin in newly diagnosed fit intermediate genetic risk acute myeloid leukemia patients.

Gemtuzumab-ozogamycin (GO) is approved in combination with high-dose chemotherapy for treatment-naïve low- and intermediate-risk acute myeloid leukemia (AML). In this retrospective real-life multicenter study, we reported efficacy and safety of GO plus high-dose chemotherapy in newly diagnosed AML patients. A total of 31 fit low- and intermediate-risk AML patients treated with GO-based regimens were retrospectively included in this real-life multicenter study, and results were compared with a control cohort treated with 3 + 7 alone. Complete remission (CR) rate after induction was 77%, and most responders (45%) underwent two GO-based consolidation, and minimal residual disease (MRD) negativity was observed in 17 cases (55%) after the end of consolidation. Low genetic risk was associated with increased CR rate compared with intermediate-risk AML (88% vs. 33%; p < .001), as well as prolonged overall survival (OS; hazard ratio, 0.16; 95% confidential interval, 0.02-0.89; p < .001). GO addition resulted in a survival benefit for low-risk AML (median OS not reached vs. 25 months; p = .19) while not for intermediate-risk subjects (10 vs. 13 months; p = .92), compared with the control group. Moreover, GO-treated patients experienced fever of unknown origin or sepsis in 42% or 36% of cases, respectively, with one death during induction due to septic shock, with similar rates compared with the control group (p = .3480 and p = .5297, respectively). No cases of veno-occlusive disease after allogeneic transplantation were observed. Our real-life multicenter study confirmed GO-based treatment efficacy with high MRD negativity rates in fit newly diagnosed AML patients, especially in those with low genetic risk and core binding factor, while limited benefits were observed in intermediate-risk AML. However, further validation on larger prospective cohorts is required.

Abstract 5071: Minimal residual disease (MRD) status by peripheral blood mononuclear cells (PBMCs) and circulating tumor DNA (ctDNA) demonstrates rapid, deep, and sustained response in patients (Pts) with relapsed/refractory follicular lymphoma (R/R FL) treated with subcutaneous (SC) epcoritamab monotherapy in the pivotal phase 1/2 EPCORE™ NHL-1 trial

Abstract Introduction: Outcomes in high-risk R/R FL are poor. Epcoritamab SC, a CD3xCD20 bispecific antibody, demonstrated promising efficacy with a manageable safety profile in pts with R/R FL after ≥2 prior lines of therapy (phase 1/2 EPCORE NHL-1; NCT03625037). Here we evaluated MRD with PBMCs and ctDNA in pts with R/R FL and correlated the results with clinical findings. Methods: Adults with R/R FL 1-3A enrolled in EPCORE NHL-1 received epcoritamab SC in 28-day cycles. MRD analysis was performed on longitudinal plasma and PBMC samples collected at prespecified timepoints (clonoSEQ assay, Adaptive Biotechnologies). Screening tumor biopsies were used to identify trackable tumor clones; samples were quantified as tumor clones detected per mL plasma for ctDNA and per one million nucleated cells for PBMC. Overall response and progression-free survival (PFS) were assessed using Lugano criteria by independent review committee. Results: Of 128 pts in the R/R FL 1-3A cohort, 91 with PBMC data and 100 with ctDNA data were MRD evaluable. Overall MRD negativity was achieved in 67.0% [95% CI: 56.4-76.5] of pts per PBMC and 68.0% [95% CI: 57.9-77.0] of pts per ctDNA. Concordance of subject-level MRD status was high (79 of 89 with PBMC and ctDNA data; 88.8%). In most pts, MRD negativity was reached prior to radiographic complete response (PBMC, 76.4%; ctDNA 58.5%). MRD negativity by PBMC preceded ctDNA (median days to MRD negativity, 28 [PBMC] vs 57 [ctDNA]), suggesting a difference in methodology in detecting tumor DNA. Pts who became MRD negative had prolonged PFS (median not reached). Baseline MRD levels were not associated with clinical outcomes (PBMC; Wilcoxon P=0.59, ctDNA P=0.39). PFS was similar in pts achieving MRD negative status (median not reached, PBMC and ctDNA), independent of high-risk/difficult-to-treat disease (≥4 prior lines, Ann Arbor stage III-IV, bulky disease, double refractory, FLIPI 3-5, and POD24). The overall MRD negativity rate was also similar in high-risk pts, except those with ≥4 prior lines of therapy. Conclusions: Based on the EPCORE-NHL-1 study, one of the first pivotal studies to report MRD in pts with R/R FL, epcoritamab drives rapid, deep, and sustained responses as supported by MRD assessment by both PBMC and ctDNA. MRD results correlate with clinical outcome, and achieving MRD negativity is associated with longer PFS. PFS was similar among all pts who achieved MRD negativity, including those with high-risk disease. Citation Format: David Soong, Işıl Altıntaş, John Karavitis, Kim M. Linton, Wojciech Jurczak, Catherine Thieblemont, Kevin Zhao, Edith Szafer-Glusman, Daniela Hoehn, Elena Favaro, Mariana Sacchi, Maria Jure-Kunkel. Minimal residual disease (MRD) status by peripheral blood mononuclear cells (PBMCs) and circulating tumor DNA (ctDNA) demonstrates rapid, deep, and sustained response in patients (Pts) with relapsed/refractory follicular lymphoma (R/R FL) treated with subcutaneous (SC) epcoritamab monotherapy in the pivotal phase 1/2 EPCORE™ NHL-1 trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5071.

Venetoclax plus a hypomethylating agent versus cytarabine, aclarubicin, and granulocyte colony-stimulating factor chemotherapy as a first-line therapy for newly diagnosed acute myeloid leukemia: A propensity score-matched analysis.

Both venetoclax plus a hypomethylating agent (VEN/HMA) and cytarabine, aclarubicin, and granulocyte colony-stimulating factor (CAG) are low-intensity regimens for older patients with acute myeloid leukemia (AML) that show good efficacy and safety. It is unknown how VEN/HMA compares with the CAG regimen for the treatment of newly diagnosed AML. The outcomes of patients with newly diagnosed AML treated with VEN/HMA were compared with those of patients treated with a CAG-based regimen. Propensity score matching between these two cohorts at a 1:1 ratio was performed according to age at diagnosis, sex, Eastern Cooperative Oncology Group performance status, state of fitness, and European LeukemiaNet (ELN) 2022 risk stratification to minimize bias. A total of 84 of 96 patients in the VEN/HMA cohort were matched with 84 of 147 patients in the CAG cohort. VEN/HMA resulted in a better response than the CAG-based regimens, as indicated by a higher composite complete remission (CRc) rate (82.1% vs. 60.7%; p=.002) and minimal residual disease negativity rate (88.2% vs. 68.2%; p=.009). In patients with an ELN adverse risk, VEN/HMA was associated with a higher CRc rate compared to CAG (80.5% vs. 58.3%; p=.006). VEN/HMA was associated with longer event-free survival (EFS) (median EFS, not reached vs. 4.5 months; p=.0004), whereas overall survival (OS) was comparable between the two cohorts (median OS, not reached vs. 18 months; p=.078). The VEN/HMA regimen may result in a better response than CAG-based treatment in older patients with newly diagnosed AML.

Clinical efficacy and safety of flumatinib versus dasatinib combined with multi-drug chemotherapy in adults with Philadelphia-positive acute lymphoblastic leukemia

Introduction: Flumatinib, a highly selective ABL kinase inhibitor, exhibits stronger inhibition of intracellular BCR-ABL tyrosine kinase activity, compared to Imatinib. However, there is limited research comparing the real-world efficacy and safety of flumatinib and dasatinib in patients with Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL). Objective: Investigating the differences in therapeutic efficacy and safety between flumatinib and dasatinib in combination with multi-drug chemotherapy for the treatment of newly diagnosed Ph+ ALL. Method: In this study, we assessed 43 patients with newly diagnosed Ph+ ALL (20 in the flumatinib group, 23 in the dasatinib group). Results: There were no significant differences in gender, age, fusion gene type, initial blood routine, bone marrow blast cell ratio or chromosome karyotype between the two groups. Within 1 month, there were no significant differences in the complete response (CR), major molecular response (MMR) or minimal residual disease (MRD) negativity rate between the flumatinib and dasatinib groups. Similarly, within 3 months, there were no significant differences in CR or MMR rates between the two groups. However, the rates of complete molecular response (CMR) and MRD negativity within 3 months were significantly higher in the flumatinib group, compared to the dasatinib group (P < 0.05). Additionally, the flumatinib group exhibited fewer adverse reactions compared to the dasatinib group. Conclusion: These findings suggest that flumatinib is a safe and effective tyrosine kinase inhibitor (TKI) for achieving CMR and MRD negativity in patients with Ph+ ALL, as supported by this small series of patients.

Low-Dose IA with Venetoclax Regimen As Induction Therapy for Newly Diagnosed Acute Myeloid Leukemia

Abstract Background: The IA regimen (combination of idarubicin and cytarabine) is used as the most common induction of remission therapy for acute myeloid leukemia, with the complete response (CR) rates of up to 70%. Addition of the BCL-2 inhibitor venetoclax(Ven) to chemotherapy can increase apoptosis priming. In order to further improve the remission rate and prolong survival, our center uses a low-dose IA regimen combined with Venetoclax to treat newly diagnosed primary acute myeloid leukemia under 60 years old. Methods: We retrospectively analyzed 15 patients with newly diagnosed AML, who was under 60 years old. Patients received idarubicin (6mg/m2 IV for 3-days) and cytarabine (60mg/m2 IV for 5-days) with oral venetoclax (400mg daily for 2 weeks) for induction, followed by the same chemo-free regimen for consolidation if patients responded to induction therapy. And then analyze the effects of this regimen on complete remission (CR) rate, minimal residual disease (MRD) negative CR rate, relapse-free survival (RFS), overall survival (OS), and adverse events. Findings: Between January, 2021 and June, 2023, 15 patients were treated with this regimen. The median age was 43 years (IQR, 36-43) and the median follow-up was 4.25 (IQR, 2.73-15.6) months. Among all patients, the ORR was 86.7% (95% CI 62, 96), the CR rate was 80.0% (95% CI 55, 93), and the MRD negative rate was 66.7% (95% CI 42, 85). According to 2022 ELN risk classification by genetics, the ORR in favorable risk patients were 50.0% (1/2), intermediate risk patients were 100% (7/7), adverse risk patients were 83.3%(5/6). Those who had epigenetic modification mutations (NPM1, FLT3-ITD, CEBPA) were more likely to benefit from this regimen. The most common grade 3 and 4 adverse reactions were neutropenia, thrombocytopenia, and anemia. Conclusion: As induction and consolidation therapy whose adverse reactions were tolerable, the low-dose IA with Venetoclax regimen produces deep remission for the patients with newly diagnosed primary AML.

A Phase II Study of Zanubrutinib-Based Induction and Maintenance Therapy in Young and Fit Patients with Untreated Mantle Cell Lymphoma (BRIDGE): An Updated Analysis with Long-Term Follow up

Introduction Studies showed that remission after induction therapy is associated with better prognosis in mantle cell lymphoma (MCL) patients, and minimal residual disease (MRD) is also considered as an independent and sensitive factor in MCL patients. As R-CHOP/R-DHAOx is the most common used induction regimen in China, we investigate the benefit of zanubrutinib-based induction (zanubrutinib plus R-CHOP) in untreated young MCL patients. We previously reported a promising result of an ORR of 100% with MRD negative rate of 100% after induction treatment in 2022 PPLC. Here, we reported a long-time (median follow-up: 25.9 months) efficacy and safety in the study. Methods In this prospective, single-center, single-arm, phase II study (NCT04736914), patients aged 18-65 years with previously untreated, Ann Arbor stage II-IV, histologically confirmed MCL will be enrolled to alternately receive R-CHOP + zanubrutinib and R-DHAOx induction for 6 cycles (every 21 days per cycle). Zanubrutinib will be administered in cycle 1, 3, 5 (R-CHOP), 160 mg BID, d1-21, and not in combination with R-DHAOx. Patients who achieve remission (≥PR) will be allowed to proceed to ASCT or maintenance depending on the investigator's evaluation and discretion. In patients who do not achieve a remission at the end of induction (treatment failure), no specific treatment is defined; rather, the further salvage treatment is upon the discretion of investigators. Patients will receive zanubrutinib maintenance for two years in case of remission at ASCT assessment or end of induction assessment. Zanubrutinib is administrated orally at 160 mg BID, continuously for 2 years or until progressive disease, unacceptable toxicity, or death, whichever occurs first. The primary endpoint was bone marrow MRD negative rate after induction therapy (at the completion of cycle 6 or at premature discontinuation). Results A total of 7 patients were enrolled, the median age was 56.3, and bone marrow (BM), peripheral blood (PB) MRD showed positive at baseline. After 6 cycles of R-CHOP + zanubrutinib and R-DHAOx induction treatment, BM and PB MRD negative rate was 100% (7/7). One patient proceeded to ASCT. At the data cut-off date of 30 Jun 2023, one patient has completed the study at week 53 with zanubrutinib maintenance treatment due to the progressive disease, while the other 6 patients remain in the zanubrutinib maintenance treatment and are still under follow-up (Figure). With a median follow-up of 25.9 months, all patients showed good tolerance, with no dose modification and discontinuation during zanubrutinib-based induction therapy, either no BTKi interested AE (includes diarrhea, hypertension, major hemorrhage, and atrial fibrillation/flutter) was observed (Table). Conclusions This prospective, phase II study with a relatively longer follow-up duration estimated the treatment regimen in untreated young MCL patients. At the time of data cut-off, zanubrutinib-based induction therapy was well tolerated in all patients and showed a promising results in response and MRD. With a median treatment duration of 16.6 months, most patients (6/7) did not relapse. The study is ongoing and further results will be continuously released.

Zanubrutinib and Venetoclax As Initial Therapy for CLL/SLL with Obinutuzumab Triplet Consolidation in Patients with Minimal Residual Disease Positivity (BruVenG)

Background: Bruton's tyrosine kinase inhibitors (BTKi), anti-CD20 antibodies, and B cell lymphoma 2 inhibitors (BCL-2i) are essential therapeutic drug classes in the treatment of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). Clinical synergy of BTKi and BCL-2i combinations have been observed, which allow for an oral regimen, that can be safely administered in a clinic setting for most patients (Tam et al., 2022; Wierda et al., 2021). Still, it remains uncertain if anti-CD20 antibodies meaningfully add to the effectiveness of oral combination therapy. Recent reports of triplet regimens demonstrate modest improvement in minimal residual disease (MRD) negativity with similar response rates when compared to oral doublets (Davids et al., 2021; Soumerai et al., 2021; Wierda et al., 2021). Additionally, anti-CD20 antibody use causes significant B cell depletion resulting in prolonged immune suppression. Recent reports suggest BTKi use may in fact impair clinical activity of anti-CD20 antibodies, which can be mitigated by using selective BTKi and incorporating anti-CD20 later in the treatment course when lower disease burden is present (Da Roit et al., 2015; Flinsenberg et al., 2020; Pavlasova et al., 2016; Rawstron et al., 2018). Therefore, anti-CD20 therapy may not be required for all patients and could be optimized within a response-adapted strategy. This trial has been developed to assess efficacy and safety of a response adapted consolidative treatment approach utilizing obinutuzumab triplet consolidation in CLL/SLL patients who remain MRD positive after an oral doublet fixed duration treatment with zanubrutinib and venetoclax. This approach looks to maximize MRD negative remissions, spare toxicity by limiting anti-CD20 exposure, and provide a finite therapy. This study will utilize once daily zanubrutinib for which there is limited data in regard to safety and efficacy particularly in combination with venetoclax. Study Design and Endpoints: This is a single center, open label, phase II, investigator initiated clinical trial enrolling 50 subjects evaluating the efficacy and safety of zanubrutinib and venetoclax with obinutuzumab triplet consolidation in subjects who remain MRD positive (BruVenG). Eligible patients must have treatment naïve CLL/SLL and treatment indications per the International Workshop on CLL 2018 guidelines. Subjects with Richter's transformation are excluded. Treatment will consist of lead-in, combination, and consolidation phases. All subjects will be treated with a 3-cycle lead-in of 320mg oral, once daily zanubrutinib monotherapy. Venetoclax will be incorporated at cycle 4, per the standard prescriber insert ramp-up schedule. A final dose of 400mg oral, once daily venetoclax, in combination with 320mg oral, once daily zanubrutinib will be used in all subsequent cycles after ramp-up. At cycle 16, MRD will be assessed in the peripheral blood (PB) and bone marrow (BM) via clonoSEQ (Adaptive Biotechnologies). Subjects who are MRD negative (&amp;lt;1x10 -4 ) in both compartments will stop therapy. Subjects who are MRD positive in PB or BM will continue zanubrutinib and venetoclax for an additional 6 cycles. Obinutuzumab will be added to the oral doublet starting at cycle 17. Standard intravenous obinutuzumab lead-in will occur during cycle 17, followed by standard monthly intravenous dosing of 1000mg through cycle 22. Depending on MRD status, subjects will be treated for 16 or 22 cycles. All subjects who receive consolidation will stop treatment at cycle 23 regardless of end of treatment MRD status. The primary endpoint is cycle 16 PB and BM MRD negativity rates. A co-primary endpoint will be cycle 23 PB and BM MRD negativity rates in subjects who were MRD positive at C16 and who went on to receive at least 1 dose of obinutuzumab. Key secondary endpoints will include cycle 16 overall response rate, 36-month progression free survival, 36-month overall survival, 36-month time to next treatment, 24- and 36-month PB MRD negativity rates, tumor lysis risk reduction rates, and safety. Exploratory endpoints will assess the positive predicative value of the ∆400 biomarker (Soumerai et al., 2021) on MRD negativity at cycle 16. This biomarker will be assessed between cycle 4 and 6. The MRD negative rates at cycle 16 and cycle 23 will be estimated with a 90% confidence interval using the Clopper-Pearson method based on exact binomial distribution.

MRD Monitoring By Euroclonality IGH Based NGS Approach Predicts Outcome in Follicular Lymphoma Patients Lacking a Conventional BCL2::IGH Marker: A Substudy from the Fondazione Italiana Linfomi (FIL) FOLL12 Trial

Background. Despite durable clinical responses achieved by chemo-immunotherapy in follicular lymphoma (FL) patients, most of them eventually relapse. Actually, minimal residual disease (MRD) analysis based on the detection of BCL2::IGH rearrangement by PCR is the most widely used and standardized approach, able to early identify patients at high risk of disease reappearance. Nevertheless, this tool fails the molecular marker definition in up to 45% of cases, hampering the disease monitoring in a large group of patients. In the last decade, the continuous improvement of next-generation sequencing (NGS) techniques allowed to introduce these novel tools for MRD monitoring in some hematologic diseases, as acute lymphoblastic leukemia and multiple myeloma, thus reducing PCR limitations and increasing the number of patients eligible for MRD. Nonetheless, applications of NGS tools for MRD detection in FL are still scant. Aims. Therefore, we tested the feasibility of the EuroClonality (EC) IGH-based NGS approach [Brüggeman, Leukemia 2019] to identify novel molecular markers suitable for MRD monitoring in the context of the large prospective trial “FOLL12” (EudraCT: 2012-003170-60) by the Fondazione Italiana Linfomi (FIL), where 57% of patients were already studied for MRD by classic PCR methods targeting the BCL2::IGH rearrangement.[Luminari, JCO2022] Methods. Advanced FL patients received upfront treatment with either R-CHOP or BR, followed by a combined PET/MRD response-based maintenance with rituximab. Bone marrow (BM) samples were centralized to the FIL MRD Network for standardized MRD analysis. Baseline gDNA of “no marker” patients was screened by IGH-based NGS using EC-IGH two-steps PCR approach in the EuroMRD certified lab of Torino university; then MRD was monitored in those patients harboring a IGH clonal marker at baseline by one step EC-IGH method. The identification of baseline clonotypes and MRD clones was performed by ARRest/Interrogate tool. Results. 343/786 enrolled patients (43%) lacked a conventional BCL2::IGH marker and 161/343 (47%) showed morphologic BM lymphoma infiltration: of these, 124 (77%) had an available BM baseline sample for IGH screening and were thus included in the analysis. Overall, IGH clonotypes suitable as novel molecular markers were identified in 75/124 patients (60%), of which 73 monoclonal and 2 biclonal. Of this series, 47 patients had centralized a BM sample for MRD analysis at end of induction. Median age of this subset was 59 years (33-81), 53% were female, all were Ann Arbor stage IV, 34% were FLIPI intermediate and 43% high risk, respectively. Moreover, 56% received R-CHOP and 44% BR as induction treatment, resulting in a 79% CR rate and 89% MRD negativity rate (in line with the results of the general trial population). PFS at 3 years for this series was 69%: however, the 5 patients who scored MRD positive (MRD+) showed statistically significant worse PFS at 3 years than MRD negative cases (22% vs 73%, respectively, p=0.0069, Figure 1). Notably, 4 out of 5 MRD+ patients experienced POD24. Focusing on biclonal cases, one presented superimposable MRD trends between clones (both achieving MRD negativity), while in the other both clones remained MRD positive but showing one Log difference between them. Interestingly, only one of the two clones showed a MRD increase in the following timepoint (6 months after end of induction), heralding the clinical relapse subsequently occurred at month 12 (Figure 2). On the other hand, no IGH clonotype was identified in the first 17 patients who were screened for a novel MRD marker despite the absence of BM infiltration. Conclusions. The first data on the large-scale application of NGS-based marker screening tools in FL patients lacking a conventional BCL2::IGH marker for MRD enrolled in a prospective clinical trial showed that the EC IGH-based NGS approach was able to provide a new molecular marker in 60% of patients with evidence of BM infiltration (that means about the 28% of “no marker” FL patients); importantly, this approach was predictive of worse PFS for MRD+ cases. Overall, these data are promising for the wide employment of novel, effective MRD monitoring tools, able to recover more than one fourth of FL patients lacking a conventional molecular marker and so, by combining conventional and NGS-based techniques, potentially rising the percentage of MRD evaluable cases up to at least 70% cases.

Will Survival Improve By Treating Multiple Myeloma Patients at MRD Relapse? the Remnant Study

Background: Although many new treatment options have become available, multiple myeloma (MM) is still considered an incurable disease. The importance of achieving minimal residual disease (MRD) negativity in MM patients has become clearer in recent years. Multiple studies show that bone marrow based MRD assessment is one of the strongest prognostic factors, and deeper responses correlate with more favorable outcomes. The REMNANT study will evaluate if treating at MRD relapse after first line (1.L) treatment prolongs progression-free survival (PFS) and overall survival (OS) in MM patients. Methods: The REMNANT study (RElapse from Mrd Negativity As iNdication for Treatment) is an academic, multicenter, open-label, randomized phase 2/3 study of newly diagnosed (ND) MM patients eligible for autologous stem cell transplant (ASCT). The study has a population-based approach with few exclusion criteria, implying that patients with kidney failure, amyloidosis, plasma cell leukemia and other comorbidities are enrolled. To increase enrollment in part 2, patients who have received 1.L treatment outside the REMNANT study can be enrolled directly if they are &amp;gt;CR/MRD negative. 391 NDMM patients (age 18-75 years) eligible for ASCT will be enrolled in part 1 (phase 2) of the study and receive standard of care Norwegian 1.L treatment; 4 pre-transplant induction and 4 post-transplant consolidation cycles of bortezomib, lenalidomide and dexamethasone (VRd). After induction, patients will undergo tandem or single transplant, depending on toxicity and response to first transplant. All patients receive lenalidomide maintenance. Following 1.L treatment 176 patients achieving MRD negative (Euroflow NGF 10 -5) complete response will be enrolled in part 2 (phase 3) of the study. Patients will be randomized in a 1:1 ratio to receive second line treatment (2.L) at MRD relapse in arm A or at PD in arm B. At loss of MRD negativity in arm A or at PD in arm B, 2.L treatment will be daratumumab, carfilzomib and dexamethasone until PD. The primary endpoint of part 1 (phase 2) of the study is the number of patients who achieve MRD negative (Euroflow NGF 10 -5) complete response 30-45 days post consolidation. Secondary endpoints includes response rates, safety evaluations and patient-reported outcome. The co- primary endpoints in part 2 (phase 3) are PSF and OS from randomization to progressive disease or death on 2.L treatment. We will also compare different methods for measuring MRD: NGF Euroflow, Next Generation Sequencing, mass spectrometry and PET-CT. We want to evaluate how the different methods compare when it comes to sensitivity and outcome (PFS and OS). Results: As of July 18 th 2023, 291 patients are enrolled in part 1 and 97 in part 2 (23 directly enrolled). Baseline characteristics, safety summary and preliminary results can be found in Table 1. The ORR on first line treatment is 95% and 65 of 152 patients (45%) were &amp;gt;CR and MRD negative at the post-consolidation visit. Patients achieving &amp;gt; VGPR but not CR MRD negativity post consolidation are followed for up to 24 months on lenalidomide maintenance, and 11 of 74 patients (15%) in follow-up have converted to &amp;gt;CR/MRD negativity at a median time of seven months (range 2-16). Nine patients have started 2.L treatment in part 2 (phase 3), eight in arm A (MRD guided) and one in arm B (control arm). Median time to loss of MRD negativity among the eight patients in arm A was four months (range 1-6). The most common adverse events were infections, occurring in 24% of patients (any grade). During 1.L treatment, 61 patients have left the study. Seven patients have died, 27 discontinued due to disease progression, 12 patients have withdrawn from the study and seven discontinued due to adverse events. 59% of the patients who progressed during 1. L treatment had high-risk cytogenetics (with gain1q and/or del17p and/or t(4;14)). Conclusion: Standard of care Norwegian first line treatment has an ORR of 95%. The MRD negativity rate among patients who have finished 1.L treatment was 43% (65 of 152). The median time to loss of MRD negativity in arm A (MRD guided) was 4 months.

Safety and Efficacy Outcomes for Patients with High-Risk Multiple Myeloma Receiving Idecabtagene Vicleucel: The MD Anderson Experience

Background: There is a paucity of data regarding the impact of high-risk features on the efficacy and safety of B-cell maturation antigen (BCMA)-directed autologous chimeric antigen receptor (CAR)-T therapy in patients with multiple myeloma (MM). Methods: In this retrospective single-center study we included all MM patients who received idecabtagene vicleucel (ide-cel) between 12/2019-10/2022, either in the setting of a clinical trial (i.e. KarMMa-2 and KarMMa-3) or as a standard of care (SOC). We evaluated the impact of high-risk disease features on the efficacy and safety outcomes. Patients with high-risk MM (HRMM) were defined as having at least one of the following: high-risk cytogenetic abnormalities prior to CAR-T infusion (deletion 17p, translocation (t)(4:14), t(14:16) or 1q gain/amplification (1q+)), extramedullary disease (EMD), plasma cell leukemia and Revised International Staging System (R-ISS) stage 3. Minimal residual disease (MRD) was evaluated using 8-color next-generation flow cytometry (NGF), with a sensitivity of 1/10-5 cells (0.001%) based on the acquisition and analysis of at least 2 million events. Efficacy outcomes included response rates, progression free survival (PFS) and overall survival (OS). Safety outcomes included incidence/grade of cytokine release syndrome (CRS), Immune effector cell-associated neurotoxicity syndrome (ICANS), hematological toxicity and infections. Results: A total of 74 patients were included in our analysis, 49 received SOC ide-cel and 25 were treated on clinical trial. The median age was 65.3 (range 37.9-90.3) years, and 49 patients (66%) were male. Median number of previous lines of therapy was 6 (range 1-18). The HRMM group included 52 patients (70%), and the most prevalent high-risk features were high-risk cytogenetic abnormalities (43%, most often 1q+ (n=26, 81%), followed by del17p (n=17, 33%), t(4:14) (n=9, 17%) and t(14:16) (n=4, 8%)) and EMD (19%). Seventy five percent of patients who received SOC ide-cel had HRMM compared to 25% of those who received ide-cel on clinical trial (p=0.014). Compared to patients with standard-risk MM (SRMM), those with HRMM more often had disease refractory to proteasome inhibitors (p=0.042) or anti-CD38 antibodies (p=0.01), and more often received bridging therapy prior to CAR-T infusion (p=0.021). After bridging therapy, 43% of HRMM patients had progressive disease, compared to 20% of SRMM patients (p=0.21). Sixty seven percent of the entire cohort received prior BCMA-directed therapy before ide-cel, without a significant difference between the two risk groups (p=0.80) ( Table 1). For the entire cohort, overall response rate was 85%, and 51% achieved ≥CR at best response. There was no significant difference between the HRMM and SRMM groups in response rates or in rates of MRD negativity at day 30 and at 3/6/9 months after CAR-T infusion, yet fewer HRMM had MRD negativity at 12 months after CAR-T (50% vs. 100% of evaluable patients, p=0.019). The 6-months PFS for the HRMM group and the SRMM group was 64% and 81%, respectively (p=0.11) ( Figure 1A), and the 6-months OS was 80% and 90%, respectively (p=0.067) ( Figure 1B); Thirty-nine patients in the HRMM group developed CRS (83% of evaluable patients), including one grade 3 and one grade 5 CRS, compared to 15 (75%, p=0.65) in the SRMM group (all grade &amp;lt;3). Eight patients in the HRMM group developed ICANS (17%), including two grade 4 ICANS, compared to 3 (15%, p=0.93) in the SRMM group (all grade &amp;lt;3). We did not observe a difference in rates of neutropenia (p=0.63), anemia (p=0.75) or thrombocytopenia (p=0.53) by day 30, and also not in the rates of infection (p=0.16) between the two groups. In multivariate analysis on the entire cohort, receiving &amp;lt;4 prior lines of therapy (HR 0.06, 95% CI 0.004-0.71, p=0.026) and ECOG≤2 (HR 0.07, 95% CI 0.08-0.53, p=0.01) were associated with superior OS. Conclusions: Patients with HRMM receiving ide-cel had mostly comparable response rates compared to those with SRMM. HRMM patients had numerically worse PFS and OS compared to patients with SRMM, though not reaching statistical significance. Overall rates of CRS/ICANS were comparable between the two groups, yet only patients with HRMM had grade ≥3 of these complications. Patients who received ide-cel after less than four previous lines of therapy had better overall survival.

Sequential Chemotherapy and Blinatumomab to Improve Minimal Residual Disease in Adult Ph- B-Lineage Acute Lymphoblastic Leukemia. Final Results of the Phase II Gimema LAL2317 Trial

Introduction. The outcome of adult patients with acute lymphoblastic leukemia (ALL) has markedly improved following the introduction of a pediatric inspired chemotherapy backbone coupled with minimal residual disease (MRD) monitoring at well-defined timepoints (TP), translating into a rational patients' stratification for allogeneic transplantation (Tx). Immunotherapy, in particular blinatumomab, represents a further advancement in the management of ALL. We designed a phase II trial (GIMEMA LAL2317) for adult Ph- CD19+ B-lineage ALL (Ph- B-ALL) consisting of a pediatric chemotherapy backbone - with dose adjustment in patients &amp;gt;55 years - to which 2 cycles of blinatumomab were added, the first after early consolidation cycle 3 (high-dose methotrexate and Ara-C) and the second after late consolidation cycle 6. Tx allocation was based on MRD assessment, carried out in most cases by RQ-PCR and by flow cytometry when a sensitive molecular marker was not identified. The primary objective of the trial was to assess the impact of blinatumomab in increasing the rate of early MRD negativity at end of week 14 (TP3). Patients and methods. The protocol was designed for adults up to the age of 65 years with newly diagnosed Ph- B-ALL; 149 patients were enrolled. Median age was 41 years (18-65), with 28 patients (19%) being older than 55. Eighty-one patients were males, and the median white blood count (WBC) was 4.5x10 9/l (1-474); 12 cases harbored the KMT2A rearrangement, 5 the TCF3:: PBX1 transcript and 31 were classified as Ph-like according to the BCR/ABL1-like predictor . The median follow-up is 37.5 months (0.55-62.8) Results. At the end of induction (TP1, after cycles 1 and 2), 131 patients (88%) were in complete remission (CR), with a significant difference according to age: 94%, 92% and 64% in the 18-40, 40.55 and &amp;gt;55 years cohorts, respectively (p&amp;lt;0.001). All patients with KMT2A and TCF3::PBX1 rearrangements achieved a CR, while 5 Ph-like patients did not. At TP2, i.e. after early consolidation, 85 patients (70%) became MRD-negative (MRD neg). TP3, after the 1 st blinatumomab cycle, 102 patients were MRD neg; the rate of MRD negativity increased to 93% (p&amp;lt;0.001). Imposable results were obtained considering only paired MRD samples. Eight patients remained MRD pos, including 4 with a KMT2A rearrangement and 1 with a E2A::PBX1 rearrangement. OS and DFS at 36 months are 71% and 66% on the whole cohort. OS was significantly different (p=0.00013) according to age cohorts: 76%, 74% and 49% for patients aged 18-40, 40-55 and &amp;gt;55 years, respectively. Likewise, DFS was 71%, 62% and 42% for the same age cohorts, without reaching statistical significance. When patients were stratified for TP2 MRD, OS and DFS were significantly better for MRD neg vs MRD pos cases (p=0.0006 and p&amp;lt;0.0001, respectively). At variance, at TP3, with the caveat of the small sample size of MRD pos patients, the differences between MRD neg and MRD pos patients at TP3 were abolished: indeed, OS and DFS were 82% and 68% for MRD neg, 80% and 70% for MRD pos and 88% and 72% for those lacking MRD evaluation (Figure). Finally, 30 relapses have so far occurred, including 10 Ph-like, 1 KMT2A and 3 TCF3::PBX1 rearranged cases. The overall cumulative incidence of relapse (CIR) was 27.5%; of note, within TP3 MRD neg patients CIR was 42.5% in Ph-like cases vs 17.5% in the remaining patients. By univariate analysis, significant factors for OS were age (p&amp;lt;0.001), CR achievement (p&amp;lt;0.001) and TP2 MRD (p=0.002); TP2 MRD retained significance in multivariate analysis (p=0.001). Univariate analysis for DFS showed as significant the Ph-like signature (p=0.026) and TP2 MRD (p&amp;lt;0.001); both retained statistical significance in multivariate analysis (p=0.021 and &amp;lt;0.001, respectively). Toxicity details will be provided. Conclusions. This phase II trial shows the benefit of adding blinatumomab for the management of Ph- B-ALL, with the primary objective being achieved with 93% of patients being MRD neg after the 1 st cycle of blinatumomab. With a median follow-up of 37.5 months, OS and DFS are 71% and 66%, respectively, better than in historical results, particularly in patients up to the age of 55. Importantly, at TP3 the MRD status no longer impacted, highlighting the therapeutic role of blinatumomab, as observed in Ph+ ALL. Finally, the Ph-like signature retains its negative prognostic impact, suggesting that a combination strategy, similar to that in place for Ph+ ALL, is required.

Reduced-Dose Chemotherapy Followed By Blinatumomab As Induction Therapy in Treatment of Newly Diagnosed Philadelphia Chromosome-Negative B-Cell Precursor Acute Lymphoblastic Leukemia - Interim Results from a Multicenter, Single-Arm, Phase 2 Study

Introduction: Although intensive pediatric chemotherapeutic regimens have shown good efficacy in the treatment of Philadelphia Chromosome-negative (Ph-negative) B-cell precursor acute lymphoblastic leukemia (BCP-ALL) in adults, the high incidence of chemotherapy-related toxicities limits their use. Blinatumomab, a CD3/CD19 bispecific T-cell antibody, has shown high efficacy in relapsed/refractory or minimal residual disease (MRD) positive BCP-ALL; however, the efficacy of single-agent blinatumomab does not meet the treatment needs of adult patients. Therefore, combining low-intensity chemotherapy with blinatumomab could be a better induction regimen for newly diagnosed adult patients with BCP-ALL. Methods: This multicenter, single-arm, phase 2 trial (NCT05557110) enrolled adult patients (aged 15-59 years) with newly diagnosed Ph-negative BCP-ALL. The induction regimen comprised reduced intensity chemotherapy (idarubicin 8 mg/m 2 on day 1, vindesine 4 mg on day 1, and dexamethasone 9 mg/m 2/day from day 1-7) followed by 2 weeks of blinatumomab (9 ug/day from day 8-14, 28 ug/day from day 15-21). The primary endpoint was to assess the overall response rate (ORR=complete remission [CR] + CR with partial hematologic recovery [CRh] + CR with incomplete hematologic recovery [CRi]) of this induction regimen. Secondary endpoints were MRD negativity (&amp;lt;1x10 -4 by flow cytometry), event-free survival (EFS), overall survival (OS) and safety. Bone marrow evaluation and one intrathecal injection chemotherapy were performed on day 22±2. Patients not achieving ORR continued blinatumomab for another 2 weeks (28 ug/day from day 1-14), followed by bone marrow re-evaluation. Consolidation therapy was given after achieving ORR with recommended multidrug combination chemotherapy (including high-dose methotrexate or cytarabine combined with asparaginase) or alternating with blinatumomab (28 ug/day for 28 days). If allogeneic hematopoietic stem cell transplantation (allo-HSCT) is not performed, consolidation therapy needs at least 4 courses before 2 years of maintenance therapy. Results: Interim results are presented here.By July 6, 2023 (data cut-off), 25 patients were enrolled with a median age of 42 years (range: 15-53); 68% were females. The Eastern Cooperative Oncology Group Performance Status score ranged from 0-1. Eight (32.0%) patients had poor cytogenetic risk factors, including 3 with P2RY8::CRLF2, 2 with hypodiploidy, 2 with KMT2A rearranged and 1 with alterations of IKZF1 (Table 1). The bone marrow evaluation done in 19 patients on day 8 prior to blinatumomab treatment showed that none of the patients had got ORR. All 21 (100%) patients evaluable for the primary endpoint attained CR/Cri - 19 at the end of 2 weeks of blinatumomab and the remaining 2 after another 2 weeks of blinatumomab (Table 2). The MRD negativity rate was 90.5% (19/21) after 2 weeks of blinatumomab which increased to 95.5% (20/21) after another 2 weeks of treatment with blinatumomab. In 21 patients evaluated for safety, blinatumomab-related cytokine release syndrome was reported in 10 (47.6%) patients (grade 1: n=6, grade 2: n=3 and grade 3: n=1). No incidence of neurotoxicity was reported. Febrile neutropenia was reported in 4 (19%) patients (all ≥grade 3). The non-hematological AEs reported were fever in 7 (33.3%) patients (any grade), increased ALT in 10 (47.6%) patients (any grade) and infections in 4 (19%) patients, including pneumonia in 2 and sepsis in 2 (all ≥grade 3). The median duration of neutrophil deficiency (&amp;lt;0.5×10 9/L) and platelet deficiency (&amp;lt;20×10 9/L) during induction therapy was 9 days (range: 0-20) and 1 day (range: 0-18), respectively. The median follow-up time was 4 months and no relapse or leukemia-related deaths were observed. The median EFS and OS were not yet reached. All enrolled patients are alive except one who died of infection after multidrug combination consolidation chemotherapy. The median cycles for consolidation were 2 (range: 1-5) with 3 patients undergoing allo-HSCT. Conclusion: Thesepreliminary results indicate that the reduced intensity chemotherapy followed by blinatumomab is an effective regimen in adults with newly diagnosed Ph-negative BCP-ALL, resulting in favorable response rates, deep remission, and low-grade treatment-related AEs. These promising findings may provide a rationale for integrating blinatumomab into future induction therapy recommendations.

Venetoclax Combined with Homoharringtonine,Cytarabine and Aclacinomycin (HAAV) As Induction Therapy in Newly Diagnosed Young Adult Acute Myeloid Leukemia

Background: The remission rate of acute myeloid leukemia (AML) patients using traditional induction chemotherapy is approximately 60-70%. Venetoclax (Ven), a b-cell lymphoma 2 (BCL-2) inhibitor, in combination with chemotherapy or hypomethylating agents, has shown a significant increase in remission rates and improvement in patient survival for elderly or unfit for intensive chemotherapy newly diagnosed AML patients. The HAA regimen (consisting of Homoharringtonine, Cytarabine and Aclacinomycin), a specific traditional induction therapy for acute myeloid leukemia in China. The HAA regimen achieved complete remission rates about 70% as an induction regimen for newly diagnosed AML. Whether the combination of Ven with HAA regimen as an induction treatment can further enhance the complete remission rate in newly diagnosed adult AML patients requires investigation through well-designed clinical trials. Objective: To evaluate the efficacy and safety of HAA combined with Ven as induction regimen (HAAV) in young adult patients with newly diagnosed AML. Design, setting and participants: Single-arm, prospective clinical trial conducted at 8 hospitals in China. Eligible patients (16-60 years old) with newly diagnosed AML (exclude acute promyelocytic leukemia) were enrolled. The trial was registered on ClinicalTrials.gov (NCT05893472) and continues to accrue patients. Induction regimen: The induction regimen consisted of Homoharringtonine (2.5mg/㎡/d，d3-7 ), cytarabine (100mg/㎡/d by continuous intravenous infusion daily on d3-7) and Aclacinomycin (20mg/d, d3-7) combined with venetoclax (100mg d1, 200mg d2, 400mg d3-8). Main outcomes and measures: The primary endpoint was the overall response rate (ORR) after once cycle of HAAV regimen, which included complete remission (CR), complete remission with incomplete count recovery (CRi), morphologic leukemia-free state (MLFS) and partial remission (PR). Secondary endpoints included minimal residual disease (MRD), overall survival (OS), event-free survival (EFS) and adverse events. Results: Untill June 30, 2023, 40 patients were enrolled. The median age is 43 years (range, 18-60), with 60% (24/40) was male. According to the European Leukemia Network prognostic group (2022), 14 (35.0%), 14 (35.0%), and 12 (30.0%) patients were considered to belong to the favorable, intermediate, and adverse groups, respectively. Further details of the patients' characteristics are provided in Table 1. The ORR (CR+PR) was 97.5% (39/40 patients) after one cycle of the induction regimen with the CR rate was 95.0% (38/40). According to the ELN prognostic group (2022), the CR was 100% in favorable-risk patients (14/14), 100% in intermediate-risk patients (14/14), and 83.3% in adverse-risk patients (10/12). For patients who achieved CR, MRD negative rate was 88.9% (32/36) by flow cytometry. During the induction treatment, all patients experienced ≥Grade 3 hematological toxicity, the remaining common adverse reactions were infections and fever. None of patients died during the induction therapy. In patients who achieved response, the median time to recovery of the white blood count (WBC) to ≥1.0 × 10 9/L and the platelet count to ≥20 × 10 9/L after induction therapy was 13 (range: 10-52) and 13 days (range: 2-33), respectively. ( Table 1) Conclusions: Ven combined with HAA (HAAV) is a highly effective and safe induction therapy for young adult patients with de novo AML. To the best of our knowledge, this is the first report about Ven combined with HAA.