Minimal Residual Disease Status Research Articles

Minimal Residual Disease Status in Multiple Myeloma 1 Year After Autologous Hematopoietic Cell Transplantation and Lenalidomide Maintenance Are Associated With Long-Term Overall Survival.

Prognostic Immunophenotyping in Myeloma Response (PRIMeR) is an ancillary study of minimal residual disease (MRD) assessment for multiple myeloma by next-generation multiparameter flow cytometry (MFC). Patients were enrolled on a three-arm randomized control trial (Blood and Marrow Transplants Clinical Trials Network 0702 Stem Cell Transplant for Myeloma in Combination of Novel Agents [STaMINA]; ClinicalTrials.gov identifier: NCT01109004). Four hundred and thirty-five patients consented to the MRD panel, which included 10 monoclonal antibodies measured via six-color MFC. MRD was measured at baseline/preautologous hematopoietic cell transplant (BL/preAutoHCT), premaintenance (PM), and 1 year (Y1) after AutoHCT with a sensitivity of 10-5 to 10-6. The primary objective was to assess MRD-negative (MRDneg) at 1 year after AutoHCT and progression-free survival and overall survival (PFS/OS). Similar to the STaMINA results, at a median follow-up of 70 months, there was no significant difference in PFS/OS by treatment arm in the PRIMeR patients. MRDneg at all three time points was associated with significantly improved PFS, and MRDneg at Y1 had significantly longer OS. Multivariate analysis of PFS, adjusting for disease risk and treatment arm, demonstrated hazard ratios (HRs) in MRD-positive patients compared with MRDneg patients at BL, PM, and Y1 of 1.55 (P = .0074), 1.83 (P = .0007), and 3.61 (P < .0001), respectively. Corresponding HRs for OS were 1.19 (P = .48), 0.88 (P = .68), and 3.36 (P < .001). Patients with sustained MRDneg or who converted to MRDneg by Y1 had similar PFS/OS. To our knowledge, this first, prospective US cooperative group, multicenter study demonstrates that MRDneg at Y1 after AutoHCT with lenalidomide maintenance is prognostic for improved 6-year PFS and OS. Serial MRD measurements may direct trials to test how further therapy may improve long-term PFS and OS.

Abstract PO3-19-06: MRD Assay evaluates Recurrence and response via a tumor Informed Assessment: MARIA-Breast Observational Trial

Abstract Background: Detectable ctDNA in patients with solid tumors has been associated with disease prognosis pre-treatment, assessing response to therapy in the form of minimal residual disease (MRD), and monitoring for recurrence after curative intent treatment. Utilizing patient-specific genomic mutation profiling of an individual’s cancer from a tissue sample, in conjunction with the patient’s germline DNA, to create a personalized sequencing panel to analyze for a subset of these genetic mutations from ctDNA in blood is a strategy that has high sensitivity for detecting MRD. Studies have shown that pretreatment levels of ctDNA using this approach are a potential early indicator of disease recurrence after surgery, that ctDNA clearance may be an early predictor of favorable outcomes and has been shown to correlate with pathologic complete response (Forde et al. N Engl J Med. 2022, PMID:35403841), and that this approach has high sensitivity for detecting recurrence for patients in advance of the current standard of care (Abbosh et al. Cancer Res (2020) 80 (16_Supplement): CT023). Methods: This is a multi-site, prospective, observational trial in the United States of 200 patients with early stage breast cancer using a patient-specific tumor-informed MRD assay for ctDNA analysis. Participants are asked to provide study specimens prior to initial treatment intervention, after curative intent surgical resection, during adjuvant therapy (as applicable) and pre-recurrence follow-up. ctDNA will be analyzed with an NGS-based, tumor-informed MRD assay that identifies somatic mutations from DNA obtained from the patient’s tumor tissue, subtracts germline variants via NGS-based analysis of the patient’s germline DNA, and detects a selected set of between 18-50 tumor-specific ctDNA in their blood. All primary tumor specimens will undergo full exome sequencing using the Personalized Cancer Monitoring (PCM) assay. Impact of results of this CLIA-approved MRD assay on clinical decision making will be captured. The primary objective is to assess the ability of MRD to predict post-treatment recurrence. Further objectives are to correlate MRD status with pathologic complete response, determine the lead time to detection of recurrence compared to standard of care, and the association of MRD status with overall survival. Active enrollment started in March, 2022. Support: Invitae. Clinical trial information: NCT05219734. Citation Format: Edward Esplin, Kelli Swan, Lee Ifhar, Brandie Heald, Sarah Nielsen, Daniel Pineda-Alvarez, William O'Callaghan, Robert Daber, Darrel Ross, Carlos Vieira, Aadel Chaudhuri, W. Korn. MRD Assay evaluates Recurrence and response via a tumor Informed Assessment: MARIA-Breast Observational Trial [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-19-06.

Survival after allogeneic transplantation according to pretransplant minimal residual disease and conditioning intensity in patients with acute myeloid leukemia

BackgroundThe measurement of minimal residual disease (MRD) by multiparametric flow cytometry (MFC) before hematopoietic stem cell transplantation (HSCT) in patients with acute myeloid leukemia (AML) is a powerful prognostic factor. The interaction of pretransplant MRD and the conditioning intensity has not yet been clarified.ObjectiveThe aim of this study is to analyze the transplant outcomes of patients with AML who underwent HSCT in complete remission (CR), comparing patients with positive MRD (MRD+) and negative MRD (MRD−) before HSCT, and the interaction between conditioning intensity and pre-HSCT MRD.Study designWe retrospectively analyzed the transplant outcomes of 118 patients with AML who underwent HSCT in CR in a single institution, comparing patients with MRD+ and MRD− before HSCT using a cutoff of 0.1% on MFC, and the interaction between conditioning intensity and pre-HSCT MRD.ResultsPatients with MRD+ before HSCT had a significantly worse 2-year (2y) event-free survival (EFS) (56.5% vs. 32.0%, p = 0.018) than MRD− patients, due to a higher cumulative incidence of relapse (CIR) at 2 years (49.0% vs. 18.0%, p = 0.002), with no differences in transplant-related mortality (TRM) (2y-TRM, 19.0% and 25.0%, respectively, p = 0.588). In the analysis stratified by conditioning intensity, in patients who received MAC, those with MRD− before HSCT had better EFS (p = 0.009) and overall survival (OS) (p = 0.070) due to lower CIR (p = 0.004) than MRD+ patients. On the other hand, the survival was similar in reduced intensity conditioning (RIC) patients regardless of the MRD status.ConclusionsPatients with MRD+ before HSCT have worse outcomes than MRD− patients. In patients who received MAC, MRD− patients have better EFS and OS due to lower CIR than MRD+ patients, probably because they represent a more chemo-sensitive group. However, among RIC patients, results were similar regardless of the MRD status.

Abstract PO2-20-01: The STOP-HER2 Trial: A Phase 2 Study of Stopping Trastuzumab - Outcomes in Patients with HER2+ Metastatic Breast Cancer (TBCRC 062)

Abstract BACKGROUND: Anti-HER2 therapies have transformed the trajectory for patients with HER2-positive (HER2+) MBC. A subset of patients with HER2+ MBC do exceptionally well and remain on maintenance anti-HER2 therapy for many years. However, current therapy is non-curative and patients are treated indefinitely. While these therapies often are well-tolerated, they may cause significant toxicities, are expensive, and typically require frequent infusion and provider visits. Case reports and retrospective series demonstrate that some patients may do well after stopping anti-HER2 treatment. We currently lack prospective data on the likelihood of clinical impact of successful treatment discontinuation, outcomes among patients who progress and restart HER2-directed therapy, and tools to predict who may safely stop therapy. In this study, we will enroll pts with an exceptional response to anti-HER2 therapy. Pts may elect to either continue or stop anti-HER2 therapy and will be followed clinically and radiographically on a protocol-specified schedule. Considering the central role of patients in choosing the study intervention arm, and the unique nature of stopping therapy as a treatment intervention, patient advocates have been deeply involved in the study design to ensure patient concerns are being heard and addressed. We will retrospectively assess minimal residual disease (MRD), measured in plasma, as a biomarker of ongoing response, in a step toward shifting the treatment paradigm for pts with HER2+ MBC. METHODS: STOP-HER2 is a prospective, non-randomized, phase II, multicenter study of either continuation (cohort 1) or cessation (cohort 2) of anti-HER2 therapy in exceptional responders with HER2+ MBC. Eligible patients must have biopsy-proven HER2+ MBC by ASCO/CAP guidelines and must have been receiving first-line anti-HER2 therapy for MBC for at least 3 years without evidence of progressive disease (PD) as determined by the treating investigator. Patients with prior brain-only PD or oligo-PD outside the brain are eligible at least 2 years after local treatment to the central nervous system (CNS) and in absence of subsequent PD. Up to fifty-two participants will be enrolled into cohort 2, and an additional thirty participants enrolled into the cohort 1, at 10 US sites within the Translational Breast Cancer Research Consortium. Co-primary endpoints are the 1-year progression-free survival (PFS) in cohorts 2 and 1, separately. Secondary endpoints include the clinical benefit rate upon re-initiation of anti-HER2 therapy for patients in cohort 2 experiencing PD after treatment discontinuation; and 3-year overall survival in both cohorts. Correlative endpoints include MRD status at baseline and the correlation between MRD dynamics and outcomes. Patient-reported outcomes will be collected and analyzed, including quality of life, illness intrusiveness, financial toxicity, anxiety, and decision regret. The study will use a two-stage design to assess the primary objective of estimating the rate of participants who are free of progression at one year after discontinuing anti-HER2 therapy. If 50% or less are free of progression at one year, stopping HER2 therapy would not be considered a viable treatment plan (null hypothesis). The study is designed to have 80% power to reject the null hypothesis at the 10% type I error rate when 68% of exceptional responders are free of progression at one year after stopping HER2 therapy. STOP-HER2 began enrollment in Q2 2023 (NCT05721248). Citation Format: Heather Parsons, Kathryn Ruddy, Stefania Morganti, Karen Smith, Victoria Attaya, Eliza Kallfelz, Michelle DeMeo, Jamie LaScala, Shirley Mertz, Teri Pollastro, Patricia Spears, Adam Brufsky, Chau Dang, Susan Dent, Ahmed Elkhanany, WIlliam Gwin, Ciara O'Sullivan, Kathy Miller, Sara Nunnery, Elaine Walsh, Anna Maria Storniolo, Sara Tolaney, Nabihah Tayob, Antonio Wolff, Eric Winer, Mothaffar Rimawi, Ian Krop, Nancy Lin. The STOP-HER2 Trial: A Phase 2 Study of Stopping Trastuzumab - Outcomes in Patients with HER2+ Metastatic Breast Cancer (TBCRC 062) [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-20-01.

Abstract PO5-16-04: Tissue-informed personalized MRD detection assay may outperform tumor-informed fixed panel strategy in Triple Negative Breast Cancer (TNBC)

Abstract Background: Minimal residual disease (MRD) detection by ctDNA analysis enables identifying patients with high recurrence risk and refining risk stratification to guide treatment selection precisely, which may improve patient survival or avoid overtreatment. We previously developed a 1021-gene fixed panel MRD detection assay, MNavigator V1, demonstrating high prognostic evaluation value in various solid tumors, including lung cancer, colorectal cancer, and esophageal carcinoma, and relevant research results have been published. Recently, the assay upgraded to MNavigator V2, a customized patient-specific panel strategy to ultra-deep sequencing, with higher clinical performance and more economical. Here, we head-to-head compared the performance of MNavigator V1 with V2, using the same collection of blood samples from TNBC patients. Methods: The retrospective study recruited 48 patients diagnosed with stage II~III TNBC with adequate samples (NCT04501523/NCT04803539). Five patients in the cohort received neoadjuvant therapy (Neoad-group), and the standard treatment regimen of the remaining 43 patients was adjuvant therapy (ad-group) after surgery. The surgical tumor tissue of all these patients was collected. Peripheral blood samples were collected at various time points, baseline samples before neoadjuvant therapy, 7-day after neoadjuvant therapy, 1-month postoperative, 7-day after adjuvant therapy, and subsequent every 3~6 months follow-up. The personalized, tumor-informed MRD detection approach MNavigator V2 started by identifying somatic mutation of the resected tumor with a 1021-gene panel covering 1.6Mb of the human genome. Then, a customized panel consisting of up to 20 top-ranked patient-specific somatic variants was designed. After that, unique molecular identifiers (UMI) based 100,000X ultra-deep next-generation sequencing on plasma samples was conducted by adopting the mix panel of the patient-specific panel and a 5kb breast cancer universal core panel. MNavigator V1 assay, a fixed panel assay also applied the same off-the-shelf 1021-genes panel with a sequencing depth of 10,000X to detect MRD of blood samples. Results: Until May 2023, the median follow-up time of 660 days, and 8 patients were recurrence confirmed by CT imaging. The median tracked tissue-informed mutations was 7 (2~18). In this study, the screening time point was defined as the combined MRD status of the blood samples collected before and after neoadjuvant therapy, and 1-month post-surgery for the Neoad-group, as for the ad-group, the time point referred to 1-month post-surgery and post-adjuvant therapy. If any one of these time nodes' MRD was positive, the screening period MRD was positive. During the screening period, MNavigator V1 and V2 accurately predicted 6/8 (75.0%) recurrence. MRD-positive status was associated with a worse prognosis, compared to the MRD-negative population, with hazard ratios of 9.0 and 19.9 for V1 and V2 assay, respectively. The longitudinal MRD evaluation yield a higher sensitivity of 7/8 (87.5%) for recurrence prediction with MNavigator V2 at a median lead time of 104 days, whereas the V1 assay predicted 6/8 (75.0%) at 94 days, and the hazard ratio was 40.4 vs 8.5. In one brain-only metastasis patient, MRD was undetectable, which may be due to the limitation of the blood-brain barrier. For recurrence-free patients with 1 year of follow-up, 92.5% (37/40) were MRD-negative with MNavigator V2 assay. These three patients who detected MRD-positive after surgery, ctDNA cleared after adjuvant therapy, and persistently negative during follow-up, may benefit from treatment. Conclusion: Based on the patient-specific tumor mutation profile, the personalized MRD detection assay achieved better clinical performance than the fixed panel strategy. Citation Format: Shunying Li, Wei Gao, Ning Fu, Wuqiang Cao, Xiaoling Zeng, Xinhua Du, Qiang Liu. Tissue-informed personalized MRD detection assay may outperform tumor-informed fixed panel strategy in Triple Negative Breast Cancer (TNBC) [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-16-04.

Donor matters: Donor selection impact on hematopoietic stem cell transplantation outcomes in Hispanic patients with B-cell acute lymphocytic leukemia: Insights from a myeloablative HSCT study

BackgroundHematopoietic stem cell transplantation (HSCT) is a pivotal treatment for high-risk acute lymphocytic leukemia (ALL), although limited by suitable human leukocyte antigen (HLA)-matched sibling donors (MSD). This study evaluates the impact of donor selection on outcomes in post-HSCT Hispanic B-cell ALL patients. MethodologyThis single-center retrospective study evaluates outcomes in 88 adult Hispanic B-cell ALL patients who underwent haploidentical, MSD, or MUD myeloablative HSCT between 2013 and 2023. ResultsCompared to Haploidentical transplants, MSD exhibited worse cumulative incidence of relapse (CIR) (HR = 3.39; P = 0.014) and disease-free survival (DFS) (HR = 2.44; P = 0.048) whereas MUD outcomes did not differ. This effect persisted even when controlling for pre-HSCT stage and Minimal residual disease (MRD) status. In addition, Ph-like was a significant predictor of worse DFS (HR = 3.60; P=0.014) and CIR (HR = 2.97; P=0.035) on multivariate analysis. Older donor age correlated with worse GVHD-free, relapse-free survival (GRFS) in haploidentical transplants (HR = 1.05; P=0.036). ConclusionOur data highlights improved outcomes with younger, haploidentical donors among Hispanic B-cell ALL patients undergoing myeloablative HSCT. This underscores the importance of donor selection in optimizing outcomes for ALL patients.

Abstract CT245: Circulating tumor DNA and nivolumab maintenance: A pilot study in diffuse large B cell lymphoma

Abstract Introduction: Molecular minimal residual disease (MRD) status correlates with disease relapse in patients (pts) with diffuse large B cell lymphoma (DLBCL). However, the clinical impact of early treatment intervention a time of detectable MRD (dMRD) prior to clinical relapse is unknown. Checkpoint inhibitor (CPI) therapy has activity in some pts with DLBCL. We hypothesized that early CPI therapy in patients with dMRD without clinical relapse may lower relapse rate. We conducted a pilot study in high risk pts in remission after most recent line of therapy (LOT) in whom maintenance nivolumab (MN) was offered at time of dMRD to assess effect on MRD clearance and relapse rate. Methods: Pts &amp;gt;18 years (yrs) with high-risk DLBCL (ABC-subtype, high grade B cell lymphoma (HGBCL), MYC translocation, relapsed/refractory disease, or Ki67 &amp;gt;90%) who had achieved CR on most recent LOT were eligible. Patients were monitored for detectable MRD (dMRD) based on the clonoSEQ assay for circulating tumor DNA (ctDNA). Pts had monthly MRD assessment and every 4 month imaging for 2 yrs. If conversion from uMRD to dMRD without clinical relapse, pts received MN (240 mg IV q2 weeks) for up 2 yrs. Pts with overt relapse at time of dMRD or dMRD at initial MRD assessment were ineligible for MN. The primary endpoint was rate of conversion from dMRD to undetectable MRD (uMRD). Results: 20 pts were screened and 15 pts enrolled between June 2018 and March 2022. 4 had transformed DLBCL (2 from FL, 1 from MZL, and 1 Richter’s transformation from CLL), 2 pts had HGBCL (one of which was also transformed). All pts with dMRD had radiographic relapse within 4 months of molecular relapse. No pts with uMRD by ctDNA had clinical relapse on study during 2 yrs follow up. Of the 8 pts who enrolled after first LOT, none had molecular or clinical relapse. Of the 7 pts with 2+ prior LOT, 3 had dMRD: two had clinical relapse at same time as dMRD and were taken off study (one had dMRD at baseline MRD assessment and the other 135 days post enrollment after initial period of uMRD). In the single patient eligible for MN, dMRD preceded radiographic relapse by 105 days, 410 days after enrollment. The pt received 2 cycles of MN before clinical progression and was taken off study. This pt failed to achieve conversion of dMRD to uMRD. Conclusion: Due to small sample size and lower than expected relapse, we were unable to demonstrate conversion of dMRD to uMRD using MN. However, this pilot study did confirm high correlation of uMRD and dMRD status with disease free survival and clinical relapse within 4 months, respectively. If strong negative predictive value is confirmed in a larger study, ctDNA MRD testing may be used to spare pts from imaging or to guide additional work up in pts with inconclusive findings on scans. Citation Format: Shazia Nakhoda, Tamarrah Sklarz, Cheyenne Pagan, Matthew Matasar, Zachary A. Frosch, Marcus Messmer, Asya Varshavsky Yanovsky, Rashmi Khanal, Carlyn Tan, Eli Mikkelsen, Henry Fung, Eric Ross, Mark Roschewski, Allison Jacob, Nadia Khan. Circulating tumor DNA and nivolumab maintenance: A pilot study in diffuse large B cell lymphoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT245.

Real-world advantage and challenge of post-autologous stem cell transplantation MRD negativity in high-risk patients with double-hit multiple myeloma

BackgroundAutologous stem-cell transplantation (ASCT) remains a beneficial approach for patients with newly diagnosed multiple myeloma (NDMM) in the age of novel therapeutic agents. Nevertheless, limited real-world data is available to establish criteria for identifying high-risk ASCT patients.MethodsWe analyzed outcomes for 168 NDMM patients who underwent ASCT at our center from December 2015 to December 2022. We investigated the impact of the number of high-risk cytogenetics (HRCA), defined as t(4;14), t(14;16), 1q21 gain/amplification, and del(17p), as well as the post-ASCT minimal residual disease (MRD) status as prognostic indicators. We assessed progression-free survival (PFS) and overall survival (OS), and focused on identifying risk factors.ResultsThe cohort included 42% of patients (n = 71) with 0 HRCA, 42% (n = 71) with 1 HRCA, and 16% (n = 26) with ≥ 2 HRCA. After a median follow-up of 31 months, the median PFS was 53 months (95% CI, 37–69), and OS was not reached for the entire cohort. Despite similar rates of MRD-negativity post-ASCT, patients with ≥ 2 HRCA, termed “double hit” (DH), had a significantly higher risk of progression/mortality than those with 0 or 1 HRCA. Multivariate analysis highlighted DH (HR 4.103, 95% CI, 2.046–8.231) and MRD positivity post-ASCT (HR 6.557, 95% CI, 3.217–13.366) as adverse prognostic factors for PFS, with DH also linked to inferior OS. As anticipated, DH patients with post-ASCT MRD positivity displayed the poorest prognosis, with a median PFS of 7 months post-ASCT. Meanwhile, DH patients with MRD negativity post-ASCT showed improved prognosis, akin to MRD-negative non-DH patients. It is noteworthy to exercise caution, as DH patients who initially achieved MRD negativity experienced a 41% cumulative loss of that status within one year.ConclusionsThis study strongly advocates integrating DH genetic assessments for eligible ASCT patients and emphasizes the importance of ongoing MRD monitoring, as well as considering MRD-based treatment adaptation for those patients in real-world settings.

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.

Abstract 5656: Longitudinal spatial profiling reveals chemoresistance mechanisms and characteristics of minimal residual disease in high-grade serous ovarian cancer

Abstract High-grade serous ovarian cancer (HGSOC) is the most lethal gynecologic malignancy globally. Despite an initial response to upfront surgery and platinum-based chemotherapy in most cases, over 70% will relapse. A critical source of recurrence is minimal residual disease (MRD), which persists after upfront treatment yet is clinically undetectable. In this study, we performed second look laparoscopy (SLL) on advanced stage HGSOC patients who had received neoadjuvant chemotherapy (NACT) followed by interval debulking surgery and adjuvant chemotherapy and were in complete clinical remission by imaging and CA-125 tumor marker. Surgical MRD status was determined by pathological review of SLL biopsies. Matched samples from pre-treatment biopsy, interval debulking surgery and SLL in 4 MRD+ and 3 MRD- cases were analyzed using GeoMx Digital Spatial Profiling. Among them, samples from 1 MRD+ and 1 MRD- case were also profiled with Visium. The tumor cells of MRD+ cases exhibited stronger signaling related to hypoxia, angiogenesis, and epithelial-mesenchymal transition at baseline as well as diminished apoptosis signaling after NACT. In addition, progressively upregulated expressions of ATP binding cassette transporters were also observed over time in the tumor compartment of MRD+ cases, potentially contributing to chemoresistance. In the tumor microenvironment, MRD- cases displayed increased abundance of plasma cells, conventional dendritic cells and lymphocytes in both pre-treatment and interval debulking samples compared to MRD+ cases. Notably, Visium data of the MRD- case revealed tertiary lymphoid structures (TLS) in the pre-treatment sample, which became better organized following NACT, with plasma cells disseminating into adjacent tumor areas. Conversely, TLS were fewer and poorly organized in the MRD+ case. Longitudinal comparison of the 3 timepoints in MRD+ cases revealed more regulatory T cells in the stromal compartments of the MRD lesions. Furthermore, from Visium data, exclusion of CD8 T and plasma cells from the tumor core was evident in the MRD lesion. In line with this, strong TGF-β, IL-1β, IL6 and FGF2 signaling surrounding the tumor were noted, likely contributing to immune exclusion. The spatial distribution of multiple immune checkpoint molecules highly overlapped with that of CD8 T cells, indicating T cell exhaustion in the MRD lesion. In summary, these data suggested distinct cancer phenotypic states and immune features in surgically detected MRD+ HGSOC, shedding light on potential chemoresistance and immune evasion mechanisms that contribute to the MRD phase of disease. This study represents the first systemic characterization of ovarian cancer MRD by leveraging SLL, providing insights for designing personalized therapies aimed at eradicating these chemoresistant lesions and ultimately preventing disease recurrence. Citation Format: Yibo Dai, Anne Knisely, Barrett Craig Lawson, Sanghoon Lee, Khalida M. Wani, Rossana N. Lazcano Segura, Brenda Melendez, Jianfeng Chen, Yunhe Liu, Manoj Chelvanambi, Laura A. Gibson, Sarah B. Johnson, Chih-Chen Yeh, Davis R. Ingram, Courtney W. Hudgens, Kyung Serk Cho, Guangsheng Pei, Jiahui Jiang, Yanshuo Chu, Alexander J. Lazar, Jianjun Gao, Jennifer Wargo, Linghua Wang, Amir A. Jazaeri. Longitudinal spatial profiling reveals chemoresistance mechanisms and characteristics of minimal residual disease in high-grade serous ovarian cancer [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 5656.

Abstract 6881: Investigating the role of post-transplant bone marrow immune dysregulation in multiple myeloma

Abstract Multiple myeloma (MM) is a cancer of bone marrow plasma cells (BMPCs), which to date remains incurable. Standard of care for qualifying patients involves high-dose chemotherapy followed by autologous stem cell transplant (ASCT), after which minimal residual disease (MRD) testing is used to assess the degree of tumor clearance. Though strongly associated with better survival, MRD-negativity is an imperfect predictor for patient outcomes and fails to account for the pro-tumorigenic BM dysregulation often found in MM patients. As the post-transplant BM milieu in MM is not well understood, we conducted 3' single-cell RNA sequencing (scRNAseq) of 49 newly diagnosed (NDMM) and 79 day-100 post-ASCT whole-BM aspirates to investigate how immunosuppressive microenvironmental signatures may persist or develop following ASCT to influence patient outcomes. 68 of 79 post-ASCT samples come from uniformly-treated clinical trial enrollees with progression-free survival (PFS) ranging from 10 months to over 7 years, with both MRD- and MRD+ cases at either PFS extreme. We observe that although post-ASCT samples have uniformly lower PC count than NDMM samples, only erythroblasts and B cells appear relatively depleted in NDMM samples to compensate for higher PC proportions. T/NK cells and myeloid lineages, though similar in percentage across samples, exhibit clear subtype bias between the two timepoints. Post-ASCT samples are significantly enriched for GZMH+ CD8+ T and NK cells, HIF1A+ hypoxia-responsive monocytes, and depleted for S100A8/9-high CD14+ monocytes. NDMM samples are also enriched for SPINK2+, CDK6+, and AVP+ neutrophils, which are rare in post-ASCT samples. Notably, higher HIF1A expression in myeloid cells post-ASCT is further associated with longer PFS. Regardless of MRD status, NFKBIA, FOS, and GNLY upregulation and GZMK downregulation in post-ASCT T cells are associated with worse PFS. Conversely, enrichment of CD16+ IFN-responsive monocytes and depletion of ARG1+/FUT4+/CEACAM8+ myeloid-derived suppressor cells (MDSCs) are associated with longer PFS. Beyond such general trends, we observe MRD-dependent PFS-association of several CD8+ T cell subsets. Overall, this study enhances our understanding of how post-transplant BM repopulation and immune interaction may impact treatment response in MM. Citation Format: Julia T. Wang, Mark Fiala, Kazuhito Sato, Julie Fortier, Ravi Vij, Li Ding. Investigating the role of post-transplant bone marrow immune dysregulation in multiple myeloma [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 6881.

The value of minimal residual disease and IKZF1 deletion for predicting prognosis in adult patients with B-cell acute lymphoblastic leukemia

Objective: To reassess the prognostic value of minimal residual disease (MRD) and IKZF1 gene deletions in adults with B-cell acute lymphoblastic leukemia (B-ALL) who received pediatric-specific chemotherapy regimens during the Nanfang Hospital PDT-ALL-2016 trial. Methods: We retrospectively analyzed the prognosis of 149 adult patients with B-ALL who were admitted to Nanfang Hospital from January 2016 to September 2020. Prognostic factors were identified using Cox regression models. Results: The complete remission rate was 93.2% in 149 patients, with a 5-year overall survival (OS) rate of (54.3±5.0) % and a cumulative incidence of relapse (CIR) of (47.5±5.2) %. The Cox regression analysis revealed that MRD positivity at day 45 (MRD(3)) after induction therapy was independently associated with relapse risk (HR=2.535, 95%CI 1.122-5.728, P=0.025). Deletion of IKZF1 gene was independently associated with mortality risk (HR=1.869, 95%CI 1.034-3.379, P=0.039). Based on MRD(3) and IKZF1 gene status, we categorized adult patients with B-ALL into the low-risk (MRD(3)-negative and IKZF1 gene deletion-negative) and high-risk (MRD(3)-positive and/or IKZF1 gene wild type) groups. The 5-year OS and CIR rates were (45.5±6.0) % vs (69.4±8.6) % (P<0.001) and (61.6±8.3) % vs (25.5±6.5) % (P<0.001), respectively, in the high-risk and low-risk groups, respectively. The multivariate analysis showed that the high-risk group was an independent risk factor for OS (HR=3.937, 95%CI 1.975-7.850, P<0.001) and CIR (HR=4.037, 95%CI 2.095-7.778, P<0.001) . Conclusion: The combined use of MRD and IKZF1 gene in prognostic stratification can improve clinical outcome prediction in adult patients with B-ALL, helping to guide their treatment.

Outcomes and prognosis of haploidentical haematopoietic stem cell transplantation in children with FLT3-ITD mutated acute myeloid leukaemia.

The presence of internal tandem duplication mutations in the FMS-like tyrosine kinase 3 receptor (FLT3-ITD) is a poor prognostic predictor in paediatric patients with acute myeloid leukaemia (AML). We evaluated the treatment outcomes and prognostic factors of 45 paediatric patients with FLT3-ITD AML who achieved complete remission before haploidentical haematopoietic stem cell transplantation (haplo-HSCT) at our institution from 2012 to 2021. Among the 45 patients, the overall survival (OS), event‑free survival (EFS), and cumulative incidence of relapse (CIR) rates were 74.9% ± 6.6%, 64.1% ± 7.2%, and 31.4% ± 7.1%, respectively, with 48.8 months of median follow-up. Univariate and multivariate analyses associated positive minimal residual disease (MRD) at pre-HSCT and non-remission (NR) after introduce 1 with inferior long-term survival. The 100-day cumulative incidence of grade II-IV acute graft-versus-host disease (aGVHD) was 35.6% ± 5.2%, and that of grade III-IV aGVHD was 15.6% ± 3.0% The overall 4-year cumulative incidence of chronic graft-versus-host disease after transplantation was 35.7% ± 9.8%, respectively. In conclusion, haplo-HSCT may be a feasible strategy for paediatric patients with FLT3-ITD AML, and pre-HSCT MRD status and NR after introduce 1 significantly affected the outcomes.

Abstract A077: The utility of surgical minimal residual disease after frontline treatment for prognostic and investigational opportunities in advanced ovarian cancer

Abstract Cure rates for patients with advanced stage ovarian cancer have not changed significantly over the last four decades likely due to inability to eradicate residual cancer cells after frontline therapy. Identifying clinically undetectable minimal residual disease (MRD) after frontline therapy by second look laparoscopy (SLL) has potential to a) uncover mechanisms of chemoresistance and tumor dormancy, b) identify MRD-specific therapeutic targets, and c) allow for earlier intervention with investigational therapies. The objective of this study is to describe the initial safety and feasibility of SLL and illustrate clinical and pathological correlates. Methods: This IRB-approved observational, single-center study includes patients with epithelial high-grade ovarian cancer with complete CA-125 and radiologic response after frontline treatment (combination of surgery and platinum-taxane chemotherapy) who underwent SLL from 4/2017-6/2023. Patients were subsequently offered standard of care or investigational maintenance therapy options based on homologous recombination deficiency (HRD) and MRD status. Summary statistics described the study population, chi-square tests compared categorical variables, and progression free survival (PFS) based on MRD status was estimated using Kaplan-Meier method and compared using log rank test. Results: 70 patients underwent SLL with a median of 8.5 biopsies (range 3-16). The majority of patients had stage III-IV disease (90%), and high-grade serous histology (90%). Approximately half (51.4%) of patients underwent neoadjuvant chemotherapy (NACT) with interval tumor reductive surgery (TRS). MRD was present in 32 patients (45.7%), and the presence of MRD was associated with a worse PFS (HR 3.0, 95% CI 1.5-5.8; 12.5 vs. 24.8 months; p=0.001). MRD was more frequent among NACT recipients compared to those who underwent primary TRS (63% vs 26%, P=0.002), those with HRD negative tumors (58% vs 24%, P=0.025), and those with R1 versus R0 resections (71% vs 39%, P=0.024). Of patients with MRD, 22 patients (71%) received bevacizumab until progression as part of a clinical trial (NCT02884648), 3 (10%) received bevacizumab off trial, 5 (16%) received a PARP inhibitor (all HRD positive), and 1 received other therapy. There were two (2.9%) intraoperative complications (both enterotomies) requiring conversion to laparotomy. Conclusions: SLL is feasible, overall safe, and detected MRD in 46% of ovarian cancer patients who were in radiologic and CA-125 remission after frontline therapy. PFS was significantly shorter for patients with residual disease, despite those patients all receiving additional therapy. Knowledge of MRD status in this patient population enables interventional, observational, and translational opportunities, as well as personalized prognostic counseling. MRD rate may also have utility as an early surrogate for efficacy in trials evaluating novel frontline investigational therapies. Future studies will compare the performance of circulating tumor DNA (ctDNA) versus surgical MRD. Citation Format: Anne Knisely, Roni Nitecki, J. Alejandro Rauh-Hain, R. Tyler Hillman, Jolyn S. Taylor, Lois M. Ramondetta, Michaela O. Grinsfelder, Lauren P. Cobb, David M. Boruta, Gwyn Richardson, Pamela T. Soliman, Aaron Shafer, Shannon N. Westin, Nicole D. Fleming, Travis T. Sims, Anil K. Sood, Pedro T. Ramirez, Karen H. Lu, Amir A. Jazaeri. The utility of surgical minimal residual disease after frontline treatment for prognostic and investigational opportunities in advanced ovarian cancer [abstract]. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_2):Abstract nr A077.

Real-world prognostic significance of attaining minimal residual disease negativity in newly diagnosed multiple myeloma

The aim of the study was to evaluate the prognostic impact of minimal residual disease (MRD) in the real-world setting and the interaction between MRD and molecular risk, clinical response and autologous stem-cell transplant (ASCT). A retrospective analysis of 275 newly diagnosed multiple myeloma (NDMM) patients who achieved very good partial remission (VGPR) or better before maintenance were involved. We examined MRD status by multiparameter flow cytometry (MFC). At a median follow-up of 37 months (4–88 months), In patients who achieved ≥ VGPR, those with MRD negativity had significantly longer PFS (51 vs. 26 months; P < 0.001) and OS (Not reached: NR vs. 62 months, P < 0.001) than those with MRD positivity. MRD positivity was the independent prognostic factor for PFS with hazard ratios of 2.650 (95% CI 1.755–4.033, P < 0.001) and OS with hazard ratios of 2.122 (95% CI 1.155–3.899, P = 0.015). Achieving MRD negativity was able to ameliorate a poor prognosis associated with genetic high risk. MRD negativity was associated with better PFS regardless of ASCT treatment. MRD status was more predictable for clinical outcome than conventional clinical responses. Moreover, Sustained MRD negativity ≥ 12 or ≥ 24 months improved both PFS and OS. Patients with NDMM who achieved MRD-negative status or sustained MRD negativity had deep remission and improved clinical outcomes regardless of high-risk cytogenetics, ASCT and clinical responses in a real-world setting.

[Effects of Pre-Transplant CONUT and Post-Transplant MRD on Prognosis of Patients with Multiple Myeloma after Auto-HSCT].

To explore the effects of pre-transplant controlling nutritional status (CONUT) and post-transplant minimal residual disease (MRD) on prognosis of patients with multiple myeloma (MM) after autologous hematopoietic stem cell transplantation (auto-HSCT). The clinical data of 79 patients who received auto-HSCT from 2011 to 2020 in The First Affiliated Hospital of Chongqing Medical University were retrospectively analyzed. The patients were divided into Low-CONUT group (n=62) and High-CONUT group (n=17) according to whether the CONUT score was less than 5. The differences in clinical features, hematopoietic reconstruction, adverse reactions, efficacy and survival between the two groups were compared. In addition, the prognostic risk factors were analyzed and verified by time-dependent ROC curve. The proportions of male patients and bone marrow plasma cells>30% at initial diagnosis in High-CONUT group were both higher than those in Low-CONUT group (both P <0.05). While, there were no significant differences in hematopoietic reconstruction and adverse reactions (>grade 2) between the two groups. The complete response (CR) rate and CR+very good partial response (VGPR) rate before transplantation in Low-CONUT group were both significantly higher than those in High-CONUT group (both P <0.05). After 3 months of transplantation, the CR+VGPR rate still remained an advantage in Low-CONUT group compared with High-CONUT group (P <0.01), but CR rate did not(P >0.05). The overall survival (OS) and progression-free survival (PFS) in Low-CONUT group were both superior to those in High-CONUT group (both P <0.05). Low CONUT score (0-4) before transplantation and negative MRD at 6 months after transplantation were favorable factors affecting OS and PFS (both P <0.05), while the International Myeloma Working Group (IMWG) high-risk at initial diagnosis and lactate dehydrogenase (LDH) level>250 U/L before transplantation were only risk factors for PFS (both P <0.05). Time-dependent ROC curve analysis showed that pre-transplant CONUT score and MRD status at 6 months after transplantation could independently or jointly predict 1- and 2-year OS and PFS, and the combined prediction was more effective. The combination of pre-transplant CONUT and post-transplant MRD can better predict the prognosis of MM patients.

Six-year follow-up and subgroup analyses of a phase 2 trial of venetoclax for del(17p) chronic lymphocytic leukemia

AbstractChromosome 17p deletion (del[17p]) is associated with poor prognosis in patients with chronic lymphocytic leukemia (CLL). Venetoclax is approved for treatment of previously untreated and relapsed/refractory (R/R) CLL, including patients with del(17p), based on the open-label, multicenter, phase 2 M13-982 trial (NCT01889186). Here, we detail the 6-year follow-up analysis for M13-982. A total of 158 patients with previously untreated (n = 5) or R/R (n = 153) del(17p) CLL received 400 mg venetoclax daily after initial ramp-up until progressive disease. After a median follow-up of 70 months, the best objective response rate (ORR) was 77% (21% complete remission [CR] and 49% partial remission [PR]), with a median duration of response (DOR) of 39.3 months (95% confidence interval [CI], 31.1-50.5). The median progression-free survival (PFS) was 28.2 months (95% CI, 23.4-37.6), and median overall survival (OS) was 62.5 months (95% CI, 51.7-not reached), with 16% of patients remaining on treatment after 6 years. Multivariable analysis did not identify statistically significant correlation between patient subgroups defined by clinical or laboratory variables and ORR or PFS. The most common grade ≥3 adverse events were neutropenia (42%), infections (33%), anemia (16%), and thrombocytopenia (16%). Post hoc comparative analyses of PFS and OS from treatment initiation, from a 24-month landmark, and by minimal residual disease status were performed between patients with del(17p) in the M13-982 and MURANO studies in the interest of understanding these data in another context. These long-term data show the continued benefits of venetoclax in patients with del(17p) CLL. The trial was registered at www.clinicaltrials.gov as #NCT01889186.

Early prognosis prediction in acute myeloid and acute lymphoid leukemia patients using cell-free DNA concentration ratios.

Background: Cell-free DNA (cfDNA) is a promising biomarker for disease prediction in many cancers, including acute leukemia (acute myeloid leukemia [AML] and acute lymphoblastic leukemia [ALL]). This study investigated the role of cfDNA in predicting relapse or unfavorable outcomes in acute leukemia patients upon initial diagnosis. Methods: Paired peripheral blood samples of 25 patients with ALL and AML were compared at baseline and induction/follow-up and clinically correlated with clinicopathological and outcome variables according to the risk category. cfDNA was isolated using commercial cfDNA extraction kits. The probability of poor outcomes in high-risk groups and a cut-off value for risk stratification minimal residual disease (MRD) positivity and outcome prediction were derived. Results: Twenty-five patients diagnosed with AML and ALL were risk-stratified based on NCI risk stratification, and of these 25 patients, 4 patients were of standard risk (SR) and 1 patient was of intermediate risk (IR), while a majority of patients (80%) were of high risk (HR). Of these, four HR patients passed away. The ratio of cfDNA reduction at baseline and the end of induction was a strong predictor of poor outcomes in high-risk patients, regardless of the MRD status. A cfDNA ratio score of 2.6 or higher at diagnosis/remission predicted poor outcomes, with higher accuracy than conventional MRD detection by flow cytometry. Conclusion: A higher cfDNA ratio at diagnosis/remission or at baseline predicts poor outcomes in acute leukemia patients. This pilot study suggests that cfDNA ratio scoring may be a useful tool for predicting prognosis in acute leukemia patients, regardless of the MRD status.

Prognostic value of minimal residual disease profiling in resectable hepatocellular carcinoma.

530 Background: Detecting post-surgical residual disease is a critical clinical requirement in resectable hepatocellular carcinoma (HCC). Previous studies focused on specific genomic regions have indicated that ctDNA holds promise as a tool for prognostic assessment. Nevertheless, these methods exhibited limited sensitivity and failed to meet the minimal residual disease (MRD) threshold. Here we report the prognostic value of MRD profiling in HCC patients who have undergone hepatectomy. Methods: This retrospective study involved 88 HCC patients who underwent surgical resections in China, from January to May in 2016. During surgery, tumor and normal tissue specimens were collected. Plasma samples were obtained 7 days post-surgery. PredicineBEACON, a baseline tissue- or blood-informed MRD assay, was used for MRD profiling. This entailed identifying tumor-specific mutations through whole exon sequencing of tissue samples. Subsequently, a personalized MRD panel, selecting up to 50 mutations via bioinformatics pipelines merged with a fixed panel featuring 500 tumor actionable hotspots, was created for each patient. To detect MRD in post-surgery plasma samples, we employed ultra-deep sequencing at a coverage of 100,000X, utilizing the designed panel. Results: In the cohort of 88 patients, the distribution based on Barcelona Clinic Liver Cancer (BCLC) staging was as follows: 79.5% stage A (N=70), 12.5% stage B (N=11), and 8.0% stage C (N=7,). The MRD assay identified 36 patients as MRD+ and 52 patients as MRD-. We observed significant correlations between MRD status and both relapse-free survival (RFS) and overall survival (OS). For MRD+ patients, the median RFS was 17.1 months, while it was not reached for MRD- patients (p=0.0013). Likewise, the median OS for MRD+ patients was 40.1 months, in contrast to it not being reached for MRD- patients (p=0.0012). The MRD positivity rate stood at 100% in stage C patients, a significantly higher percentage compared to the rates observed in stage B (36.4%, p=0.0256) and stage A (36.2%, p=0.0042). Significantly, MRD status emerged as a pivotal prognostic differentiator among clinically low-risk patients in stage A: among MRD+ patients, the median RFS was 23.3 months, whereas it was not reached for MRD- patients (p=0.05). Additionally, the median OS of both MRD+ and MRD- was not reached but their survival curves showed significant differences (p=0.038). Conclusions: This study demonstrated the clinical utility of ctDNA MRD assay in patients with resectable HCC, as notably evident in the robust detection of MRD using plasma samples collected 7 days after surgery. Furthermore, the assessment of post-surgical MRD status provided valuable prognostic insights into both patient survival and the risk of disease relapse. ctDNA MRD status played a pivotal role as a prognostic differentiator, particularly among clinically low-risk patients.

Intensified conditioning regimens with total marrow irradiation/etoposide/cyclophosphamide and busulfan/etoposide/cyclophosphamide overcome the impact of pre-transplant minimal residual disease on outcomes in high-risk acute lymphoblastic leukemia patients in complete remission.

Among high-risk acute lymphoblastic leukemia (ALL) patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT), those with positive minimal residual disease (MRD) are susceptible to poor outcomes. Therefore, it is necessary to determine the most suitable preparatory regimen for these patients. Data were analyzed from 141 patients who received allo-HSCT and were diagnosed with high-risk ALL. These patients underwent intensified conditioning regimens, including either total marrow and lymphoid irradiation (TMLI)-etoposide (VP16)-cyclophosphamide (CY) or busulfan (BU)-VP16-CY between October 2016 and November 2022. A total of 141 individuals were in complete remission (CR) before transplantation and, among all patients, 90 individuals exhibited a negative MRD status and 51 patients had a positive MRD status. In patients who tested negative for MRD, the incidence of relapse within a 2-year timeframe was 25.0% (24.8%-25.5%), compared with 32.2% (31.2%-33.2%) in MRD-positive patients; however, this difference was not statistically significant. There were no significant differences in the 2-year disease-free survival (DFS) and 2-year overall survival (OS) rates between the MRD-negative and MRD-positive groups (DFS: 67.2% (57.9%-78.1%) vs. 55.5% (42.6%-72.3%); OS: 69.0% (61.9%-88.2%) vs. 66.7% (53.9%-82.5%)). Furthermore, no notable variations were observed in the occurrence of transplant-related mortality (TRM) and graft-versus-host disease (GVHD) across the two groups. This study reveals the benefits of TMLI-VP16-CY and BU-VP16-CY conditioning regimens in high-risk ALL patients with CR and MRD-positive status. A large-scale prospective clinical trial is warranted in the future.