Larson, Richard A.

AbstractBackgroundAcute lymphoblastic leukemia (ALL) in adults is aggressive, with long‐term outcomes impacted by treatment resistance and toxicity. CD52 is expressed in most cases of B‐ and T‐lineage ALL. Alemtuzumab, a humanized immunoglobulin G1 monoclonal antibody that targets CD52, was identified as a potential agent to improve treatment efficacy without increasing toxicity.MethodsIn this phase 1/2 study (Cancer and Leukemia Group B [CALGB] 10102, NCT00061945), a course of single‐agent alemtuzumab was intercalated into CALGB 19802 backbone chemotherapy after the third course of intensive chemotherapy in those who were CD52+ at diagnosis. Phase 1 tested three dose levels of subcutaneous alemtuzumab (10, 20, and 30 mg 3 times weekly for 4 weeks/12 doses) and demonstrated that 30 mg was tolerable. Phase 2 established feasibility.ResultsThe study enrolled 295 evaluable patients (115 in phase 1, 180 in phase 2); 206 (69.8%) were CD52+. Among evaluable CD52+ patients, 43.7% (90/206) completed the first three treatment modules; 97.8% (88 of 90) were treated with alemtuzumab. Alemtuzumab was associated with cytomegalovirus viremia, which occurred in 23.3% (14 of 60) of patients during and 29.2% (19 of 65) after alemtuzumab treatment. With a median follow‐up of 101.2 months, median overall survival (OS) was 26.3 months (3‐year rate, 44%; 5‐year rate, 36%; 10‐year rate, 31%). Landmark analysis at the start of the fourth course of treatment demonstrated no difference in OS or disease‐free survival between patients who did and who did not receive alemtuzumab.ConclusionAlemtuzumab was feasible to administer in adults with ALL receiving intensive chemotherapy, but was without evidence of benefit.

Introduction: TP53 mutations are found in 18% of adult patients (pts) with acute lymphoblastic leukemias (ALL), and portends poor prognosis (Saygin, Blood Cancer Discov 2024). TP53 mutations are often associated with low hypodiploidy and Li Fraumeni syndrome (germline) in children. However, we and others have shown that TP53-mutant (TP53-m) ALL arises from pre-existing TP53-m clonal hematopoiesis in adults as opposed to germline origin. The impact of co-occurring mutations, TP53 allelic frequency (AF) and different types of treatment on outcomes of TP53-m ALL are not fully characterized. We set out to investigate the clinical and molecular predictors of outcomes in adults with TP53-mutant ALL. Methods: We retrospectively studied 107 patients with TP53-m ALL treated at seven different academic centers in North America. Genetic profiling of pre-treatment bone marrow samples was performed with a comprehensive panel covering 147 myeloid and lymphoid genes. We also performed RNA-sequencing to identify fusions that define ALL subtypes. Single nucleotide polymorphism (SNP) array was used to define low hypodiploidy. Results: The median age at diagnosis was 59 years (range, 10-80), 42% were female, 70% White. 89% of pts had B-ALL while 11% had T-lineage ALL. 24% of pts were classified to have therapy-related ALL based on their history of exposure to genotoxic therapy for another cancer. 45% of pts had hypodiploid karyotype, 79% of whom were low-hypodiploid. 7% had hyperdiploid karyotype and 5% had BCR::ABL1. 11 pts had two different TP53 variants. 90% of TP53 variants involved the DNA binding domain. Most frequently observed co-occurring mutations involved CDKN2A (20%), NOTCH1 (12%) and RB1 (10%) genes. 71% of pts were treated with standard cytotoxic chemotherapy, while the remaining pts received newer antibody-based therapies (i.e., inotuzumab, blinatumomab) or venetoclax in first-line setting. 11% of pts received allogeneic hematopoietic cell transplant (HCT) in first complete remission (CR1) while 3% received HCT after relapse (CR2 or CR3). When patients with vs without low hypodiploidy were compared, we did not observe a significant difference in overall survival (OS) as outcomes were poor in both groups (median, 17 vs 19 months, p= 0.89). However, pts who had TP53 AF >0.5 had significantly worse OS when compared to pts with TP53 VAF <0.5 (13 vs 25 months, p= 0.03). Conclusions: TP53-m ALL is a very high-risk disease subtype and its dismal outcome is independent from presence of co-existing low hypodiploidy. Loss of heterozygosity, characterized by TP53 AF >0.5 is associated with even worse survival. New therapies are urgently needed to improve outcomes in this subset.

Background: C10603/RATFIY was the first AML trial to show the benefit of adding a targeted agent to intensive chemotherapy for a specific genetically determined subset (Stone R et al, NEJM 2017). The addition of the multi-kinase inhibitor midostaurin (M) to chemotherapy in previously untreated adults with FLT3-mutant AML resulted in superior event-free (EFS) and overall survival (OS) compared to placebo (P) and led to the approval of this agent in combination therapy. Subsequently, additional targeted drugs including gilteritinib for relapsed/refractory FLT3-mutant AML and quizartinib plus chemotherapy in untreated adults with AML with FLT3-ITD disease have gained approval. Long-term follow-up after reporting of the primary endpoint, especially if met, is important in oncology. Objective: We report the EFS and OS data from C10603 using 10 years of follow up to determine the persistence of a midostaurin benefit and to assess the nature of late relapses or toxicity. Methods: C10603 enrolled 717 pts (360 on the M and 357 on the P arm; median age 47.8 years (range 18-61), 398 women (55.5%) of whom 51.7% were randomized to M and 59.4% to P (p=0.04), and 89% white) from 2011-2015 with previously untreated AML who had either a FLT3-TKD or ITD mutation with allelic ratio of >0.05 to receive daunorubicin/cytarabine (3+7) induction (one reinduction permitted) followed by up to 4 consolidation cycles with cytarabine 3 g/m2 every 12h on days 1, 3 and 5. M (50 mg bid) or P was given orally on days 8-22 of each chemotherapy cycle as well as daily during one year of single-agent maintenance. Allogeneic transplantation (alloHCT) was employed at investigator's discretion; study drug was not continued post-HCT. Pts stayed on their randomized arm and were not re-randomized prior to maintenance. Pts were followed for relapse and survival after the end of protocol therapy, regardless of subsequent therapy, for 10 years. Log-rank tests, Kaplan-Meier methods, and Cox proportional hazard models were used to evaluate the treatment effect in EFS and OS, as well as the alloHCT effect. All p values are two-sided. Results: We have completed the 10-year FU on this trial and data collection has concluded. The median EFS was 8.2 months (95% CI, 5.5-11.4) on the M arm compared with 3.0 months for P (95% CI, 1.9-6.0) with a HR of 0.79 (95% CI 0.67-0.94, p=0.0067). Among the 420 CR pts who achieved complete remission (CR) by the protocol specified time of 60 days, 253 have had an event (death in 69 and relapse in 184); these events were relatively equal on each arm. OS, the co-primary endpoint, remained marginally superior for those randomized to M compared to P; the 10-year OS estimate was 43.7% (95% CI, 38.7-49.3%) vs 38.6% (95% CI, 33.6-44.4%) (p= 0.0485). The hazard ratios for OS favored randomization to M in each key biological subgroup (FLT3-ITD low or high allelic ratio or FLT3-TKD), but smaller subsets precluded statistical significance. There was a 10-year OS benefit in favor of M in men (p=0.005), but not women (p=0.9). A total of 414 transplants were performed: only 5 in the latter half of the follow-up period. Transplantation in CR1 was highly beneficial overall (10-year OS, 56% vs 35.8% without transplantation, p=0.001). Among those transplanted in CR1, randomization to M was marginally better than P (61.5% vs 49%, p=.064). After censoring for alloHCT in CR1, there was an OS trend in favor of M (51.8% v 48.0%, p=0.102). In CR1 patients who were randomized to maintenance therapy, M reduced the cumulative incidence of relapse in ELN 2017 favorable and intermediate risk pts, but not in those with adverse risk disease (HR 0.71, 0.47, and 1.01, respectively); maintenance M had no effect on OS. Only 3 pts relapsed after 5 years (all randomized to M). 25 pts randomized to M vs 13 P pts died after 5 years of follow-up. 5 pts on each arm died of a new primary cancer whereas 17 M and 5 P pts were coded as having died from treatment-related causes. None of the 3 pts who relapsed after 4 years had spliceosome mutations at diagnosis; whereas 18% (21/117) patients pts who had relapsed earlier had spliceosome mutations at diagnosis (p=0.419). Conclusions: The EFS benefit of randomization to midostaurin vs placebo when added to chemotherapy was maintained over time, although the benefit for OS was diminished, likely due in part to aging. Patient and disease factors differed between early vs late relapses, which could suggest the use of alternative therapies during distinct therapeutic stages.

Introduction: The development of increasingly sensitive tests for the detection of measurable residual disease (MRD), such as multiparameter flow cytometry (MFC) and next-generation sequencing (NGS) assays, has changed clinical practice in acute lymphoblastic leukemia (ALL). IGH V(D)J-based NGS MRD is the most sensitive assay to predict relapse in patients (pts) with B-ALL (Short, Blood Adv 2022). However, data regarding the use of T-cell receptor (TR) NGS MRD in T-ALL are limited and recent reports from pediatric cohorts suggest that persistent TR MRD may not predict relapse in T-ALL (Roy, ASH 2023, abstract 2976). With limited options for the treatment of relapsed/refractory T-ALL, accurate prediction of high relapse risk may provide an opportunity for early intervention. In this study, we evaluated the prognostic utility of TRB/TRG NGS MRD and its correlation with MFC MRD in adult patients with T-ALL. Methods: We retrospectively evaluated the MRD data and clinical outcomes of precursor T (pre-T) and early T precursor (ETP) ALL patients treated at four academic centers in the US. MRD was evaluated using MFC in CLIA-certified labs at individual sites with a sensitivity of 10-4, and the clonoSEQ (Adaptive Technologies, lnc) NGS assay, with a sensitivity of 10-6. Pts were included if they had a trackable TR clone and NGS MRD remission assessment in at least one time point. The correlation between the percentage of MRD by MFC vs NGS was calculated with the Pearson correlation coefficient, using every available MRD assessment for T-ALL pts in complete remission. Relapse-free survival was stratified based on NGS MRD level at the time of post-induction and post-consolidation assays, and comparisons were made with the log-rank test. The positive predictive value (PPV) for relapse of NGS MRD was calculated for pts with MRD > 10-6 at the post-induction and post-consolidation period. Results: A total of 19 pts who met our inclusion criteria, with a median age of 30 years (range, 18-65). 9 pts (47%) had ETP-ALL, 10 pts had pre-T ALL. Pts had a trackable TRB/TRG clone in 76% of cases, with 66% having a trackable TRG clone and 38% having a trackable TRB clone. 10 pts (53%) were treated with a modified AALL0434 regimen as first line therapy, 6 pts (32%) were treated with CALGB10403, 1 pt (5%) was treated with hyperCVAD, 1 pt (5%) was treated with a BFM regimen, and 1 pt (5%) was treated with CALGB9511. Out of 11 T-ALL pts with MRD data available post-induction, 6 pts (55%) had detectable MRD by NGS and no detectable MRD by MFC. Out of 13 pts with available post-consolidation MRD data, 2 pts (15%) had undetectable MRD by both NGS and MFC and 9 pts (69%) had detectable MRD by NGS only. There were no pts with detectable MRD by MFC and undetectable MRD by NGS at either timepoint. A total of 64 MRD data points from 19 pts were available to evaluate MRD correlation by MFC vs NGS, for which the Pearson correlation coefficient showed a statistically significant linear correlation (p < 0.01). At post-induction, 9 pts had NGS MRD > 10-4 and 2 pts had NGS MRD < 10-4. With a median follow-up time of 19.8 months, pts with NGS MRD > 10-4 had a median RFS of 19.8 months and pts with NGS MRD < 10-4 had a median RFS of 14.8 months. The log-rank test comparing RFS between these two groups was not statistically significant (p= 0.18). Persistent NGS MRD at post-induction had a PPV for relapse of only 18%. At post-consolidation, 7 pts had NGS MRD > 10-4, 4 pts had NGS MRD < 10-4, and 2 pts had undetectable MRD by NGS. With a median follow-up time of 17.3 months, pts with NGS MRD > 10-4 had a median RFS of 15.3 months and pts with NGS MRD < 10-4 or undetectable had a median RFS of 20.6 months. The log-rank test comparing RFS between these two groups was not statistically significant (p= 0.6). Persistent NGS MRD at post-consolidation had a PPV for relapse of only 27%. Conclusion: Despite statistically significant linear correlation between MFC and NGS MRD testing, there were no RFS differences between pts with NGS MRD > 10-4 vs NGS MRD < 10-4. All patients had persistent NGS MRD post-induction, which is markedly lower than the reported 20-25% NGS undetectable MRD rate in B-ALL post-induction. Persistent NGS MRD has low PPV for relapse in T-ALL, which limits its utility in clinical decision making for this population.

Abstract A041202 (NCT01886872) is a phase 3 study comparing bendamustine plus rituximab (BR) with ibrutinib and the combination of ibrutinib plus rituximab (IR) in previously untreated older patients with chronic lymphocytic leukemia (CLL). The initial results showed that ibrutinib-containing regimens had superior progression-free survival (PFS) and rituximab did not add additional benefits. Here we present an updated analysis. With a median follow-up of 55 months, the median PFS was 44 months (95% confidence interval [CI], 38-54) for BR and not yet reached in either ibrutinib-containing arm. The 48-month PFS estimates were 47%, 76%, and 76% for BR, ibrutinib, and IR, respectively. The benefit of ibrutinib regimens over chemoimmunotherapy was consistent across subgroups of patients defined by TP53 abnormalities, del(11q), complex karyotype, and immunoglobulin heavy chain variable region (IGHV). No significant interaction effects were observed between the treatment arm and del(11q), the complex karyotype, or IGHV. However, a greater difference in PFS was observed among the patients with TP53 abnormalities. There was no difference in the overall survival. Notable adverse events with ibrutinib included atrial fibrillation (afib) and hypertension. Afib was observed in 11 patients (pts) on BR (3%) and 67 pts on ibrutinib (18%). All-grade hypertension was observed in 95 pts on BR (27%) and 263 pts on ibrutinib (55%). These data show that ibrutinib regimens prolong PFS compared with BR for older patients with treatment-naïve CLL. These benefits were observed across subgroups, including high-risk groups. Strikingly, within the ibrutinib arms, there was no inferior PFS for patients with abnormalities in TP53, the highest risk feature observed in CLL. These data continue to demonstrate the efficacy of ibrutinib in treatment-naïve CLL.

Background: First-line therapies for chronic-phase (CP) CML include the tyrosine kinase inhibitors(TKIs) dasatinib, nilotinib, bosutinib or imatinib, while ponatinib and asciminib are indicated only in later lines. There are typically high response rates to first-line therapy in CP-CML, with responses to second- and third-line therapy lower and highly dependent on the specific TKI. Our goal in this study is to evaluate the role of ponatinib in the treatment of patients with CML using data from routine clinical practice. Study design and methods: Data will come from the H. Jean Khoury Cure CML Consortium (HJKC3) CML registry, a North American multi-site research database. Participating sites include the HJKC3 members (curecml.org). Patient inclusion criteria include a diagnosis CML in chronic phase, receiving second line therapy after initial therapy with a second generation TKI (dasatinib, nilotinib, or bosutinib) or receiving third or later line TKI therapy for CML. Participating patients provide consent to collect their data both retrospectively and prospectively for 1 year. Clinical data, including toxicities and complications of TKI therapy, are abstracted from the electronic health record. Participating patients are invited to complete a questionnaire to assess health-related quality of life. Data are managed using REDCap, a secure web application. Study Objectives: The primary objective is to compare the outcome of patients treated with ponatinib vs. other TKIs as second or later line therapy. Secondary objectives are to evaluate patient-reported outcomes (PRO) for CML treated with second or later line therapy and to determine if there are any patient or disease characteristics that can predict outcomes. Statistical plan for clinical outcomes: Descriptive statistics will be used to compare baseline demographic characteristics. Categorical variables will be compared using the Chi-square test. Continuous variables will be compared using ANOVA. Overall survival will be calculated from the time of diagnosis to death from any cause and patients will be censored if they were alive at the last follow-up. Survival probabilities will be computed using the Kaplan-Meier method and compared with the log-ranktest. Cox regression analyses will be used to determine significant factors that influence survival, and hazard ratios with 95% confidence intervals will be presented. Event free survival (EFS) and transformation free survival (TFS) will be calculated for patients. For EFS, loss of complete hematologic remission, loss of major cytogenetic response, progression to accelerated or blast phase, or death from any cause at any time will be considered an event. For TFS, transformation to accelerated or blast phase while on therapy or death on study will be considered an event. Statistical plan for PRO: Different PRO domains will be analyzed separately (for example, depression separate from fatigue, etc.). Descriptive statistics for each PRO measure will be reported and compared to previously published studies. Differences by treatment type will be evaluated.

Background and significance: There are typically high response rates to first line TKI therapies in chronic phase chronic myeloid leukemia (CP-CML). However, responses in later lines (second line and beyond) are diminished and highly dependent on the specific tyrosine kinase inhibitors (TKIs) used. Asciminib received FDA approval in October 2021 for the treatment of adult patients with Philadelphia chromosome-positive (Ph+) CML-CP who were previously treated with two or more TKIs, and in patients with Ph+ CML-CP with the T315I mutation. Our goal in this study is to evaluate the role of asciminib therapy for patients with CML beyond clinical studies, in routine clinical practice. Study Design and methods: Data for this study will be abstracted from the HJKC3 (H. Jean Khoury Cure CML Consortium) CML registry project (HJKC3-0005); the HJKC3 CML Registry is a collaborative academic multi-site registry. Patients will be consented to allow collection of both retrospective and prospective data for the HJKC3 CML Registry. The data forms and surveys will be built and managed through the Research Electronic Data Capture (REDCap), a secure web application managed by the Clinical & Translational Science Institute. Participating sites include members of the HJKC3 (curecml.org). This study will be an opportunity to evaluate asciminib usage in ‘real-world’ academic practices across the United States. This observational study will include cohorts of patients diagnosed with CP-CML previously treated with two or more tyrosine kinase inhibitors and/or receiving asciminib and/or those with a T315I mutation, not currently enrolled in a randomized controlled trial. The HJKC3 CML Registry intends to collect clinical and patient reported outcome (PRO) data. After obtaining patient consent, patients will be invited to complete PRO assessments. The study will attempt to collect PRO data regardless of disease or treatment status. PRO assessments will be primarily administered online, though study staff will offer alternatives (e.g., phone) for participants without internet access. Study subjects will be emailed a link to access a secure platform hosted by one of the study sites, Medical College of Wisconsin (MCW), using the REDCap platform. Study Objectives: The primary objective of the study is to describe characteristics of patients who were previously treated with two or more TKIs and treated with asciminib or with any other TKIs. The secondary objectives are to describe the clinical outcomes and PRO of those patients. Exploratory objectives include description of characteristics, treatment outcome and PRO for patients with T315I mutation. Statistical plan: The sample size of approximately 225 participants during the 5-year recruitment period is based on the available clinical expertise and ongoing recruitment data in the HJKC3 CML registry in lieu of statistical power analysis. We estimate that 150 patients in the HJKC3 CML registry will be treated with other TKI and 75 treated with asciminib. Among a total of 225 patients, we estimate that 75 patients with the T315I mutation will be enrolled in the registry. No formal statistical inference will be drawn to compare the outcomes between these two groups. Bayesian predictive probability (PP) will be utilized for the exploratory analysis of Major Molecular Response (MMR). Survival probabilities will be computed using the Kaplan-Meier method, and the p-values from the log-rank test will be provided. Different PRO domains of the patient's symptoms and functioning will be analyzed separately (e.g., depression separate from fatigue, separate from GI symptoms, etc.) since combining them into a summary score may dilute the effects of the individual (and not necessarily related) components and mask actual change. The main objective for the analyses of PRO data from the registry is to describe any differences by treatment type in patients treated with asciminib and other TKIs.

Abstract Asparaginase is a key component of pediatric-inspired regimens in young adults with acute lymphoblastic leukemia (ALL). Truncation of asparaginase therapy is linked to inferior outcomes in children with ALL. However, a similar correlation in adults is lacking. Here, we studied the prevalence and risk factors associated with pegylated (PEG)-asparaginase discontinuation in young adults with ALL treated on the US intergroup Cancer and Leukemia Group B (CALGB) 10403 study and examined the prognostic impact of early discontinuation (ED) (defined as <4 of 5 or 6 planned doses) on survival outcomes. The analysis included 176 patients who achieved complete remission and initiated the delayed intensification (DI) cycle. The median number of PEG-asparaginase doses administered before DI was 5 (range, 1-6), with 57 (32%) patients with ED. The ED patients were older (median, 26 vs 23 years; P = .023). Survival was apparently lower for ED patients compared with those receiving ≥4 doses, but this finding was not statistically significant (hazard ratio [HR], 1.82; 95% confidence interval [CI], 0.97-3.43; P = .06), with corresponding 5-year overall survival (OS) rates of 66% and 80%, respectively. In patients with standard-risk ALL, the ED of PEG-asparaginase adversely influenced OS (HR, 2.3; 95% CI, 1.02-5.22; P = .04) with a trend toward inferior event-free survival (EFS) (HR, 1.84; 95% CI, 0.92-3.67; P = .08). In contrast, there was no impact of early PEG-asparaginase discontinuation on OS (P = .64) or EFS (P = .32) in patients with high-risk disease based on the presence of high-risk cytogenetics, Ph-like genotype, and/or high white blood cell count at presentation. In conclusion, early PEG-asparaginase discontinuation is common in young adults with ALL and may adversely impact survival of patients with standard-risk ALL.

Abstract In this secondary analysis of Hispanic adolescents and young adults (AYA) with acute lymphoblastic leukemia (ALL) treated on Cancer and Leukemia Group B (CALGB) 10403, we evaluated outcomes and geographic enrollment patterns relative to US population data. We used demographic, clinical, and survival data on AYAs enrolled on CALGB 10403 (N = 295, 2007-2012). Surveillance, Epidemiology, and End Results registries provided overall survival (OS) for US AYA ALL by ethnicity/race. North American Association of Cancer Registries provided AYA ALL incidence overall and proportion among Hispanics by US state. Of AYAs enrolled on CALGB 10403, 263 (89%) reported ethnicity/race: 45 (17%) Hispanic, 172 (65%) non-Hispanic White (NHW), 25 (10%) non-Hispanic Black (NHB), and 21 (8%) other. Compared with NHWs, Hispanic and NHB patients had lower household income, and Hispanic patients were more likely to harbor high-risk CRLF2 aberrations. Relative to US estimates, where Hispanic patients represented 46% of newly diagnosed AYA ALL patients and experienced inferior OS compared with NHW (P < .001), Hispanic AYAs on CALGB 10403 did as well as NHW patients (3 year OS, 75% vs 74%; P = NS). Hispanic patients also had higher rates of protocol completion (P = .05). Enrollments on CALGB 10403 differed relative to the distribution of Hispanic AYA ALL in the United States: enrollment was highest in the Midwest; t and only 15% of enrollees were from states with a high proportion of Hispanic AYA ALL patients. In summary, Hispanic patients treated on CALGB 10403 did as well as NHWs and better than population estimates. Geographical misalignment between trial sites and disease epidemiology may partially explain the lower-than-expected enrollment of Hispanic AYA ALL patients.