TP53 mutation does not confer a poor outcome in adult patients with acute lymphoblastic leukemia who are treated with frontline hyper-CVAD-based regimens

Case report: TP53 c.848G>A germline mutation as a possible screening target at initial diagnosis for acute lymphoblastic leukemia

BACKGROUD

Li-Fraumeni syndrome is a hereditary tumor syndrome characterized by an elevated risk of malignancy, particularly acute lymphoblastic leukemia (ALL), which can be caused by the heterozygous germline mutation. TP53 gene germline mutation is considered a potential risk factor and crucial prognostic parameter for acute leukemia development and diagnosis, but rarely occurs in adults, and its specific pathogenic significance in acute leukemia is unclear.

CASE PRESENTATION

We describes a case of a 45-year-old woman diagnosed with ALL. Whole-exome sequencing approach identified one of the TP53 germline mutations from her bone marrow sample with possible pathogenic significance, c.848G>A (p.Arg283His) heterozygous missense mutation located on exon 8, which was further verified in her hair, oral mucous and nail samples. Family pedigree screening revealed that the same TP53 genetic variant was present in the patient's father and non-donor son, whereas not in the donor. Digital PCR observed that this point mutation frequency dropped post-transplantation but remained low during maintenance therapy when the patient was leukemia-free.

CONCLUSION

This suspected Li-Fraumeni syndrome case report with a likely pathogenic heterozygous TP53 variant expands the cancer genetic spectrum. Screening her family members for mutations facilitates identifying the optimal relative donor and avoids unnecessary treatment by monitoring TP53 germline mutations for minimal residual disease following hematopoietic stem cell transplantation. Its potential roles in hematological malignant tumor development and clinical pathogenic implications necessitate further probing.

Prognostic impact of TP53 mutations in adult acute lymphoblastic leukemia treated with a pediatric-type regimen

The prognostic impact of TP53 mutations (TP53mut) in adult acute lymphoblastic leukemia (ALL) remains debatable. Herein, we determined the clinical significance of TP53mut in 283 adult ALL patients treated with a pediatric-type regimen. TP53mut were found in 11.0% (31) of patients, including 19 cases in adolescent and young adult (AYA) patients and 12 cases in non-AYA patients. Patients with TP53mut had poorer overall survival (OS) and event-free survival (EFS) in the non-AYA subgroup (n = 64) (3-year OS, 18.2% vs 50.9%, p = .0033; 3-year EFS, 0 vs 45.3%, p = .00028). however, this had to be taken cautiously due to a limited number of patients. In the AYA subgroup (n = 219), TP53mut did not impact OS or EFS (3-year OS, 60.6%vs71.0%, p = .55; 3-year EFS, 52.5%vs59.6%, p = .57). Collectively, our data reveal that the pediatric-type regimen eliminated the poor prognostic impact of TP53mut in AYA ALL. However, in non-AYA ALL patients, TP53mut remain a potential biomarker associated with poor outcomes.

Characteristics of Molecular Genetic Mutations and Their Correlation with Prognosis in Adolescent and Adult Patients with Acute Lymphoblastic Leukemia

INTRODUCTION

The prognosis of acute lymphoblastic leukemia (ALL) in adolescents and adults is poor, and recurrence is an important cause of their death. Changes of genetic information play a vital role in the pathogenesis and recurrence of ALL; however, the impact of molecular genetic mutations on disease diagnosis and prognosis remains unexplored. This study aimed to explore the frequency spectrum of gene mutations and their prognostic significance, along with the minimal residual disease (MRD) level and hematopoietic stem cell transplantation (HSCT), in adolescent and adult patients aged ≥15 years with ALL.

METHODS

The basic characteristics, cytogenetics, molecular genetics, MRD level, treatment regimen, and survival outcome of patients with untreated ALL (≥15 years) were collected, and the correlation and survival analysis were performed using the SPSS 25.0 and R software.

RESULTS

This study included 404 patients, of which 147 were selected for next-generation sequencing (NGS). NGS results revealed that 91.2% of the patients had at least one mutation, and 67.35% had multiple (≥2) mutations. NOTCH1, PHF6, RUNX1, PTEN, JAK3, TET2, and JAK1 were the most common mutations in T-ALL, whereas FAT1, TET2, NARS, KMT2D, FLT3, and RELN were the most common mutations in B-ALL. Correlation analysis revealed the mutation patterns, which were significantly different between T-ALL and B-ALL. In the prognostic analysis of 107 patients with B-ALL, multivariate analysis showed that the number of mutations ≥5 was an independent risk factor for overall survival and the RELN mutation was an independent poor prognostic factor for event-free survival.

DISCUSSION

The distribution of gene mutations and the co-occurrence and repulsion of mutant genes in patients with ALL were closely related to the immunophenotype of the patients. The number of mutations ≥5 and the RELN mutation were significantly associated with poor prognosis in adolescent and adult patients with ALL.

Adult Low-Hypodiploid Acute Lymphoblastic Leukemia Emerges from Preleukemic TP53-Mutant Clonal Hematopoiesis

Low hypodiploidy defines a rare subtype of B-cell acute lymphoblastic leukemia (B-ALL) with a dismal outcome. To investigate the genomic basis of low-hypodiploid ALL (LH-ALL) in adults, we analyzed copy-number aberrations, loss of heterozygosity, mutations, and cytogenetics data in a prospective cohort of Philadelphia (Ph)-negative B-ALL patients (n = 591, ages 18-84 years), allowing us to identify 80 LH-ALL cases (14%). Genomic analysis was critical for evidencing low hypodiploidy in many cases missed by cytogenetics. The proportion of LH-ALL within Ph-negative B-ALL dramatically increased with age, from 3% in the youngest patients (under 40 years old) to 32% in the oldest (over 55 years old). Somatic TP53 biallelic inactivation was the hallmark of adult LH-ALL, present in virtually all cases (98%). Strikingly, we detected TP53 mutations in posttreatment remission samples in 34% of patients. Single-cell proteogenomics of diagnosis and remission bone marrow samples evidenced a preleukemic, multilineage, TP53-mutant clone, reminiscent of age-related clonal hematopoiesis.

SIGNIFICANCE

We show that low-hypodiploid ALL is a frequent entity within B-ALL in older adults, relying on somatic TP53 biallelic alteration. Our study unveils a link between aging and low-hypodiploid ALL, with TP53-mutant clonal hematopoiesis representing a preleukemic reservoir that can give rise to aneuploidy and B-ALL. See related commentary by Saiki and Ogawa, p. 102. This article is highlighted in the In This Issue feature, p. 101.

B-cell acute lymphoblastic leukaemia: recent discoveries in molecular pathology, their prognostic significance, and a review of the current classification

Acute lymphoblastic leukaemia (ALL) remains a leading cause of non-traumatic death in children, and the majority of adults diagnosed will succumb to the disease. Recent advances in molecular biology and bioinformatics have enabled more detailed genomic analysis and a better understanding of the molecular biology of ALL. A number of recurrent genomic drivers have recently been described, which not only aid in diagnosis and prognostication, but also may offer opportunities for specific therapeutic targeting. The present review summarises B-ALL genomic pathology at diagnosis, including lesions detectable using traditional cytogenetic methods as well as those detected only through advanced molecular techniques.

Molecular-based and antibody-based targeted pharmacological approaches in childhood acute lymphoblastic leukemia

Introduction: Despite the significant survival improvement in childhood acutelymphoblastic leukemia (ALL), 15-20% of patients continue to relapse; outcomes following relapse remain suboptimal and have room for further improvement. Advances in genomics have shed new insights on the biology of ALL, led to the discovery of novel genomically defined ALL subtypes, refined prognostic significance and revealed new therapeutic vulnerabilities.Areas covered: In this review, the authors provide an overview of the genomic landscape of childhood ALL and highlight recent advances in molecular-based and antibody-based pharmacological approaches in the treatment of childhood ALL, from emerging preclinical evidence to published results of completed clinical trials.Expert opinion: Molecularly targeted therapies and immunotherapies have expanded the horizons of ALL therapy and represent promising therapeutic avenues for high-risk and relapsed/refractory ALL. These novel therapies are now moving into frontline ALL therapy and may define new treatment paradigms that aim to further improve survival and reduce chemotherapy-related toxicities in the management of pediatric ALL.

[Clinical and prognostic values of TP53 mutation in patients with B-lineage acute lymphoblastic leukemia]

Objective: To investigate the survival and prognosis of B-lineage acute lymphoblastic leukemia (B-ALL) patients with TP53 mutation. Methods: The clinical data of 479 newly diagnosed B-ALL patients treated in the First Affiliated Hospital of Soochow University from January 2016 to December 2019 were retrospectively analyzed. Results: Among 479 B-ALL patients, 34 cases (7.1%) were positive for TP53 gene mutation, and a total of 36 TP53 mutations were detected, including 10 frameshift gene mutations (27.8%) , 23 missense mutations (63.9%) and 3 nonsense mutations (8.3%) . A total of 34 (94.4%) mutations were located in the DNA binding domain (exons 5-8) .The average number of mutated genes in patients with TP53 gene mutation (2.3) and the group without TP53 gene mutation (1.1) were statistically different (P<0.001) . The proportion of Ph positive and Ph-like positive patients in the TP53 gene mutation negative group was significantly higher than that of the TP53 mutation positive group, and the difference was statistically significant (P<0.001) . The 3-year OS and EFS rates of the TP53 gene mutation negative group were significantly higher than those of the TP53 gene mutation positive group. The differences in OS and EFS rates between the two groups were statistically significant (χ(2)= 4.694, P = 0.030; χ(2)= 5.080, P= 0.024) . In the multivariate analysis, failure to achieve remission (CR) after one course of induction chemotherapy was an independent adverse prognostic factor affecting OS.Of the 34 patients with TP53 mutation, 16 underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the CR(1) state, and 2 patients with recurrence after transplantation obtained CR(2) after infusion of donor-derived anti-CD19 chimeric antigen receptor T (CAR-T) cells. Among the 11 patients with TP53 gene mutation who relapsed during consolidation chemotherapy, 6 received anti-CD19 CAR T cell therapy, 4 patients achieved remission and minimal residual disease (MRD) turned negative, followed by bridging allo-HSCT, and 2 of them sustained CR. Conclusion: Missense mutations are the most common in B-ALL patients with TP53 gene mutation, and the majority of mutations were located in the DNA binding domain. B-ALL patients with TP53 gene mutation should undergo allo-HSCT as soon as possible after CAR-T cell therapy has cleared the MRD after recurrence. B-ALL patients with TP53 gene mutation still have a higher recurrence rate after allo-HSCT, and the infusion of donor-derived CAR-T cells can achieve better sustained remission.

[The effect of TP53 mutations on the clinical outcomes of Ph-negative B-acute lymphoblastic leukemia following allogeneic hematopoietic stem cell transplantation]

Objective: To evaluate the association of TP53 mutations with the clinical outcomes of Ph-negative B-ALL following allogeneic hematopoietic stem cell transplantation (allo-HSCT) . Methods: Total 300 patients with Ph-negative B-ALL who underwent allo-HSCT at the Hebei Yanda Ludaopei Hospital from May 2012 to May 2017 were retrospectively analyzed; their clinical characteristics, TP53 gene mutation type, and association between TP53 mutations and transplantation outcomes, including leukemia-free survival (LFS) , overall survival (OS) , non-relapse mortality (NRM) , relapse, and GVHD, were evaluated. Results: Total 23 patients had TP53 mutations; all the TP53 mutations affected P53'DNA-binding domain. The 5-year-LFS, OS, and RI were 34.8% and 62.3% (P=0.001) , 41.9% and 65.1% (P=0.020) , and 47.8% and 14.8% (P=0.000) , respectively, for TP53 mutations and wild-type TP53 patients. However, there were no significant differences in NRM and GVHD. Multivariate analysis showed that TP53 mutations remained adverse prognostic factors for LFS, OS, and RI after allo-HSCT. Conclusion: Some patients with TP53 mutations can achieve long-term survival with allo-HSCT. TP53 mutations are adverse prognostic factors for Ph-negative B-ALL patients who undergo allo-HSCT.

Immature Immunoglobulin Gene Rearrangements Are Recurrent in B Precursor Adult Acute Lymphoblastic Leukemia Carrying TP53 Molecular Alterations

Here, we describe the immunoglobulin and T cell receptor (Ig/TCR) molecular rearrangements identified as a leukemic clone hallmark for minimal residual disease assessment in relation to TP53 mutational status in 171 Ph-negative Acute Lymphoblastic Leukemia (ALL) adult patients at diagnosis. The presence of a TP53 alterations, which represents a marker of poor prognosis, was strictly correlated with an immature DH/JH rearrangement of the immunoglobulin receptor (p < 0.0001). Furthermore, TP53-mutated patients were classified as pro-B ALL more frequently than their wild-type counterpart (46% vs. 25%, p = 0.05). Although the reasons for the co-presence of immature Ig rearrangements and TP53 mutation need to be clarified, this can suggest that the alteration in TP53 is acquired at an early stage of B-cell maturation or even at the level of pre-leukemic transformation.

Antileukemia Effects of Notch-Mediated Inhibition of Oncogenic PLK1 in B-Cell Acute Lymphoblastic Leukemia

In B-cell acute lymphoblastic leukemia (B-ALL), activation of Notch signaling leads to cell-cycle arrest and apoptosis. We aimed to harness knowledge acquired by understanding a mechanism of Notch-induced cell death to elucidate a therapeutically viable target in B-ALL. To this end, we identified that Notch activation suppresses Polo-like kinase 1 (PLK1) in a B-ALL-specific manner. We identified that PLK1 is expressed in all subsets of B-ALL and is highest in Philadelphia-like (Ph-like) ALL, a high-risk subtype of disease. We biochemically delineated a mechanism of Notch-induced PLK1 downregulation that elucidated stark regulation of p53 in this setting. Our findings identified a novel posttranslational cascade initiated by Notch in which CHFR was activated via PARP1-mediated PARylation, resulting in ubiquitination and degradation of PLK1. This led to hypophosphorylation of MDM2Ser260, culminating in p53 stabilization and upregulation of BAX. shRNA knockdown or pharmacologic inhibition of PLK1 using BI2536 or BI6727 (volasertib) in B-ALL cell lines and patient samples led to p53 stabilization and cell death. These effects were seen in primary human B-ALL samples in vitro and in patient-derived xenograft models in vivo These results highlight PLK1 as a viable therapeutic target in B-ALL. Efficacy of clinically relevant PLK1 inhibitors in B-ALL patient-derived xenograft mouse models suggests that use of these agents may be tailored as an additional therapeutic strategy in future clinical studies.

Inotuzumab ozogamicin in combination with low-intensity chemotherapy (mini-HCVD) with or without blinatumomab versus standard intensive chemotherapy (HCVAD) as frontline therapy for older patients with Philadelphia chromosome-negative acute lymphoblastic leukemia: A propensity score analysis

BACKGROUND

The outcome of older patients with newly diagnosed, Philadelphia chromosome (Ph)-negative acute lymphoblastic leukemia (ALL) is poor. The combination of targeted therapy with low-intensity chemotherapy is safe and effective. The objective of the current analysis was to compare the outcome of patients who received a combination of inotuzumab ozogamicin plus low-intensity chemotherapy (mini-hyperfractionated cyclophosphamide, vincristine, and dexamethasone [mini-HCVD]) with or without blinatumomab versus the outcome of those who received the standard, intensive, hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (HCVAD) regimen.

METHODS

The authors analyzed 135 older patients with newly diagnosed, Ph-negative ALL who were treated prospectively with standard HCVAD (n = 77) or with the combination of inotuzumab ozogamicin plus mini-HCVD with or without blinatumomab (n = 58). A propensity score analysis was conducted using 1:1 matching using the nearest neighbor matching method.

RESULTS

Propensity score matching identified 38 patients in each cohort. The antibody plus low-intensity chemotherapy combination induced higher response rates (98% vs 88%), with lower rates of early death (0% vs 8%) and lower rates of death in complete remission (5% vs 17%). With propensity score matching, the 3-year event-free survival rates for patients who received HCVAD and those who received the combination of inotuzumab ozogamicin plus mini-HCVD with or without blinatumomab were 34% and 64%, respectively (P = .003), and the 3-year overall survival rates were 34% and 63%, respectively (P = .004). By multivariate analysis, age (P = .019; hazard ratio, 1.045) and the combination of inotuzumab plus mini-HCVD with or without blinatumomab (P = .020; hazard ratio, 0.550) were identified as independent prognostic factors for survival.

CONCLUSIONS

The combination of inotuzumab ozogamicin plus mini-HCVD with or without blinatumomab is safe and effective in older patients with newly diagnosed, Ph-negative ALL and confers a better outcome compared with standard HCVAD chemotherapy.

Treatment with a 5-day versus a 10-day schedule of decitabine in older patients with newly diagnosed acute myeloid leukaemia: a randomised phase 2 trial

BACKGROUND

Hypomethylating agents, such as decitabine, are the standard of care for older patients with newly diagnosed acute myeloid leukaemia. Single-arm studies have suggested that a 10-day schedule of decitabine cycles leads to better outcomes than the usual 5-day schedule. We compared the efficacy and safety of these two schedules.

METHODS

Eligible patients were aged 60 years or older with acute myeloid leukaemia but unsuitable for intensive chemotherapy (or <60 years if unsuitable for intensive chemotherapy with an anthracycline plus cytarabine). The first 40 patients were allocated equally to the two treatment groups by computer-generated block randomisation (block size 40), after which a response-adaptive randomisation algorithm used all previous patients' treatment and response data to decide the allocation of each following patient favouring the group with superior response. Patients were assigned to receive 20 mg/m² decitabine intravenously for 5 or 10 consecutive days as induction therapy, every 4-8 weeks for up to three cycles. Responding patients received decitabine as consolidation therapy on a 5-day schedule for up to 24 cycles. We assessed a composite primary endpoint of complete remission, complete remission with incomplete platelet recovery (CRp), and complete remission with incomplete haematological recovery (CRi) achieved at any time and assessed by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01786343.

FINDINGS

Between Feb 28, 2013, and April 12, 2018, 71 patients were enrolled. 28 received decitabine for 5 days and 43 for 10 days, and all were assessable for efficacy and safety. The primary endpoint was achieved in similar proportions of patients in the two treatment groups (12 [43%] of 28 in the 5-day schedule group, 95% credible interval 26-60, and 17 [40%] of 43 in the 10-day schedule group, 26-54, p=0·78; difference 3%, -21 to 27). Total follow-up was 38·2 months, during which the median duration of overall survival was 5·5 months (IQR 2·1-11·7) in the 5-day group and 6·0 months (1·9-11·7) in the 10-day group. 1-year overall survival was 25% in both groups. Complete remission, CRp, CRi, and overall survival did not differ between groups when stratified by cytogenetics, de-novo versus secondary or therapy-related acute myeloid leukaemia, or TP53^mut status. The most common grade 3-4 adverse events were neutropenic fever (seven patients [25%] in the 5-day group and 14 [33%] in the 10-day group) and infection (five [18%] and 16 [37%], respectively). One patient (4%) died from sepsis in the context of neutropenic fever, infection, and haemorrhage in the 5-day group, and in the 10-day group six patients (14%) died from infection. Early mortality was similar in the two groups.

INTERPRETATION

In older patients with newly diagnosed acute myeloid leukaemia, efficacy and safety did not differ by the 5-day or the 10-day decitabine schedule.

FUNDING

University of Texas MD Anderson Cancer Center and National Cancer Institute Specialized Programs of Research Excellence.

Novel Therapies for Older Adults With Acute Lymphoblastic Leukemia

PURPOSE OF REVIEW

Older adults with acute lymphoblastic leukemia (ALL) have worse survival compared to their younger counterparts. Here, we review the reasons for the poorer outcomes of older patients with ALL and also summarize the current and future therapeutic approaches to ALL in the elderly population.

RECENT FINDINGS

The poor outcomes of older adults with ALL are driven largely by lack of tolerance to standard-dose chemotherapy, which leads to unacceptably high rates of myelosuppression-related deaths. Recent studies have shown promising results with the use of low-intensity or chemotherapy-free regimens in older patients with ALL, which are able to retain efficacy without excess toxicity. Novel antibody constructs such as inotuzumab ozogamicin and blinatumomab as well as potent later-generation tyrosine kinase inhibitors such as ponatinib hold significant promise in the management of ALL in the older adult. Innovative combination strategies may further improve the outcomes of these patients.

TP53 in adult acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is characterized by a great biological and clinical heterogeneity. Despite most adult patients enter complete hematologic remission after induction therapy only 40% survive five or more years. Over the last 20 years, the definition of an accurate biologic leukemia profile and the minimal residual disease evaluation in addition to conventional risk criteria led to a significant improvement for the risk stratification. The alterations of the oncosuppressor gene TP53, including deletions, sequence mutations and defect in its expression due to regulatory defects, define a new important predictor of adverse outcome. More recently, new drugs have been developed with the aim of targeting p53 protein itself or its regulatory molecules, such as Mdm2, and restoring the pathway functionality. Therefore, TP53 alterations should be considered in the diagnostic work-up to identify high risk ALL patients in need of intensive treatment strategies or eligible for new innovative targeted therapies.