Humanized CD19-Targeted Chimeric Antigen Receptor (CAR) T Cells in CAR-Naive and CAR-Exposed Children and Young Adults With Relapsed or Refractory Acute Lymphoblastic Leukemia.

2021

JCO2003458

2021 Jun 22

1527-7755

<p><strong>PURPOSE: </strong>CD19-targeted chimeric antigen receptor (CAR)-modified T cells demonstrate unprecedented responses in B-cell acute lymphoblastic leukemia (B-ALL); however, relapse remains a substantial challenge. Short CAR T-cell persistence contributes to this risk; therefore, strategies to improve persistence are needed.</p>

<p><strong>METHODS: </strong>We conducted a pilot clinical trial of a humanized CD19 CAR T-cell product (huCART19) in children and young adults with relapsed or refractory B-ALL (n = 72) or B-lymphoblastic lymphoma (n = 2), treated in two cohorts: with (retreatment, n = 33) or without (CAR-naive, n = 41) prior CAR exposure. Patients were monitored for toxicity, response, and persistence of huCART19.</p>

<p><strong>RESULTS: </strong>Seventy-four patients 1-29 years of age received huCART19. Cytokine release syndrome developed in 62 (84%) patients and was grade 4 in five (6.8%). Neurologic toxicities were reported in 29 (39%), three (4%) grade 3 or 4, and fully resolved in all cases. The overall response rate at 1 month after infusion was 98% (100% in B-ALL) in the CAR-naive cohort and 64% in the retreatment cohort. At 6 months, the probability of losing huCART19 persistence was 27% (95% CI, 14 to 41) for CAR-naive and 48% (95% CI, 30 to 64) for retreatment patients, whereas the incidence of B-cell recovery was 15% (95% CI, 6 to 28) and 58% (95% CI, 33 to 77), respectively. Relapse-free survival at 12 and 24 months, respectively, was 84% (95% CI, 72 to 97) and 74% (95% CI, 60 to 90) in CAR-naive and 74% (95% CI, 56 to 97) and 58% (95% CI, 37 to 90) in retreatment cohorts.</p>

<p><strong>CONCLUSION: </strong>HuCART19 achieved durable remissions with long-term persistence in children and young adults with relapsed or refractory B-ALL, including after failure of prior CAR T-cell therapy.</p>

10.1200/JCO.20.03458

J Clin Oncol

34156874

Clinical impact of genomic characterization of 15 patients with acute megakaryoblastic leukemia-related malignancies.

2021

2021 Apr

2373-2873

<p>Acute megakaryoblastic leukemia (AMKL) is a rare subtype of acute myeloid leukemia but is approximately 500 times more likely to develop in children with Down syndrome (DS) through transformation of transient abnormal myelopoiesis (TAM). This study investigates the clinical significance of genomic heterogeneity of AMKL in children with and without DS and in children with TAM. Genomic evaluation of nine patients with DS-related TAM or AMKL, and six patients with non-DS AMKL, included conventional cytogenetics and a comprehensive next-generation sequencing panel for single-nucleotide variants/indels and copy-number variants in 118 genes and fusions involving 110 genes. Recurrent gene fusions were found in all patients with non-DS, including two individuals with complex genomes and either a or a - fusion, and the remaining harbored a fusion, which arose from both typical and atypical cytogenetic mechanisms. These fusions guided treatment protocols and resulted in a change in diagnosis in two patients. The nine patients with DS had constitutional trisomy 21 and somatic mutations, and those with DS-AMKL had two to four additional clinically significant somatic mutations. Comprehensive genomic characterization provides critical information for diagnosis, risk stratification, and treatment decisions for patients with AMKL. Continued genetic and clinical characterization of these rare cancers will aid in improving patient management.</p>

10.1101/mcs.a005975

Cold Spring Harb Mol Case Stud

33832921

Risk-Adapted Preemptive Tocilizumab to Prevent Severe Cytokine Release Syndrome After CTL019 for Pediatric B-Cell Acute Lymphoblastic Leukemia: A Prospective Clinical Trial.

2021

JCO2002477

2021 Jan 08

1527-7755

<p><strong>PURPOSE: </strong>To prospectively evaluate the effectiveness of risk-adapted preemptive tocilizumab (PT) administration in preventing severe cytokine release syndrome (CRS) after CTL019, a CD19 chimeric antigen receptor T-cell therapy.</p>

<p><strong>METHODS: </strong>Children and young adults with CD19-positive relapsed or refractory B-cell acute lymphoblastic leukemia were assigned to high- (≥ 40%) or low- (&lt; 40%) tumor burden cohorts (HTBC or LTBC) based on a bone marrow aspirate or biopsy before infusion. HTBC patients received a single dose of tocilizumab (8-12 mg/kg) after development of high, persistent fevers. LTBC patients received standard CRS management. The primary end point was the frequency of grade 4 CRS (Penn scale), with an observed rate of ≤ 5 of 15 patients in the HTBC pre-defined as clinically meaningful. In post hoc analyses, the HTBC was compared with a historical cohort of high-tumor burden patients from the initial phase I CTL019 trial.</p>

<p><strong>RESULTS: </strong>The primary end point was met. Seventy patients were infused with CTL019, 15 in the HTBC and 55 in the LTBC. All HTBC patients received the PT intervention. The incidence of grade 4 CRS was 27% (95% CI, 8 to 55) in the HTBC and 3.6% (95% CI, 0.4 to 13) in the LTBC. The best overall response rate was 87% in the HTBC and 100% in the LTBC. Initial CTL019 expansion was greater in the HTBC than the LTBC ( &lt; .001), but persistence was not different ( = .73). Event-free and overall survival were worse in the HTBC ( = .004, &lt; .001, respectively). In the post hoc analysis, grade 4 CRS was observed in 27% versus 50% of patients in the PT and prior phase I cohorts, respectively ( = .18).</p>

<p><strong>CONCLUSION: </strong>Risk-adapted PT administration resulted in a decrease in the expected incidence of grade 4 CRS, meeting the study end point, without adversely impacting the antitumor efficacy or safety of CTL019.</p>

10.1200/JCO.20.02477

J Clin Oncol

33417474

Identification of Predictive Biomarkers for Cytokine Release Syndrome after Chimeric Antigen Receptor T-cell Therapy for Acute Lymphoblastic Leukemia.

2016

664-79

2016 06

2159-8290

<p><strong>UNLABELLED: </strong>Chimeric antigen receptor (CAR)-modified T cells with anti-CD19 specificity are a highly effective novel immune therapy for relapsed/refractory acute lymphoblastic leukemia. Cytokine release syndrome (CRS) is the most significant and life-threatening toxicity. To improve understanding of CRS, we measured cytokines and clinical biomarkers in 51 CTL019-treated patients. Peak levels of 24 cytokines, including IFNγ, IL6, sgp130, and sIL6R, in the first month after infusion were highly associated with severe CRS. Using regression modeling, we could accurately predict which patients would develop severe CRS with a signature composed of three cytokines. Results were validated in an independent cohort. Changes in serum biochemical markers, including C-reactive protein and ferritin, were associated with CRS but failed to predict development of severe CRS. These comprehensive profiling data provide novel insights into CRS biology and, importantly, represent the first data that can accurately predict which patients have a high probability of becoming critically ill.</p>

<p><strong>SIGNIFICANCE: </strong>CRS is the most common severe toxicity seen after CAR T-cell treatment. We developed models that can accurately predict which patients are likely to develop severe CRS before they become critically ill, which improves understanding of CRS biology and may guide future cytokine-directed therapy. Cancer Discov; 6(6); 664-79. ©2016 AACR.See related commentary by Rouce and Heslop, p. 579This article is highlighted in the In This Issue feature, p. 561.</p>

10.1158/2159-8290.CD-16-0040

Cancer Discov

27076371

Pediatric chronic myeloid leukemia with inv(3)(q21q26.2) and T lymphoblastic transformation: a case report.

2016

14

2016

2050-7771

<p><strong>BACKGROUND: </strong>Chronic myeloid leukemia (CML) comprises ~3&nbsp;% of pediatric leukemia. Although therapy with tyrosine kinase inhibitors (TKIs) is highly effective for CML, multiple factors have been identified as predictive of treatment failure. Chromosomal abnormalities involving the MECOM locus at 3q26 portend therapy resistant disease in adults, yet have never been described in pediatric patients and have not been associated with T lymphoblastic progression.</p>

<p><strong>CASE PRESENTATION: </strong>We present a case of an 11-year-old boy with CML possessing the unique combination of T lymphoblastic transformation and a subclone harboring inv(3)(q21q26.2) at diagnosis. This is the first reported case of pediatric CML with inv(3)(q21q26.2) and the first case of T lymphoblastic progression associated with this karyotype. The patient was treated with single agent TKI therapy with robust initial response. Marrow histology at one month showed restoration of trilineage hematopoiesis and BCR-ABL RT-PCR at three months showed a 1.4 log reduction in transcript levels.</p>

<p><strong>CONCLUSIONS: </strong>The karyotypic abnormality of inv(3)(q21q26.2) in CML is not restricted to adult patients. Moreover, while chromosome 3 abnormalities are markers of TKI resistance in adults, our patient showed a robust early response to single agent TKI therapy. This finding suggests pediatric CML with inv(3)(q21q26.2) may have distinct features and more favorable treatment responses than those described in adults.</p>

10.1186/s40364-016-0069-0

Biomark Res

27453784

Marked eosinophilia masking B lymphoblastic leukemia.

2015

2015 Dec 10

1096-8652

10.1002/ajh.24266

Am. J. Hematol.

26662494

Atypical Chronic Myeloid Leukemia in Two Pediatric Patients.

2016

156-9

2016 Jan

1545-5017

<p>Atypical chronic myeloid leukemia, BCR-ABL1-negative, (aCML) is a rare myeloid neoplasm. Recent adult data suggest the leukemic cells in a subset of patients are dependent on JAK/STAT signaling and harbor CSF3R-activating mutations. We hypothesized that, similar to adult patients, the presence of CSF3R-activating mutations would be clinically relevant in pediatric myeloid neoplasms as patients would be sensitive to the JAK inhibitor, ruxolitinib. We report two cases of morphologically similar pediatric aCML, BCR-ABL1-negative based on WHO 2008 criteria. One patient had CSF3R-activating mutation (T618I) and demonstrated a robust response to ruxolitinib, which was used to bridge to a successful stem cell transplant. The other patient did not have a CSF3R-activating mutation and succumbed to refractory disease &lt;6 months from diagnosis. This report documents CSF3R-T618I in pediatric aCML and demonstrates the efficacy of ruxolitinib in a pediatric malignancy. As the third documented case successfully treating aCML with ruxolitinib, this case highlights the importance of prompt CSF3R sequencing analysis for myeloproliferative and myelodysplastic/myeloproliferative neoplasms. Pediatr Blood Cancer © 2015 Wiley Periodicals, Inc.</p>

10.1002/pbc.25694

Pediatr Blood Cancer

26274939

CLL/SLL diagnosed in an adolescent.

2014

1107-10

2014 Jun

1545-5017

<p>Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) is a disease of older adults. Pediatric CLL/SLL is vanishingly rare in the literature. We present a case of CLL/SLL diagnosed in a 17-year-old male. The pathologic findings of this case were those of classic CLL/SLL with an ATM deletion, a characteristic genetic abnormality in CLL/SLL. Management guidelines for CLL/SLL are tailored to older adults making determination of the optimal therapy for this patient a unique challenge.</p>

10.1002/pbc.24884

Pediatr Blood Cancer

24281971

Acquired isochromosome 12p, somatic TP53 and PTEN mutations, and a germline ATM variant in an adolescent male with concurrent acute megakaryoblastic leukemia and mediastinal germ cell tumor.

2014

153-9

2014 Apr

2210-7762

<p>Previous reports have described an association between hematologic malignancies (HMs) and extragonadal germ cell tumor (GCT). Most patients have been adolescent males with mediastinal nonseminomatous GCT. Although a variety of HMs have been reported, there is a striking predilection toward acute megakaryoblastic leukemia (AMKL). Shared cytogenetic anomalies--particularly isochromosome 12p [i(12p)]--have suggested common clonal origins to the tumors. We report the case of a 17-year-old boy presenting with AMKL and a synchronous mediastinal GCT, with the characteristic i(12p) in both neoplasms. The common clonal origin of the AMKL and GCT was further confirmed with massively parallel sequencing, which identified somatic TP53 and PTEN mutations, as well as a rare germline ATM variant. Although these represent commonly mutated genes in cancer, this combination of mutations is not typically associated with either GCT or AMKL, suggesting that these tumors may represent unique biologic entities when they co-occur.</p>

10.1016/j.cancergen.2014.03.009

Cancer Genet

24831771