The JAK3Q988P mutation reveals oncogenic potential and resistance to ruxolitinib

T-cell acute lymphoblastic leukemia (T-ALL) arises from the malignant transformation of T-cell progenitors at various differentiation stages. Given that patients who relapse have a dismal prognosis, there is an urgent need to identify the molecular alterations that are present in such patients and promote leukemogenesis to implement personalized therapies with higher efficacy and fewer adverse effects. In the present manuscript, we identified the JAK3Q988P mutation in a T-ALL patient who did not achieve a durable response after the conventional treatment and whose tumor cells at relapse presented constitutive activation of the JAK/STAT pathway. Although JAK3Q988P has been previously identified in T-ALL patients from different studies, the functional consequences exerted by this mutation remain unexplored. Through the combination of different hematopoietic cellular models, we functionally characterize JAK3Q988P as an oncogenic mutation that contributes to leukemogenesis. Notably, JAK3Q988P not only promotes constitutive activation of the JAK/STAT pathway in the absence of cytokines and growth factors, as is the case for other JAK3 mutations that have been functionally characterized as oncogenic, but also functions independently of JAK1 and IL2RG, resulting in high oncogenic potential as well as resistance to ruxolitinib. Our results indicate that ruxolitinib may not be efficient for future patients bearing the JAK3Q988P mutation who instead may obtain greater benefits from treatments involving other pharmacological inhibitors such as tofacitinib.

SOCS3 deregulation contributes to aberrant activation of the JAK/STAT pathway in precursor T-cell neoplasms

Despite the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway being frequently altered in T-ALL/LBL, no specific therapy has been approved for T-ALL/LBL patients with constitutive signalling by JAK/STAT, so there is an urgent need to identify pathway members that may be potential therapeutic targets. In the present study, we searched for JAK/STAT pathway members potentially modulated through aberrant methylation and identified SOCS3 hypermethylation as a recurrent event in T-ALL/LBL. Additionally, we explored the implications of SOCS3 deregulation in T-ALL/LBL and demonstrated that SOCS3 counteracts the constitutive activation of the JAK/STAT pathway through different molecular mechanisms. Therefore, SOCS3 emerges as a potential therapeutic target in T-ALL/LBL.

Novel Germline TET2 Mutations in Two Unrelated Patients with Autoimmune Lymphoproliferative Syndrome-Like Phenotype and Hematologic Malignancy

Somatic mutations in the ten-eleven translocation methylcytosine dioxygenase 2 gene (TET2) have been associated to hematologic malignancies. More recently, biallelic, and monoallelic germline mutations conferring susceptibility to lymphoid and myeloid cancer have been described. We report two unrelated autoimmune lymphoproliferative syndrome-like patients who presented with T-cell lymphoma associated with novel germline biallelic or monoallelic mutations in the TET2 gene. Both patients presented a history of chronic lymphoproliferation with lymphadenopathies and splenomegaly, cytopenias, and immune dysregulation. We identified the first compound heterozygous patient for TET2 mutations (P1) and the first ALPS-like patient with a monoallelic TET2 mutation (P2). P1 had the most severe form of autosomal recessive disease due to TET2 loss of function resulting in absent TET2 expression and profound increase in DNA methylation. Additionally, the immunophenotype showed some alterations in innate and adaptive immune system as inverted myeloid/plasmacytoid dendritic cells ratio, elevated terminally differentiated effector memory CD8 + T-cells re-expressing CD45RA, regulatory T-cells, and Th2 circulating follicular T-cells. Double-negative T-cells, vitamin B12, and IL-10 were elevated according to the ALPS-like suspicion. Interestingly, the healthy P1's brother carried a TET2 mutation and presented some markers of immune dysregulation. P2 showed elevated vitamin B12, hypergammaglobulinemia, and decreased HDL levels. Therefore, novel molecular defects in TET2 confirm and expand both clinical and immunological phenotype, contributing to a better knowledge of the bridge between cancer and immunity.

A phase 3 trial of azacitidine versus a semi-intensive fludarabine and cytarabine schedule in older patients with untreated acute myeloid leukemia

BACKGROUND

Options to treat elderly patients (≥65 years old) newly diagnosed with acute myeloid leukemia (AML) include intensive and attenuated chemotherapy, hypomethylating agents with or without venetoclax, and supportive care. This multicenter, randomized, open-label, phase 3 trial was designed to assess the efficacy and safety of a fludarabine, cytarabine, and filgrastim (FLUGA) regimen in comparison with azacitidine (AZA).

METHODS

Patients (n = 283) were randomized 1:1 to FLUGA (n = 141) or AZA (n = 142). Response was evaluated after cycles 1, 3, 6, and 9. Measurable residual disease (MRD) was assessed after cycle 9. When MRD was ≥0.01%, patients continued with the treatment until relapse or progressive disease. Patients with MRD < 0.01% suspended treatment to enter the follow-up phase.

RESULTS

The complete remission (CR) rate after 3 cycles was significantly better in the FLUGA arm (18% vs 9%; P = .04), but the CR/CR with incomplete recovery rate at 9 months was similar (33% vs 29%; P = .41). There were no significant differences between arms in early mortality at 30 or 60 days. Hematologic toxicities were more frequent with FLUGA, especially during induction. The 1-year overall survival (OS) rate and the median OS were superior with AZA versus FLUGA: 47% versus 27% and 9.8 months (95% confidence interval [CI], 5.6-14 months) versus 4.1 months (95% CI, 2.7-5.5 months; P = .005), respectively. The median event-free survival was 4.9 months (95% CI, 2.8-7 months) with AZA and 3 months (95% CI, 2.5-3.5 months) with FLUGA (P = .001).

CONCLUSIONS

FLUGA achieved more remissions after 3 cycles, but the 1-year OS rate was superior with AZA. However, long-term outcomes were disappointing in both arms (3-year OS rate, 10% vs 5%). This study supports the use of an AZA backbone for future combinations in elderly patients with AML.

Contribution of JAK2 mutations to T-cell lymphoblastic lymphoma development

The JAK-STAT pathway has a substantial role in lymphoid precursor cell proliferation, survival and differentiation. Nonetheless, the contribution of JAK2 to T-cell lymphoblastic lymphoma (T-LBL) development remains poorly understood. We have identified one activating TEL-JAK2 translocation and four missense mutations accumulated in 2 out of 16 T-LBL samples. Two of them are novel JAK2 mutations and the other two are reported for the first time in T-LBL. Notably, R683G and I682T might have arisen owing to RNA editing. Mutated samples showed different mutated transcripts suggesting sub-clonal heterogeneity. Functional approaches revealed that two JAK2 mutations (H574R and R683G) constitutively activate JAK-STAT signaling in γ2A cells and can drive the proliferation of BaF3-EpoR cytokine-dependent cell line. In addition, aberrant hypermethylation of SOCS3 might contribute to enhance the activation of JAK-STAT signaling. Of utmost interest is that primary T-LBL samples harboring JAK2 mutations exhibited increased expression of LMO2, suggesting a mechanistic link between JAK2 mutations and the expression of LMO2, which was confirmed for the four missense mutations in transfected γ2A cells. We therefore propose that active JAK2 contribute to T-LBL development by two different mechanisms, and that the use of pan-JAK inhibitors in combination with epigenetic drugs should be considered in future treatments.

Absence of influence of prior treatment with interferon on the outcome of allogeneic bone marrow transplantation for chronic myeloid leukemia

Timing of transplantation in the chronic phase of chronic myeloid leukemia (CML) and previous treatment with interferon remains controversial. We have tried to discover what influence pretreatment with interferon alpha (IFN-A) has on the results of allogeneic bone marrow transplantation for CML patients treated in a single institution. Fifty-one consecutive patients with chronic phase Ph-positive CML who received an allogeneic bone marrow transplantation from a HLA-identical familial donor were evaluated. Thirty had been treated with IFN-A (IFN+ group) prior to BMT and twenty-one had not (IFN- group). Both groups were homogeneous for clinical characteristics such as age, sex, previous chemotherapy, disease status, and time from diagnosis to transplant. No difference was found in neutrophil and platelet count recovery between the IFN+ and IFN- group. The incidence of acute and chronic GVHD, VOD and severe mucositis was not significantly different. Relapse and both overall survival and DFS were similar for both groups. No adverse effects of prior IFN exposure on the outcome of HLA-identical sibling donor BMT for chronic phase CML patients were found in this study.

Comparison of peripheral blood progenitor cell mobilization in patients with multiple myeloma: high-dose cyclophosphamide plus GM-CSF vs G-CSF alone

The best method for peripheral blood progenitor cell (PBPC) mobilization in patients with multiple myeloma (MM) remains controversial. We report the results of two different methods of PBPC collection for autologous transplantation in 40 patients with stage II or III MM. In group I (n = 18), HD-CY, 4 g/m2 i.v., was administered followed by GM-CSF, 8 microg/kg/day s.c., until the end of collection, starting the leukaphereses after hematological recovery (>1 x 10(9)/l WBC). In group II (n = 22), G-CSF, 10 microg/kg/day s.c., was used alone until the last day of collection, starting consecutive aphereses on the 5th day. A minimum of two aphereses were performed to collect at least 2 x 10(6)/kg CD34+ cells. Both patient groups were comparable for age, sex and clinical prognostic features as well as previous therapies. In group I, the median yields per pheresis were: MNC 1.47 (1.38-2.32) x 10(8)/kg, CFU-GM 0.82 (0.18-13.2) x 10(4)/kg and CD34+ cells 1.98 (0.96-6.96) x 10(6)/kg. In group II these results were: MNC 2.44 (2.06-3.6 x 10(8)/kg) (P = 0.03), CFU-GM 0.75 (0.16-7.8) x 10(4)/kg and CD34+ 1.05 (0.32-3.4) x 10(6)/kg (P = 0.02). The median number of aphereses performed in each group was 5 (4-12) with a median of 5.24 +/- 2.51 in group I and 3 (2-6) with a median of 3.1 (+/- 0.91) in group II (P = NS). Hospitalization for PBPC mobilization was required in all patients in group I and the treatment-related toxicity was greater in this group: 12 patients (66%) developed fever requiring antibiotics during the neutropenic period after HD-CY and six (33%) patients required transfusion support. After receiving busulfan 12 mg/kg p.o. and melphalan 140 mg/m2 i.v., as the conditioning regimen, the median periods to reach granulocytes (>0.5 x 10(9)/l) and platelet (>20 x 10(9)/l) engraftment were 12 and 11 days respectively (ranges 8-20 and 10-16) in group I (HD-CY plus GM-CSF group), and 11 and 13 days respectively (ranges 7-42 and 10-38) in group II (G-CSF group) (P = NS). In conclusion, these data suggest that although HD-CY plus GM-CSF is superior to G-CSF alone based on mean CD34+ cell yield per pheresis, adequate CD34+ cell collections can be achieved with G-CSF alone in most MM patients with less toxicity and with simplification of the procedure.

Results of a pilot study of 40 patients using high-dose therapy with hematopoietic rescue after standard-dose adjuvant therapy for high-risk breast cancer

The study was designed to determine the toxicity, feasibility, and effectiveness of high-dose cyclophosphamide (6 g/m2), thiotepa (500 mg/m2) and carboplatin (800 mg/m2 (CTCb) with hematopoietic rescue as consolidation after standard-dose adjuvant chemotherapy treatment of primary high-risk breast cancer. From October 1991 to September 1994, 40 patients with stage II or III breast cancer involving 10 or more nodes were treated with CTCb after six cycles of adjuvant therapy with an anthracycline-containing regimen. Bone marrow (BM) was used as the source hematopoietic stem cell in the first 23 patients and G-CSF-mobilized peripheral blood progenitor cells (PBPC) in the other 17. No therapy-related deaths occurred, but three life-threatening Complications were recorded which resolved: bilateral pulmonary hemorrhage, veno-occlusive disease of the liver and pulmonary thromboembolism. PBPC result in faster hemopoietic reconstitution with significantly lower transfusion requirements. With a median follow-up of 35 months (23-59) actuarial event-free survival for the study patients at 3 years is 72% (CI 95%: 66-81%). Even in patients over 50-60 years, CTCb is a relatively well tolerated regimen which appears, after a median follow-up of nearly 3 years, to decrease relapse frequency as compared with historical series, although a definite role of HDT in the treatment of high-risk primary breast cancer needs confirmation in prospective randomized trials.

[Imipenem combined with teicoplanin or vancomycin in the initial empirical treatment of febrile neutropenia. Analysis of the primary response and of a global sequential strategy in 126 episodes]

The results of empiric antibiotic therapy in 126 episodes of febrile neutropenia in patients with hematologic neoplasms postchemotherapy and bone marrow transplantation are presented. The main objective of this work was the study of the initial control of infection comparing two glycopeptidic antibiotics: vancomycin and teicoplanin combined with imipenem in first line of empiric therapy. The secondary objective was to analyze the overall control of infection during the complete episode of neutropenia using a sequential empiric antibiotic therapy course which included the addition of amikacin followed by intravenous amphotericin B when fever persisted or recurred without microbiological documentation. Both initial courses (no guidelines), imipenem + vancomycin (arm A) and imipenem + teicoplanin (arm B) resulted in a similar percentage of response at 72 hours, both in episodes of fever of unknown origin (FUO) (55% and 68%, respectively; p = NS) and in those microbiologically documented (54% and 34.5%, p = NS); 58% and 79% of these episodes, respectively, were caused by gram-positive organisms. About 60% of patients in both arm ultimately required the empiric addition of amikacin, with or without amphotericin B, because of persistence or recurrence of fever; the percentage of overall responses in both arm did not differ significantly, both in FUO (70% and 86%, p = NS) and in microbiologically documented episodes (71% and 45%, p = NS). The overall infectious mortality for the whole group was 1.58%. In conclusion, no significant differences were observed in the clinical response or in toxicity between the combination of imipenem with any of the two glycopeptides: vancomycin or teicoplanin, for the initial empiric therapy of febrile neutropenia. The sequential empiric use of amikacin followed by amphotericin B assured an adequate overall control of infection in a group of patients with prolonged severe neutropenia.

Autologous or allogeneic bone marrow transplantation for acute myeloblastic leukemia in second complete remission. Importance of duration of first complete remission in final outcome

Between May 1983 and March 1994, 31 patients with AML in second CR underwent BMT. Fifteen underwent allogeneic BMT from an HLA-identical sibling donor and 16 without a donor, unpurged ABMT. Two different preparative regimens were used: CY (120 mg/kg) and 12 Gy of fractioned TBI (19 patients), and Bu (16 mg/kg) and Cy (120 mg/kg) (BuCy2) in 12 patients. Main clinical characteristics including age, sex, length of first remission, FAB type, and number of leukocytes at diagnosis were similar in both groups. A combination of MTX and CsA was used in 13 cases whereas either CsA or MTX alone was employed in the other two patients. With a median follow-up of 5 years the actuarial 5 year probability of disease-free survival (DFS) for the whole group was 39.8% (95% CI: 29.5-50.1%). The 5 year DFS was equivalent for those who received either ABMT (41.6 +/- 14.2%) or allogeneic BMT (40 +/- 15%). Probabilities of relapse and non-relapse mortality for ABMT and allo BMT patients were 48.7 +/- 16.1 and 18.7 +/- 14.3, and 30.1 +/- 19.2 and 40.7 +/- 16.9, respectively. DFS was better in those patients with a longer duration of first CR (> 18 months) 62.5 +/- 14.4 vs 30.4 +/- 17.9%, attributable to a significantly lower relapse rate in this group of patients 16.6 +/- 12.8 vs 57.8 +/- 22.7 (P 0.05). In conclusion, similar results were observed when ABMT and allo BMT were compared for AML in CR2. A higher antileukemic effect associated with the allo BMT is balanced by an increase in transplant-related mortality. Duration of first remission was the most important factor affecting DFS and better outcome was observed for patients with longer CR1.